JP3709810B2 - Drop test device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drop test device for a device such as a portable device, and more particularly to a drop test device capable of dropping a test object while maintaining the same posture as that at the start of dropping.
[0002]
[Prior art]
As electronic devices have become smaller, portable electronic devices have been increasingly used recently. Since portable electronic devices are often carried or used by hand, there is a risk of inadvertent dropping. Therefore, it is necessary to take measures against dropping, and it is necessary to make a highly reliable device that is resistant to dropping impact so that the device does not malfunction even if it is accidentally dropped. For this reason, manufacturers conduct tests for drop impacts in advance to improve the drop impact resistance.
Conventionally, in a drop test, a method has been used in which a strain gauge, an impact measurement sensor, or the like is attached to a test object such as a portable device and dropped manually from an appropriate height. However, since this method relies on human hands, it is difficult to let go in the same state, and it is difficult to obtain accurate measurement values with high reproducibility by changing the posture of the test object to be dropped every time. It was. Therefore, a drop test apparatus that attempts to drop the test object in the same posture by mechanically holding the posture of the test object has been studied. For the structure that mechanically holds the test object, it can be simply held by a mechanical hand mechanism instead of a human hand, or it can continue to fall while being held by the hand mechanism. There are also things to cancel.
[0003]
Japanese Patent Application Laid-Open No. 9-318484 and Japanese Patent Application Laid-Open No. 2000-55778 disclose a dropping device having a holding unit that drops along a guide while mechanically holding the test object until just before the test object hits the collision surface. It is disclosed. In this conventional example, the test object is held by a mechanical hand mechanism instead of a human hand until just before colliding with the collision surface, and is held by opening the hand mechanism when approaching just before the collision surface. The test object is dropped in a state close to free fall.
[0004]
However, in the case of this apparatus, since it is necessary to release the test object from the hand mechanism at the moment of collision, there is a problem that a very high-speed driving mechanism is required for driving the hand mechanism and the cost of the apparatus is increased. . There is also a problem that the posture of the test object at the time of dropping is disturbed if the timing at which the left and right arms of the hand mechanism are separated from each other even a little. Furthermore, when the shape of the portion sandwiched between the arms of the hand mechanism is different, such as when the test object is not symmetrical, it is difficult to always hold in the same posture, and the posture may be disturbed when the arm is released. There is also the problem of becoming higher.
[0005]
Japanese Laid-Open Patent Publication No. 2000-65677 discloses a drop test apparatus that suspends a device under test using a string-like material and drops it while maintaining an arbitrary posture. However, in this method, there is a problem that the DUT may be shaken due to air buoyancy or vibration at the start of dropping, and an accurate drop test cannot be performed. Furthermore, in the above drop test device, when the holder falls until it comes into contact with the lower stopper, the DUT is in contact with the base and breaks. However, since the impact of the holder hitting the stopper is transmitted to the object under test at the same time, there is a problem that an accurate test cannot be performed. Regarding the angle when dropping, it is very difficult to adjust the angle of the DUT because there is no mechanism to adjust the length of the string-like material. For example, adjusting the DUT to a certain angle such as a horizontal state Was difficult.
[0006]
[Problems to be solved by the invention]
The prior art described above has been found to have the following problems. The first problem is that undesired shaking and rotation occur in the test object during the fall. If the test object is shaken or rotated during the fall, the test object will collide with the collision surface in a posture different from the intended posture, and the test object will be subjected to the drop test in the planned posture. It becomes impossible to do. The second problem is that the posture control of the test object cannot be easily performed. That is, in the drop test, it is required to drop the test object at various collision angles, but the above-described drop test apparatus cannot easily meet this request.
The object of the present invention is to solve these problems. First, in the drop test of a test object such as a portable device, the object is to prevent shaking and rotation when the test object is dropped. Thus, it is possible to always maintain a constant posture, and secondly, it is possible to easily control the posture when the test object is dropped.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, an arm that holds a thin suspension line for suspending a test object, a guide rail that guides the arm, and a collision surface on which the test object collides. If, and an arm stopper for stopping the falling of the arm in place, the drop test device for impinging on the impingement surface remains dropped the test object suspended state to said arm, said test with shaking prevention mechanism for preventing shaking of the object, the sway prevention mechanism is Ru attached to the test object, and anti-swing plate having a slit, which is fixed to the arm, the slit of the anti-swing plate drop test apparatus characterized that you and a anti-swing bar through, is provided.
And, preferably, the anti-swing plate and the provided with a plurality a combination of anti-swing rod, the direction of the slit provided in each shake preventing plate is different. Preferably, a length adjustment mechanism for adjusting the length of the suspension line is provided.
[0008]
Preferably, an angle adjustment mechanism for adjusting the angle of the collision surface is provided. And, more preferably, the angle adjustment mechanism, the base and screwed angle adjusting screw is screwed and which through the collision block, or that said collision block be under the collision block is placed It is comprised by the screw for angle adjustment to do.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments and examples of the present invention will be described in detail with reference to the drawings.
FIG. 7 is a front view showing an outline of a drop test apparatus devised in the present invention. A test object 1 such as a portable electronic device that is a subject of a drop test is suspended by a thin wire 3 made of resin, metal, fiber, or the like attached to an arm 2. The arm 2 has a structure that is movable in the vertical direction along the guide rail 5 attached between the device exterior 4 and the device base 8. Here, since the arm 2 and the guide rail 5 are attached via bearings and the like, and the friction resistance is very small, the arm 2 from which the test object 1 is suspended is in a state close to free fall. It becomes possible to fall. The device exterior 4 is fixed on the device base 8. An arm stopper 6 for stopping the fall of the arm 2 is also fixed on the apparatus base 8, and a collision block on which the test object 1 collides is installed. Here, the length of the thin wire 3 is longer than the difference in height between the arm stopper 6 and the collision block 7. Thereby, the fall of the arm 2 is stopped after the test object 1 collides with the collision block 7. The arm stopper 6 is made of a soft resin such as a rubber material or a shock absorbing material such as a spring so as not to generate vibration when the arm 2 collides. Further, a magnetic body 10 made of iron, cobalt, nickel, or an alloy thereof is attached to the upper portion of the arm 2, and this magnetic body 10 is fixed by the magnetic force of the electromagnet 9 installed on the upper portion of the apparatus exterior 4. As a result, the arm 2 in a state where the test object 1 is suspended is held at the upper part of the apparatus.
[0010]
Here, energization of the electromagnet 9 can be turned on and off, so that the arm 2 can be held and released. In this way, the method of holding and releasing a fallen object by electromagnetic force is less likely to give vibration or shock to the test object when starting the fall compared to other methods such as a mechanical type. Further, it is preferable for dropping the test object in a predetermined posture.
The collision block 7 is prepared using materials that are expected to collide when the mobile device falls, such as concrete, metal, wood, flooring, etc., and these are exchanged for testing. Can be done.
[0011]
Next, the operation of the drop test apparatus shown in FIG. 7 will be described in detail. FIG. 7 is a diagram illustrating a state before the drop test is started, and the test object 1 is suspended from the arm 2 by a thin wire 3 attached to the arm 2. Further, the arm 2 is fixedly held by the magnetic force of the electromagnet 9 installed on the upper portion of the apparatus exterior 4 so that the arm 2 in a state where the test object 1 is suspended is fixed to the arm 2. Held at the top of the device.
FIG. 8 is a cross-sectional view of the state at the start of dropping as seen from the side surface direction of the drop test apparatus. When the energization to the electromagnet 9 is turned off, the magnetic force of the electromagnet 9 disappears, the magnetic body 10 is separated from the electromagnet 9, and the test object 1 suspended from the arm 2 and the arm 2 moves along the guide rail 5. Start falling in a state close to free fall. After the test object 1 continues to fall in the vertical direction, it finally collides with the collision block 7 as shown in FIG. At that time, the deformation state of the test object 1 and the generated strain are measured using a measuring device such as a high-speed camera or a strain gauge, and the durability against the drop of the test object 1 is measured. At that time, after the test object 1 collides with the collision block 7, the arm 2 is buffered and collided with the arm stopper 6 so that the arm 2 does not collide with the test object 1. Further, as shown in FIG. 9, when the test object 1 collides with the collision block, the thin wire 3 is loosened so that the test object 1 is restrained or has excessive vibrations after the collision. I will not give it. Moreover, since it falls in the state suspended by the thin wire | line 3, and it is not the system which hold | grips the test object 1 directly at the time of a drop test, dropping posture may be disturb | confused by the holding release of the test object 1. In addition, it is possible to cause a collision in a state in which the posture at the start of dropping is substantially maintained.
[0012]
[First embodiment]
FIG. 1 is a front view showing a main part of a first embodiment of the present invention. Also in the drop test apparatus of the present embodiment, the guide rail 5 is installed between the apparatus base (8) and the apparatus exterior (4), and the collision block (7) is provided below the test object 1 and the arm. An arm stopper (6) is disposed below 2, but the configuration thereof is the same as the configuration illustrated in FIG. The arm 2 is attached to the guide rail 5 using a bearing or the like, and is configured to move along the guide rail 5 in the vertical direction with low frictional resistance. In this embodiment, the test object 1 is suspended from the arm 2 by three thin wires 3, but the three thin wires 3 are fixed to the arm 2 at different positions. By doing in this way, it becomes possible to support the test object 1 more stably.
[0013]
The arm 2 is provided with two anti-swaying rods 12 which are anti-swaying mechanisms for maintaining the posture of the test object 1 when it is dropped, and the test object 1 has two anti-swaying plates 13. It is attached. As shown in FIGS. 2 (a) and 2 (b), the anti-swaying rod 12 has a structure that can freely move in the longitudinal direction of the long hole 13a opened in the anti-swaying plate 13, and each of the anti-swaying bars 12 can be moved. By forming the oblong holes 13a having different extending directions in the prevention plate 13, shaking in various directions can be prevented. By this shaking prevention mechanism, it becomes possible to prevent the posture change when the test object 1 is dropped. In this embodiment, the anti-swaying rod 12 and the anti-swaying plate 13 are attached at two locations, but the number of the anti-swaying mechanism is not limited to this. However, it is preferable to provide a plurality of sets of anti-sway bars and anti-sway plates so that the directions of the long holes formed in the anti-sway plates intersect.
Before the fall starts, the arm 2 is fixed by adsorbing the magnetic body 10 on the arm 2 by the electromagnet (9) fixed to the device exterior (4). When energization of the electromagnet is turned off, the arm 2 falls along the guide rail 5 while the test object 1 is suspended. Then, the test object collides with the collision block (7), and then the arm 2 is buffered and collided with the arm stopper (6), so that the fall ends. In this process, the test object 1 is naturally dropped. It falls in a state close to, and does not shake or rotate, and collides with the collision block while maintaining the posture almost immediately after the start of dropping.
[0014]
[Second Embodiment]
FIG. 3 is a front view showing the main part of the second embodiment of the present invention. The difference of the present embodiment from the first embodiment shown in FIG. 1 is that the thin wire 3 is fixed to a winding screw 11 which is a thin wire length adjusting mechanism. In FIG. 3, parts that are the same as the parts of the first embodiment shown in FIG. 1 are given the same reference numerals, and descriptions thereof will be omitted as appropriate (the same applies to other embodiments). The winding screw 11 is rotatably attached to the arm 2. By rotating the take-up screw 11, the take-up screw 11 moves in the vertical direction, and accordingly, the thin wire 3 attached to the take-up screw 11 moves in the vertical direction. As a result, the inclination of the test object 1 can be changed, and a drop test is performed by controlling the collision angle of the test object 1 to the collision block (7) so that the angle is the same as that at the time of actual fall. It is possible to do. Although the figure shows a state in which the test object 1 is suspended by three thin wires 3 that are highly stable for suspending the test object 1, the number of the thin wires 3 and the winding screws 11 should be appropriately selected. Can do.
[0015]
In this embodiment, the twist of the thin wire 3 due to the rotation of the winding screw 11 is not transmitted to the test object 1 side. FIG. 4 is a perspective view showing a state of the attachment portion of the thin wire 3 to the test object. The fine wire 3 is passed through a hole of a spherical fine wire receiver 14 having a through hole, and is prevented from being pulled out by connecting the fine wire node 3a on the lower side. The thin wire receiver 14 supports the test object 1 in contact with the test object jacket 1a.
In this embodiment, a twist (rotation) transmission prevention mechanism is provided on the test object side of the thin wire 3, but conversely, the winding screw 11 is rotated at the connecting portion between the winding screw 11 and the thin wire 3. You may make it provide the mechanism which is not transmitted to the thin wire | line 3 side. In addition, as a method of adjusting the length of the thin wire 3, an appropriate method such as a method in which a winding screw for the thin wire is laid down or a method in which the thin wire is sandwiched between clips can be employed.
[0016]
[Third embodiment]
FIG. 5 is a front view showing an essential part of a third embodiment of the present invention. In this embodiment, the test object 1 is fixed in the frame 16 with a fixing screw 15 and a drop test is performed. In the case of this structure, the test object 1 to be subjected to the drop test can be used when it is desired to collide indirectly through the frame 16 without directly colliding with the collision block (7). The frame 16 is manufactured using an appropriate material such as a material used for a housing of an electronic device such as a plastic material or a metal material. Further, the structure for fixing the test object 1 in the frame 16 may be a structure other than the fixing screw.
[0017]
[Fourth embodiment]
FIG. 6 is a front view showing a fourth embodiment of the present invention. In this embodiment, an angle adjusting screw 17 is rotatably attached to the collision block 7, and the collision block 7 is rotatably supported on a rotation shaft 18 held by a bearing 19. Therefore, the angle of the collision surface of the collision block 7 can be changed by rotating the angle adjusting screw 17. In this drop test apparatus, it is possible to perform a collision test substantially equivalent to a state in which the test object 1 is dropped in a state where it is suspended horizontally and tilted and dropped.
In the present embodiment, the angle adjustment is performed by the angle adjustment screw 17 attached to the collision block 7, but the angle adjustment screw 17 may be provided on the device base 8 side below the angle adjustment screw collision block 7. Also, other appropriate means such as a structure in which one side is floated with a spacer sandwiched below the collision block 7 can be employed. The configuration of this embodiment can be applied to the first embodiment. It can also be used in combination with the second embodiment.
[0018]
【The invention's effect】
As described above, the drop test apparatus according to the present invention is provided with a shaking prevention mechanism in a state where the test object is dropped in a state where it is suspended by an arm. Rotation will not occur, and the test object will fall in a state close to free fall while maintaining the state at the start of dropping without disturbing the posture, and it is possible to perform a drop impact test in a desired posture Become.
In addition, it is equipped with a mechanism that can change the angle of the collision surface of the collision block and adjust the length of the thin line that suspends the test object, so that the test object is angled. It is possible to easily perform a drop test.
[Brief description of the drawings]
FIG. 1 is a front view of an essential part of a first embodiment of the present invention.
FIG. 2 is a perspective view of a shaking prevention mechanism used in the first embodiment of the present invention.
FIG. 3 is a front view of an essential part of a second embodiment of the present invention.
FIG. 4 is a partial perspective view of a second embodiment of the present invention.
FIG. 5 is a front view of an essential part of a third embodiment of the present invention.
FIG. 6 is a front view of a fourth embodiment of the present invention.
FIG. 7 is a front view showing an outline of the present invention.
FIG. 8 is a side sectional view showing an outline of the present invention.
FIG. 9 is an operation explanatory diagram of the outline of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Test object 1a Test object jacket 2 Arm 3 Fine wire 3a Fine wire node 4 Equipment exterior 5 Guide rail 6 Arm stopper 7 Collision block 8 Equipment base 9 Electromagnet 10 Magnetic body 11 Winding screw 12 Shake prevention bar 13 Shake prevention plate 13a Slot 14 Thin wire receiver 15 Fixing screw 16 Frame 17 Angle adjusting screw 18 Rotating shaft 19 Bearing

Claims (10)

An arm that holds a thin suspension line for suspending the test object, a guide rail that guides the arm, a collision surface on which the test object collides, and an arm that stops dropping of the arm at a predetermined position A drop test apparatus that drops the test object while being suspended from the arm and collides with the collision surface, and includes a shaking prevention mechanism that prevents shaking of the test object, anti-swing mechanism, Ru attached to the test object, to the anti-swing plate having a slit, which is fixed to the arm, characterized that you and a anti-swing bar through a slit of the anti-swing plate Drop test device. The drop test apparatus according to claim 1, wherein a plurality of combinations of the anti-sway plate and the anti- sway bar are provided, and the directions of the slits provided on each anti-sway plate are different. Drop test apparatus according to claim 1 or 2, characterized in that the length adjusting mechanism for adjusting the length of the suspension lines are provided. 4. The drop test apparatus according to claim 3, wherein the length adjusting mechanism is a take-up screw that holds the suspension line and is screwed into the arm. The drop test apparatus according to claim 4, wherein a mechanism for preventing twisting of a suspension line is provided between the winding screw and the test object. Drop test device according to any one of claims 1 to 5, characterized in that the angle adjusting mechanism for adjusting the angle of the impact surface is provided. 7. A drop test apparatus according to claim 6 , wherein a collision block having the collision surface is installed, and the angle adjusting mechanism adjusts an inclination of the collision block. The angle adjusting mechanism includes an angle adjusting screw that penetrates and engages with the collision block, or an angle adjusting screw that engages with a base under the collision block on which the collision block is placed. The drop test apparatus according to claim 7 , wherein the drop test apparatus is provided. Falling of said arm, drop test device according to any one of claims 1-8, characterized in that it is initiated by the opening of the electromagnetic force acting on the arm. The drop test apparatus according to any one of claims 1 to 9 , wherein the arm holds a plurality of thin lines for suspending the test object at different positions.

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