JPH04130071U - Pendulum type acceleration sensor - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a pendulum-type acceleration sensor equipped with a magnetic damper with different response characteristics during acceleration and deceleration. [Structure] A notch 11 is provided in a portion of the pendulum 2 facing the magnetic damper 4 on one side in the swinging direction of the pendulum 2 to allow the magnetic flux of the magnetic damper 4 to pass through. The eddy current generated when the portion of the pendulum 2 provided with the notch 11 crosses the magnetic flux of the magnetic damper 4 is smaller than the eddy current generated when the portion on the opposite side crosses the magnetic flux. Therefore, when the pendulum 2 swings in the direction of arrow B in FIG.
It is smaller than when it swings in the direction.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a pendulum-type acceleration sensor whose pendulum is braked by an eddy current brake. In particular, it relates to the structure of a pendulum on which an eddy current brake acts.

0002

[Conventional technology]

Conventionally, sensors for detecting acceleration (inclination angle) include pendulum type, leaf spring type, etc. Some devices are composed of tilt angle detectors. Both of them are acceleration or Optical sensors and magnetic sensors measure the amount of displacement caused by the vibration of a pendulum due to gravity, the bending of a leaf spring, etc. Alternatively, it can be converted into an electrical signal by changes in capacitance, etc., and the It detects the acceleration (angle of inclination) of the object to be measured. These acceleration (tilt angle) detection The detector detects the resonance of movable objects such as pendulums and leaf springs due to external vibrations. A damper mechanism is provided for the purpose of preventing this or providing appropriate response characteristics. For example, the damper mechanism uses a liquid such as silicone oil or antifreeze. There is something. When a damper mechanism is constructed using liquid in this way, its sealed structure The problem is that it is costly. In addition, the viscosity of the liquid increases due to temperature changes. Due to this change, the damping characteristics will change. In other words, using a liquid In conventional damper mechanisms, the response characteristics change due to temperature changes, which is an unavoidable problem. There is no problem. Therefore, these drawbacks of the damper mechanism using liquid are eliminated. For this purpose, damper mechanisms that utilize magnetism have come to be adopted. This magnetic da The damper mechanism has a structure in which permanent magnets are placed facing each other with a pendulum made of non-magnetic conductive material in between. The eddy currents generated as the pendulum swings act as a brake on the pendulum. It was configured. In other words, this magnetic damper mechanism is not affected by temperature changes. Therefore, it has excellent temperature characteristics. This acceleration sensor equipped with a conventional magnetic damper mechanism This will be explained with reference to FIGS. 5 to 8.

0003 Figure 5 is a perspective view showing the schematic configuration of a conventional pendulum-type acceleration sensor, and Figure 6 is a perspective view of a conventional pendulum-type acceleration sensor. A front view of a pendulum-type acceleration sensor, and Figure 7 is a side view of a conventional pendulum-type acceleration sensor. 8 is a plan view of a conventional pendulum type acceleration sensor. In these figures, 1 is the vibration This acceleration sensor 1 has a pendulum 2 as a swinging body. It has a structure that swings around 3. The pendulum 2 is made of non-magnetic conductive material. It is formed into a fan shape. In addition, in FIGS. 5 to 8, the pendulum 2 is shown to be swingable. Detects the displacement of the supporting base of the acceleration sensor 1 and the pendulum 2 and converts it into an electrical signal. Detection means and the like to be replaced are omitted.

0004 4 is a magnetic damper, and this magnetic damper 4 includes a yoke 5 having a U-shaped cross section, and this yoke. The yoke 5 and the permanent magnet 6 are connected to the pendulum 2. They are placed facing each other on both sides. The yoke 5 having a U-shaped cross section has magnetic pole portions at both ends. 5a is fixed to a support stand (not shown) so that it faces the pendulum 2 side, and the permanent magnet 6 is It is attached to the center of the arc 5 in the width direction. That is, the tip of the magnetic pole portion 5a The magnetic pole face 5b faces the side surface of the pendulum 2. In addition, the permanent magnet 6 is a pendulum. It is magnetized in a direction parallel to the axial direction of 2. Furthermore, the installation position of the yoke 5 is as follows: A permanent magnet 6 is positioned directly below the spindle 3 and faces the outer periphery of the pendulum 2. It is set as follows.

[0005] Next, the operation of the conventional pendulum-type acceleration sensor configured as described above will be explained. External acceleration is applied to the pendulum 2 or the pendulum support is tilted. Then, the pendulum 2 swings around the support shaft 3. And the pendulum 2 is facing The magnetic flux crosses the magnetic flux between the permanent magnets 6 and between the yokes 5. This magnetic flux is shown in Figure 7. and is indicated by an arrow Φ in FIG. As pendulum 2 crosses the magnetic flux in this way, the pendulum An eddy current is generated in the pendulum 2, which acts as an eddy current brake and brakes the pendulum 2. Become.

[0006]

[Problem that the idea aims to solve]

However, a pendulum-type acceleration sensor equipped with a damper mechanism that uses magnetism In this case, it is difficult to make the damper effect different depending on the direction of pendulum displacement. It was. In other words, a pendulum swings when acceleration is applied and when it swings. From the relationship that the damper is damped with the same damping effect when it stops moving and returns, Responsiveness becomes low.

[0007]

[Means to solve the problem]

The pendulum-type acceleration sensor according to the present invention faces a magnetic damper in the pendulum. An opening on one side of the pendulum in the swinging direction that allows the magnetic flux of the magnetic damper to pass through. It has been established.

[0008]

[Effect]

Vortex generated when the open part of the pendulum crosses the magnetic flux of the magnetic damper The current is small compared to the eddy current that occurs when the opposite side of the opening crosses. It gets colder. Therefore, the damper effect when the pendulum swings to the side opposite to the opening side is becomes smaller than when swinging in the opposite direction.

[0009]

【Example】

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a front view of a pendulum-type acceleration sensor according to the present invention. In the same figure, Components that are the same or equivalent to those explained in Figures 5 to 8 are designated by the same reference numerals. Detailed explanation will be omitted. In addition, in FIG. 1, a part of the pendulum is shown broken. figure 1, 11 is a notch that constitutes an opening, and this notch 11 is attached to the pendulum 2. The outer peripheral edge of the part facing the magnetic damper 4 in the pendulum 2 on one side in the swinging direction is formed. Moreover, the notch width A of this notch 11 is over the entire notch area. The outer circumferential edge thereof is formed into an arc shape centered on the support shaft 3.

0010 In the pendulum-type acceleration sensor equipped with the pendulum 2 formed as described above, the external When the pendulum 2 swings in the direction of arrow A in FIG. 1 due to acceleration etc. from It crosses the total magnetic flux between the opposing permanent magnet 6 and yoke 5, but if it swings in the B direction, In some cases, only a portion of the magnetic flux passes through the notch 11 without passing through.

[0011] Therefore, the portion of the pendulum 2 provided with the notch 11 crosses the magnetic flux of the magnetic damper 4. The eddy current generated when the cutout 11 is It is smaller than the eddy current that occurs when it is cut. For this reason, pendulum 2 is at B in the diagram. The damper effect when swinging in direction A is smaller than when swinging in direction A. .

0012 The pendulum-type acceleration sensor according to the present invention is installed in a car, for example, when the tires are empty. Used in systems that control rolling and anti-lock braking systems. This type of system uses a rotation sensor installed on the vehicle's axle to measure the rotation of the tires. In addition to detecting the speed, the acceleration sensor of this invention also detects the acceleration of the vehicle, and the tire The engine is designed so that the tires always grip the road surface based on the rotational speed of the vehicle and the acceleration of the vehicle. It is configured to control the engine rotation speed and braking force. In other words, the tire When the vehicle is not accelerating even though the rotational speed is increasing, It determines that the tires are spinning and controls the engine speed to lower. , if the vehicle is not decelerating even though the rotational speed of the tires is decreasing, the It determines that the ear is locked and controls the brakes to be loosened.

[0013] Using traditional acceleration sensors in such systems typically reduces vehicle Since the speed (braking force) fluctuates more rapidly than when accelerating, If the response characteristics of the acceleration detector are made faster, the pendulum may become unstable due to vibrations from the road surface, etc. It ends up. When using the pendulum type acceleration sensor of this invention, it is possible to The response can be delayed and the response can be accelerated only during deceleration, allowing optimal vehicle control. become able to.

[0014] In addition, in the above embodiment, an example was shown in which the opening part was constituted by the notch 11, but this embodiment The invention is not limited by this limitation and is constructed as shown in Figures 2 to 4. You can also do that. Figure 2 is a front view showing another embodiment in which the pendulum is provided with an opening, and Figure 3 is a cutout of the notch. Figure 4 is a front view showing another embodiment in which the width of the pendulum is gradually increased. It is a front view which shows another Example which provided many. In these figures, the explanation in Figure 1 above is shown. Parts that are the same as or equivalent to those described above will be given the same reference numerals and detailed explanations will be omitted. Omitted.

[0015] In FIG. 2, 12 is an opening provided in the pendulum 2, and this opening 12 is approximately a fan. It is formed into a shape, and is formed so as to pass through the pendulum 2 on one side in the swing direction of the pendulum 2. has been done. Note that the location of this opening 12 is also determined by the magnetic damper in the pendulum 2. It is set in the part opposite to 4.

[0016] In FIG. 3, 13 is a notch formed on the outer peripheral edge of the pendulum 2; 13, the notch width is as follows from the center of the pendulum 2 toward one swinging end. It is formed to be the second widest. When the notch 13 is formed in this way, the When child 2 swings in the direction of arrow B, the damper effect increases as the amount of swing increases. becomes smaller.

[0017] In FIG. 4, 14 is a small hole bored in the pendulum 2; 2, which faces the magnetic damper 4 and is disposed on one side in the swinging direction. , a large number of holes are provided in the pendulum 2. Even with the configuration shown in FIGS. 2 to 4, when the pendulum 2 swings in the direction B in the figure, The damper effect is smaller than when swinging in the A direction.

[0018]

[Effect of the idea]

As explained above, the pendulum-type acceleration sensor according to the present invention has a magnetic field in the pendulum. The magnetic flux of the magnetic damper is applied to one side of the pendulum in the swinging direction, which is the part facing the magnetic damper. Since the opening is provided to allow the pendulum to pass through, the part of the pendulum with the opening is the part of the magnetic damper. The eddy current that occurs when the magnetic flux crosses is the one that crosses the side opposite to the opening side. This is smaller than the eddy currents that sometimes occur. Therefore, the pendulum is opposite to the opening side. The damper effect when rocking to the opposite side is smaller than when rocking to the opposite side. It gets colder. Therefore, the damper effect differs depending on the direction of pendulum displacement. Pendulum acceleration with different response characteristics during acceleration and deceleration. sensor can be obtained. In addition, the opening area of the opening should be adjusted relative to the direction of the pendulum swing. The pendulum swings toward either acceleration or deceleration by changing the Sometimes, there is also the effect that the response characteristics can be changed at any point.

[Brief explanation of drawings]

FIG. 1 is a front view of a pendulum-type acceleration sensor according to the present invention.

FIG. 2 is a front view showing another embodiment in which a pendulum is provided with an opening.

FIG. 3 is a front view showing another embodiment in which the width of the notch is gradually increased.

FIG. 4 is a front view showing another embodiment in which a pendulum is provided with a large number of small holes for transmitting magnetic flux.

FIG. 5 is a perspective view showing a schematic configuration of a conventional pendulum-type acceleration sensor.

FIG. 6 is a front view of a conventional pendulum-type acceleration sensor.

FIG. 7 is a side view of a conventional pendulum-type acceleration sensor.

FIG. 8 is a plan view of a conventional pendulum-type acceleration sensor.

[Explanation of symbols]

1 Pendulum type acceleration sensor 2 Pendulum 4 Magnetic damper 5 York 6 Permanent magnet 11 Notch 12 Opening 13 Notch 14 Small hole

Claims (1)

[Scope of utility model registration request] 1. A magnetic damper is disposed on the side of the sector pendulum, and includes a yoke with a U-shaped cross section facing toward the pendulum and a permanent magnet, and which brakes the pendulum using an eddy current brake. A pendulum-type acceleration sensor for detecting a pendulum-type acceleration sensor, characterized in that an opening is provided on one side in the swinging direction of the pendulum in a portion of the pendulum that faces the magnetic damper and allows the magnetic flux of the magnetic damper to pass through. .