JP2012198056A - Acceleration recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acceleration recorder capable of acquiring only maximum acceleration or its equivalent acceleration generated in a structure by vibration or shocks of earthquakes or the like.SOLUTION: An acceleration meter 1 is provided to record maximum acceleration generated by vibration or shocks. The acceleration recorder includes a mass part 2 receiving acceleration to linearly move, a helical spring 3 having one end connected to the mass part and the other end immovable with respect to the mass part, a ratchet claw 4 attached to the mass part, and a ratchet tooth part 5 engaged with the ratchet claw to prevent the movement caused by the contracting force of the helical spring.

Description

  The present invention relates to an acceleration recorder for recording acceleration when a ground or a structure vibrates due to an earthquake or an impact.

  Conventionally, when a building is damaged by an earthquake, a method of determining the damage degree of the building from the magnitude of the maximum acceleration generated in the building at the time of the earthquake is known (see Patent Document 1 and the like).

  This Patent Document 1 discloses a building damage degree determination apparatus including an acceleration sensor installed in a building. When determining the building damage degree using this apparatus, the maximum acceleration data measured by the acceleration sensor is used. I use it.

  Since such an acceleration sensor is normally operated by electric power supplied from a commercial power source such as an electric power company, it is necessary to perform wiring to a place where the acceleration sensor is installed.

  On the other hand, Patent Documents 2 and 3 disclose mechanical strain gauges and displacement meters that do not require electric power for measurement. That is, in Patent Documents 2 and 3, problems such as the cost of a measuring device as disclosed in Patent Document 1 that always requires electric power to perform measurement are listed, and an inexpensive mechanical strain gauge is used. It is proposed to record the maximum strain and deformation generated in the structure by the earthquake.

JP 2009-20056 A JP 2008-215961 A JP 2002-188968 A

  However, the mechanical measurement devices disclosed in Patent Documents 2 and 3 are strain gauges or displacement meters for recording the maximum strain or displacement generated in a structure or the like, and the structure or the like has been recorded in the past. It is not possible to determine the maximum acceleration received or the equivalent acceleration.

  In order to measure the acceleration received by structures, etc. and record the maximum value, monitoring using an accelerometer and a data recording device is generally performed. It is to be measured and must be expensive and expensive. In addition, since this monitoring requires a power supply, it must be operated at all times in order to prepare for an event that cannot be predicted when it occurs, such as an earthquake, and high running costs and frequent maintenance are required. Requires management.

  Accordingly, the present invention provides an acceleration that can measure and record only the maximum acceleration generated in a structure or the like due to vibration or shock due to an earthquake or the like or only the acceleration corresponding to the maximum acceleration with no power source or little electric power. The purpose of this is to provide a recorder.

  In order to achieve the above object, an acceleration recorder of the present invention is an acceleration recorder for recording the maximum acceleration generated by receiving a vibration or impact or an acceleration corresponding to the maximum acceleration. A mass part that moves linearly, a spring part that has one end connected to the mass part and the other end is a fixed point with respect to the mass part, a ratchet claw attached to the mass part, and meshed with the ratchet claw And a ratchet tooth portion for preventing movement due to a contracting force of the spring portion.

  Here, it can be set as the structure provided with the scale part which enables the reading of the acceleration converted from the movement amount of the said mass part, or its movement amount. Moreover, it is good also as a structure provided with the displacement meter which electrically measures the moving amount | distance of the said mass part.

  Furthermore, the ratchet tooth portion may be configured to extend linearly toward the moving direction of the mass portion. Further, the ratchet tooth portion is a gear attached to the mass portion, and is linearly directed toward a moving direction of the gear-type pinion rotating coaxially with the gear-type and the gear-type pinion. The structure provided with the extended rack may be sufficient.

  Further, the ratchet tooth portion is extended linearly, the mass portion is formed in a symmetrical shape around the ratchet tooth portion, and the spring portion is also symmetric around the ratchet tooth portion. A plurality of mass parts may be connected to the mass part.

  The acceleration recorder of the present invention configured in this way mechanically records the amount of movement of the mass portion that moves by the action of acceleration. The movement amount once recorded does not become smaller than that, and is updated only when an acceleration larger than the acceleration that generated the movement amount is applied.

For this reason, even if there is no power source such as a commercial power supply or a battery, the maximum acceleration that the structure has received in the past or the acceleration corresponding thereto can be obtained. In addition, since there is no need for wiring to supply power, the degree of freedom of installation location is high, and the simple mechanical configuration enables stable operation even outdoors or in harsh environments where temperature differences are severe. .
Moreover, if the scale part which enables the reading of the movement amount of a mass part or the acceleration converted from a movement amount is provided, a maximum acceleration can be grasped | ascertained easily visually. Furthermore, if a displacement meter that electrically measures the amount of movement is provided, the maximum amount of movement can be recorded for each update, and recording can be collected remotely.

  Moreover, the direction of the measured acceleration can be correctly grasped | ascertained by combining with the ratchet tooth | gear part extended linearly in the moving direction to which a mass part moves.

  Furthermore, by increasing the diameter (peripheral length) and tooth spacing by interposing a gear-shaped ratchet tooth portion, it is possible to finely set the increase step (resolution) of the recorded acceleration.

  Further, by configuring the mass part and the spring part symmetrically with the ratchet tooth part as the center, it is difficult for the mass part to move, and the acceleration can be accurately recorded. In particular, when the ratchet teeth are set up vertically, the acceleration in the vertical direction can be accurately recorded.

It is explanatory drawing which showed the structure of the recorder for acceleration of embodiment of this invention. (A) is the figure which showed the initial state of the recorder for acceleration, (b) is the figure which showed the state of the recorder for acceleration at the time of vibration generation. It is a figure explaining the relationship between the waveform of the acceleration used as an input value, and the maximum acceleration recorded by the recorder for acceleration. It is explanatory drawing which showed the structure for recording the maximum acceleration of 2 directions. FIG. 3 is an explanatory diagram illustrating a configuration of an acceleration recorder according to the first embodiment. It is explanatory drawing which showed the structure of the recorder for acceleration of Example 2. FIG. FIG. 6 is a perspective view with a part broken away to show the configuration of an acceleration recorder of Example 3.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view illustrating a configuration of an accelerometer 1 as an acceleration recorder described in the present embodiment.

  The accelerometer 1 is installed in an arbitrary place such as a building such as a building or a house, a civil structure such as a bridge, a dam or a tunnel, and the maximum acceleration received by the structure due to an earthquake or an impact or the like. Used to record the corresponding acceleration.

  Here, “maximum acceleration or acceleration corresponding to it” means that the acceleration recorded by the accelerometer 1 of the present embodiment is represented by a stepwise numerical index, and the precise maximum acceleration is not necessarily recorded. The expression is used because it is approximate acceleration rather than. In this specification, “maximum acceleration or acceleration corresponding thereto” may be simply referred to as “maximum acceleration”, and a value measured by the accelerometer 1 may be referred to as “acceleration”.

  As shown in FIG. 1, the accelerometer 1 of the present embodiment includes a mass part 2 that moves linearly by the action of acceleration, one end connected to the mass part 2, and the other end serving as a fixed point with respect to the mass part 2. A string winding spring 3 as a spring portion; a ratchet pawl 4 attached to the mass portion 2; a ratchet tooth portion 5 which is engaged with the ratchet pawl 4 and prevents movement due to the contraction force of the string spring 3; The housing case 11 is mainly provided.

  The housing case 11 is, for example, a rectangular parallelepiped hollow box, and the side surface is closed with a glass plate or a transparent acrylic plate so that a scale portion 6 described later can be seen. The longitudinal direction of the housing case 11 is a moving direction for linearly moving the mass portion 2.

  Further, the mass portion 2 is, for example, a rectangular parallelepiped molded to a predetermined mass m, and is configured to be smoothly linearly moved by the wheels 21 and 21. The mass part 2 accommodated in the accommodation case 11 can reciprocate in the longitudinal direction of the accommodation case 11.

  On the other hand, a linear ratchet tooth portion 5 is laid on the bottom surface of the housing case 11 like a monorail. The ratchet tooth portion 5 is provided with a plurality of teeth having a right triangle shape protruding upward. That is, inclined surfaces 5a and step surfaces 5b are alternately formed on the upper portion of the ratchet tooth portion 5 to form a tooth shape.

  Moreover, the mass part 2 supported by the wheels 21 and 21 on both sides is arranged so as to straddle the ratchet tooth part 5 and moves in the extending direction of the ratchet tooth part 5 without being interfered with the ratchet tooth part 5. Can do.

  Furthermore, a ratchet claw 4 that can mesh with the ratchet tooth portion 5 is attached to the mass portion 2. The ratchet pawl 4 is formed in a trapezoidal shape having, for example, an inclined surface 4a that matches the inclined surface 5a of the ratchet tooth portion 5 and an upright surface 4b that intersects the inclined surface 4a.

  The ratchet pawl 4 is attached to the mass portion 2 so as to be swingable about the shaft 41. When the mass portion 2 moves in a direction in which the inclined surface 4a facing downward of the ratchet claw 4 is pressed against the inclined surface 5a facing upward of the ratchet tooth portion 5, the ratchet claw 4 approaches the inclined surface 5a. In this case, the movement of the mass portion 2 in this direction is not hindered.

  On the other hand, when the mass portion 2 moves in the direction in which the upright surface 4b of the ratchet claw 4 is pressed against the step surface 5b of the ratchet tooth portion 5, the upright surface 4b of the ratchet claw 4 hits the step surface 5b and is pushed back. The movement of the mass part 2 in this direction is prevented. For this reason, the mass part 2 can move only to one direction (left direction in FIG. 1).

  Then, the rear end of the mass portion 2, that is, the end portion in the direction in which the movement is prevented, and the inner end surface in the longitudinal direction of the housing case 11 are connected by the string spring 3. The end portion of the coiled spring 3 fixed to the inner end surface of the housing case 11 becomes a fixed point with respect to the movable mass portion 2.

  In addition, the coiled spring 3 having one end connected to the rear end of the mass portion 2 can be extended by the movement of the mass portion 2, but when trying to contract, the ratchet pawl 4 and the ratchet tooth portion 5 mesh with each other to contract. Be blocked.

  In order to be able to confirm the movement amount of the mass portion 2 by visual observation, for example, the indicator needle 61 is protruded upward from the ratchet claw 4. On the other hand, on the upper part of the housing case 11 that can be instructed by the indicating needle 61, the scale portion 6 is provided in accordance with the movement range of the mass portion 2.

  The scale unit 6 may be a scale indicating the movement amount itself, or a scale indicating an acceleration converted from the movement amount. Further, the interval between the scales is made to coincide with the interval between the teeth of the ratchet teeth portion 5 (the interval between the step surfaces 5b and 5b).

  Next, a method for recording the maximum acceleration using the accelerometer 1 will be described with reference to FIG.

  First, the storage case 11 is fixed to the floor of a building where the maximum acceleration is to be recorded so that the floor and the storage case 11 vibrate together. Then, as shown in FIG. 2A, the mass part 2 is moved to the string spring 3 side, and the indicator needle 61 is set at a position indicating “0” of the scale part 6. The string winding spring 3 at this position is in a stable state where neither expansion nor contraction occurs, and there is no force acting on the mass portion 2 from the string winding spring 3.

  When an earthquake occurs in this state and a rightward acceleration a acts on the accelerometer 1 as shown in FIG. 2B, the mass part 2 rotates the wheels 21 and 21 by a leftward inertial force F generated by the acceleration a. Move to the left.

  The movement of the mass portion 2 in the left direction is performed while resisting the reaction force due to the elongation δ of the string spring 3, but the ratchet tooth portion 5 does not hinder the movement in the left direction.

  Here, if the relationship between the movement amount δ of the mass portion 2 of the mass m (= elongation of the string wound spring) and the acceleration a is a static acceleration a, the balance of force using the spring constant k of the string spring 3 From the formula m × a = k × δ, a = kδ / m can be obtained. The frictional resistance of the wheels 21 and 21 is assumed to be negligibly small.

  However, the following equation of motion is applied when acceleration acts dynamically, such as the acceleration generated during an earthquake.

Formula 1

  As shown in Equation 1, since there is an influence of the first and second terms on the left side, an accurate value cannot be obtained at a = kδ / m as in the case where static acceleration is applied. I can see. However, by conducting an experiment in advance and appropriately selecting the mass m of the mass portion 2 and the spring constant k of the string spring 3, the approximate acceleration a can be obtained even when a = kδ / m.

  On the other hand, if the position where the mass portion 2 is moved by the action of the maximum acceleration is a position where the upright surface 4b of the ratchet claw 4 and the step surface 5b of the ratchet tooth portion 5 are separated as shown in FIG. The mass portion 2 is pulled back by the restoring force of the coiled spring 3 to a position where the upright surface 4b and the stepped surface 5b come into contact with each other.

  Thus, the acceleration a recorded by the accelerometer 1 becomes a stepwise value that matches the interval of the step surface 5 b of the ratchet tooth portion 5. FIG. 3 is a diagram showing a result of simulating the operation of the accelerometer 1 of the present embodiment by numerically analyzing the equation of motion of Equation 1.

  In this analysis, the mass m of the mass part 2 is 40 g (gram), the spring constant k of the coiled spring 3 is 20000 dyn / cm, the damping constant h = 0.05 in the vibration of the mass part 2, and the step surface 5b of the ratchet tooth part 5 0.2 cm (corresponding to a resolution of 100 Gal of action acceleration), and the input value was a waveform that attenuated after 20 sine waves with a period of 0.4 seconds gradually increased to an amplitude of 550 Gal as the action acceleration a (t). .

  As shown in FIG. 3, it can be seen that when the acting acceleration increases, the acceleration recorded by the accelerometer 1 also increases stepwise. For example, when the acceleration up to 500 Gal is divided into five steps by the interval of the step surface 5b of the ratchet tooth portion 5, the step of recording is sequentially increased as the action acceleration increases, and the maximum acceleration 550 Gal is Recorded in the fifth row corresponding to 500 Gal.

  Once recorded in the accelerometer 1, the mass part 2 does not move unless an acceleration that causes a movement amount reaching a level higher than the recorded level is applied. For example, as shown in FIG. 3, the action acceleration decreases after reaching 550 Gal, but the fifth-stage record of the ratchet tooth portion 5 does not go down.

  For this reason, the scale pointed by the indicator needle 61 when the accelerometer 1 is collected indicates the maximum acceleration that has occurred in the past at the place where the accelerometer 1 is installed.

  In addition, after the accelerometer 1 is collected and the maximum acceleration is confirmed, the ratchet claw 4 can be removed from the ratchet tooth portion 5 and used again as the accelerometer 1.

  When one accelerometer 1 described above is used, only the maximum acceleration acting in one direction (the right direction in FIG. 2B) can be recorded. Therefore, in order to record the maximum acceleration in both positive and negative directions, an accelerometer 1A having the opposite direction to the accelerometer 1 may be disposed as shown in FIG.

  For example, the accelerometer 1 is arranged to record the maximum acceleration in the R1 direction, and the accelerometer 1A facing away from the accelerometer 1 so as to be aligned with the accelerometer 1 is arranged in the L1 direction which is the opposite of the R1 direction. Maximum acceleration can be recorded.

  Although not shown, when recording the maximum acceleration in the direction perpendicular to the R1 direction on the plane, the vertical direction, etc., the accelerometers 1,.

  Next, the operation of the accelerometer 1 of the present embodiment will be described.

  The accelerometer 1 according to the present embodiment configured as described above mechanically records the movement amount of the mass portion 2 that moves due to the action of acceleration by meshing the ratchet claw 4 and the ratchet tooth portion 5. The movement amount once recorded does not become smaller than that, and is updated only when an acceleration larger than the acceleration that generated the movement amount is applied.

  For this reason, the maximum acceleration received in the past by a structure such as a building or a bridge where the accelerometer 1 is installed or an acceleration corresponding thereto can be obtained without wiring for connecting to a commercial power source.

  For example, in the event of a major earthquake, the maximum acceleration is read from the accelerometer 1 installed in the building or bridge, etc., and the recorded maximum acceleration is analyzed, so that the building may enter or the bridge will pass. It is possible to quickly determine whether or not it is possible. Furthermore, when making a post-earthquake recovery plan, it is possible to make an accurate recovery plan based on the recorded maximum acceleration data.

  In such analysis, if you can quantitatively know the acceleration at which the building was actually shaken, the data obtained from the seismometer at the nearest point installed by the Japan Meteorological Agency or public institution Much more accurate analysis is possible than using it.

  In addition, the accelerometer 1 does not require wiring for power supply, so it has a high degree of freedom in installation location, and since it has a simple mechanical configuration, it can be stably used outdoors or in severe environments with severe temperature differences. Can be operated. Furthermore, since the accelerometer 1 according to the present embodiment has a simple configuration, the manufacturing cost can be reduced.

  Moreover, if the scale part 6 which enables the reading of the movement amount of the mass part 2 or the acceleration converted from the movement amount is provided, the maximum acceleration can be easily grasped visually.

  Furthermore, after adjusting the movement sensitivity of the mass part 2 by combining the mass m of the mass part 2 and the spring constant k of the string spring 3, the distance between the teeth of the ratchet teeth part 5 and the distance between the scales of the scale part 6 are adjusted. Thus, the resolution of the recorded acceleration can be defined. For example, if the range from 0 g (g is gravitational acceleration) to 2 g is divided into 10 steps, the resolution is 0.2 g. Further, by adjusting the length of the ratchet tooth portion 5, the recordable acceleration range can be adjusted.

  Furthermore, by combining with the ratchet teeth portion 5 extending linearly in the moving direction in which the mass portion 2 moves, the moving direction of the mass portion 2 can be easily determined, and the recorded acceleration can be accurately determined. And the above analysis can be performed.

  Hereinafter, in Example 1, an embodiment different from the above-described embodiment will be described with reference to FIG. The description of the same or equivalent parts as those described in the above embodiment will be given the same reference numerals.

  In the above-described embodiment, the accelerometers 1 and 1A including the visually observable scale portion 6 have been described. However, in the first embodiment, the acceleration as an acceleration recording meter including the displacement meter 7 that electrically measures the movement amount is described. The total 1B will be described.

  The accelerometer 1B has the same configuration as the accelerometer 1 described in the above embodiment, except for the configuration related to the displacement meter 7 that measures the movement amount. The displacement meter 7 is connected to a slide type terminal 73 and a fixed type terminal 72.

  These terminals 72 and 73 are connected to a variable resistor 71 that extends in a straight line toward the moving direction of the mass portion 2 at the upper part of the housing case 11. The sliding terminal 73 is fixed to the mass part 2 and slides as the mass part 2 moves.

  And the displacement meter 7 measures the change of the electrical resistance between the terminals 72 and 73 as a displacement amount (movement amount). That is, when acceleration acts on the accelerometer 1B and the mass part 2 moves, the terminal 73 slides accordingly, and the distance between the terminals 72 and 73 changes, whereby the electrical resistance between the terminals 72 and 73 changes. . The displacement meter 7 converts this change in electrical resistance into a moving amount.

  The displacement meter 7 includes a storage unit (not shown) that records the measured movement amount. A storage medium such as a flash memory, a RAM (Random Access Memory), a hard disk, or an optical disk can be used for the storage unit.

  Further, the displacement meter 7 is connected to a communication network 74 such as the Internet, and can move the movement amount data recorded in the storage unit to the counting device 75 installed in the remote place sequentially.

  In this way, if the displacement meter 7 that electrically measures the movement amount of the mass part 2 is provided, an update record of the maximum movement amount can be recorded each time, and remote record collection is also possible. It becomes possible.

  Other configurations and functions and effects are substantially the same as those in the above-described embodiment, and thus description thereof is omitted.

  Hereinafter, in Example 2, an embodiment different from the above-described embodiment and Example 1 will be described with reference to FIG. In addition, about the description of the part same or equivalent to the content demonstrated in the said embodiment or Example 1, detailed description is abbreviate | omitted by using the same term.

  The accelerometer 81 serving as an acceleration recorder according to the second embodiment includes a mass portion 82 that moves linearly by the action of acceleration, and a spring that has one end connected to the mass portion 82 and the other end serving as a fixed point with respect to the mass portion 82. A string-wound spring 83 as a portion, a ratchet pawl 84 attached to the side surface of the mass portion 82, a ratchet gear 85 as a ratchet tooth portion meshed with the ratchet pawl 84, and a rectangular parallelepiped box-shaped housing case 811 for housing them It is mainly equipped with.

  Instead of the wheels 21 and 21 of the mass part 2 described in the above embodiment, gear-type pinions 821 and 822 are rotatably attached to the mass part 82 on the side surfaces.

  The gear type pinions 821 and 822 are meshed with teeth 824 of a rack 823 spanned like a linear rail in the longitudinal direction of the housing case 811. For this reason, the mass portion 82 is not pulled back by the restoring force of the chord spring 3 unless the gear-type pinion 821 rotates in the reverse direction.

  A ratchet gear 85 is attached to the same shaft 851 as the front gear type pinion 821. That is, when the gear type pinion 821 makes one rotation, the coaxial ratchet gear 85 also makes one rotation.

  When the ratchet gear 85 rotates in the S direction in FIG. 6, the ratchet pawl 84 attached to the side surface of the mass portion 82 so as to be swingable by the shaft 841 is lifted and can freely rotate.

  On the other hand, when the ratchet gear 85 tries to rotate in the direction opposite to the S direction, the ratchet pawl 84 prevents the rotation. That is, when the mass portion 82 moves in the direction in which the string spring 83 extends, the ratchet gear 85 rotates in the S direction, and thus the movement is not limited. When the mass portion 82 moves in the direction in which the string spring 83 contracts, Since the ratchet gear 85 rotates in the direction opposite to the S direction, the movement of the mass portion 82 is prevented.

  Further, in order to make it possible to visually confirm the amount of movement of the mass portion 82, for example, the indicator needle 861 is protruded upward from the rear end of the mass portion 82. On the other hand, a scale portion 86 is provided on the upper portion of the housing case 811 that can be designated by the indicator needle 861 according to the movement range of the mass portion 82.

  The scale portion 86 may be a scale indicating the movement amount itself or a scale indicating an acceleration converted from the movement amount. The interval between the scales is set in accordance with the interval between the teeth of the ratchet gear 85.

  The accelerometer 81 configured as described above can finely set the increasing step (resolution) of the recorded acceleration by interposing the ratchet gear 85 and adjusting the diameter (peripheral length) and the tooth interval. it can.

  Other configurations and functions and effects are substantially the same as those of the above-described embodiment or Example 1, and thus description thereof is omitted.

  Hereinafter, in Example 3, an embodiment different from the above-described embodiment and Examples 1 and 2 will be described with reference to FIG. In addition, detailed description is abbreviate | omitted by using the same term about description of the same thru | or equivalent part as the content demonstrated in the said embodiment or Example 1,2.

  FIG. 7 is a perspective view of the accelerometer 91 serving as an acceleration recorder according to the third embodiment as cut from above and viewed obliquely from above. The accelerometer 91 is housed in a rectangular parallelepiped box-shaped housing case 911.

  In addition, a square columnar ratchet tooth portion 95 having tooth shapes 951 and 951 formed on both side surfaces thereof is erected vertically at substantially the center of the housing case 911. The mass portion 92 is formed in a shape surrounding the ratchet tooth portion 95.

  The mass portion 92 is formed in a symmetrical shape around the ratchet tooth portion 95. More specifically, the mass portion 92 is formed into a rectangular parallelepiped shape, and a rectangular parallelepiped through-hole 921 is drilled at substantially the center. The through hole 921 is formed in a quadrilateral slightly larger than the cross section of the ratchet tooth portion 95 in plan view. That is, the mass portion 92 can linearly move along the ratchet tooth portion 95 by the action of acceleration in the longitudinal direction of the ratchet tooth portion 95 (in the vertical direction in the third embodiment).

  Further, ratchet claws 94, 94 which are respectively meshed with the tooth forms 951, 951 on both sides of the ratchet tooth portion 95 are attached to the mass portion 92.

  The outer surface of the mass portion 92 on the side where the ratchet claws 94 are provided is provided as a spring portion extending in a direction substantially perpendicular to the longitudinal direction of the ratchet tooth portion 95 (moving direction of the mass portion 92). One ends of the leaf springs 93 are connected. The pair of leaf springs 93 and 93 are respectively connected to positions that are symmetrical about the ratchet tooth portion 95.

  The other ends of the leaf springs 93 and 93 are fixed to the inner surface of the housing case 911 and serve as a fixed point. That is, the mass portion 92 is supported in a hollow manner by leaf springs 93 and 93 attached to both sides sandwiching the mass portion 92.

  When the mass portion 92 is moved downward in the horizontal state by the action of the acceleration a in the upward direction, the leaf springs 93 and 93 are bent and an upward restoring force is applied. However, the ratchet pawls 94, 94 mesh with the tooth forms 951, 951 so that the upward movement of the mass portion 92 is prevented.

  In the accelerometer 91 according to the third embodiment configured as described above, the mass portion 92 and the leaf springs 93 and 93 are symmetrical with respect to the ratchet tooth portion 95, so that the mass portion 92 is not biased when moving. Since it is difficult to get up and can be moved while maintaining a horizontal state, acceleration is accurately recorded.

  Other configurations and functions and effects are substantially the same as those of the above-described embodiment or other examples, and thus description thereof is omitted.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment or example, and the design changes are within the scope of the present invention. Are included in the present invention.

  For example, in the above-described embodiment or example 1, the description has been given using the mass portion 2 formed into a rectangular parallelepiped, but the present invention is not limited to this, and for example, a cross-sectional portal shape that straddles the ratchet tooth portion 5. May be a mass part.

  In the second embodiment, the ratchet gear 85 and the gear type pinions 821 and 822 are attached to the side surface of the mass portion 82. However, the present invention is not limited to this, and a groove is formed on the lower surface of the mass portion 82. It can also be housed inside.

1,1A Accelerometer (Acceleration recorder)
2 Mass part 3 String-wound spring (spring part)
4 ratchet claws 5 ratchet teeth 6 scale 1B accelerometer (acceleration recorder)
7 Displacement meter 71 Variable resistor 81 Accelerometer (accelerometer)
82 Mass part 821 Gear type pinion 823 Rack 83 String winding spring (spring part)
84 Ratchet claw 85 Ratchet gear 851 Shaft 86 Scale unit 91 Accelerometer (accelerometer)
92 Mass 921 Through-hole 93 Leaf Spring (Spring)
94 Ratchet claw 95 Ratchet tooth portion 951 Tooth profile a Acceleration δ Travel distance

Claims (6)

An acceleration recorder for recording the maximum acceleration generated by receiving a vibration or impact or an acceleration corresponding thereto;
A mass part that moves linearly by the action of acceleration;
A spring portion having one end connected to the mass portion and the other end fixed to the mass portion;
A ratchet claw attached to the mass portion;
An acceleration recorder comprising: a ratchet tooth portion that engages with the ratchet claw and prevents movement due to a force by which the spring portion contracts.   The acceleration recorder according to claim 1, further comprising a scale portion that enables reading of a movement amount of the mass portion or an acceleration converted from the movement amount.   The acceleration recorder according to claim 1, further comprising a displacement meter that electrically measures a movement amount of the mass part.   The acceleration recorder according to any one of claims 1 to 3, wherein the ratchet teeth are linearly extended in a moving direction of the mass part.   The ratchet tooth portion is a gear attached to the mass portion, and extends in a straight line toward the moving direction of the gear-type pinion rotating coaxially with the gear-type and the mass-type pinion meshed with the gear-type pinion. The acceleration recorder according to any one of claims 1 to 3, further comprising a rack.   The ratchet tooth portion extends linearly, the mass portion is shaped symmetrically about the ratchet tooth portion, and the mass of the spring portion is also symmetrical about the ratchet tooth portion. The acceleration recorder according to claim 1, wherein a plurality of the recorders are connected to the unit.