A method and system for preventing secondary impact during a drop test

Abstract

The present application belongs to the technical field of drop test, and in particular to a method and system for preventing secondary collision in drop test, which comprises the following steps: step one, when the sample is dropped at an angle or an edge, it is fixed by the support arm on the drop support, and then the fixed lasso is tied to the machine body, and the initial length of the lasso is just enough to place the prototype on the drop bottom surface; step two, the drop support is raised to the test height according to the test standard, and the fixed cable is lifted at the same time, and the corresponding length of the raised cable is loosened through the pulley; the test method and test system solve the problem that the sample drop plane is easy to roll and cause uncontrollable secondary collision when the sample is dropped at an angle or an edge in free drop test, greatly improve the accuracy of the test, avoid manual disassembly and blocking, and improve the test efficiency.

Description

Technical Field

[0001] This invention relates to the field of drop testing technology, and in particular to a method and system for preventing secondary collisions during drop testing. Background Technology

[0002] Drop testing simulates the drops a product may experience during handling. It is used to assess the drop height and impact resistance of product components, understand the damage to the product, and improve and refine the design based on the actual product conditions and national standards. However, in actual testing, when a sample lands on an edge or corner, it may fall onto another surface or undergo uncontrollable continuous tumbling collisions instead of landing back on the test surface as expected. The IEC 60068-2-31 standard clearly requires that this be avoided by appropriate methods. The usual practice is to add a barrier to the bottom of the test sample, but this still cannot completely prevent secondary collisions during the test; it only reduces the number of collisions.

[0003] Therefore, we propose a method and system to prevent secondary collisions during drop tests. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, this invention provides a method and system for preventing secondary collisions during drop tests. This solves the problem that the sample's falling plane is prone to tumbling and causing uncontrollable secondary collisions when falling at angles or edges during free fall tests. This greatly improves the accuracy of the test, avoids the need for manual barriers and enclosures, and improves the efficiency of the test.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preventing secondary collisions during drop tests, the method comprising the following steps:

[0006] Step 1: When the sample is about to fall to a corner or edge, place it on the drop support and fix it with the support arm. Then, tie the fixing sling to the machine body. The initial length of the sling should be just enough to place the sample on the bottom of the drop surface.

[0007] Step 2: Raise the drop tower to the test height according to the test standard. At this time, the fixing cable is also raised, and the corresponding height is released through the pulley.

[0008] Step 3: Press the start button during the test. The drop support will retract, and the prototype will fall freely. The corner or edge will collide with the bottom surface. Instantly after the collision, the fixing cable before the prototype rolls will straighten and be pulled up. The bottom pull-down spring will be stretched, the manual switch will be pulled open from the normally closed state to the normally open state, the relay circuit will change to a low level and switch from the normally open state to the normally closed state, and the cable stepper drive motor will start.

[0009] Step 4: The drive motor pulls down the rope through the hook on the rope to reel in the rope. The manual switch loses its pulling force and is pulled back to the closed state by the pull-down spring. The relay circuit forms a circuit and switches from normally closed to normally open to cut off the drive motor circuit and stop the rope reeling.

[0010] Step 5: The fixed cable is retracted to a certain length by the drive motor, and the prototype is pulled up to avoid secondary collision and loss of control.

[0011] As a preferred technical solution of the present invention, the test sample can be fixed by the fixing sling.

[0012] As a preferred technical solution of the present invention, the fixed cable of the test prototype can be automatically adjusted to follow the test height of the drop frame.

[0013] As a preferred technical solution of the present invention, the test prototype is triggered to automatically retrieve the fixing rope and pull up the test prototype immediately after it falls to the bottom surface and collides with the ground, so as to avoid secondary collision and loss of control.

[0014] As a preferred embodiment of the present invention, after the test prototype is pulled up, the fixed rope recovery drive motor automatically stops retracting the rope, thus completing the test.

[0015] A system for preventing secondary collisions during drop testing includes a pull-down spring, a hook, a cable drive motor, a fixed cable, a first fixed pulley, a second fixed pulley, a drive motor circuit, and a fixing sling. The entire system is mounted on a test frame. The first and second fixed pulleys are located on opposite sides of the top of the test frame. The hook connects the fixed cable to the cable drive motor turntable to control the cable. The two ends of the fixed cable are located at the two ends of the test frame and pass through the first and second fixed pulleys. The drive motor circuit can instantly control the motor to retract the fixing sling after a test collision.

[0016] As a preferred embodiment of the present invention, the pull-down spring can control the drive motor circuit switch to be in a normally closed state.

[0017] As a preferred embodiment of the present invention, the rope drive motor can retract the rope according to the drive motor circuit signal, and the fixed rope and fixed lasso are used to fix the test sample.

[0018] As a preferred embodiment of the present invention, the fixed pulley can adjust the rope length according to the test height and the rope retrieval signal.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] The testing method and system of this invention solve the problem that the sample is prone to rolling and causing uncontrollable secondary collisions when falling at angles and edges during free fall testing. This greatly improves the accuracy of the test, avoids the need for manual barriers and enclosures, and improves the efficiency of the test. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a method and system device for preventing secondary collisions during drop testing provided by the present invention;

[0022] Figure 2 The present invention provides a system device for preventing secondary collisions during drop tests, including a drive motor circuit diagram.

[0023] Figure 3 This is a schematic flowchart of a method for preventing secondary collisions during drop tests provided by the present invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] To facilitate understanding of the present invention, a more comprehensive description of the invention will be provided below with reference to relevant embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] Implementation examples, by Figure 1This invention discloses a method for preventing secondary collisions during drop tests, the method comprising the following steps:

[0029] Step 1: When the sample is about to fall to a corner or edge, place it on the drop support and fix it with the support arm. Then, tie the fixing sling to the machine body. The initial length of the sling should be just enough to place the sample on the bottom of the drop surface.

[0030] Step 2: Raise the drop tower to the test height according to the test standard. At this time, the fixing cable is also raised, and the corresponding height is released through the pulley.

[0031] Step 3: Press the start button during the test. The drop support will retract, and the prototype will fall freely. The corner or edge will collide with the bottom surface. Instantly after the collision, the fixing cable before the prototype rolls will straighten and be pulled up. The bottom pull-down spring will be stretched, the manual switch will be pulled open from the normally closed state to the normally open state, the relay circuit will change to a low level and switch from the normally open state to the normally closed state, and the cable stepper drive motor will start.

[0032] Step 4: The drive motor pulls down the rope through the hook on the rope to reel in the rope. The manual switch loses its pulling force and is pulled back to the closed state by the pull-down spring. The relay circuit forms a circuit and switches from normally closed to normally open to cut off the drive motor circuit and stop the rope reeling.

[0033] Step 5: The fixed cable is retracted to a certain length by the drive motor, and the prototype is pulled up to avoid secondary collision and loss of control.

[0034] Implementation examples, by Figure 2 and Figure 3 This invention discloses a system device for preventing secondary collisions during drop testing, comprising a pull-down spring, a hook, a cable drive motor, a fixed cable, a first fixed pulley, a second fixed pulley, a drive motor circuit, and a fixing sling. The entire system is mounted on a test frame. The first and second fixed pulleys are located on opposite sides of the top of the test frame. The hook connects the fixed cable to the cable drive motor turntable to control the cable. The two ends of the fixed cable are located at the two ends of the test frame and pass through the first and second fixed pulleys. The drive motor circuit can instantly control the motor to retract the fixing sling after a test collision. The pull-down spring can keep the drive motor circuit switch in a normally closed state. The cable drive motor can retract the cable according to the drive motor circuit signal. The fixed cable and fixing sling are used to fix the test sample. The fixed pulleys can adjust the cable length according to the test height and the cable retraction signal. In summary, based on the above test method and test system, the test process for preventing secondary collisions during drop testing is as follows:

[0035] 1. Begin;

[0036] 2. Secure the fixing sling to the body of the test sample. The sling should be made of a thin but strong material that does not affect the weight of the sample. Once secured, the sample should hang just below the bottom surface.

[0037] 3. Place the sample to be tested on the test rack and drop test bracket, and use the bracket arm to fix the corner or edge of the drop test bracket;

[0038] 4. Raise the prototype to the test height using the lifting bracket, and loosen the fixing cable by the corresponding lifting length;

[0039] 5. Connect the cable drive motor turntable to the fixed cable hook above, and prepare for testing;

[0040] 6. Press the drop machine start button, the drop bracket retracts, the prototype falls freely, and the corner or edge collides with the bottom surface. Instantly after the collision, the fixing rope of the prototype before tumbling straightens, the rope is pulled up, the bottom pull-down spring is stretched, the manual switch is pulled open from the normally closed state to the normally open state, the relay (model HFS32) circuit changes to low level, switching from the normally open state to the normally closed state, the rope stepper drive motor (model 57HS09) is activated, and it can start quickly within 0.01s;

[0041] 7. The fixed cable is retracted to a certain length by the cable drive motor, and the prototype is pulled up to avoid secondary collision and loss of control;

[0042] 8. When the rope drive motor retracts the rope to a certain length, the manual switch loses its upward pull and is pulled back to the closed state by the pull-down spring. The relay circuit forms a circuit and switches from normally closed to normally open to cut off the drive motor circuit and stop the rope retraction.

[0043] 9. Remove the hook and return the long rope to prepare for the second test. During the process, the fixed rope is retracted to a certain length by the rope drive motor, and the prototype is pulled up to avoid secondary collision and loss of control.

[0044] 10. One drop test completes the test process.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preventing secondary collisions during drop tests, characterized in that: This method is based on a secondary collision prevention system, which includes a pull-down spring, a hook, a cable drive motor, a fixed cable, a first fixed pulley, a second fixed pulley, a drive motor circuit, and a fixed lasso. The entire system is set up on a test frame. The first and second fixed pulleys are located on the top two sides of the test frame. The hook connects the fixed cable to the cable drive motor turntable to control the cable. The two ends of the fixed cable are located at the two ends of the test frame and pass through the first and second fixed pulleys. The drive motor circuit can instantly control the motor to retract the fixed lasso after a test collision. The method includes the following steps: Step 1: When the sample is about to fall to a corner or edge, place it on the drop support and fix it with the support arm. Then, tie the fixing sling to the machine body. The initial length of the sling should be just enough to place the sample on the bottom of the drop surface. Step 2: Raise the drop tower to the test height according to the test standard. At this time, the fixing cable is also raised, and the corresponding height is released through the pulley. Step 3: Press the start button during the test. The drop support will retract, and the prototype will fall freely. The corner or edge will collide with the bottom surface. Instantly after the collision, the fixing cable before the prototype rolls will straighten and be pulled up. The bottom pull-down spring will be stretched, the manual switch will be pulled open from the normally closed state to the normally open state, the relay circuit will change to a low level and switch from the normally open state to the normally closed state, and the cable stepper drive motor will start. Step 4: The drive motor pulls down the rope through the hook on the rope to reel in the rope. The manual switch loses its pulling force and is pulled back to the closed state by the pull-down spring. The relay circuit forms a circuit and switches from normally closed to normally open to cut off the drive motor circuit and stop the rope reeling. Step 5: The fixed cable is retracted to a certain length by the drive motor, and the prototype is pulled up to avoid secondary collision and loss of control.

2. The method for preventing secondary collisions during drop testing according to claim 1, characterized in that: The test sample can be fixed by the fixing sling.

3. The method for preventing secondary collisions during drop testing according to claim 2, characterized in that: The fixing cable attached to the test prototype can automatically adjust to the test height of the drop test bracket.

4. The method for preventing secondary collisions during drop testing according to claim 3, characterized in that: Upon impact with the ground, the test prototype was triggered to automatically retract and secure the cable motor, pulling up the prototype to prevent a secondary collision and loss of control.

5. The method for preventing secondary collisions during drop testing according to claim 4, characterized in that: After the test prototype was pulled up, the fixed rope recovery drive motor automatically stopped retracting the rope, completing the test.

6. The method for preventing secondary collisions during drop testing according to claim 1, characterized in that: The pull-down spring can control the drive motor circuit switch to be in a normally closed state.

7. The method for preventing secondary collisions during drop testing according to claim 1, characterized in that: The cable drive motor can retract the cable according to the drive motor circuit signal, and the fixed cable and fixed lasso are used to fix the test sample.

8. The method for preventing secondary collisions during drop testing according to claim 1, characterized in that: The fixed pulley can adjust the cable length according to the test height and the cable retrieval signal.

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