JPH0356841A - Drop and impact testing device - Google Patents

Abstract

PURPOSE:To facilitate control over a shock waveform and to shorten an operation time by enabling an impact head of a drop table on which a body to be tested is placed and freely drops and a piston of a cylinder to be replaced freely and freely varying the internal capacity of the cylinder with injected liquid. CONSTITUTION:The internal capacity of the cylinder 17 is adjusted substantially freely by an upper space where compressed gas varying with the quantity of injected liquid is supplied. Further, a piston 19 or 19A having a diameter corresponding to the detachable impact head 4A or 4A' of the drop table which dropped freely along a guide rail and mounts the body to be tested is selected according to a selection of a cylindrical body 18 or 18A mounted on the cylinder 17 and a lid body 21 or 21A. Consequently, a shock waveform is easily adjusted by the replacement, the cylinder and drop table themselves need not be changed, and the operation time can be shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement in the structure of a drop*i test device used for measuring the mechanical impact resistance strength of various products, etc. be.

(Prior Art) Figures 3 and 344 show a conventional drop impact testing device used to measure the impact resistance of commercially available products. (2) is a pair of guide rods erected on both sides of this base (1), and (3) is a pair of guide rods (2) that pass through this pair. A drop table that can be raised and lowered freely.
This drop table (3) is equipped with an impact head (4) directed vertically downward, and is moved up and down by a lifting device (not shown). And this falling table (3)
A product (5), which is a sample to be measured, is fixed by a jig (not shown).

In addition, (6) is a cylinder mounted on the base (1), and the upper part of this cylinder (6) has a through hole (7) that is penetrated by the impact head (4) when the drop table (3) falls. (See Figure 4). (8) is a piston that is disposed inside the cylinder (6) and can be freely slid in the vertical direction, and this piston (8) has a plurality of O-rings (9) as shown in Fig. 4.
) is fitted, and this O-ring (9) is fitted into the cylinder (6
) acts to maintain airtightness within the interior. When the drop table (3) falls, the piston (8) is struck by an impact head (4) passing through the through hole (7) and is pushed downward from the position shown in FIG.

On the other hand, (10) is a high-pressure gas container filled with inert nitrogen gas, and (11) is a gas supply vibrator that connects this high-pressure gas container (10) and the cylinder (6). ) functions to guide the nitrogen gas in the high pressure gas container (10) into the cylinder (6) and raise the piston (8) to the position shown in FIG. And the cylinder (
6) The nitrogen gas filled inside acts as a spring to restrict the downward sliding movement of the piston (8), which has risen to the position shown in FIG. 4, and to return it to its original position. (12) is a gas pressure regulator provided on this gas supply vibrator (11), and this gas pressure regulator (12) is comprised of a gas pressure regulating valve (13) that functions to regulate gas pressure, and a gas pressure regulating valve (13) that functions to regulate gas pressure. Pressure gauge to display (l4
).

Further, (15) is a control device that controls the lowering operation of the male dropping table (3).

Therefore, when measuring the impact resistance strength of the product (5) (sample), first place and fix the product (5) to be measured on the drop table (3) using a jig (not shown). do. Next, operate the control device (l5) to raise and lower the drop table (3) using the lifting device to move the impact head (
Set the distance between the tip of the cylinder (4) and the top surface of the cylinder (6) to a predetermined test drop height, and once the setting is complete, set the drop table (3) at that position using a positioning mechanism (not shown).
Retained by Next, the gas pressure regulating valve (13) of the gas pressure regulator (12) is operated so that the nitrogen gas supplied from the high pressure gas container (10) reaches a predetermined gas pressure within the cylinder (6). Adjust while checking with the meter (l4) and raise the piston (8) to the position shown in Figure 4. Note that by changing the set value of the gas pressure, the resistance during sliding of the piston (8) and the maximum value of the grass-weeding acceleration generated on the falling table (3) change.

When the above preparations are completed, the control device (15) is operated to open the positioning mechanism and the drop table (3) is allowed to fall by itself. The falling table (3) falls freely while being guided by the guide rod (2), and the impact head (4) hits the cylinder (6).
) and collides with the piston (8). Upon this collision, the piston (8) falls onto the falling table (3).
) is pushed downward and slides inside the cylinder (6), compressing the nitrogen gas inside the cylinder (6) and increasing the pressure. And the falling table (
When the kinetic energy of 3) becomes 0 and the sliding displacement of the piston (8) reaches its maximum position, the piston (8) returns to the position shown in Fig. 4 due to the energy (pressure) of the compressed nitrogen gas. the falling table (3) along the guide rod (2) and suddenly rebounds upwards. However, the falling table (3
) while it is floating, the positioning mechanism holds the falling table (3) to prevent the impact head (4) from colliding again, thereby completing the work.

Next, impact acceleration will be explained based on FIGS. 5 and 6.

Figure 5 is a load-displacement diagram when the impact head (4) pushes down the piston (8), and Figure 6 is an impact velocity-time diagram. (B) shows the spring characteristics of the nitrogen gas filled in the sill (6).

The value of the impact acceleration generated on the drop table (3) when the impact piston (4) collides with the piston (8) becomes abrupt until the kinetic energy and the pressure of the nitrogen gas pushing the piston (8) upward are balanced. (Fig. 5, 6)
(from the origin of the figure to (A)). When the screw 5 (8) returns to its original position due to the rise in gas pressure stored and compressed, it gently rises in a chevron shape and then descends ((B) in Figures 5 and 6). )), then there is a sharp decline. However, the piston (
8), the impact acceleration value becomes O as the impact head (4) separates from the impact head (4).

If we consider these behaviors as shock waveforms over time in Figure 6, the value of shock acceleration is determined by the spring characteristics of nitrogen gas (
B) Due to the sudden sliding movement of the piston (8), the steady acceleration portion (B) appears as a trapezoidal impact acceleration waveform with a chevron shape.

Furthermore, as a prior art document of this kind, Japanese Patent Publication No. 54-402
No. 9, No. 55-5456, No. 59-33852, etc.

[Problem to be solved by the invention]

The conventional drop impact test device is constructed as described above, and since the internal volume of the cylinder (6) and the diameter of the piston (8) are always the same, the pressure inside the cylinder (6) increases and the trapezoidal impact occurs. As the waveform changes to a half-sine a5tE waveform, the impact duration becomes shorter, and to solve this problem, several types of impact heads (4), cylinders (6), and pistons (8) must be used. There wasn't. And these several types of impact heads (4) cylinders (6)
and work/storage space for the piston (8) must be secured, which generally results in increased work time for replacing the impact head (4) cylinder (6) or piston (8). There was a point.

The present invention has been made in view of the above points, and an object of the present invention is to provide a drop impact test device in which the impact waveform can be controlled by freely changing the internal volume of the cylinder and the diameter of the piston.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention includes a cylinder disposed on a base, a liquid filled in a lower space in the cylinder, and a cylinder containing the liquid. a cylindrical body inserted into the upper space in the cylinder; a piston movable up and down inside the cylindrical body; A lid body is heavily attached to the top of the cylindrical body, a drop table that can be raised and lowered to collide with the cylinder while being guided by a pair of guide rods erected on both sides of the base, and a suspended table at the bottom of the drop table. A drop impact test device is composed of an impact head that passes through the through hole of the lid body and collides with the piston, and a drop table equipped with a sample is dropped into the cylinder to apply an impact to the sample. It is characterized by

[Effect]

According to the present invention, there is provided a cylinder disposed on a base, a liquid filled in a lower space in the cylinder, a gas filled in an upper part of the lower space containing the liquid, and a cylinder disposed on a base. A cylindrical body inserted into the upper space, a piston disposed inside the cylindrical body so as to be movable up and down, a lid having a through hole and heavily attached to the top of the cylindrical body, and the base. A drop table that can be raised and lowered and collides with the cylinder while being guided by a pair of guide rods erected on both sides of the base, and a drop table that is suspended at the bottom of the drop table and passes through the through hole of the lid body and collides with the piston. Since the impact head is equipped with a drop impact test device, the internal volume of the cylinder can be freely changed and the impact waveform can be determined very easily. Can be wholesaled.

〔Example〕

Hereinafter, the present invention will be described in detail based on an embodiment shown in FIGS. 1 and 2. In the figure, (4A) is an impact head detachably suspended vertically at the bottom of the drop table (3); This impact head (4A) has different diameters (4A) and (4A') depending on the assumed weight and fragility strength of the product (5), as shown by the LL line in Figure 2. It can be installed selectively from among them. (16) is a high-rigidity pad attached to the lower tip of this impact head (4A), and this pad (16) has a high pitch when the pad (16) hits a piston (19), which will be described later. It acts to prevent waves from forming.

(17) is a cylinder mounted on the base (1), and a gas inlet (17a) is bored in the center of the left side wall of this cylinder (17) in Fig. 1, and a water inlet is bored in the lower part of the right side wall. entrance(
17b), and a drain port (17c) communicating with the outside is provided at the bottom of the cylinder (17).

(18) is a cylindrical body attached to the upper part of the opening of the cylinder (l7) via a screw, and inside the cylindrical body (18) located in the upper space of this cylinder (17), As shown, a piston (19) that performs the same function as the conventional example is arranged so as to be able to slide vertically, and this piston (19)e has a plurality of O-rings (20) that perform the same function as the conventional example. It is fitted. The piston (19) is replaced with a piston (19) or (19A) having a different diameter depending on the weight and fragility strength of the product (5), as shown by the line L-L in Figure 2. It is now possible to do so. This also applies to the cylindrical bodies (18) and (18A). (21) is a lid attached to the cylindrical body (18) via a screw, and this planar circular lid (21) fc has a through hole with a smaller diameter than the cylindrical diameter of the cylindrical body (18). A hole (22) is provided to prevent the piston (19) from coming out upwards (see Figure 2). And this lid body (21) is the second
As shown by the L-L line in the figure, the through hole (22) may be replaced with one (21) or (21A) with a different diameter depending on the weight and fragility strength of the product (5). It has become.

(23) is a water tank that stores a large amount of water, and (24) is this water tank (23) and the water inlet (17b) of the cylinder (17).
This water supply vibrator (24) is connected to the water supply vibrator.
has the function of guiding water in the water tank to the lower space of the cylinder (17). The water filled in the cylinder (17) functions to change the internal volume of the cylinder (17).

(25) is a water meter provided on the water supply vibrator (24), which functions to display the amount of water supplied from the water tank (23) into the cylinder (17). (26) is the water supply pipe (24)
This water supply valve cock has the function of not only allowing and shutting off water, but also preventing backflow of water filled into the cylinder (17) from the water tank (23). (27) is the cylinder (17
) is connected to the drain port (17c), and this drain vibe (27) is equipped with a drain valve cock (28), and when this drain valve cock (28) is operated, the cylinder (17) The water inside is drained to the outside.

(10) is a high-pressure gas container filled with inert nitrogen gas;
(11) is this high pressure gas container (10) and cylinder (17).
This gas supply pipe (11) is connected to the gas inlet (17a) of the high pressure gas container (10).
The function is to guide the nitrogen gas inside the cylinder (17) to the upper part of the lower space inside the cylinder (17) to raise the piston (19) to the position shown in FIG. The nitrogen gas filled in the space inside the cylinder (17) has a spring function that restricts the downward sliding movement of the piston (19) that has risen to the position shown in Figure 1, and returns it to its original position. run (12) is a gas pressure regulator provided on this gas supply vibrator (11), and this gas pressure regulator (12) is comprised of a gas pressure regulating valve (13) that functions to regulate gas pressure, and a gas pressure regulating valve (13) that functions to regulate gas pressure. Pressure gauge (1
4). Therefore, when measuring the impact resistance strength of the product (5), first determine the weight and resistance strength of the product (5), and then measure the piston (19 ), the cylindrical body (18), and the lid body (21) are respectively connected to the cylindrical body (1
8), the inside of the cylinder (17), or the cylindrical body (1
8) Attach it to the top. Similarly, an impact head (4A) is also selected and attached to the lower part of the drop table (3). Next, the water supply valve cock (26) is operated so that the water supplied from the water F' (23) reaches a predetermined amount of water in the cylinder (17) according to the above assumption. ) to the specified internal volume while checking with the water meter (25).

Next, the product to be measured (
5) is placed and fixed on the drop table (3). After this fixation is completed, operate the control device (15) to raise and lower the drop table (3) using the lifting device to raise and lower the upper surface of the high-rigidity pad (16) and cylinder (17) (lid (21)).
The distance between the top surface of the drop table (3) and the drop table (3) is set to a predetermined test drop height, and once the setting is completed, the drop table (3) is held at that position by a positioning mechanism (not shown). Next, operate the gas pressure regulating valve (13) of the gas pressure regulator (12) to adjust the pressure so that the nitrogen gas supplied from the high-pressure gas container (10) reaches a predetermined gas pressure within the cylinder (17). Total (l4)
Adjust while checking with , and raise the piston (19) to the position shown in Figure 1. Note that by changing the set value of the gas pressure, the resistance during sliding of the piston (19) and the maximum value of the impact acceleration generated on the drop table (3) change.

When the above preparations are completed, the control device (15) is operated to open the positioning mechanism and the drop table (3) is allowed to fall freely. The drop table (3) falls freely while being guided by the guide rod (2), and the high-rigidity pad (l6) penetrates the cylinder (17), in other words, the through hole (22) of the lid (2l), and the piston. (19). Due to this collision, the piston (19) is pushed down by the kinetic energy of the drop table (3), but until the kinetic energy and the pressure of the nitrogen gas are balanced, the piston (19) only moves a small amount, and therefore , the impact acceleration value generated on the falling table (3) increases rapidly (see Figures 5 and 6).
19) slides downward within the cylindrical body (18), but the impact acceleration value at this time has a tendency to increase or is suppressed compared to the rapid increase described above (see Figures 5 and 6). ).

Then, when the kinetic energy of the drop table (3) reaches O and the sliding displacement of the piston (19) reaches its maximum, the piston (19) gradually moves due to the energy (pressure) of the compressed nitrogen gas. The drop table (3) is guided by the guide rod (2) and bounced upward (see Figures 5 and 6). reference).

However, while the falling table (3) is floating, the positioning mechanism holds the falling table (3) to prevent the high rigidity pad (16) from colliding again, thereby completing the work.

As described above, according to the present invention, the internal volume of the cylinder (17) can be freely changed by filling the cylinder (17) with water from the water tank (23), so the shape of the shock waveform can be extremely easily changed. It becomes possible to control. Then, a piston (19) is installed depending on the weight and fragility strength of the product (5).
, it becomes extremely easy to control the shape of the shock waveform. In addition, filling the cylinder with water (
Since the internal volume of 17) can be changed freely,
There is no need to replace the cylinder, so effective use of work/storage space and a significant reduction in work time can be expected.

In the above embodiment, a plurality of pistons (19) and (19A) having different diameters are indicated by the line LL in FIG. It has the following effects.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a drop impact testing device that facilitates control of impact waveforms, makes effective use of work/storage space, and significantly shortens working time.

[Brief explanation of drawings]

FIG. 1 is an overall view showing an embodiment of the drop impact test device according to the present invention, FIG. 2 is a cross-sectional explanatory view showing the drop impact test device according to the present invention, and FIG. 3 is a diagram of a conventional drop impact test device. Overall view, Figure 4 is a sectional view of main parts showing a conventional drop impact test device, Figure 5 is a load-displacement diagram of a conventional drop impact test device,
FIG. 6 is a one-hour impact acceleration diagram obtained by a conventional drop impact testing device. In the figure, (1) is a base, (2) is a pair of guide rods, (
3) is a drop table, (4) , (4A) . (4
A') is the impact head, (5) is the product (sample), (
8), (17) are cylinders, (7) . (22) is a through hole, (8), (19), (19A) are pistons, (18) is a cylindrical body, (21). (21A) is a lid body. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A cylinder arranged on a base, a liquid filled in a lower space in this cylinder, a gas filled in an upper part of the lower space containing this liquid, and a gas inserted into the upper space in the cylinder. A cylindrical body, a piston disposed inside the cylindrical body so as to be movable up and down, a lid having a through hole and heavily attached to the top of the cylindrical body, and erected on both sides of the base. a drop table that can be raised and lowered to collide with the cylinder while being guided by a pair of guide rods, and an impact head that is suspended from the lower part of the drop table and that penetrates the through hole of the lid body and collides with the piston; A drop impact testing device characterized by dropping a drop table equipped with a sample into a cylinder to apply an impact to the sample.