JP2019184487A - Shock test method of eaves - Google Patents

Abstract

To provide a shock test method capable of reducing the number of trials of shock tests to test eaves of a house or the like.SOLUTION: As a test sample 10, eaves 12 are provided in a single flow shape in a form that protrudes from a wall 11. The weight 21 is a bag of polyethylene filled with sand adjusted to a density of 1,500 kg/m, and an opening of the bag is closed in the binding band 22 so that the void does not remain in the bag. A rope 24 attached to the weight 21 is hung on a pulley 23, and the other end 24b of the rope 24 is held by a clamp 36. Thus, the weight 21 is in a suspended state by the pulley 23 at a predetermined height of h2 position. When the other end 24b of the rope 24 is released from the clamp 36, the weight 21 falls by the gravity toward the eaves 12 and collides with the eaves 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an impact test method for a bag. More specifically, the present invention relates to an impact test method for measuring the impact resistance of a fence such as a house when a falling object such as snowfall collides.

  2. Description of the Related Art Conventionally, as an impact test for a building, a test has been performed on the assembled building itself or a test object (outer wall, roof, fence, flooring, etc.) attached in a state according to use. Steel balls and sand bags (sandbags) are often used as impact imparting bodies that impact the test object. The impact resistance is evaluated based on whether or not a decrease in function or a change in appearance (deformation, damage, etc.) has occurred in the test object due to the collision (Non-Patent Document 1).

  A conventional impact test method for firewood such as a house will be described with reference to FIG. FIG. 3 is a schematic view of the test sample 10 attached to the wall 11 in a state in which the scissors 12 to be tested are in accordance with normal use. In the test sample 10, the scissors 12 are provided on the wall 11 in a single flow shape so as to protrude from the wall 11.

  As shown in FIG. 3, the rope 14 is connected to the weight 13 and the rope 14 is lifted, so that the weight 13 is positioned at a predetermined height h1 above the barb 12 (hanging state). Thereafter, by lifting the rope 14 that has been lifted, the suspended state of the weight 13 is released and the weight 13 is dropped as indicated by the arrow in the figure. Then, the weight 13 is caused to collide with the saddle 12 installed immediately below it, and the state of the saddle 12 after the collision is verified.

  As the weight 13, a leather bag filled with sand is often used. In FIG. 3, since the weight 13 is suspended, it is in a state of spreading downward in a fan shape by gravity. The upper portion of the fan-shaped weight 13 becomes a void S that is not filled with sand.

Japan Architecture Research Institute, “Easy-to-understand test series, pressure 06, torsional strength, vertical load strength, impact resistance test of doorset”, [online], [searched March 26, 2018], Internet < URL: http://www.gbrc.or.jp/assets/test_series/documents/cl_06.pdf>, Japan Building Research Institute Testing Research Center Environment Department Wind Resistance Test Room

  In such an impact test by free fall of the weight 13, the sand moves in the bag due to the presence of the gap S, and the shape of the weight 13 at the time of collision and the variation thereof vary. As a result, the impact (impact force) on the flange 12 is likely to vary. Therefore, it was necessary to perform a number of tests in order to determine the impact resistance of the ridge 12.

  Since an impact test on a building such as a fence is performed on a test object attached to the building itself or in a state according to use, there is a problem that it takes cost and labor if the number of trials of the impact test is large.

  This invention is made | formed in view of the said situation, and provides the impact test method which can reduce the frequency | count of the trial of the impact test which makes a test object the fence of a house.

In order to solve the above-mentioned problem, the impact test method for scissors according to the first invention is as follows:
Dropping the impact imparting body from a state of being arranged at a predetermined height from the scissors, and impacting the impact imparting body with the scissors, thereby evaluating the impact resistance of the scissors,
The impact imparting body is a bag filled with sand adjusted to a density of 1,500 kg / m ³ , and the opening of the bag is closed so that no gap is formed between the inner surface of the bag and the sand. And
The bag is polyethylene;
One end of a rope is attached to the impact imparting body,
A fixed pulley for hanging the impact imparting body in a dropable state;
A holding part capable of holding the impact imparting body at the position of the predetermined height and releasing the holding;
Is provided,
Hanging the rope on the fixed pulley, and holding the other end of the rope to the holding portion, thereby hanging the impact imparting body at the predetermined height; and
Releasing the holding of the other end of the rope by the holding unit, and releasing the impact imparting body by dropping the impact imparting body toward the bag;
It is characterized by having.

According to the first invention, the impact imparting body is a polyethylene bag filled with sand having a density of 1,500 kg / m ³ . And after the said impact imparting body is filled with sand, the opening part is closed so that a space | gap may not arise in a bag. Since the polyethylene bag is excellent in flexibility, the shape of the bag can be made to follow the shape of the filled sand, and it is easy to seal so as not to generate a void. And since such an impact imparting body has almost no voids that are not filled with sand in the bag, even if it is dropped from a suspended state, it is difficult for sand to move within the bag, and impact is applied at the time of dropping or collision. The shape of the body is difficult to change, and the variation in shape change is reduced. Thereby, variation in impact (impact force) can be suppressed.

  Therefore, according to the first aspect of the present invention, it is possible to reduce the variation in impact, thereby reducing the number of trials of the impact test.

The impact test method of the second invention is the first invention,
The weight of the impact imparting body is 3 kg or more and less than 6 kg, and the predetermined height is 4 m or more and 6 m or less, or the weight of the impact imparting body is 6 kg or more and the predetermined height is It is 2 m or more and 6 m or less.

  When the weight of the impact imparting body and the drop height at which the impact imparting body is dropped satisfy the above conditions, the impact test can be performed with further reduced variation.

The impact test method of the third invention is the first or second invention,
The impact imparting body is provided with a string that hangs downward,
In the suspension step, the impact imparting body is suspended to the predetermined height using the length of the string as an index.

  When performing an impact test, first, it is necessary to arrange the impact imparting body at a predetermined height. When the impact imparting body is suspended, the string hangs down toward the dropping point. Thereby, it becomes an index of a predetermined height when the impact imparting body is in the suspended state, and it is excellent in convenience.

  The impact test method of a fourth invention is characterized in that, in any one of the first to third inventions, the sand is adjusted in density by adding water.

  The sand in the bag is wet and adjusted, so that the sand in the bag becomes wet. Such wet sand is less likely to move in the bag than dry sand. Thereby, the change of the shape of the impact imparting body at the time of dropping or collision can be further suppressed, and the variation in the change of the shape can be further suppressed.

The conceptual diagram which shows an example of an impact test method. The figure which shows the apparatus of verification experiment. The conceptual diagram which shows the impact test of the conventional fences, such as a house.

  When a fallen object collides with a fence such as a house due to snowfall, the fence may be deformed or destroyed by the applied impact. The present embodiment is an impact test method for evaluating the impact resistance of a kite for the purpose of ensuring the strength of the kite so that the kite is not destroyed by the collision of such falling objects.

  Hereinafter, the impact test method of the present invention will be described based on the embodiment shown in FIG. In the embodiment, a case where the test object for evaluating the impact resistance is a housing urn will be described as an example.

  FIG. 1 is a schematic view of a test object attached to a wall in a state in accordance with normal use. As the test sample 10, the scissors 12 are provided on the wall 11 in a single flow shape so as to protrude from the wall 11. Hereinafter, the protruding direction of the flange 12 means a direction perpendicular to the wall 11, and the width direction of the flange 12 means a direction parallel to the wall 11.

  A hoist crane 31 (only part of which is shown) is disposed above the cage 12. The hoist crane 31 is provided with a hook 32, and the hook 32 is located above the point of dropping onto the cage 12 that is the subject of the impact test (for example, above the protruding direction of the kite and the central portion in the width direction). Is arranged. A pulley 23 is hung on the hook 32. The hoist crane 31 and the hook 32 hold the pulley 23 so as not to move during the impact test. Therefore, the “constant pulley” is constituted by the hoist crane 31, the hook 32 and the pulley 23.

  A rope 24 is hung on the pulley 23, and a weight 21 is suspended from one end 24 a of the rope 24. That is, one end 24a of the rope 24 is attached to the weight 21 (for example, a binding band 22 described later), and the rope 24 is hung on the pulley 23, so that the weight 21 is lifted by the rope 24 and above the cage 12. It is held by (hanging state). The pulley 23 supports that the weight 21 is suspended at a predetermined height h2.

  A stand 35 (only part of which is shown) is installed on the front side of the bowl 12 which is the test sample 10, and a clamp 36 is provided on the stand 35. The other end 24 b of the rope 24 is fastened to the clamp 36. In the present embodiment, the other end 24 b of the rope 24 is formed in a ring shape, and the other end 24 b of the rope 24 is held by the clamp 36 by hanging the ring portion on the clamp 36. Thereby, the weight 21 is suspended by the pulley 23 and is held by the stand 35 and the clamp 36 so as to have a predetermined height h2.

  In the impact test method of this embodiment, when the other end 24b of the rope 24 fastened to the clamp 36 is released from the clamp 36 (the holding is released), the weight 21 falls due to gravity. As a method of releasing the other end 24b of the rope 24 by the clamp 36, an operator may remove the ring portion from the clamp 36, or the operator may cut off the other end 24b (ring portion or the like) of the rope 24. It may be released from the clamp 36.

  In other words, the stand 35 and the clamp 36 can hold the weight 21 at a predetermined height h2 and release the held state (in other words, the suspended state of the weight 21). The stand 35 and the clamp 36 correspond to a “holding portion”.

  One end 25 a of the string 25 is attached to the lowermost part of the weight 21. One end 25a of the string 25 is attached by being sewn to the weight 21 or attached with a tape or the like. The length of the string 25 is the same length as the predetermined height h2. The other end 25b of the string 25 is fixed to the target drop point of the basket 12 with a tape or the like (not shown). Thereby, it becomes an index when the string 25 lifts the weight 21 to a predetermined height h2.

In this embodiment, the weight 21 is a bag filled with sand adjusted to a density of 1,500 kg / m ³ , and the opening of the bag is closed with a binding band 22 so that no gap is generated in the bag. ing. The weight 21 corresponds to an “impact imparting body”.

  In this embodiment, a polyethylene bag is used as the bag filled with sand. If the bag is made of polyethylene, the bag can be deformed along the shape of the filled sand, so that it can be closed by the binding band 22 so as not to generate a gap in the bag (between the inner surface of the bag and the sand).

  The shape of the polyethylene bag is not particularly limited, such as a flat bag, a self-supporting bag, a gusset bag, and the like, but a flat bag shaped sandbag is particularly preferable. The size of the sandbag is preferably 480 mm wide × 620 mm long.

As the sand filled in the bag, sand conforming to JIS A1518 (1996) is used. That is, sand that passes through a 2 mm sieve and stays on a 0.6 mm sieve is adjusted to a density of 1500 kg / m ³ . For example, it may be adjusted by adding water to sand so that the density is 1,500 kg / m ³ . By adjusting the density by adding water to the sand, the sand in the bag becomes wet. The wet sand suppresses the movement of the sand in the bag as compared with the dry sand, which further suppresses the change in the shape of the weight 21 when dropped or collides, and further suppresses the variation in the change in the shape. The Therefore, the sand filled in the weight 21 is adjusted by adding water, thereby reducing the variation in impact. Further, if the sand is moist, the weight 21 is similar to the snow condition, and therefore, it is preferable as the weight 21 for the impact test on the hail caused by falling snow.

  Here, in the impact test method of the present embodiment, the weight of the weight 21 is preferably 2 kg or more, more preferably 4 kg or more, and further preferably 6 kg or more. The upper limit of the weight of the weight 21 is not particularly limited, but is preferably 20 kg or less, more preferably 18 kg or less, and even more preferably 15 kg or less from the practical aspect when performing an impact test. .

  In the impact test method of the present embodiment, the height h2 at which the weight 21 is dropped is not particularly limited, but a lower one is preferable from a practical aspect when performing an impact test. Accordingly, the drop height h2 is preferably 30 cm to 10 m, more preferably 50 cm to 8 m, still more preferably 1 m to 6 m, and particularly preferably 2 to 6 m.

  Since variation in impact is affected by weight and height, it is preferable to consider the balance. For example, when the weight of the weight 21 is 3 kg or more and less than 6 kg, the variation in impact is reduced when the predetermined height (falling height) h2 is 4 m or more (preferably 4 m or more and 6 m or less). When the weight of the weight 21 is 6 kg or more, the variation in impact is sufficiently reduced if the predetermined height h2 is 2 m or more (preferably 2 m or more and 6 m or less).

  The shape of the weight 21 (the shape after being closed by the binding band 22) is a spherical shape so that the collision with the rod 12 at the time of initial collision is close to the point from the viewpoint of shape stability. However, other shapes may be used.

  The size of the portion filled with sand in the weight 21 (excluding the corner portion of the sandbag) is preferably substantially spherical with a diameter of 30 cm or less in the suspended state, and is substantially spherical with a diameter of 25 cm or less. Is more preferable. Further, it is preferably substantially spherical with a diameter of 12 cm or more, and more preferably substantially spherical with a diameter of 15 cm or more.

  In addition, since the sandbag is closed so as not to generate a gap, the gap is also minimized in the corner portion of the sandbag. In this embodiment, since water is added to the sand, the movement of the sand in the bag is suppressed as compared with dry sand. Therefore, even if there are slight voids at the corners, the influence of the voids (sand movement into the voids) can be suppressed.

  In the impact test method of the present embodiment, the rope 24 is used to suspend the weight 21 and is not particularly limited as long as it has sufficient strength to hold the weight 21. Cotton, hemp, nylon, polyester, polyethylene , Polypropylene, vinylon, or the like may be used. The length and width of the rope 24 may be appropriately selected depending on conditions such as the weight of the weight 21 and the height h2.

  The string 25 is preferably a thin or thin string compared to the rope 24 so as not to become an obstacle at the time of dropping and collision. As the string 25, one made of cotton, hemp, silk, nylon, polypropylene, or the like can be used as appropriate.

  Further, the size and the like of the pulley 23 are not particularly limited, and may be appropriately selected according to the weight of the weight 21 and the shape of the rope 24. The hoist crane 31 and the hook 32 that hold the pulley 23, the stand 35 that holds the rope 24, the clamp 36, and the like may be substituted by other means that can obtain the same effect.

  Next, the test procedure will be described.

  It is confirmed that there is no distortion or the like in the portion to which the impact is applied (target drop point) in the ridge 12. Thereafter, the rope 24 attached to the weight 21 is hung on the pulley 23, and the other end 24 b of the rope 24 is held by the clamp 36 of the stand 35. Thereby, the weight 21 will be in a suspended state.

  Next, the hoist crane 31 is moved so that the weight 21 in the suspended state is positioned at the target drop point and the slack of the string 25 is eliminated. As a result, the weight 21 is directly above the target drop point and is suspended from the predetermined height position h2. This process corresponds to a “hanging process”.

  Then, after confirming that the weight 21 has stopped swinging, the other end 24b of the rope 24 is released from the clamp 36, whereby the suspended state of the weight 21 is released. When the suspended state is released, the weight 21 freely falls toward the saddle 12 (arrow in FIG. 1), and the weight 21 collides with the vicinity of the target drop point of the saddle 12. This process corresponds to a “dropping process”.

  After the collision of the weight 21, the heel 12 is visually inspected for deformation or damage such as dents, cracks, peeling, and bending. Record test results for deformation and damage. In addition, when recording the test result, the test conditions (drop height h2, weight of weight 21, size of scissors 12 to be tested, number of impacts (drops), etc.) are added.

  The impact test method of this embodiment can confirm that the reproducibility is high (the variation is small) by, for example, a verification method described later. If the conditions are more preferable, it can be confirmed that the error of the impact force is less than 10% by the verification method described later. That is, the impact test method of the present embodiment suppresses a change in the shape of the weight 21 when the weight 21 is dropped and collided toward the test object (庇) in a free fall state or a state close to free fall. The variation of the change of the is suppressed. Thereby, variation in impact can be reduced, and the number of trials of the impact test can be reduced.

  Hereinafter, according to the impact test method of the present embodiment, an experiment was conducted to verify that the test has a small variation in impact force.

Verification experiment 1
FIG. 2 shows an apparatus for performing a verification experiment.

  As shown in FIG. 2, a steel plate 42 was installed, and three load cells 41a, 41b, 41c were installed on the surface of the steel plate 42 so that each load cell 41a, 41b, 41c was a vertex of an equilateral triangle. And the steel plate 43 was mounted on each load cell 41a, 41b, 41c, and it was set as the state by which each load cell 41a, 41b, 41c was clamped by the steel plates 42,43.

  Each load cell 41a, 41b, 41c is connected to the data logger 45 by each wiring 44a, 44b, 44c.

  As shown in FIG. 2 (similar to FIG. 1), the weight 21 is suspended using a hoist crane 31, a pulley 23, a stand 35, a clamp 36, and the like. In this experiment, a weight 26 is attached to the other end 25 b of the string 25, and the weight 26 is disposed at the drop target point 46. Also in the above embodiment, a weight 26 may be attached instead of fixing the other end 25b of the string 25 to the collar 12 as in this experiment. Note that the fall target point 46 is near the center of gravity of an equilateral triangle formed by the load cells 41a, 41b, 41c.

  The weight 21 was prepared as follows.

Water was added to the sand density 1464kg / ^{m 3,} to adjust the density of the sand 1500 kg / ^{m 3.} The adjusted sand was filled in a polyethylene sandbag (width 48 cm × length 62 cm, product name: sandbag), and the mouth of the bag was closed with a binding band 22 so that no gap remained. The weight 21 was suspended, and the sand-filled portions were substantially spherical with the following sizes, except for the corner portions of the sandbags. In addition, since the sandbag is closed so as not to generate a gap, the gap is also minimized in the corner portion of the sandbag.

・ 3 kg weight 21: almost spherical shape with a diameter of 16 cm ・ 4 kg weight 21: almost spherical shape with a diameter of 17 cm ・ 5 kg weight 21 ... substantially spherical shape with a diameter of 19 cm ・ 6 kg weight 21: almost spherical shape with a diameter of 20 cm

  The tools used in the verification experiment are shown below.

Pulley 23: diameter 60 mm, rotating part (steel) width 20 mm
Load cell 41a, 41b, 41c: Used in combination of two types of load cells; one load converter 200kgf (model number: 9E01-L21-200K, diameter 100 mm, height 80 mm) and load converter 5tf (model number: 9E01-L22) -5T, diameter 100mm, height 80mm) Data Logger 45: Universal Data Acquisition System Data Logger (Model: UDAS)
Rope 24: Cotton string with a thickness of 5 mm Steel plates 42, 43: Size 90 cm × 90 cm (thickness 9 mm).

  In the verification experiment 1, the operator removed the other end 24b (ring part) of the rope 24 fastened to the clamp 36, and the operator dropped the weight 21 by releasing the other end 24b of the rope 24. Then, by changing the weight of the weight 21 and the height h2, the impact force (N) generated by the weight 21 falling was measured using each load cell 41a, 41b, 41c. The impact force (N) due to the fall of the weight 21 is a value obtained by adding the impact forces (N) measured by the load cells 41a, 41b, 41c. In addition, the maximum value of impact force was employ | adopted as impact force measured by each load cell 41a, 41b, 41c.

  The measurement under the same conditions was performed 10 times, and the impact force error value (%) was calculated as the impact force average value and the degree of variation of the impact force (± 3σ) for the impact force obtained by 10 experiments. (See Table 1).

  From the results in Table 1, the condition that the error of impact force is less than 10% was obtained. It is considered that the weight 21 and the dropped height h2 satisfy the following conditions.

(1) The weight of the weight 21 is 3 kg or more and less than 6 kg, and the drop height h2 is 4 m or more. (2) The weight 21 is 6 kg or more and the drop height h2 is 2 m or more.

  Therefore, it was suggested that if the above (1) or (2) is selected, the number of trials can be further reduced because the reproducibility is higher than other conditions of the verification experiment 1.

  It should be noted that the variation in impact is theoretically reduced as the fall height increases and the weight increases. Therefore, when the error becomes less than 10%, the impact test (validation experiment) at the weight 21 is completed. Therefore, if the drop height h2 is 6 m, it is considered that the weight 21 has an error of less than 10% when it is 3 kg or more and less than 6 kg, and an error of less than 6.5% when the weight 21 is 6 kg.

Comparative experiment In order to compare with the result of the verification experiment 1, comparative experiments 1 to 5 were performed.

Comparative experiment 1
In Comparative Experiment 1, without using the pulley 23, the rope 24 attached to the weight 21 was held by hand, and the weight 21 was dropped by releasing the rope 24 from the hand. That is, with the verification experiment 1 except that the rope 24 is held by hand at a position where the height of the weight 21 is h2, and then the weight 21 is dropped by releasing the rope 24 from the hand at the position of the height h2. An experiment was conducted in the same manner, and an average value of impact force and an error of impact force were calculated (Table 2).

Comparative experiment 2
In Comparative Experiment 2, the rope 24 attached to the weight 21 was held by the clamp 36 without using the pulley 23, and the weight 21 was dropped by releasing the rope 24 from the clamp 36. That is, except that the rope 24 is held by the clamp 36 of the stand 35 at the position where the height of the weight 21 is h2, and then the weight 21 is dropped by releasing the rope 24 from the clamp 36 at the position of height h2. The experiment was performed in the same manner as in the verification experiment 1, and the average value of the impact force and the error of the impact force were calculated (Table 2).

  From the results of Comparative Experiments 1 and 2, it was confirmed that the error of the impact force was large when the pulley 23 was not used. It can be seen that when the impact test is performed by this method, the reproducibility is low, so that a large number of trials are required.

Comparative experiment 3
In Comparative Experiment 3, an experiment similar to Comparative Experiment 1 was performed using the following weights.

A polyethylene sandbag was filled with sand having a predetermined weight density adjusted to 1,500 kg / m ³ , and then the sandbag was closed with a string attached to the top of the sandbag to make a weight. Therefore, the weight includes a space (void) that is not filled with sand.

  In comparative experiment 3, an experiment was performed in the same manner as in comparative experiment 1 except that 3 kg and 6 kg weights closed by the string at the top of the bag were used instead of the weight 21. In the comparative experiment 3, when the weight is 3 kg, the impact force error is 37.3% (average impact force is 897 N) when dropped from 1 m, and when the weight is 6 kg, the impact force error is caused by dropping from 1 m. It was 60.4% (average of impact force: 1871N).

Comparative experiment 4
In comparative experiment 4, the same experiment as comparative experiment 2 was performed using the weight of comparative experiment 3.

  In comparative experiment 4, when the weight is 3 kg, the impact force error is 95.6% (average impact force is 620 N) when dropped from 1 m, and when the weight is 6 kg, the impact force error is 47 after dropping from 1 m. 0.1% (average of impact force 1199N).

  From the results of Comparative Experiments 3 and 4, it was confirmed that the error of the impact force is larger than that of Comparative Experiments 1 and 2 when the weight is not closed by the binding band 22. Therefore, it was suggested that it is important that the weight 21 in the impact experiment is closed so that no gap is generated.

Comparative experiment 5
Comparative experiment 5 was performed in the same manner as in verification experiment 1 except that the weight 21 bag was changed from a polyethylene soil bag to a polypropylene soil bag (width 48 cm × length 62 cm). However, since it was made of polypropylene, the entire bag was not flexible, and even when the bag mouth was closed so as not to generate a void, the void remained and the sand in the bag could move.

An impact test was conducted by dropping a weight of a polypropylene soil bag filled with 6 kg of sand having a density of 1500 kg / m ³ from a position of 2 m in height. As a result, the error of the impact force was 10.8% (impact force average 3141N).

  It was confirmed by Comparative Experiment 5 that the impact variation was reduced by making the weight 21 bag made of polyethylene when dropped under the same conditions. The reason why polyethylene is preferable to polypropylene is that polyethylene bags are more flexible than polypropylene bags. That is, when closing so that a space | gap does not arise in a bag with the binding band 22, the bag made from polyethylene can deform | transform along the shape of the sand filled with compared with the bag made from polypropylene. Thereby, the polyethylene bag can be closed by the binding band 22 in a state where the gap can be reduced as compared with the polypropylene bag.

  As described above, from the results of the verification experiment 1 and the comparison experiments 1 to 5, in the system of the verification experiment 1, there are many conditions (the weight of the weight 21 and the drop height h2) that allow the error to be less than 20%, for example. I understand that. Thereby, it can be said that the impact test method of this embodiment has reduced variation in impact and improved reproducibility. That is, the weight 21 is filled with sand in a polyethylene bag, the bag is closed so as not to form a gap, and the pulley 23 is used when the weight 21 is released from the suspended state. Variation is reduced and reproducibility is improved.

  Further, if the error of the impact force is less than 10%, it can be said that this is an impact test method in which reproducibility is higher and the number of trials can be further reduced. The condition that the error of the impact force is less than 10% is that the weight 21 is filled with sand in a polyethylene bag, the bag is closed so that no gap is formed, and the suspended state of the weight 21 is released. A pulley 23 is used, and it is considered that the weight 21 and the dropped height h2 satisfy the condition (1) or (2). Further, under the condition (2), the impact force error can be less than 6.5%, so that the number of impact test trials can be further reduced.

  12 ... １２, 21 ... Weight, 22 ... Binding band, 23 ... Pulley, 24 ... Rope, 24a ... One end of rope 24, 25 ... Rope, 35 ... Stand, 36 ... Clamp, h2 ... Predetermined height.

Claims (4)

Dropping the impact imparting body from a state of being arranged at a predetermined height from the scissors, and impacting the impact imparting body with the scissors, thereby evaluating the impact resistance of the scissors,
The impact imparting body is a bag filled with sand adjusted to a density of 1,500 kg / m ³ , and the opening of the bag is closed so that no gap is formed between the inner surface of the bag and the sand. And
The bag is polyethylene;
One end of a rope is attached to the impact imparting body,
A fixed pulley for hanging the impact imparting body in a dropable state;
A holding part capable of holding the impact imparting body at the position of the predetermined height and releasing the holding;
Is provided,
Hanging the rope on the fixed pulley, and holding the other end of the rope to the holding portion, thereby hanging the impact imparting body at the predetermined height; and
Releasing the holding of the other end of the rope by the holding unit, and releasing the impact imparting body by dropping the impact imparting body toward the bag;
An impact test method for scissors. The weight of the impact imparting body is 3 kg or more and less than 6 kg, and the predetermined height is 4 m or more and 6 m or less, or the weight of the impact imparting body is 6 kg or more and the predetermined height is The impact test method for scissors according to claim 1, wherein the impact test method is 2m or more and 6m or less. The impact imparting body is provided with a string that hangs downward,
The hook impact test method according to claim 1, wherein, in the suspending step, the impact imparting body is suspended to the predetermined height using the length of the string as an index.   The dredge impact test method according to any one of claims 1 to 3, wherein the sand has been subjected to density adjustment by adding water.

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