JPH09311139A - Acceleration sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sensitivity and detecting precision by pressing a push button against the elastic member of a mechanical key switch by a weight, and performing a switch-on operation. SOLUTION: A weight 3 is mounted on a push button 11 by press fitting a mounting shaft part 13 to its mounting hole part 14. An acceleration sensor is fixed by soldering its terminals 8, 9 to a printed board. When an acceleration is added to the weight 3, a mechanical key switch 1 is not moved, but the weight 3 is inclined to press the button 1 against the force of a spring member 10. Then, the member 10 is reversed to make contact with a first contact 6, and the contact 6 and a second contact 7 are mutually connected through the member 10 and laid in switch-on state. The switch 1 is quickly reacted by the weight 3 in this way, whereby the sensitivity is enhanced, and the detection of acceleration can be precisely performed. The weight of the weight 3 is changed, or its center-of-gravity position is changed, whereby the further improvement in detecting sensitivity and the change and regulation of sensitivity can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration sensor provided on a moving body such as a vehicle and detecting the acceleration of the moving body.

[0002]

2. Description of the Related Art As a conventional acceleration sensor of this type, as shown in FIG. 11, one fixing piece 52 connected to one terminal 51 and another fixing piece 54 connected to the other terminal 53 are provided in a case 50. Are positioned above and below, a recess 55 is formed in the other fixed piece 54, and a hard ball 56 is placed in this recess 55.
The magnet 57 is fixed to the bottom of the case 50,
Magnetically attracts the hard sphere 56 and places it in the recess 55,
There is one in which this state is set to neutral and the switch is turned off.

The acceleration sensor configured as described above is provided on a moving body such as a vehicle, and the moving body collides (accelerates).
In this case, the hard sphere 56 pops out of the recess 55, and one fixed piece 52 and the other fixed piece 5 are shown as shown by phantom lines.
4 and by short-circuiting between the one and the other fixing pieces 52 and 54, the switch is turned on.

[0004]

However, in the above-mentioned conventional acceleration sensor, the hard ball 56 resists the elasticity of the one and the other fixing pieces 52 and 54, and between the one and the other fixing pieces 52 and 54. However, there is no force (contact follow) to push the hard sphere 56 at the time of contact with one and the other of the fixed pieces 52, 54 of the hard sphere 56, and the hard sphere 56 bounces back. There was a problem that the resistance became large, the detection duration was short, and the sensitivity was poor.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an acceleration sensor having high sensitivity and capable of accurately detecting acceleration. is there.

[0006]

In order to achieve the above object, an acceleration sensor according to the invention of claim 1 is a switch which is turned on by pushing a push button against an elastic member, and a switch of the switch. A weight to which the push button is attached.

With this structure, the moving body collides (accelerates).
In other words, when the acceleration is applied to the weight, the switch does not move, for example, by being mounted (fixed) on a printed circuit board or the like, but the elastic member does not move against the force to hold the push button neutrally. When the force that the weight tries to move increases, the weight tilts like pushing the push button, and pushes the push button. For this,
Since the switch has a weight so that the switch is turned on, the switch can immediately react to improve the sensitivity, and the acceleration can be detected accurately.

In order to achieve the above object, an acceleration sensor according to a second aspect of the present invention is the acceleration sensor according to the first aspect, further comprising weight changing means for changing the weight of the weight.

With such a construction, not only the same operation as the operation of the invention of claim 1 described above can be achieved, but when the acceleration a is applied, F is between the load F applied to the weight and the mass m of the weight. = M × a, the sensitivity of the acceleration sensor can be changed or adjusted by changing the mass m of the weight by the weight changing means.

In order to achieve the above object, the acceleration sensor according to the invention of claim 3 is the acceleration sensor according to claim 2, wherein the weight changing means is a partial deletion of the weight.

With such a construction, not only the same operation as that of the above-described invention of the first aspect can be achieved, but when the acceleration a is applied, F is between the load F applied to the weight and the mass m of the weight. = M × a, the sensitivity of the acceleration sensor can be changed or adjusted by changing the mass m of the weight by deleting a part of the weight.

In order to achieve the above object, the acceleration sensor according to the invention of claim 4 is the acceleration sensor according to claim 2, wherein the weight changing means is addition of another member to the weight. .

With such a construction, not only the same operation as the operation of the invention of claim 1 described above can be achieved, but F is between the load F applied to the weight and the mass m of the weight when the acceleration a is applied. However, the sensitivity of the acceleration sensor can be changed and adjusted by changing the mass m of the weight by injecting another member, for example, a molten metal into the weight.

In order to achieve the above object, an acceleration sensor according to a fifth aspect of the present invention is the acceleration sensor according to the first aspect, further comprising a center of gravity changing means for changing the center of gravity of the weight.

With such a configuration, not only the same operation as that of the invention of claim 1 described above can be achieved, but the sensitivity of the acceleration sensor is changed and adjusted by changing the center of gravity of the weight by the center of gravity changing means. be able to.

In order to achieve the above object, the acceleration sensor according to the invention of claim 6 is the acceleration sensor according to claim 5, wherein the center of gravity changing means is attached to the push button of the switch. A fixed side weight, a movable side weight that moves in the axial direction of the fixed side weight, and an engagement means that releasably engages the movable side weight with a predetermined position in the axial direction of the fixed side weight. .

With such a construction, not only the same operation as that of the invention of the above-mentioned claim 1 can be achieved, but also the movable side weight is positioned above the fixed side weight through the engaging means, so that the center of gravity can be adjusted. It moves to the upper part of and becomes in a state where it is easy to react to acceleration. Further, by positioning the movable weight under the fixed weight via the engaging means, the center of gravity moves to the lower portion of the weight and it becomes difficult to react to acceleration.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a first embodiment of an acceleration sensor according to the present invention, FIG. 2 (1) is a front view of the acceleration sensor in a disassembled state, and FIG. 2 (2) is the acceleration sensor. It is a front view. 3 is a longitudinal sectional view of a mechanical key switch of the acceleration sensor, FIG. 4 (1) is a front view of the acceleration sensor in a neutral state, and FIG. 4 (2) is a front view of the collision detection.

As shown in FIG. 1, the acceleration sensor A is generally composed of a mechanical key switch 1 and a weight 3 provided on a push button 11 of the mechanical key switch 1. This mechanical key switch 1
Has a housing 5 having an opening 4 on the upper surface side as shown in FIG. 3, and at the bottom of the housing 5, a first contact portion 6 is provided at the center portion thereof. Second contact portions 7 are arranged on the left and right sides sandwiching 6, and the first contact portion 6 is connected to a pair of terminals 8 projecting to the outside of the bottom of the housing 5, and the second contact portion 7 is It is connected to a pair of other terminals 9 protruding to the outside of the bottom of the housing 5.

A spring member 10, which is a dome-shaped elastic member, is housed inside the housing 5, and the peripheral edge portion of the spring member 10 is in contact with the second contact portion 7. A push button 11 is arranged above the spring member 10. The push button 11 has a peripheral edge portion 11A.
Is blocked by the lid 12 provided in the opening 4 of the housing 5 to prevent the protrusion from protruding, and the protrusion 1 of the push button 11 is prevented.
1B is in contact with the top of the spring member 10. A mounting shaft 13 is provided at the center of the upper surface of the push button 11.

The weight 3 is a solid cylindrical body, and a mounting hole portion 14 is formed in the lower surface portion 3A of the weight 3, and the mounting shaft portion 13 is inserted into the mounting hole portion 14 of the weight 3 ( Press fit)
It is attached to the push button 11 in the pressed state.

The acceleration sensor A thus constructed is provided with the terminals 8 and 9 soldered to the printed circuit board B, mounted on the printed circuit board B, and provided on a moving body such as a vehicle. Then, the weight 3 is positioned at the neutral position in the upright state by the load of the spring member 10 as shown in (1) of FIG. 4, and the mechanical key switch 1 is switched off.

Next, the operation of the acceleration sensor configured as described above will be described. When the moving body collides (accelerates), that is, when acceleration is applied to the weight 3, the mechanical key switch 1 does not move because it is mounted (fixed) on the printed circuit board B, but the spring member 10 pushes it. If the force for moving the weight 3 becomes larger than the force for holding the button 11 neutrally, the weight 3
Tilts so that push button 11 is pushed in, and push button 1
Push 1 in. For this purpose, the projection 1 of the push button 11
When 1B pushes the top of the spring member 10, the spring member 10 is inverted, and the top of the spring member 10 comes into contact with the second contact portion 7 to be switched on. As described above, the presence of the weight 3 allows the mechanical key switch 1 to react immediately and the sensitivity is improved, so that the acceleration can be accurately detected.

In the acceleration sensor A, the acceleration a
Is applied, there is a relationship of F = m × a between the load F applied to the weight 3 and the mass m of the weight 3.
The sensitivity of the acceleration sensor A can be changed and adjusted by changing the mass m of the acceleration sensor A.

As a weight changing means for changing the weight (mass m) of the weight 3, the upper portion (dotted line portion) of the weight 3 is cut off as shown in FIG. 5, or the upper end surface of the weight 3 is shown as shown in FIG. A concave portion 15 is formed in 3B, and a molten metal, which is another member, such as solder 16, is injected into the concave portion 15 to change the weight (mass m) by adjusting the injection amount.

In the acceleration sensor A, the sensitivity of the acceleration sensor A can be changed or adjusted by changing the center of gravity of the weight 3. Such an acceleration sensor A is shown in FIGS. 7 and 8. FIG. 7 shows a state where the acceleration sensor according to the present invention is in a neutral state and easily reacts to the acceleration, and FIG. 8 shows a state where the acceleration sensor is in a neutral state and hardly reacts to the acceleration.

That is, in the acceleration sensor A having the center-of-gravity changing means, the weight 3 is composed of a fixed side weight 3-1 and a movable side weight 3-2, and a screw portion is provided on the peripheral surface of the fixed side weight 3-1. A state in which the mounting shaft portion 13 is inserted (press-fitted) into the mounting hole portion 14 by forming the screw portion 17B on the inner peripheral portion of the movable side weight 3-2 while forming the 17 It is attached to the push button 11 with and the movable weight body 18 is screwed into the thread portion 17 of the fixed weight 3-1. In this case, the threaded portion 17 of the fixed-side weight 3-1 and the threaded portion 17B of the movable-side weight 3-2 form an engaging means.

Then, the movable side weight 3-2 is rotated and screw-fed to position the movable side weight 3-2 above the fixed side weight 3-1 as shown in FIG. It moves to the upper part of and becomes in a state where it is easy to react to acceleration. Further, by rotating the movable side weight 3-2 in the reverse direction and screwing it, the movable side weight 3-2 is moved to the fixed side weight 3 as shown in FIG.
By positioning it at the lower part of -1, the center of gravity moves to the lower part of the weight 3 and it becomes difficult to react to the acceleration.

Further, as the engaging means, a plurality of engaging concave portions 19 are formed on the peripheral surface of the fixed weight 3-1 at a predetermined interval in the upper and lower portions of the fixed weight 3-1. 3-2, the engaging convex portion 1 that engages with the engaging concave portion 19 in a disengageable manner.
8 may be provided. The engaging convex portion 18 is provided with a hole 23 extending in the radial direction in the movable weight 3-2, and the ball 21 and the ball 21 are provided in the hole 23.
The spring 22 for urging the center of 2 and the closing body 24
Are inserted, and a part of the ball 21 is projected to the inner peripheral side of the movable side weight 3-2 by the urging force of the spring 22.

Then, as shown in FIG. 9, the movable side copper body 3-2 is moved to the upper portion of the fixed side weight 3-1 so that the ball 21 of the engaging convex portion 21 is engaged with the upper engaging concave portion 19. Let
By positioning the movable weight 3-2 on the upper side of the fixed weight 3-1, the center of gravity moves to the upper side of the weight 3 so that the weight easily reacts to the acceleration. Further, as shown in FIG. 10, the movable side copper body 3-2 is moved to the lower part of the fixed side weight 3-1 to engage the ball 21 of the engaging convex portion 21 with the lower engaging concave portion 19. , This movable side weight 3-2 to the fixed side weight 3
By positioning it at the lower part of -1, the center of gravity moves to the lower part of the weight 3 and it becomes difficult to react to the acceleration.

[0032]

As described above, according to the acceleration sensor of the first aspect of the present invention, the switch that is turned on by pushing the push button against the elastic member of the push button and the attachment of the push button of the switch. When the moving body is collided (accelerated), that is, when acceleration is applied to the weight, the switch does not move by being mounted (fixed) on a printed circuit board or the like, for example. However, when the elastic member tries to hold the push button neutrally and the force of the weight moving increases, the weight tilts to push the push button and pushes the push button. For this reason, the switch can immediately react due to the presence of the weight so that the switch is turned on, the sensitivity is improved, and the acceleration can be accurately detected.

According to the acceleration sensor of the second aspect of the present invention, the acceleration sensor of the first aspect is provided with a weight changing means for changing the weight of the weight. Not only can the same effects as the effects be obtained, but when the acceleration a is applied, there is a relationship of F = m × a between the load F applied to the weight and the mass m of the weight. The sensitivity of the acceleration sensor can be changed or adjusted by changing the mass m of the weight.

According to the acceleration sensor of the third aspect of the present invention, in the acceleration sensor of the second aspect, the weight changing means is a partial deletion of the weight. Not only the same effect as the effect of the invention can be obtained, but when the acceleration a is applied, there is a relation of F = m × a between the load F applied to the weight and the mass m of the weight. The sensitivity of the acceleration sensor can be changed or adjusted by changing the mass m of the weight by deleting a part thereof.

According to the acceleration sensor of the fourth aspect of the present invention, in the acceleration sensor of the second aspect, the weight changing means is the addition of another member to the weight. Not only the same effect as the effect of the invention of 1 can be obtained, but when the acceleration a is applied, there is a relation of F = m × a between the load F applied to the weight and the mass m of the weight. The sensitivity of the acceleration sensor can be changed and adjusted by changing the mass m of the weight by injecting another member, for example, molten metal into the weight.

According to the acceleration sensor of the fifth aspect of the present invention, the acceleration sensor of the first aspect is provided with a center of gravity changing means for changing the center of gravity of the weight. Not only the same effects as the effects can be obtained, but also the sensitivity of the acceleration sensor can be changed and adjusted by changing the center of gravity of the weight by the center of gravity changing means.

According to the acceleration sensor of the sixth aspect of the present invention, in the acceleration sensor of the fifth aspect, the center of gravity changing means is a fixed weight attached to the push button of the switch, and the fixed weight. The movable side weight that moves in the axial direction of the side weight, and the engaging means that removably engages the movable side weight with a predetermined position in the axial direction of the fixed side weight, thereby providing the above-mentioned claim. Not only can the same effects as the effects of the first aspect of the invention be exhibited, but by arranging the movable side weight on the upper side of the fixed side weight through the engaging means, the center of gravity moves to the upper side of the weight and easily reacts to acceleration. It becomes a state. Further, by positioning the movable weight under the fixed weight via the engaging means, the center of gravity moves to the lower portion of the weight and it becomes difficult to react to acceleration.

[Brief description of drawings]

FIG. 1 is a perspective view of an acceleration sensor (Embodiment 1) according to the present invention.

FIG. 2 (1) is a front view of the acceleration sensor in a disassembled state. (2) is a front view of the acceleration sensor.

FIG. 3 is a vertical sectional view of a mechanical key switch of the acceleration sensor.

FIG. 4 (1) is a front view of the acceleration sensor in a neutral state. (2) is a front view at the time of collision detection.

FIG. 5 is a front view of an acceleration sensor in which a part of the weight is removed as a weight changing means.

FIG. 6 is a front view of an acceleration sensor having another weight changing unit.

FIG. 7 is a front view of an acceleration sensor having a center of gravity changing means and a center of gravity positioned on an upper portion.

FIG. 8 is a front view of a state where a center of gravity is located below the acceleration sensor.

FIG. 9 is a front view of an acceleration sensor including another center-of-gravity changing unit and having a center of gravity located at an upper portion.

FIG. 10 is a front view showing a state where a center of gravity is located below the acceleration sensor.

FIG. 11 is a vertical sectional view of a conventional acceleration sensor.

[Explanation of symbols]

 A Acceleration sensor 1 Mechanical key switch (switch) 3 Weight 10 Spring member (elastic member) 11 Push button

Claims (6)

[Claims] 1. An acceleration sensor, comprising: a switch that is turned on by being pushed against an elastic member of a push button; and a weight attached to the push button of the switch. 2. The acceleration sensor according to claim 1, further comprising weight changing means for changing the weight of the weight. 3. The acceleration sensor according to claim 2, wherein the weight changing means is a partial deletion of the weight. 4. The acceleration sensor according to claim 2, wherein the weight changing means is addition of another member to the weight. 5. The acceleration sensor according to claim 1, further comprising a center of gravity changing means for changing a center of gravity of the weight. 6. The center of gravity changing means includes a fixed side weight attached to the push button of the switch, a movable side weight that moves in the axial direction of the fixed side weight, and the movable side weight as the fixed side weight. 6. The acceleration sensor according to claim 5, wherein the acceleration sensor is configured to be engageable with and disengageable from a predetermined position in the axial direction of the.