JP2019118638A - Fall prevention method - Google Patents

Abstract

To provide an easily-usable fall prevention method capable of preventing movement or fall of a store fixture caused by external vibration, by a simple constitution.SOLUTION: In a fall prevention method of a store fixture placed on an installation surface, a first frictional coefficient between a first friction part near the front side of a bottom surface of the store fixture and the installation surface is formed larger than a second frictional coefficient between a second friction part near the rear side of the bottom surface of the store fixture and the installation surface, and a back surface member erected on the rear side of the store fixture is connected to the store fixture, to thereby prevent fall of the store fixture caused by external vibration.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for preventing overturning, which prevents shaking or falling out of a fixture installed in a bookshelf or a factory or warehouse of an office or library due to an earthquake or the like.

  Conventionally, various inventions have been proposed for preventing the movement or falling of a fixture in the event of an earthquake or an unintended collision of an article.

  For example, the furniture overturn prevention device disclosed in Patent Document 1 inserts a variable-length member between the top plate and the ceiling of the furniture to suppress shaking of the furniture due to external vibration.

  Moreover, the fall prevention device of the arrangement disclosed in Patent Document 2 has a locking portion at the top of the arrangement placed on the floor, and a support wire suspended from the ceiling is locked to the locking portion from the outside Vibration of the arrangement is suppressed by the vibration of the.

JP, 2014-45920, A JP 10-323250 A

  However, the device for preventing the fall of the fixture disclosed in Patent Document 1 is a device that prevents the fall of the fixture by the ceiling, and the implementation is limited because the presence of a sturdy ceiling is assumed to be realized, so that the usability is limited. There was a problem of improvement.

  Further, in the overturn preventing method disclosed in Patent Document 2, the overturn preventing device of the arrangement is provided with a locking portion at the top of the arrangement placed on the floor and the supporting wire suspended from the ceiling is engaged with the locking portion Since it stops and sway of arrangement thing by vibration from the outside is suppressed, there is a problem that it is necessary to prepare a stop part which connects a wire in the upper part and arrangement thing of a arrangement thing, and an effort of construction is needed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a convenient overturn prevention method for preventing movement and overturning due to external vibration of a fixture with a simple configuration in view of the above-mentioned circumstances.

  The overturn preventing method of the present invention is a method for preventing overturning of a container placed on a mounting surface, wherein a first friction coefficient between a first friction portion near the front side of a bottom surface of the container and the mounting surface It is formed larger than the second friction coefficient between the second friction portion near the rear side of the bottom surface and the installation surface, and the rear member erected on the rear side of the case and the case are connected to each other. It is characterized by preventing a fall due to external vibration.

  The first friction coefficient between the first friction portion near the front side of the bottom surface of the case and the installation surface is larger than the second friction coefficient between the second friction portion near the rear side of the bottom surface of the case and the installation surface Since the back member formed and connected to the rear member erected on the rear side of the case and the case is connected, movement and falling of the case due to external vibration can be effectively prevented.

  In the overturn preventing method of the present invention, the first friction member is provided with the first friction member, and the second friction member is provided with the second friction member, and the coefficient of friction between the first friction member and the installation surface is the second friction member It is characterized in that the coefficient of friction with the installation surface is made larger.

  A first friction member is provided near the front of the bottom of the cabinet, and a second friction member is provided at the second friction near the rear of the bottom. Floors and other installation surfaces near the front and back of the cabinet The coefficient of friction of the case can be controlled to make the coefficient of friction near the front side of the container in contact with the installation surface larger than the coefficient of friction near the rear side.

  In the overturn preventing method of the present invention, the friction coefficient of the first contact surface in contact with the first friction portion of the installation surface with the first friction portion is the second contact surface of the installation surface in contact with the second friction portion It is characterized in that the coefficient of friction with the second friction portion is made larger.

  The coefficient of friction with the fixture near the front is made greater than the coefficient of friction with the fixture near the rear by changing the aspect of the installation surface such as the floor where the bottom of the fixture contacts the front and back of the fixture be able to.

  In the overturn preventing method of the present invention, the first friction member is provided in the first friction portion near the front side of the bottom surface of the fixture, and the second friction member is provided in the second friction portion near the rear side of the bottom surface. It is characterized in that a non-slip sheet or a surface rough surface member is used, or a slip sheet, a member bearing oil or fat or grease, or a caster is used as the second friction member.

  A non-slip sheet or a rough surface member is used for the first friction portion near the front side of the bottom surface of the container or a sliding sheet, a member bearing oil or fat or grease is used for the second friction portion near the rear side of the bottom surface Because of this, the coefficient of friction with the floor is larger near the front of the case than near the rear.

  In the overturn prevention method of the present invention, the first contact surface in contact with the front side of the bottom surface of the fixture on the installation surface is provided with a non-slip sheet or rough surface member or the second contact surface in contact with the rear side of the installation surface. The sliding sheet is used, or a member bearing oil or fat or oil is used.

  A non-slip sheet or rough surface member is placed on the first contact surface in contact with the front side of the bottom surface of the fixture on the installation surface, or a slip sheet or grease on the second contact surface in the vicinity of the rear side of the installation surface Since a loaded member is used, the coefficient of friction between the fixture and the floor is larger near the front of the fixture than near the rear.

  The overturn preventing method of the present invention is characterized in that an impact absorbing material is provided between the fixture and the back member.

  Since the shock absorber is provided between the fixture and the back member, the shock to the back member due to the fall to the back side of the fixture can be mitigated.

It is explanatory drawing of a mode that the fall prevention method of this invention was used. It is explanatory drawing of the behavior of the fixture when a floor surface moves to the (A) right, and (B) moves to the left. It is explanatory drawing of the force added to the fixture placed on the floor. It is explanatory drawing of the relationship of the force concerning a fixture which inclined as the floor shakes. It is an example of measurement of the coefficient of friction between furniture (furniture) and the floor. It is a figure which shows the magnitude | size of the acceleration by a seismic intensity and a vibration period.

  Embodiments of the present invention will be described based on the drawings. FIG. 1 shows an embodiment for realizing the fall prevention method of the present invention. A fixture 1 such as a furniture or an article shelf is placed on a floor 4 which is an installation surface. In general, most of the fixtures have a wider width than the depth for convenience. Also, the fixtures are often placed in front of a rear member 5, such as a wall.

  The vicinity of the front side of the bottom surface of the fixture 1 is the first friction portion, and the vicinity of the rear side is the second friction portion. The bottom surface of the fixture may be the first friction portion and the rear side may be the second friction portion. However, the first friction member 2 is provided on the bottom surface and the second friction member 3 is provided on the rear side near the bottom surface. It may be a first friction part or a second friction part. A portion of the installation surface in contact with the first friction portion is a first contact surface, and a portion of the installation surface in contact with the second friction portion is a second contact surface.

  Let the coefficient of friction between the first friction member 2 and the first contact surface in contact with it be the first coefficient of friction, and let the coefficient of friction between the second friction surface in contact with the second friction member 3 be the second coefficient of friction .

  Here, by making the first friction coefficient larger than the second friction coefficient, the behavior in the front direction and the back direction of the fixture due to external vibration becomes different.

  The configuration of the overturn preventing method of the present embodiment will be described with reference to FIG. FIG. 2 is a view showing the relationship between the fixture and the floor as viewed from the side of the fixture. FIG. 2A is a view showing the case where the floor surface moves in the rear direction of the furniture, and FIG. 2B is a view showing the case where the floor surface moves in the front direction of the furniture.

  As shown in FIG. 2A, when the floor moves to the right in the figure, the center of gravity P of the fixture tries to maintain its position according to the law of inertia, so the upper part of the fixture is left with the first friction part 2 as a fulcrum Tilt in the direction. Also, as shown in FIG. 2 (B), when the floor moves to the left in the figure, the center of gravity P of the fixture tries to maintain its position according to the law of inertia, so the upper part of the fixture is illustrated with the second friction part 3 as a fulcrum Tilt to the right of

  The force acting on the fixture which is externally vibrated will be described with reference to FIG. Gravity G acts downward on the fixture 1 placed on the floor 4 which is the mounting surface, and a force from the floor is applied almost uniformly to the bottom. When an external force F acts in the lateral direction, a friction force μ × G, which is determined by the coefficient of friction μ between the bottom of the cabinet and the floor and the gravity G, acts against it. When F> μ × G, the fixture moves to the right in FIG. 3 by the external force F. Also, depending on the torque described below, the force received by the bottom of the fixture differs on the left and right.

  The appearance of the fixture 1 in which the horizontal external force F is given to the center of gravity P and is inclined at the angle θ will be described using FIG. 4. Due to the external force F to the center of gravity P, torque is generated clockwise in the fixture with the contact point Q between the fixture and the floor as a fulcrum. Assuming that the height of the fixture is L0 and the depth is D, the center of gravity is at the middle point of each dimension of the fixture. Assuming that the angle between the contact point Q and the bottom of the diagonal passing through the center of gravity is α, then β = α + θ.

  Assuming that the distance between the contact point Q and the center of gravity P is L1, the magnitude of the torque in the clockwise direction is L1 × Ft = L1 × F × sin β. Further, in the counterclockwise direction, a torque of L1 × Gt = L1 × G × cos β works by the component force Gt of the gravity G.

  When the bottom surface is in contact with the floor and the floor moves due to an earthquake, the center of gravity tries to maintain its position according to the law of inertia, so an inertial force is generated. The inertial force F and the gravity G act on the center of gravity, and the behavior of the fixture is determined by the size of both. Assuming that the distance from the contact point Q to the center of gravity in FIG. 4 is L1, the torque in the clockwise direction is L1 × Ft = L1 × F × sin β. In addition, the torque in the counterclockwise direction is L1 × Gt = L1 × G × cos β when the gravitational force Gt is used.

  If the torque in the clockwise direction becomes larger than the torque in the counterclockwise direction, that is, if L1 × F × sin β> L1 × G × cos β is satisfied and F> G × cos β / sin β, then the fixture 1 tilts. Since the angle β is determined from the height L0 and the depth D of the fixture, the upper part of the fixture 1 is inclined to the left in FIG. 4 when F> G × D / L.

  The external force due to the earthquake is given by the movement of the floor. When the floor moves in the right direction, a force in the right direction is exerted on the bottom of the fixture 1 by the frictional force μ × G. In opposition to this, inertia force F = μ × G acts on the center of gravity P, and torque is generated in the cabinet 1 clockwise with the contact point Q between the cabinet 1 and the floor as a fulcrum, and the upper part of the cabinet 1 is inclined leftward.

  Conversely, when the floor moves in the left direction, a force in the left direction is exerted on the bottom surface of the fixture 1 by the frictional force μ × G. In opposition to this, an inertia force F = μ × G works at the center of gravity P, and torque is generated in the counter clockwise with the point R of the fixture 1 and the floor at the fixture 1 and the upper part of the fixture 1 tilts right .

  Here, in order for the fixture 1 not to tilt, the magnitude of the force component of gravity Gt = G × cos β that generates a torque in the opposite direction to the inertia force becomes important. When the bottom of the container is in contact with the floor, that is, when inclination starts from θ = 0, θ increases, and since β = α + θ, cos β decreases and the component Gt of gravity decreases, so inclination is easy. Conversely, by applying a force to shift the balance slightly to a steady state at the beginning of tilting, it is possible to prevent tilting or falling of the fixture.

  When the floor moves to the front and back of the fixture due to an earthquake, an inertial force acts on the center of gravity, so the force received on the front and back of the fixture is different and the force on the opposite side of the moving direction of the floor increases. To simplify and model the problem, when the floor moves from side to side in FIG. 2, the fixture tilts in the direction opposite to the moving direction of the floor and causes locking. Here, the first friction coefficient between the first friction portion on the front side of the bottom surface of the case and the installation surface is greater than the second friction coefficient between the second friction portion near the rear side of the bottom surface of the case and the installation surface The movement of the fixture when it is formed large will be described.

  As shown in FIG. 2 (A), when the floor moves to the right, the fixture moves to the right with the floor while tilting to the left. When the floor stops due to inversion and moves to the left, the fixture moves to the right while tilting to the right due to inertia, and kinetic energy is consumed by friction with the floor and the relative velocity to the floor becomes zero. Next, as the floor moves to the left side, it moves to the left together with the floor while tilting to the right as shown in FIG. 2 (B).

  Conversely, as shown in FIG. 2B, when the floor moves to the left, the fixture moves to the left with the floor while tilting to the right. When the floor stops due to inversion and moves to the right, the fixtures move to the left while being inclined to the left by inertia, and kinetic energy is consumed by friction with the floor and the relative velocity to the floor becomes zero. Next, as the floor moves to the right, it moves to the right with the floor while being inclined to the left as shown in FIG. 2 (A).

Here, when the fixture is a speed obtained by the movement of the floor V, and the weight of the furniture and M, kinetic energy MV ^2/2 next to furniture, this energy is consumed as heat energy by friction with the floor. Fixture from MV ^2/2 = μGL since the distance to stop the start of the movement to MyuGL When L by inertia, L = MV ² / 2μG next travel is inversely proportional to the coefficient of friction.

  Here, in FIG. 1, the first friction coefficient between the first friction portion and the installation surface is formed larger than the second friction coefficient between the second friction portion near the rear side of the bottom surface of the fixture and the installation surface Do. That is, the first friction coefficient μ1 is larger than the second friction coefficient μ2, and μ1> μ2. Then, the movement distance is inversely proportional to the friction coefficient, so the movement distance L1 of the fixture of FIG. 2 (A) is smaller than the movement distance L2 of the fixture of FIG. 2 (B), and L1 <L2. That is, by making the front side friction coefficient larger than the rear side friction coefficient with respect to the coefficient of friction between the bottom and the floor before and after the fixture, the movement of the floor before and after the earthquake moves the fixture to the rear in the size L2-L1. Moving. Therefore, it can be understood that the movement of the fixture should be considered only for the prevention of the movement in the back direction.

  Prepare a member on the back of the case to block movement of the case to the rear side. Further, as shown in FIG. 1, since the furniture tends to fall to the front side by the movement of the floor to the rear side, the back member and the furniture are connected using the connecting member 6 in order to prevent collapse. Furthermore, a shock absorber member 7 may be placed between the fixture 1 and the back member 5 to cushion the impact of the fixture on the back member 5.

  FIG. 5 shows the value of the coefficient of friction as a combination of the material of the fixture and the material of the floor on which the fixture is placed. When wood-based furniture is placed on a wood floor, the coefficient of friction is about 0.1 to 0.5, and the width of carpet is 0.2 to 0.9. A carpet with a large coefficient of friction is placed as the first contact surface on the front part of the fixture of wood material to realize the first coefficient of friction and leave the rear side as the wood material with the floor material of the second contact surface The coefficient of friction can be smaller than the first coefficient of friction.

  Further, in FIG. 1, a non-slip sheet or a surface rough surface member can be used as the first friction portion 2 near the front side of the bottom surface to increase the first coefficient of friction μ1 with the floor material. Conversely, the second friction coefficient μ2 can be reduced by using a sliding sheet, a fat or oil or a member bearing a fat or oil, or a caster as the second friction portion in the vicinity of the rear side.

  Since the coefficient of friction is determined by the material of the fixture, the material of the floor surface, and the surface shape thereof, various combinations of making the first coefficient of friction larger than the second coefficient of friction are conceivable. The first friction coefficient can be increased by using a non-slip sheet or a rough surface member on the first contact surface of the floor surface with which the front side of the fixture contacts. Moreover, a 2nd friction coefficient can be made small by using a sliding sheet or the fats-and-oils or fats-and-oils member for the 2nd contact surface of the floor surface which the back side vicinity of the bottom face of a fixture contacts.

  The seismic intensity classified according to the magnitude of the influence on people and buildings of the earthquake is classified as shown in FIG. 6 according to acceleration (gal) and period (seconds). Table 1 shows the results of actual measurement of the effects of the present invention in a model. In the experiment, the behavior of a sample with anti-slip rubber material and a non-anti-slip product without anti-slip was examined as a measure near the front of the bottom of a rectangular parallelepiped weighing 350 g, height 180 mm, width 80 mm, and depth 40 mm. In the experiment, the sample was placed on a wooden floor and vibrated by sine wave drive. As shown in Table 1, in the case of accelerations of 250 gal and 350 gal corresponding to seismic intensity 6, the countermeasure did not fall but the countermeasure did not.

  The embodiment described above is a part of the present invention, and an embodiment including the technical idea of the present invention is included in the technical idea of the present invention.

1 Friction device on the front side of the fixture 2 (first friction member)
3 Rear friction member (second friction member)
4 floors (floor)
5 back member 6 connection member 7 shock absorbing member

Claims (8)

It is a fall prevention method of the fixture mounted on the installation surface, and
The first friction coefficient between the first friction portion near the front side of the bottom surface of the case and the installation surface is greater than the second friction coefficient between the second friction portion near the rear side of the bottom surface of the case and the installation surface Formed large,
A method for preventing overturning comprising connecting a back member erected on the rear side of the case and the case to prevent overturning due to vibration from the outside of the case.   A first friction member is provided in the first friction portion, and a second friction member is provided in the second friction portion, and a coefficient of friction between the first friction member and the installation surface is between the second friction member and the installation surface The fall prevention method according to claim 1, characterized in that the friction coefficient is made larger than the friction coefficient.   The coefficient of friction with the first friction portion of the first contact surface in contact with the first friction portion of the installation surface is the same as the second friction portion with the second contact surface in contact with the second friction portion of the installation surface The fall prevention method according to claim 1 or 2, characterized in that the friction coefficient is made larger.   3. The overturn preventing method according to claim 2, wherein a non-slip sheet or a surface rough surface member is used as the first friction member.   3. The overturn preventing method according to claim 2, wherein a sliding sheet, a fat or oil or a member bearing an fat or oil, or a caster is used as the second friction member.   4. The overturn preventing method according to claim 3, wherein a non-slip sheet or a rough surface member is used as the first contact surface.   4. The overturn preventing method according to claim 3, wherein a sliding sheet or a member bearing oil or fat or oil is used for the second contact surface.   The overturn prevention method according to any one of claims 1 to 7, wherein an impact absorbing material is provided between the case and the back member.

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