JP6459672B2 - Impact tester and impact test method - Google Patents

Description

  The present invention relates to an impact tester and an impact test method for performing an impact test on an electronic device.

In general, an electronic device called a precision device must be subjected to an impact resistance test for evaluating whether it can withstand a large impact before shipping the product. In this test, a method is used in which parameters used in the test are expressed by a shock response spectrum (hereinafter referred to as SRS) applied to an electronic device.
The SRS is represented by frequency on the horizontal axis and acceleration on the vertical axis, and indicates the maximum acceleration when an impact is applied to the one-degree-of-freedom spring-mass-damper system having the eigenvalue shown on the horizontal axis. For example, when the SRS calculated from a certain shock acceleration waveform indicates an acceleration of 1000 G at a frequency of 1000 Hz, the impact means that a maximum acceleration of 1000 G is applied to a one-degree-of-freedom spring-mass-damper system having an eigenvalue of 1000 Hz. Have.

FIG. 7 is a diagram illustrating an example of the relationship between the frequency and acceleration of a general SRS specification.
When performing an impact resistance test, SRS specifications as shown in FIG. 7 are given in three directions of X, Y, and Z. In SRS, a width called tilt, breakpoint frequency, maximum acceleration, and tolerance are mainly designated. This specification is obtained based on the results of prior analysis and experiments. In the impact resistance test, it is necessary to generate an impact that satisfies the test specifications.
The SRS specification is specified by the inclination, the breakpoint frequency, and the maximum acceleration, and these values are determined by the impact waveform. When it becomes SRS different from a test specification, it is necessary to change an impact condition and to adjust to predetermined SRS.

  In a general impact resistance test, when a shock is applied to a flat plate having a spring / mass system having a degree of freedom in the in-plane direction, a hammer with a predetermined mass is applied to a device under test at a predetermined speed. This is performed by colliding with an installed plate (for example, see Patent Document 1). At this time, a spring and a weight are added to one end of the plate for fixing the specimen, and the spring constant of the spring or the mass of the weight is changed to change the break frequency of the SRS waveform.

Japanese Patent Laid-Open No. 03-287045

In order to obtain the SRS waveform necessary for the impact resistance test, it is necessary to adjust the velocity, mass, and collision time of the collision object (the time during which the plate and the collision object are in contact). For example, in a testing machine that uses a free fall due to gravity to collide the collision body with the plate, the collision speed of the collision body can be continuously adjusted by changing the height of the free fall start of the collision body. Can do. Moreover, the mass of the collision body can be adjusted almost continuously by attaching a minute weight to the collision body.
On the other hand, the collision time needs to be changed by changing the shape and hardness of the collision body, and changing the shape of the tip of the collision body or changing the material. However, this method has a problem that it is difficult to continuously adjust the collision time, and it is difficult to obtain an SRS waveform necessary for the test.

  An object of the present invention is to provide an impact tester and an impact test method that solve the above-described problems.

The impact tester of the present invention is
A plate with electronic equipment installed;
A colliding body that collides with the plate;
A heating unit that changes the temperature of the collision body.
Further, the impact test method of the present invention includes:
A process of changing the temperature of the colliding body that collides with the plate on which the electronic device is installed, and
A process for measuring the temperature of the impactor;
When the measured temperature reaches a preset temperature, a process of causing the collision object to collide with the plate is performed.

  As described above, in the present invention, continuous adjustment of the collision time can be facilitated.

It is a figure which shows 1st Embodiment of the impact tester of this invention. It is a figure which shows 2nd Embodiment of the impact tester of this invention. It is a graph which shows an example of the relationship between the temperature and hardness for every material. It is a graph which shows an example of the temperature dependence of the hardness of a certain substance. It is a flowchart for demonstrating the impact test method in the form shown in FIG. It is a figure which shows 3rd Embodiment of the impact tester of this invention. It is a figure which shows an example of the relationship between the frequency and acceleration of a general SRS specification.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)

FIG. 1 is a diagram showing a first embodiment of an impact tester according to the present invention.
As shown in FIG. 1, the impact tester in this embodiment includes a plate 200 on which an electronic device 100 as a device under test is installed, a collision body 300, and a heating unit 400. The collision body 300 collides with the plate 200 at a predetermined speed in order to vibrate the plate 200. The heating unit 400 changes the temperature of the collision body 300.
Thus, the heating unit 400 changes the temperature of the collision body 300, and the collision body 300 whose temperature has changed collides with the plate 200 at a predetermined speed, thereby facilitating continuous adjustment of the collision time. it can.
(Second Embodiment)

FIG. 2 is a diagram showing a second embodiment of the impact tester of the present invention.
As shown in FIG. 2, the impact tester in this embodiment includes a plate 200 on which an electronic device 100 as a device under test is installed, a collision body 300, a heating section 400, a collision body clamp 500, and a temperature measurement section 600. It is equipped with. Further, the plate support portion 700 supports the plate 200. In the form shown in FIG. 2, the plate support 700 uses a spring, but the plate 200 may be hung using a wire or the like.
The plate 200 vibrates with the test specification SRS.
The collision body 300 is disposed at a predetermined height above the plate 200. Further, the collision body 300 collides with the plate 200 at a predetermined speed in order to vibrate the plate 200. Moreover, the collision body 300 is comprised from the material from which hardness or an elasticity modulus changes according to the change of own temperature.
The heating unit 400 changes the temperature of the collision body 300. The heating unit 400 can cool or heat the collision body 300 in order to change the temperature of the collision body 300.
The temperature measurement unit 600 measures the temperature of the collision body 300. Further, the temperature measuring unit 600 may measure the temperature of the collision part of the collision body 300 between the collision body 300 and the plate 200.
The collision body clamp 500 holds (grips) the collision body 300. In addition, the collision body clamp 500 releases the collision body 300 when the temperature measured by the temperature measurement unit 600 reaches a preset temperature. That is, when the temperature measured by the temperature measuring unit 600 reaches a preset temperature, the collision body 300 is separated from the collision body clamp 500 and falls toward the plate 200.

As described above, when the impact resistance test of the electronic device 100 is performed, the speed, mass, and collision time of the collision object (the time during which the plate 200 and the collision object 300 are in contact) are set so as to satisfy the SRS of the test specification. It needs to be adjusted.
In the test machine in which the collision body 300 collides with the plate 200 using the free fall due to gravity illustrated in FIG. 2, the speed when the collision body 300 collides with the plate 200 is between the collision body 300 and the plate 200. It is possible to change by changing the distance. Further, the mass of the collision body 300 can be changed by adding a weight to the collision body 300 or removing a weight that has already been added. The collision time is generally changed by changing the shape, hardness, and elastic modulus of the collision portion of the collision body 300 with the plate 200. For example, a means for exchanging a collision portion of the collision body 300 with the plate 200 with a component having a different material or a shape is used. However, with this method, it is difficult to continuously change the collision time. In addition, it takes time to replace parts, and several kinds of parts must be prepared, which is problematic in terms of time and cost.

Therefore, the impact testing machine in this embodiment adjusts the collision time by changing the physical property value of the collision part, particularly the hardness, by changing the temperature of the entire collision object 300 or the temperature of the collision part of the collision object 300.
FIG. 3 is a graph showing an example of the relationship between temperature and hardness for each material. This graph is taken from the material “High-temperature hardness characteristics of materials” from the National Institute of Advanced Industrial Science and Technology.
FIG. 4 is a graph showing an example of the temperature dependence of the hardness of a certain substance. This graph is taken from Toray Dupont's “Hytrel Mechanical Properties” document.
As shown in FIGS. 3 and 4, the hardness of the metal material, the resin material, and the ceramic material decreases when the temperature is increased. The collision time when the objects collide with each other (the time during which the objects are in contact with each other) becomes shorter as the hardness is higher, and becomes longer when the hardness is lower. Therefore, the collision time between the plate 200 and the collision body 300 can be changed by changing the temperature of the collision body 300 (particularly the collision portion). Also, as shown in FIGS. 3 and 4, the relationship between temperature and hardness is a continuous curve (the hardness does not change suddenly), so if the temperature is changed continuously, the hardness also increases. Can be changed continuously.
In the impact testing machine according to the present embodiment, the collision body 300 is disposed above the plate 200 on which the electronic device 100 to be subjected to the impact test is mounted and at a height at a predetermined speed immediately before the collision body 300 collides with the plate 200. The collision body clamp 500 holds. In this state, the heating unit 400 disposed around the collision body 300 heats the entire collision body 300 or a portion that collides with the plate 200 of the collision body 300. The temperature measurement unit 600 measures the temperature of the collision part of the collision body 300. When the temperature measured by the temperature measuring unit 600 reaches a predetermined temperature, the collision body clamp 500 releases the collision body 300. Then, the collision body 300 drops and accelerates toward the plate 200, reaches a predetermined speed, collides with the plate 200, and gives an impact to the plate 200, and the impact test of the electronic device 100 is performed. If the test specification is not SRS, the collision time is changed by changing the distance between the collision body 300 and the plate 200, changing the mass of the collision body 300, or changing the heating temperature of the collision body 300. As a result, adjustment is made so that the SRS of the test specification is obtained.

Below, the impact test method in the form shown in FIG. 2 is demonstrated.
FIG. 5 is a flowchart for explaining an impact test method in the embodiment shown in FIG.
First, the temperature measurement unit 600 measures the temperature of the collision body 300, particularly the temperature of the portion that collides with the plate 200 (step S1). Subsequently, the temperature measurement unit 600 determines whether or not the measured temperature is a preset temperature (step S2). This measurement and determination may be performed continuously. The preset temperature is a temperature according to the collision time and the material of the collision body 300 as test conditions. For example, it is obtained as a result of an experiment as shown in FIG. 3 or FIG. Temperature.
When the temperature measured by the temperature measurement unit 600 is not a preset temperature, the heating unit 400 adjusts the temperature of the collision body 300 (step S3). Specifically, when the temperature measured by the temperature measurement unit 600 is lower than a preset temperature, the heating unit 400 heats the collision body 300. On the other hand, when the temperature measured by the temperature measurement unit 600 is higher than a preset temperature, the heating unit 400 cools the collision body 300. And the temperature measurement part 600 performs the process of step S1 further.
On the other hand, when the temperature measured by the temperature measurement unit 600 is a preset temperature, that is, when the temperature measured by the temperature measurement unit 600 becomes a preset temperature, the collision object clamp 500 is 300 is released (step S4). Thereby, the released collision body 300 collides with the plate 200.

  In the form shown in FIG. 2, the heating unit 400 is disposed around the collision body 300, but the collision body 300 itself may include the heating unit 400. Further, the collision body 300 itself may have the temperature measuring unit 600. Further, the collision body 300 itself may include the heating unit 400 and the temperature measurement unit 600.

As described above, in the present embodiment, the hardness or elastic modulus of the collision body 300 is changed by changing the temperature of the collision portion of the collision body 300 using the heating unit 400, and the collision between the collision body 300 and the plate 200. Adjust time continuously. Thereby, in adjusting to SRS of a test specification, it becomes possible to change a collision time continuously, and there exists an effect that adjustment time can be shortened.
(Third embodiment)

FIG. 6 is a diagram showing a third embodiment of the impact tester of the present invention.
As shown in FIG. 6, the impact tester in this embodiment includes a plate 200 on which an electronic device 100 as a device under test is installed, a collision body 300, a heating section 400, a collision body clamp 500, and a temperature measurement section 600. And a vibration arm 800. Further, the plate support portion 710 supports the plate 200.
The plate 200 vibrates with the test specification SRS.
The collision body 300 is attached to one end of the vibration arm 800. In this embodiment, the collision body 300 is caused to collide with the plate 200 in a pendulum manner using the other end of the vibration arm 800 as a fulcrum for swinging. Further, the collision body 300 collides with the plate 200 at a predetermined speed in order to vibrate the plate 200. Moreover, the collision body 300 is comprised from the material from which hardness or an elasticity modulus changes according to the change of own temperature.
The heating unit 400 changes the temperature of the collision body 300. The heating unit 400 can cool or heat the collision body 300 in order to change the temperature of the collision body 300.
The temperature measurement unit 600 measures the temperature of the collision body 300. Further, the temperature measuring unit 600 may measure the temperature of the collision part of the collision body 300 between the collision body 300 and the plate 200.
The collision body clamp 500 holds (grips) the collision body 300. In addition, the collision body clamp 500 releases the collision body 300 when the temperature measured by the temperature measurement unit 600 reaches a preset temperature. In other words, when the temperature measured by the temperature measuring unit 600 reaches a preset temperature, the collision body 300 is separated from the collision body clamp 500, and the plate 200 is pendulum-type with the other end of the vibration arm 800 as a pivot point. Collide with. Here, the speed at which the colliding body 300 collides with the plate 200 can be adjusted by changing the height at which the colliding body clamp 500 releases the colliding body 300 as in the embodiment shown in FIG. Thereby, also in this embodiment, the same effect as the first and second embodiments can be obtained.
(Modification)

  In accelerating the collision body, not only the gravity as described above is used, but also an external force can be applied to the collision body 300 to give an initial speed. It is also possible to accelerate the collision body 300 to a predetermined speed by acceleration means other than gravity, for example, explosive force such as air pressure or explosives.

  The present invention can be applied to an impact tester in which the frequency of impact response is important as a test specification, such as an impact test for electronic devices, particularly SRS (impact response spectrum) measurement.

A part or all of the above embodiment can be described as in the following supplementary notes, but is not limited thereto.
(Appendix 1) A plate on which electronic devices are installed;
A colliding body that collides with the plate;
An impact tester having a heating unit that changes the temperature of the collision body.
(Supplementary note 2) The impact testing machine according to supplementary note 1, wherein the collision body changes in hardness or elastic modulus of the collision body in accordance with a change in temperature of the collision body.
(Appendix 3) A collision body clamp for holding the collision body;
A temperature measuring unit for measuring the temperature of the collision body,
The collision body clamp releases the collision body when the temperature measured by the temperature measurement unit reaches a preset temperature,
The impact tester according to appendix 1 or appendix 2, wherein when the colliding body is released from the colliding body clamp, it collides with the plate using gravity.
(Additional remark 4) The said temperature measurement part is an impact test machine of Additional remark 3 which measures the temperature of the collision part of this collision body and this collision body and the said plate.
(Additional remark 5) The said impact body is an impact test machine of Additional remark 3 or Additional remark 4 which has the said heating part and the said temperature measurement part.
(Additional remark 6) The said collision body has the said temperature measurement part,
The impact testing machine according to appendix 3 or appendix 4, wherein the heating unit is provided around the collision body.
Impact testing machine.
(Additional remark 7) The said collision body has the said heating part,
The impact tester according to appendix 3 or appendix 4, wherein the temperature measurement unit is provided around the collision body.
(Appendix 8) A process of changing the temperature of a colliding body that collides with a plate on which an electronic device is installed;
A process for measuring the temperature of the impactor;
An impact test method for performing a process of causing the collision object to collide with the plate when the measured temperature reaches a preset temperature.

DESCRIPTION OF SYMBOLS 100 Electronic device 200 Plate 300 Colliding body 400 Heating part 500 Colliding body clamp 600 Temperature measuring part 700,710 Plate support part 800 Vibration arm

Claims (7)

An impact tester for performing impact tests on electronic equipment,
A plate with electronic equipment installed;
A colliding body that collides with the plate;
A heating unit for changing the temperature of the collision body ;
A collision body clamp for holding the collision body;
A temperature measuring unit for measuring the temperature of the collision body,
The collision body is one whose hardness or elastic modulus changes according to a change in temperature,
The impact body clamp is an impact tester that releases the impact body and causes the impact body to collide with the plate when the temperature measured by the temperature measuring unit reaches a preset temperature . The impact tester according to claim 1 ,
When the collision body is released from the collision body clamp, the collision test machine collides with the plate using gravity. In the impact testing machine according to claim 1 or claim 2 ,
The temperature measuring unit is an impact tester that measures the temperature of a collision portion of the collision body between the collision body and the plate. In the impact testing machine according to any one of claims 1 to 3 ,
The collision body is an impact tester having the heating unit and the temperature measurement unit. In the impact testing machine according to any one of claims 1 to 3 ,
The collision body has the temperature measurement unit,
The heating unit is an impact tester provided around the collision body. In the impact testing machine according to any one of claims 1 to 3 ,
The collision body has the heating unit,
The temperature measuring unit is an impact tester provided around the collision body. An impact test method for performing an impact test on an electronic device ,
Holding a collision body whose hardness or elastic modulus changes according to a change in temperature, and changing the temperature of the collision body ;
A process for measuring the temperature of the impactor;
An impact test method for performing a process of releasing the collision body and causing it to collide with a plate on which an electronic device is installed when the measured temperature reaches a preset temperature.

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