JP2002257665A - Method and device for stress sensor inspection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stress sensor 1 inspecting method wherein a constant stress is stably applied to a stress-applied part 2, and a prescribed stress is sequentially applied to the stress-applied part 2 in two or more directions for measuring an output in response to the stress. SOLUTION: On the stress sensor 1 inspecting method, to the stress-applied part 2 to which a prescribed stress is sequentially applied in two or more directions to measure an output in response to the stress. The prescribed stress is made to be determined by the weight of a stress applying weight 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stress sensor testing method and a stress sensor testing device, and more particularly to a stress sensor which can be used for a pointing device for a personal computer, a multifunctional switch for various electronic devices, and the like. It is.

[0002]

2. Description of the Related Art There is no prior art for a stress sensor inspection method in which a predetermined stress is sequentially applied to a stressed portion from two or more directions and an output corresponding to the stress is measured. However, in general, the method of testing a stress gauge (pressure gauge) is oil,
After adjusting water or gas to a constant pressure with a cylinder,
The constant pressure is applied to the stressed portion and the inspection is performed (JP-A-7-218371).

[0003]

However, the constant pressure set in the cylinder is generally disadvantageous in terms of stability. Therefore, when a large number of stress sensors are continuously inspected, it is difficult to maintain high inspection accuracy. In particular, use in an ambient environment where the temperature difference is large is disadvantageous.

Accordingly, a first object of the present invention is to provide a stress sensor inspection method capable of stably applying a constant stress to a stressed portion. A second problem to be solved by the present invention is to sequentially apply a predetermined stress to the stressed portion from two or more directions,
An object of the present invention is to provide a stress sensor inspection method for measuring an output corresponding to the stress.

[0005]

In order to solve the above-mentioned first problem, a stress sensor 1 inspection method of the present invention applies a predetermined stress to a stressed portion 2 sequentially from two or more directions, and A stress sensor 1 inspection method for measuring an output, wherein the predetermined stress is determined by a weight of a stress applying weight 3. Here, the operation of “applying a predetermined stress sequentially from two or more directions” includes two or more continuous stress applying operations from one direction.

If the weight 3 is merely used as a stress source, the direction of applying the stress becomes only the vertical direction due to gravity. Therefore, in order to realize the application of stress in two or more directions by the weight 3, for example, a mechanism such as a pulley 6 shown in FIG. Apply stress.
FIG. 2 shows a state in which stress is applied in a direction (horizontal direction) shifted by about 90 ° from the vertical direction.

Here, since the weight of the weight 3 does not change in the use environment or the like, a constant stress can be stably applied to the stressed portion 2. This means that the variation in applied stress of the air cylinder is ± 10 g at a constant temperature, whereas the variation in applied stress when the weight 3 is used is ± 10 g.
From the experimental results under the same conditions of 1.5 g, it is clear that the weight 3 can stably apply a constant stress to the stressed portion 2. In general, using the weight 3 is simpler in structure than using a cylinder, the number of components required for the facility can be reduced, and the facility itself can be downsized. Therefore, maintenance and maintenance of the equipment are also easy. Furthermore, since the driving force is gravity, the operating and maintenance costs of the equipment can be significantly reduced.

[0008] The stress sensor 1 will be described. The stress sensor 1 shown in FIG. 1 has a resistance element 11 arranged on one surface of a substrate 4 made of, for example, a ceramic, and a substrate 4 opposite to the resistance element 11.
On the surface, a stick-shaped stressed part 2 called a post
Are fixed or integrated. When a stress is applied to the stressed portion 2, the stress slightly deflects the substrate 4, thereby stimulating the resistance element 11 and changing the resistance value of the resistance element 11. There are four resistive elements 11, which constitute, for example, a bridge circuit shown in FIG. A predetermined voltage is applied between the voltage application terminals (Vcc) and (GND) of this bridge circuit. Also, the resistance element 2 on the left side of FIG.
And the Y terminal (Yout) constitute a stress sensor in the Y-axis direction. Further, the resistance element 2 and the X terminal (Xo
out) constitutes a stress sensor in the X-axis direction. The change in the resistance value disturbs the resistance value balance of the bridge circuit, and by analyzing the change as the predetermined voltage value change, it is possible to grasp the direction and intensity of the stress applied to the stressed portion 2. it can.

The application of the stress sensor 1 is, for example, a pointing device of a personal computer, a multidirectional switch that can be used in a small electronic device, and the like. In the case of such a stress sensor 1, it is often necessary to inspect the output accuracy for applying stress in multiple directions before shipping. Further, since the shipment amount is large, it is required to apply the constant stress to the stressed portion 2 many times during the inspection. Therefore, it is particularly suitable to apply the present invention to such a stress sensor 1. However, it goes without saying that the stress sensor of the present invention can be applied to applications other than the stress sensor 1 described here.

Generally, a stress sensor functions as a stress sensor only when there is a control unit for detecting and calculating the above-mentioned electrical characteristics. However, in this specification, a portion excluding the control unit is referred to as a “stress sensor” for convenience.

In order to solve the second problem, the stress sensor 1 inspection method according to the present invention includes a first step of fixing the stress sensor 1 so that the stress sensor 1 is in a fixed state in use, and a stress applying section 2.
A second stage of applying a stress from the nth direction, a third stage of maintaining the application of the stress as a predetermined stress for a predetermined period, and an output of the stress sensor 1 corresponding to the nth direction in the third stage. A fourth step of measuring the value (F _n ), a fifth step of releasing the application of stress from the n-th direction, and F _n
Is a method for inspecting the stress sensor 1 having a sixth step of judging whether or not is within a predetermined range, characterized by having a step of repeating at least the second to fifth steps a predetermined number of times in this order. Here, n is a natural number starting from 1, and
Each time the second to fifth steps are repeated a predetermined number of times, the number is increased, and n and _n of _Fn are corresponding numbers, and the predetermined number of times is two or more n times. Hereinafter, an example of the present inspection method will be described with reference to FIGS. 1 and 2.

The method for testing the stress sensor 1 according to the present invention includes the above-described first to sixth steps. In the first stage, the stress sensor 1 is fixed so as to be in a fixed state in use. For example, in the case of the stress sensor 1 shown in FIG.
Fix it. Here, since it is complicated to realize the same fixed state at the time of inspection as at the time of use, the “fixed state at the time of use” is the same as that at the time of use when stress is applied to the stressed portion 2. The output value is defined as a fixed state that can be output.

In the second stage, a stress is applied to the stressed portion 2 from the n-th direction. The application of the stress is performed, for example, in the second
The movement of the stopper 16 and the movement of the weight 3 due to the movement of the stopper 16 by the driving means are allowed. When the stress is applied to the stressed portion 2 for the first time, the n-th direction becomes the first direction, and when the stress is subsequently applied, the second direction becomes the second direction. As the number of times of applying the stress increases, the numerical value of the natural number n increases by one. Here, for example, the first direction and the second direction may be the same direction. As a result, there are various inspection methods in which the stress application method differs depending on the purpose of the inspection, such as an inspection method in which different stresses are applied in the same stress application direction and an inspection method in which the same stress is applied twice or more in the same stress application direction. Can be applied. In order to sequentially apply stress from two or more different directions, other than the members constituting the stress sensor 1 in FIG.
Apparatus for applying stress (hereinafter referred to as stress applying apparatus)
And a means for preparing the stress applying device as a single unit and for relatively changing the positional relationship between the stress sensor 1 and the entire or a part of the stress applying device.

Here, the stress applying means in the second stage is the weight 3
Or a means using a conventional cylinder. As described above, when a cylinder is used, there is a disadvantage that the applied stress is not stable. However, depending on the inspection accuracy of the stress sensor 1, a cylinder may be used. However, it goes without saying that it is preferable to use the weight 3 in which the applied stress is stable for the above-described reason.

The third stage is a stage in which the stress applied in the second stage is maintained for a predetermined period. The reason for providing the third stage is to stabilize the output value of the stress sensor 1 after applying the stress. For example, as shown in FIG. 1, using a stress applying device in which a predetermined stress is determined by the weight 3, the stress sensor 1 changes a resistance value by bending of the resistance element 11, and outputs an output value (for example, a voltage value) after the change. When outputting, the predetermined period is preferably about 0.5 to 3 seconds.

The fourth stage is the output value of the stress sensor 1 (F _n )
Is the step of measuring Here, _n of Fn and n in the second stage have a corresponding relationship. For example stress sensor 1 output value when the stress is applied from the first direction in the second stage becomes F _1. As described above, the stress sensor 1 shown in FIG.
In _order to measure the output value (F _n ), the output voltage value and the like accompanying the change in the resistance value of the resistance element 11 in FIG. 11 are measured.

The fifth step is a step of releasing the applied stress. This corresponds to the operation of the second driving means 7 in FIG. For example, in the second stage in FIG. 2, the second driving unit 7 pulls up the weight 3 that has moved vertically in order to apply stress via the stopper 16 and the pulley 6 to bring the weight 3 into a state before applying stress. Carry. The driving source of the second driving means 7 is preferably the expansion force of the compressed gas or the driving force of the motor.

At least the operations from the second stage to the fifth stage are repeated as many times as necessary during the inspection of the stress sensor 1.

The sixth step is a step of judging whether the output value (F _n ) is within a predetermined range. Output value ( _Fn )
Is within a predetermined range, the test has passed. If the value is outside the predetermined range, the test has failed. The implementation of the sixth stage is not necessarily after the fifth stage,
After the end of the fourth step, it may be before the start of the fifth step. Further, the sixth step may be included in the repeated operation from the second step to the fifth step. The advantage of the sixth stage when the fourth stage is performed after the end of the fourth stage and before the start of the fifth stage is that the output value (F _n )
Is immediately within the predetermined range.
In that case, for example, the output value (F
Once you know that _n ) includes something out of the standard,
At that time, the inspection can be completed, and the inspection of the stress sensor 1 to be inspected next can be started. That is, it contributes to shortening the inspection time when inspecting a large number of stress sensors 1.

Of the first to sixth steps, the first step and the fourth to sixth steps do not require special equipment other than the measuring equipment, and therefore the human may intervene in this step. The stress sensor inspection method of the present invention can be implemented. However, by performing the first stage, the fourth stage to the sixth stage with equipment and devices without human intervention, continuous operation is facilitated and the reliability of inspection is improved. In particular, regarding the sixth step, if a human intervenes, there is a possibility that a misunderstanding or the like may occur, and it is preferable to perform the inspection without human intervention if the reliability of the inspection is ensured.

As described above, through the first to sixth steps, the stress sensor 1 is inspected by applying a predetermined stress to the stressed portion 2 sequentially from two or more directions and measuring the output with respect to the stress. Can be provided, and the above-described second problem can be solved.

In the above-described stress sensor 1 inspection method of the present invention and a preferred stress sensor 1 inspection method based on the stress sensor, a stress sensor in a state where no stress is applied to the stressed portion before the second stage. It is preferable to carry out a step of measuring one output value (F ₀ ) and determining whether F ₀ is within a predetermined range (hereinafter referred to as a seventh step). Before the second stage is before applying stress to the stressed portion 2 from the n-th direction or before fixing the stress sensor 1 in the first stage. FIG. 3 shows a flowchart of the inspection when the seventh step is added. Hereinafter, the seventh step will be described with reference to FIG.

In FIG. 3, the seventh step is a first step.
It is implemented after the end. This first F₀When measuring
Are the resistance values of all the resistance elements 11 and the stress sensors 1
It is possible to grasp a characteristic value or the like which is an output value at the time of use. this thing
Inspection of response characteristics to stress application
Stress sensor 1 that is not worthwhile for
It can be removed in advance. Also, as shown in FIG.
Repeating the 7 steps from the above 2nd to 5th steps
It may be included within. As a result, the second stage to the sixth stage
In the floor implementation, the stress was removed in the fifth stage
Later, the initial F ₀Check if you are back to
It becomes possible.

In the stress sensor 1 inspection method of the present invention and a preferred stress sensor 1 inspection method based on the stress sensor 1 according to the present invention, after determining whether F ₀ or F _n is within a predetermined range,
It is preferable to have a means for transmitting the determination result to any of the five senses of human beings. The main human sense here is
Hearing, visual. For example, means for displaying the result of determination on a computer display, _F0 or F
Means for sounding an alarm when _n is not within a predetermined range.

Further, the stress sensor 1 inspection apparatus of the present invention for solving the above second problem has a fixing member 22 for fixing the stress sensor so as to be in a fixed state during use, and a stress sensor 1 fixed by the fixing member 22. A stress applying section 15 for sequentially applying a predetermined stress to the stressed section 2 from two or more directions;
A first driving member that relatively moves the stressed member 2 and the stress applying section 15 and presses the stressed member 2 with a predetermined stress for a predetermined period, a measuring unit that measures an output value of the stress sensor 1 during the predetermined period, and the measurement It is characterized by having a second drive member for releasing the pressing after completion, and an output means for outputting the output value. The inspection apparatus for stress sensor 1 of the present invention and its operation state will be described below with reference to FIGS.

The fixing member 22 shown in FIG.
2. Consists of an alignment rod 9 and a fixing jig 20. When the stress sensor 1 is mounted on, for example, a small electronic device or a personal computer, a hole for fixing to the housing is an alignment hole 8, into which an alignment rod 9 is inserted, and the stress sensor 1 and the pedestal 12 are connected. Align the position. This alignment takes into account the electrical connection between the output terminal on the stress sensor 1 side and the terminal 5 on the pedestal 12. Consideration is also given to realizing accurate stress application from the intended direction at the time of inspection.
Further, the stress sensor 1 aligned by the fixing jig 20 is used.
Of the substrate 4 is fixed to a fixed state. This fixed state is a fixed state in which, when stress is applied to the stressed portion 2 so as to support the vicinity of the alignment hole 8 fixed during use, an output value similar to that during use can be output. Fixing jig 2
A gap 21 is provided on each of the four side surfaces and the top surface of the zero. The gap 21 is provided so that the stressed portion 2 of the stress sensor 1 can reach the stress applying portion 15 in FIG. Here, the fixing member 22 in FIG. 5 to FIG. 8 and FIG.
Is shown as a schematic diagram of the combination.

The first drive member comprises, for example, a weight 3, a pulley 6, a thread 13, a stress applying section 15 and a guide 14 as required, as shown in FIG. The operation of the first driving member is as follows. First, the weight 3 generates a force in the vertical direction by its own weight, and the force is converted to a horizontal direction by the thread 13 and the pulley 6 and transmitted to the stress applying section 15. Moves toward the direction of the stress applying portion 2 and moves (relative movement between the stress applying member 2 and the stress applying portion 15) to apply a predetermined stress (weight 3) to the stress applying portion 2.
Pressure is applied for a predetermined period (arbitrary) by a stress equivalent to weight. At this time, the guide 14 mounted on the peripheral surface of the weight 3 is formed of a ball spline having a frictional resistance close to zero, and prevents the lateral movement of the weight 3 when the weight 3 moves in the vertical direction. The applied stress is stabilized. The guide 14 mounted on the peripheral surface of the stress applying portion 15 is also made of a ball spline or the like having a frictional resistance close to zero, and prevents the stress applying portion 15 from moving when moving in the horizontal direction. The stress applied to the portion 2 is stabilized. Here, the weight 3 is slightly heavier than the weight corresponding to the predetermined stress. The reason is that even if the frictional resistance is close to zero, it does not become completely zero. Even in such a configuration, the predetermined stress is determined by the weight of the weight 3. The weight of the weight 3 is adjusted to a predetermined stress in anticipation of the friction.

It is conceivable that the measuring means for measuring the output value of the stress sensor 1 and the output means for outputting the output value differ depending on the electric signal output from the stress sensor 1. When the output value is a voltage value, a known measuring device capable of measuring a voltage value is required. The electric signal output from the stress sensor 1 is transmitted to the external measuring device via the terminal 5 arranged on the pedestal 12 shown in FIG.

After the completion of the measurement, a second release of the pressure is performed.
Is composed of the second driving means 7 and the stopper 16 in FIG. The second drive means 7 can use the expansion force of the compressed gas, the rotation of the motor, or the like as a drive source. For the former, for example, a known cylinder may be used. The reason is that the second driving means 7 does not need to be precise in its operation or the like. When the stress applying section 15 is pulled and moved in the horizontal direction by the second driving means 7 via the stopper 16, the thread 13 is pulled toward the second driving means 7, and the force of the movement is vertically moved by the pulley 6. The weight 3 is converted upward, and the weight 3 is lifted upward. At the same time, the stress applying section 15
By moving to the driving means 7 side, the stressed portion 2
Is released.

In the configuration of the stress sensor 1 inspection apparatus according to the present invention, the stress sensor 1 includes a judging means for judging whether or not the output value is within a predetermined range, and a means for classifying the stress sensor 1 based on the judgment. Is preferred. As a determining means for determining whether or not the output value is within a predetermined range, there is an arithmetic processing of a computer. In addition, these stress sensors 1
Are classified into those whose output values are within a predetermined range and those whose output values are not within that range, and the former can be treated as a good product and the latter as a defective product. Good products and defective products are transported to different places.

In the stress sensor 1 inspection apparatus of the present invention and a preferred configuration based on the stress sensor 1, a means for transporting the stress sensor 1 to the pedestal 12 and fixing the stress sensor 1 by the fixing member 22, and releasing the pressing by the second driving member It is preferable to have means for releasing the fixing and moving the stress sensor 1 later.

The transporting or moving means is, for example, a means for holding the stressed portion 2 of the stress sensor 1 in FIG. 4 and moving it under sequence program control or the like, or transporting the substrate 4 by placing the bottom surface of the substrate 4 on a belt conveyor. There are means to do so. The former is suitable for moving the stress sensor 1 to the pedestal 12 and fixing and releasing the fixing by the fixing member 22. The reason is that, in order to insert and remove the alignment rod 9 from the alignment hole 8, it is necessary to move the stress sensor 1 and the pedestal 12 while providing a relative height difference. It is considered that the latter is suitable as a moving means before the holding and after the detachment. The reason is that it is sufficient to carry the substrate 4 while placing it on the bottom surface, and a complicated operation such as the movement by the sequence program control is not required. However, in the case where it is difficult to use the belt conveyor and the holding / moving means together or it is inconvenient due to the complexity of the mechanism, only the holding / moving means can be used as the moving / transporting means. By providing these means, a large number of stress sensors 1 can be inspected continuously.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Four resistive elements 11 are arranged on two orthogonal straight lines along the surface of a substrate 4 having the center of the surface of the substrate 4 as an intersection and at substantially equal distances from the intersection. The stressed portion 2 is fixed or integrated such that the center of the intersection and the center of the bottom surface of the stressed portion 2 substantially coincide with each other;
An embodiment in which the stress sensor 1 capable of grasping the direction and the magnitude of the stress from a change in resistance value due to expansion and contraction of the resistance element 11 caused by the application of the stress to the stressed portion 2 is an inspection target. explain. Here, the four resistance elements 11 constitute a bridge circuit shown in FIG.

The inspection items are the following three items. (1) The output value (F₀(2) Each resistance element 11 direction with respect to the side surface of the stressed portion 2
1.96 N (200
gf) The output value of the stress sensor 1 (F ₁~
F₄(3) The direction perpendicular to the surface of the substrate 4 with respect to the top surface of the stressed portion 2
3.92N (400gf) stress was applied to the
Output value of the stress sensor 1 (F₅)

First, the entire movement of the work (stress sensor 1) from before the start of the inspection to after the end of the inspection will be described with reference to FIG. Many stress sensors 1 are conveyed by the first belt conveyor 17 in the direction of the fixing member 22. At the stage where the stress sensor 1 comes closest to the fixing member 22, the arm 19 sandwiches the stressed portion 2 and places the stress sensor 1 on the fixing member 22. At this time, the pedestal 1 is inserted into an alignment hole in the substrate 4 of the stress sensor 1 as shown in FIG.
The position is controlled by the sequence program control so that the positioning rod 9 at 2 is inserted (movement A). When the stress sensor 1 is placed on the fixing member, the arm 19 is once removed from the stress sensor 1. Next, the end of the substrate 4 of the stress sensor 1 is sandwiched between the pedestal 12 and fixed by a fixing jig 20 shown in FIG. When the inspection is completed, the pressing is released, the stressed portion 2 is again held by the arm 19, and the stress sensor 1 is removed from the fixing member 22. When it is determined that the stress sensor 1 satisfies all of the above inspection items, the stress sensor 1 is moved and placed on the second belt conveyor 18 by the arm 19 (movement B). When it is determined that the stress sensor 1 does not satisfy any one of the inspection items, the stress sensor 1 is moved to the second belt conveyor 18 without moving the container to the second belt conveyor 18 (movement C). In this way, the stress sensor 1 that has passed the inspection is distinguished from the stress sensor 1 that has not passed the inspection. After the movement B is performed as an inspection-passed product, the stress sensor 1 is transported by the second belt conveyor 18 in the transport direction.

Next, the arrangement of the stress applying section 15 in the stress applying apparatus according to the present invention will be described with reference to FIG. As for the stress application in the inspection item (2), as shown in the top view, a stress application device is arranged so as to surround the peripheral surface of the stressed portion 2 from all sides. The positional relationship between the stress applying section 15 and the stress applied section 2 is such that the side of the stress applied section 2 faces each resistance element 11 of the stress sensor 1,
The tip of the stress applying section is arranged in a direction parallel to the surface of the substrate 4.
These four stress applying devices were prepared as shown in FIG. The arrangement of the fixing jig 20 described above is such that all the stress applying portions 15 can be in contact with the stressed portions 2 so that the gaps 21 can be contacted.
Note that is located.

The stress applying device shown in FIG. 5 comprises a weight 3, a pulley 6, a thread 13, a stress applying section 15, a guide 14, a second driving means 7, and a stopper 16. Of these, the pulley 6, the guide 14, and the second driving means 7 are fixed by a casing (not shown). First, the weight 3 generates a force in the vertical direction by its own weight. The force is converted in the horizontal direction by the yarn 13 and the pulley 6 and transmitted to the stress applying section 15. The movement of the stopper 16, the stress applying portion 15, and the weight 3 is prevented by the second driving means 7 so that the force does not act (FIG. 5A). When the inhibition by the second driving means 7 is released, the stress applying section 15
In the direction of 1.96 N with respect to the stressed portion 2.
(200 gf) is pressed (stressed) for about 1 second (FIG. 5).
(B)). At this time, the guide 1 mounted on the peripheral surface of the weight 3
4 is a ball spline having a frictional resistance close to zero,
The horizontal blurring when the weight 3 moves in the vertical direction is prevented, thereby stabilizing the stress applied to the stressed portion 2. The guide 1 mounted on the peripheral surface of the stress applying section 15
4 is also a ball spline whose frictional resistance is close to zero,
This prevents blurring when the stress applying unit 15 moves in the horizontal direction, thereby stabilizing the stress applied to the stressed unit 2. After the measurement is completed, the stopper 16 is pulled by the second driving means 7 to bring the state shown in FIG. Here, the driving force of the second driving means 7 was the expansion force of the compressed air. The weight of the weight 3 was set to 203 g to compensate for the stress loss due to the friction, so that 1.96 N (200 gf) was applied to the stressed portion 2 of the stress sensor 1 to some extent accurately.

Another stress applying unit 15 in the stress applying device
Will be described with reference to FIG. As described above, in the top view of the figure, the stress applying device is arranged so as to surround the peripheral surface of the stressed portion 2 from all sides. Therefore, when it is considered that the position of the stressed portion 2 and the stress applying device is difficult to be clearly defined when all the stress applying devices are drawn in a side view, the stress applying devices located on the front and rear sides of the side view are side views. Omitted and drawn. Regarding the stress application in the above inspection item (3), as shown in the side view,
A stress applying device for applying (pressing) stress in a direction perpendicular to the surface of the substrate 4 was disposed on the top surface of the stressed portion 2.

This inspection item (3) is for measuring a change in resistance of the resistance element 11 due to, for example, bending of the stress sensor 1 in FIG. When the substrate 4 bends downward, the four resistive elements 11 become almost similarly high. By detecting this, it is recognized that the stress is applied to the stressed portion 2 in the downward direction. Therefore, as shown in FIG. 4, the pedestal 12 is provided with a depression 10 that allows the substrate 4 to bend downward.

The outline of the stress applying device for pressing will be described with reference to FIG. The stress applying device shown in FIG.
It comprises a stress applying portion 15 also serving as a 00 g weight 3, a guide 14, a second driving means 7, and a stopper 16. Of these, the guide 14 and the second driving means 7 are fixed by a casing (not shown). First, the stress applying portion 15 as the weight 3 generates a force in the vertical direction by its own weight. The movement of the weight 3 and the stress applying portion 15 is prevented by the second driving means 7 so that the force does not act (FIG. 6A). And the second
When the blocking of the driving means 7 is released, the stress applying section 15
Moves in the direction of the stressed portion 2 and presses (applies stress) 3.92 N (400 gf) to the top surface of the stressed portion 2 for about 1 second (FIG. 6B). At this time, the guide 14 mounted on the peripheral surface of the weight 3 and the stress applying portion 15 is a ball spline having a frictional resistance close to zero, and prevents the lateral displacement when the weight 3 and the stress applying portion 15 move in the vertical direction. Thereby, the stress applied to the stressed portion 2 is stabilized. After the measurement is completed, the weight 3 and the stress applying section 15 are pulled up by the second driving means 7 to bring the state shown in FIG.
The driving force of the second driving means 7 was the expansion force of the compressed air. In addition, the weight of the weight 3 was 406 g, and the stress loss due to the friction was compensated to apply 3.92 N (400 gf) to the stressed portion 2 of the stress sensor 1 to some extent accurately.

The yarn 13 shown in FIG. 5 is made of a nylon fiber. It is considered that the characteristics required for the yarn 13 are that the yarn 13 can withstand repeated bending stress under a load and that it can be easily bent. That is, it is a flexible and strong fiber. In that sense, it is considered that aramid fibers and the like can be suitably used.

The inspection flow of the stress sensor 1 of this embodiment will be described with reference to FIG. Here, the first to seventh stages in FIGS. 2 and 3 are the same as the first to seventh stages in FIG. First, in the first stage, the stress sensor 1 shown in FIG.
Is inserted into the positioning rod 9 of the pedestal 12 into the positioning hole 8 and the end of the substrate 4 of the stress sensor 1 that has been positioned is pressed down by the fixing jig 20 to be in a fixed state. The four output terminals on the back surface of the substrate 4 of the stress sensor 1 are electrically connected to the terminals 5 of the pedestal 12.

Next, at a seventh stage, the output value (F ₀ ) of the stress sensor 1 in a state where no stress is applied to the stressed portion is measured, and it is determined whether or not F ₀ is within a predetermined target range. do. As a result of the measurement, if it is not within the predetermined range, it is judged as rejected and moved to the container in FIG. As a result of the measurement, if all the output values (F ₀ ) of the resistance elements 11 are within the predetermined range, the process proceeds to the second stage.

In the second stage, a stress is applied to the stressed portion 2 from the n-th direction. When a stress is applied to the stressed portion 2 for the first time, the n-th direction is the first direction. In this example, when n = 1 to 4, the four stress applying devices shown in FIG. 5 for applying a stress to the peripheral surface of the stressed portion 2 are sequentially operated. When n = 5, the stress applying device shown in FIG. 6 is operated,
The top surface of the stressed portion 2 is pressed.

The third stage is a stage where the stress applied in the second stage is set to a predetermined stress for a predetermined period. In this example, the predetermined period is set to one second. The first reason is that when the predetermined time is set to 0.5 second, a slight variation is observed in the output value. The second reason is that even if the predetermined time is set to be longer than 1 second, the output value is as stable as 1 second. In order to inspect many stress sensors 1 per unit time, it is advantageous that the predetermined time is short. For these reasons, in this example, the predetermined time is set to 1 second.

The fourth stage is the output value of the stress sensor 1 (F _n )
Is the step of measuring Here, _n of Fn and n in the second stage are corresponding numbers. For example stress sensor 1 output value when the stress is applied from the first direction in the second stage becomes F _1. Measurements of F _n is, substantially similarly to implement the measurement of the _{F 0.}

The fifth step is a step of releasing the applied stress. This corresponds to the operation of pulling the stopper 16 by the second drive means 7 in FIGS.

The sixth step is a step of judging whether the output value (F _n ) is within a predetermined range. Output value ( _Fn )
Is out of the predetermined range, it is determined that the inspection has failed. The second to sixth steps are repeated until n = 5. If all the output values are within the predetermined range, it is determined that the inspection has passed.

FIG. 10 shows the flow of the inspection in FIG. 9 and the association with the transfer / movement of the work (stress sensor 1) in FIG. First, in the first belt conveyor 17 in FIG.
The stress sensor 1 recognition sensor (consisting of an optical sensor) for recognizing whether or not there is a signal is transmitted to the central processing unit until the stress sensor 1 is recognized. The first belt conveyor 17 as an apparatus is operated. When the stress sensor 1 recognition sensor recognizes the stress sensor 1, a signal to that effect is transmitted to the central processing unit, and the central processing unit stops the operation of the first belt conveyor 17 as the transport / moving device. At the same time, the central processing unit instructs the arm 19 as a transfer / moving device to perform the movement A, and when the movement A is completed, the arm 19 is separated from the stress sensor 1.

Next, the operation in the seventh stage in FIG. 9 is started.
The central processing unit instructs the reference voltage generator to apply a constant voltage of 5 V between the voltage application terminal (Vcc) and (GND) of the bridge circuit in FIG. The 5 V voltage generated from the reference voltage generator is applied between the (Vcc) and (GND) via the output terminal of the measuring device. The central processing unit also instructs the measuring device to measure the output value (F ₀ ). Measuring device transmits the measurement result of the F ₀ to the central processing unit. Then the central processing unit with and displays the result on the display unit, F ₀ is the determination of whether there is a predetermined range. If F ₀ is not in the predetermined range, the central processing unit instructs to the movement C of FIG. 7 the arm 19 of the transport and movement devices. If F ₀ is within the predetermined range, the process proceeds to the second stage in FIG.

The measurement result is temporarily stored in a storage medium, and the central processing unit appropriately calls up the stored measurement result and uses it when making a determination. When the determination is completed, the measurement result is deleted from the storage medium.

[0052] will be described in detail measurement of _{F 0.} Fixing member 2
FIG. 10 shows four electric wires (A, B, C, D) led from the terminal 5 on the pedestal 12 to the measuring device in FIG. The electric wires correspond to the four terminals (Vcc, GND, Xout, Yout) in FIG. 11, respectively. The correspondence is as follows. A: Vcc B: GND C: Xout D: Yout

[0053] Measurement items F _0, the resistance value of each resistor element 11, between B-C, the voltage value between the B-D, and the applied voltage from the reference voltage generator for actual value measurement A- It is a voltage value between B. Wherein a voltage value between A-B is the F ₀ is not subjected to the determination of whether there is a predetermined range, which will be described later F ₁ ~
The criteria for the F ₄ measurements. Therefore, A measured here
The voltage value between -B is stored in the storage medium until the inspection of one stress sensor is completed, and then deleted.

In the second stage, first, the central processing unit
Is an initial state of one of the stress applying devices in FIG.
The stopper 16 and the thread 13 are pulled (FIG. 5A).
As shown in FIG. 5B, the second driving means is supplied to the second driving means 7.
A state in which substantially no pressing occurs between the step 7 and the stopper 16
To the second driving means 7 to be in the state. Next, Central Performance
The arithmetic processing unit keeps the state for one second (third stage).
After that, it is instructed to return to the initial state (step 4).
Also, immediately before the initial state, the measuring device,
F₀By the same method as F₁Command to measure. Measurement
Fixed device is F₁Measurement results to the central processing unit.
You. Then, the central processing unit displays the measured value on the display.
And temporarily store the measured values on a storage medium.
I do. Then F₁To determine whether is not within the predetermined range.
₀Perform in the same manner as described above. F₁Is not within the specified range,
Arithmetic processing unit is shown on arm 19 as a transport / moving device.
Command move C at 7. F₁Is within the specified range
If it is, F explained here ₁In the process up to the end of measurement
Similarly F₂~ F₅The measurement is performed.

The measured values of F _{1 to} F ₄ are voltage values between BC and BD. When determining F _{1 to} F _{4, the difference} between the actually applied voltage value and the set voltage value of 5 V is determined in consideration of the voltage value between A and B, which is one of the F ₀ values. Is determined after correcting so as not to deviate significantly.

[0056] Measurement of F _5, that is, the output value measured when pressing the object to be stress-applying parts 2 of the stress sensor 1 by using the stress-applying apparatus shown in FIG. 6, the measurement of resistance between A-D by measuring device by. The central processing unit instructs the measuring device to perform the measurement and determines whether the measured value is within a predetermined range. Procedure of the measurement of the other _{F 5 is,} F 1 _{~F
4 is the same as} the measurement procedure.

If the measured values of F ₀ and F _{1 to} F ₅ are all within a predetermined range, it is treated as having passed the inspection. That is, the central processing unit instructs the transfer / moving device to perform the movement B, and places the passed stress sensor 1 on the second belt conveyor 18 and the second belt conveyor 18.
Is moved a predetermined distance.

By performing these series of operations, the stress sensor 1 inspection device according to the present invention can be continuously and automatically operated.

[0059] Although the resistance between the A-D in this example are not measured at F ₀ measurement may be to measure the resistance value between the A-D to the surveying scheduled. As a result, it is also possible to inspect a change in resistance value before and after applying (pressing) a stress on the top surface of the stressed portion 2 in the vertical direction. That is, the output sensitivity of the stress sensor 1 with respect to the pressing can be inspected.

In this embodiment, as shown in FIG. 8, means for applying a predetermined stress from two or more directions (five directions) using five stress applying devices and measuring the output with respect to the stress is employed. . However, when the application of stress from more directions is required as an inspection item, it can be dealt with by means for rotating the pedestal 12 of the stress sensor 1 or the like. Adopting this means has the advantage of reducing the number of stress applying devices. As a secondary effect of this advantage, a reduction in the area occupied by the stress sensor inspection device of the present invention and the like can be given.

In this embodiment, when the stress applying section 2 and the stress applying section 15 are relatively moved, the stress applying section 2 is fixed and the stress applying section 15 is moved.
5 may be fixed and the stressed portion 2 may be moved. For example, the pedestal 12 may be replaced with the stress applying portion 15 in FIGS.
Then, the stress sensor 1 is fixed thereto, and the stress applying section 2 is replaced with the stress applying section 15 in FIG.

[0062]

According to the present invention, it is possible to provide a stress sensor inspection method capable of stably applying a constant stress to a stressed portion. Also, 2
It is possible to provide a stress sensor inspection method for sequentially applying a predetermined stress from the above directions and measuring an output with respect to the stress.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a stress applying device of the present invention.

FIG. 2 is a diagram showing a flow of an example of a stress sensor inspection method of the present invention.

FIG. 3 is a diagram showing a flow of an example of a stress sensor inspection method of the present invention.

FIG. 4 is a diagram illustrating a state in which a stress sensor is fixed to a fixing member.

FIG. 5 is a diagram showing an example of the stress applying device of the present invention.

FIG. 6 is a view showing an example of the stress applying device of the present invention.

FIG. 7 is a diagram showing an example of a flow of a work in the stress applying device of the present invention.

FIG. 8 is a diagram showing a positional relationship between the stress applying device of the present invention and a stress sensor.

FIG. 9 is a diagram showing a flow of an example of the stress sensor inspection method of the present invention.

FIG. 10 is a diagram showing a block diagram of an example of a stress sensor inspection device of the present invention.

FIG. 11 is a diagram illustrating an example of an output of a stress sensor according to the present invention.

[Explanation of symbols]

 1. Stress sensor 2. Stressed part 3. Weight 4. Substrate 5. Terminal 6. Pulley 7. 7. Second drive means Alignment hole 9. Alignment rod 10. Depression 11. Resistive element 12. Pedestal 13. Thread 14. Guide 15. Stress applying section 16. Stopper 17. First belt conveyor 18. Second belt conveyor 19. Arm 20. Fixing jig 21. Gap 22. Fixing member

Claims (10)

[The claims] 1. A stress sensor inspection method for applying a predetermined stress to a portion to be stressed sequentially from two or more directions and measuring an output corresponding to the stress, wherein the predetermined stress is determined by a weight of a weight for applying a stress. A method for inspecting a stress sensor, comprising: 2. The stress sensor is set to be in a fixed state during use.
The first stage of fixing and the n-th
A second step of applying a stress from the direction of
A third step of maintaining the application of the force as a predetermined stress;
A stress sensor corresponding to the n-th direction in the third stage;
Output value (F_nA) measuring said nth method
A fifth step of releasing the application of stress from the direction;_nIs a predetermined range
A stress cell having a sixth step of determining whether
A method for inspecting a sensor, wherein at least the second to fifth steps are repeated a predetermined number of times in this order.
Wherein n is a natural number starting from 1 and each time after the repeating step,
And n and F_nof _nIs the corresponding number,
Inspection method of stress sensor in which predetermined number of times is n times or more 2 times
Law. 3. A step of measuring an output value (F ₀ ) of the stress sensor in a state where no stress is applied to the stressed portion before the second step, and after the step, F ₀ falls within a predetermined range. 3. The method for inspecting a stress sensor according to claim 2, further comprising the step of determining whether or not there is a stress sensor. 4. Whether after determining F ₀ or F _n is in a predetermined range, the stress sensor according to claim 2 or 3, wherein further comprising means for transmitting the determination result to any of the five human senses Inspection method. 5. The stress according to claim 2, wherein, after judging whether or not F ₀ or F _n is within a predetermined range, the inspection is terminated when they are not within the predetermined range. Sensor inspection method. 6. The stress sensor inspection method according to claim 2, wherein the predetermined stress is determined by a weight of the stress applying weight. 7. A fixing member for fixing a stress sensor in a fixed state during use, and a stress for sequentially applying a predetermined stress from two or more directions to a stressed portion of the stress sensor fixed by the fixing member. Imparting portion, relatively moving the stressed portion and the stress applying portion,
A first driving member for pressing for a predetermined period by a predetermined stress, a measuring unit for measuring an output value of the stress sensor in the predetermined period, a second driving member for releasing the pressing after the completion of the measurement, and outputting the output value And a stress sensor inspection device. 8. The stress sensor inspection device according to claim 7, wherein the predetermined stress is determined by a weight of the stress applying weight. 9. The stress sensor according to claim 7, further comprising: a judging means for judging whether or not the output value is within a predetermined range, and means for classifying the stress sensor based on the judgment. Sensor inspection device. And means for transporting the stress sensor to the fixing member and fixing the stress sensor by the fixing member, and means for releasing the fixing and moving the stress sensor after the pressing by the second driving member is released. Claims 7 to
The stress sensor inspection device according to any one of claims 9 to 9.