JPH10267811A - Device for measuring buckling strength and jig used to it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for measuring buckling strength by which the buckling strength of a square plate object to be measured can be measured accurately through simple operation. SOLUTION: In this device, two loading means H are secured to both facing end parts of a square plate object to be measured respectively, and when they are pressed in a manner to be close to each other, a pressing load applied by pressing them works on the total length of the end part of the object. Then a guide means 1 guides two loading means H in a manner that they may move closely along a specified route. A pressing means P presses the means H as to make them close to each other. A load detection means 2 detects a pressing load generated by the means P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buckling strength measuring device, and more particularly, to a buckling strength measuring device for measuring a buckling strength of a rectangular plate-like object to be measured and a jig used for the buckling strength measuring device.

[0002]

2. Description of the Related Art A conventional buckling strength measuring apparatus includes a base for allowing an object to be measured to stand on its lower end surface and an upper end surface of the object to be measured on the base. It is configured to include a pressing unit that presses the measurement object, to detect a pressing load by the pressing unit, and to obtain a buckling strength based on the pressing load.

[0003]

When buckling strength is measured, it is necessary to apply a pressing load uniformly to the entire end surface of the object to be measured. In a conventional apparatus, a rod-shaped measurement object such as a round bar or a square bar can easily apply a pressing load uniformly over the entire end surface. However, in the case of an object to be measured having a rectangular plate shape, the end face for applying a pressing load has an elongated shape, so that it is difficult to apply the pressing load evenly over the entire length of the elongated end face, and the measurement accuracy is high. Was bad.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a buckling strength capable of measuring the buckling strength of a rectangular plate-like measurement object with a simple operation and with high accuracy. An object of the present invention is to provide a measuring device and a jig used for the measuring device.

[0005]

According to the first aspect of the present invention, two load applying means respectively attached to opposite ends of the rectangular plate-shaped workpiece are guiding means. When pressed by the pressing means so as to approach and move along a predetermined path under the guidance of the two load applying means, the pressing load acting when pressed is applied over the entire length of the end of the measured object. To do. Then, when the load detecting means detects a pressing load when buckling occurs on the measured object, the buckling strength can be obtained based on the load. Therefore, the push load can be applied over the entire length of the end of the object to be measured by a simple operation of simply attaching the two load acting means to both ends of the rectangular plate-shaped object to be measured, respectively. The buckling strength of a rectangular plate-shaped object to be measured can be measured with a simple operation and with high accuracy.

According to the characteristic configuration of the second aspect, the object to be measured is arranged so that the surface direction thereof is along the vertical direction,
The two load applying means respectively attached to the upper end and the lower end of the object to be measured are pressed by the pressing means so as to approach and move along a predetermined vertical path by the guidance of the guiding means. Incidentally, it is assumed that the object to be measured is arranged so that its surface direction intersects the vertical direction, for example, along the horizontal direction, and the two load application means are pressed so as to approach and move along the horizontal direction. Is done. However, in this case, while the pressing load acts in the plane direction of the object to be measured, the own weight of the object to be measured acts in a direction intersecting the surface direction of the object to be measured, so that the measurement accuracy is somewhat There is a drawback that gets worse. Therefore, according to the characteristic configuration of the second aspect, it is possible to prevent the self-weight of the object to be measured from acting in a direction intersecting with the direction in which the pressing load is applied, thereby preventing a decrease in measurement accuracy due to that. can do.

According to the third aspect of the present invention, the load applying means is configured to hold and hold the end of the object to be measured over its entire length. Accordingly, the pushing action can be reliably applied to the entire length of the end of the object to be measured by the load applying means while the attachment / detachment operation of the load applying means to / from the object to be measured can be easily performed.

According to the fourth aspect of the present invention, the buckling point at which the object to be measured buckles due to the action of the pressing load is:
The detection value is detected by the buckling detecting means, and the output value of the load detecting means at the time of buckling detected by the buckling detecting means is output to the output means. Then, the buckling strength can be obtained based on the output information of the output means. Incidentally, the buckling point at which buckling occurs in the measured object may be artificially determined, and the detection value of the load detecting means at the buckling point may be artificially specified. However, in this case, not only is the artificial determination of the buckling time and the artificial identification of the detected value of the load detecting means at the time of the buckling complicated, but also the artificial identification and identification tend to vary. Therefore, there is a disadvantage that the measurement accuracy is slightly deteriorated. On the other hand, according to the characteristic configuration of the fourth aspect, the determination of the buckling time and the identification of the detection value of the load detecting means at the buckling time are automatically performed, so that the operation is simplified. And measurement accuracy can be improved.

According to a fifth aspect of the present invention, the buckling detecting means is configured to detect a point in time at which the detected value of the load detecting means becomes maximum as the buckling point. . In other words, when the two load acting means are pressed so as to approach each other by the pressing means, the pressing load increases with the elapse of time, so that the detection value of the load detecting means increases, and buckling occurs in the measured object. Then, at that moment, the force acting against the pressing load by the pressing means by the strength of the object to be measured becomes weak, and the detection value of the load detecting means decreases. Therefore, the time point at which the detection value of the load detecting means changes to a maximum over time can be detected as the buckling time point. By the way, at the moment when the buckling occurs on the object to be measured, the displacement of the load applying means becomes large, so that the buckling detecting means can be configured to detect the displacement, but in this case, the configuration becomes complicated. There are disadvantages. Therefore, when the characteristic configuration according to claim 5 is adopted, the configuration of the buckling detection unit can be simplified as compared with a case where the displacement of the load application unit is detected.

According to the characteristic configuration of the present invention, when the two load applying means are positioned and arranged by the positioning portion, the two load applying means correspond to the attachment to the object to be measured. It will be located at an interval and in a posture parallel to each other. Therefore, the two load applying means can be easily and reliably attached to both ends of the measured object in the set relative positional relationship.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the buckling strength measuring device is separately attached to opposing ends of a rectangular plate-shaped object to be measured B, and acts when pushed in a direction approaching each other. And two holders H serving as two load acting means for causing the pushing load to be applied to the entire length of the end of the object B to be measured.
A guide member 1 for guiding the two holders H to move closer to each other along a predetermined path, a pressing means P for pressing the two holders H to approach each other, and a pressing load by the pressing means P , A display unit 3 for outputting the load detected by the load cell 2, an XY recorder 4, and a control unit 5 for controlling a buckling strength measuring device.

The holder H will be described with reference to FIG. The holder H has an L-shaped member 6 which is long and has a substantially L-shaped cross-sectional shape, a square member 7 which is long and has a rectangular cross-section and is inserted into a concave portion of the L-shaped member 6, It is composed of three bolts 8 for connecting and fixing the L-shaped member 6 and the square member 7 placed in the recess. The L-shaped member 6 includes
Three counterbored bolt insertion holes 6a for inserting the bolts 8 are formed side by side along the longitudinal direction, and the square member 7 is inserted into the concave portion of the L-shaped member 6, Three screw holes 7a are formed so as to be concentric with the bolt insertion holes 6a of the L-shaped member 6, respectively. And
By tightening three bolts 8 in a state where the end of the measured object B is sandwiched between the L-shaped member 6 and the square member 7,
The holder H is configured to hold and hold the end of the object B to be measured over its entire length.

The guide member 1 will be described with reference to FIG. The guide member 1 is composed of a guide plate 1A bent and formed in a T-shape when viewed from the side, and a guide plate 1B also bent and formed in an L-shape when viewed from the side.

The pressing means P will be described with reference to FIG. The pressing means P includes an electric motor 10 attached to a column 9 erected on a base 8, a screw shaft 11 driven to rotate by the electric motor 10, and a top member 12 screwed to the screw shaft 11. The electric motor 10 is rotated forward and backward to move the pressing member 13 up and down in the vertical direction.

The load cell 2 is provided at the tip of the pressing member 13 so that a pressing load when pressing the holder H by the pressing member 13 is applied.

A jig 14 for separately attaching two holders H to both ends of the object B to be measured will be described with reference to FIGS. The jig 14 has two concave portions 14a for separately inserting two square members 7 on one surface of a rectangular parallelepiped metal block, and two holders H are attached to the workpiece B. It is formed so as to be spaced apart corresponding to each other and in a posture parallel to each other.

Referring to FIGS. 2 and 3, two holders H
Will be described below when separately attached to both ends of the object B to be measured. First, each of the two rectangular members 7 is positioned and arranged in the recess 14a of the jig 14. Next, the object to be measured B is arranged with both ends thereof straddling the two square members 7. Next, the L-shaped member 6 is placed and placed on the square member 7 in a state where the square member 7 enters the recess, and then the three bolts 8 are tightened to form the L-shaped member 6. And the rectangular member 7 are connected and fixed, and the end of the measured object B is sandwiched and held over the entire length thereof. As mentioned above,
The two holders H are separately attached to both ends of the measured object B in a posture in which they are separated by a predetermined distance and are parallel to each other. Here, a positioning portion for positioning the two holders H with the two recesses 14a at intervals corresponding to the attachment to the workpiece B and in positions parallel to each other is provided. It is composed.

The L-shaped member 6 is formed such that a holding surface for holding the end of the measured object B is perpendicular to a surface placed on the base 8. Therefore, as described above,
When one of the holders H is mounted on the base 8 in a state where the two holders H are mounted on both ends of the object B, the upper holder H is mounted on the upper end by the lower holder H. The object B in the set state can be supported in a state where the surface direction is vertical.

The procedure for measuring the buckling strength of the object B will be described. As shown in FIG. 1, two holders H are attached to both ends of the object B as described above. In the state, the upper holder H is arranged on the base 8 so that the upper holder H is located immediately below the pressing member 13, and the two guide plates 1 </ b> A and 1 </ b> B are placed on both sides of the upper and lower two holders H. It is placed on the base 8 in the attached state. Then, when the electric motor 10 is operated so that the pressing member 13 moves downward, the upper holder H is pushed vertically downward by the pressing member 13 so as to approach the lower holder H. At this time, as the two holders H are pushed in directions approaching each other, the pushing load acting when pushed is applied over the entire length of the end of the object B to be measured. Here, the upper guide H is guided by the two guide plates 1A and 1B so as to move along a vertical path, and in the case of the measurement object B having a low rigidity, the measurement object is positioned on the upper side. The holder H is prevented from tilting due to its weight.

Accordingly, the guide member 1 is configured to guide the two holders H to move closer to each other along a predetermined vertical path, and the pressing means P presses the two holders H closer to each other in the vertical direction. It is configured to be pressed to make it work.

Next, a control configuration of the control unit 5 will be described with reference to FIG. The control unit 5 is configured using a microcomputer, and is configured to input a detection value of the load cell 2 and a signal of the measurement start switch 15. The control unit 5 controls the operation of the electric motor 10 and displays the measurement results on the display unit 3 and the XY display.
It is configured to output to the recorder 4. Further, the control unit 5 includes a memory 5a that stores the detected load value of the load cell 2 in time series.

The control operation of the control unit 5 will be described.
When a measurement start is commanded by the measurement start switch 15, the electric motor 10 is operated so that the pressing member 13 moves downward, the detected load values of the load cell 2 are sequentially read and stored in the memory 5a, and the detected load values are detected. Is determined from the time series data, and the maximum value is displayed on the display unit 3 as a pressing load at the time of buckling when the object to be measured has buckled. In addition, after the set time elapses from the time when the time-series data of the detected load value reaches a maximum, the operation of the electric motor is switched so that the pressing member 13 moves upward, and the pressing member 13 rises to a predetermined standby position. Then, the operation of the electric motor is stopped. As shown in FIG. 6, the relationship between the detected load value of the load cell 2 and the time is recorded in the XY recorder 4. Therefore, the buckling detecting means 100 is configured to detect the buckling time point at which the object B is buckled by the action of the pressing load by using the control unit 5. The display unit 3 displays the load cell 2 at the time of the buckling.
Output means for outputting the detection value of

Therefore, the shape of the object B (as shown in FIG. 7), the length (the portion in contact with the load cell 2) L and the width W
And the thickness t) are the same, the display unit 3
The buckling strength of the measured object B can be evaluated based on the pushing load F1 at the time of buckling displayed in ( ₁₎ . Note that the pressing load F ₁ at the time of buckling can also be obtained from the recording result of the XY recorder 4.

By the way, as shown in FIG.
_In addition to ₁ , the weight F ₂ of the upper holder H is
Buckling. Therefore, the buckling strength can be determined based on the pressing load F ₁ at the time of buckling, the weight F ₂ of the upper holder H, and the cross-sectional area S of the object to be measured which receives the pressing load. In addition, the measured object B
The cross-sectional area S subjected to the pressing load in the above becomes t × L.

Next, an example of the application of the buckling strength measuring device configured as described above will be described. As shown in FIG. 8, one of the manufacturing processes of a sheet-like product or a felt-like product includes a process of transferring the band-shaped material B by the roller conveyor 21. If the meandering occurs in a direction perpendicular to the transport direction in the surface direction of the belt-shaped material, wrinkles may be generated in the band-shaped material B. Also, the processing conditions (for example, the bulk density in the case of felt material) of the strip material may be changed, but if the processing conditions are changed, the strength of the strip material changes, and wrinkles are easily generated during the conveyor transfer process. change. Therefore, if it is possible to predict the extent to which the processing conditions can be changed while preventing wrinkles during the conveyor transfer process, it will be extremely effective.

Considering a state in which a wrinkle-generating stress acts on the band-shaped material B while the band-shaped material B is being transported by the roller conveyor, it is considered that the stress is in the direction of the width (indicated by W in FIG. 8) of the band-shaped material B. It can be seen that the state is very similar to a state in which one end is fixed and a compressive stress is applied in the surface direction from the other end. Therefore, it is possible to evaluate the ease of wrinkling during the conveyor transfer process using the buckling strength measured by the buckling strength measuring device configured as described above.

For example, samples in which one of the processing conditions is variously changed are prepared, and the buckling strength of those samples is measured to obtain the relationship between the buckling strength and the processing conditions. In addition, the lower limit of buckling strength (hereinafter referred to as the wrinkle-free lower limit value) in which various samples of which buckling strength is known is actually transferred only once by a roller conveyor and can be transferred without generating wrinkles. ). Therefore, based on the relationship between the buckling strength and the processing conditions, and the wrinkle non-occurrence lower limit,
It is possible to predict the extent to which the processing conditions can be changed while preventing wrinkles from occurring during the conveyor transfer step.

[Another Embodiment] Next, another embodiment will be described. (A) As the specific configuration of the load applying means, various configurations other than the holder H exemplified in the above embodiment are possible. For example, in the rod-shaped member, along its length direction, the width is substantially the same as the thickness of the object B, the length is longer than the length of the end of the object B, and the bottom is A groove-like concave portion capable of contacting the entire end face is formed, and the object to be measured B is formed in the concave portion.
May be configured to be inserted and held.

(B) In the above embodiment, the case where the holder H is constituted by the L-shaped member 6, the square-shaped member 7 and the three bolts 8 for connecting and fixing them has been exemplified. The specific configuration can be variously changed. For example, the number of bolts 8 can be changed. Further, each member constituting the holder H (in the above embodiment, the L-shaped member 6 is used).
The shape of the rectangular member 7) can be variously changed. Also, L
The mold member 6 and the square member 7 may be connected so as to be able to approach and separate from each other while being urged by a spring in a direction approaching each other.

(C) As the specific configuration of the guide means, various configurations other than the guide member 1 exemplified in the above embodiment are possible. For example, it may be constituted by two guide plates 1B bent in an L-shape when viewed from the side. Alternatively, one of the two holders H may be fixedly supported and the other may be slidably supported.

(D) As the specific configuration of the pressing means P, various configurations other than the configuration exemplified in the above embodiment are possible. For example, a cylinder may be used instead of the electric motor 10 as an actuator for pressing the two holders H so as to approach each other.

As a configuration for pressing the two holders H so as to approach each other, in the above-described embodiment, 2
Although one of the holders H is configured to be pressed in a direction approaching the other, instead, each of the two holders H is configured to be pressed in a direction approaching the other. Well.

(E) As a specific configuration of the buckling detecting means,
In the above-described embodiment, a case is described in which the time point at which the detected load value of the load cell 2 reaches a maximum in the time-dependent change is detected as the buckling time point. However, various other configurations are possible. For example, load cell 2
The time when the change rate of the detected load value becomes equal to or less than a set value (for example, zero) may be detected as the buckling time. Further, a sensor for detecting the downward displacement of the upper holder H may be provided, and a point in time when the detected displacement of the sensor becomes equal to or larger than a set value may be detected as the buckling point.

(F) Input means for inputting the cross-sectional area S of the object B and the weight F ₂ of the upper holder H are provided.
May be configured to calculate the buckling strength based on input information of the input means and to display the calculated buckling strength on the display unit 3 using an arithmetic expression set and stored in advance.

(G) The specific configuration of the jig 14 can be various configurations other than the configuration exemplified in the above embodiment. For example, in the above embodiment, the two square members 7 are configured to be positioned.
The L-shaped members 6 may be configured to be positioned.
In this case, a bolt insertion hole is provided in the square member 7 and the L-shaped member 6
It is good to form a screw hole in each.

Further, the interval for positioning the two holders H may be changed freely. in this case,
It is possible to cope with the object to be measured B having various widths W.

[Brief description of the drawings]

FIG. 1 is a side view of a buckling strength measuring device.

FIG. 2 is an exploded perspective view showing a configuration of a holder and a jig.

FIG. 3 is a longitudinal sectional view showing a state where a holder is attached to an object to be measured using a jig.

FIG. 4 is a perspective view showing a configuration of a guide member.

FIG. 5 is a block diagram showing a control configuration of the buckling strength measuring device.

FIG. 6 is a diagram showing a change over time in a detected load value.

FIG. 7 is a perspective view showing the relationship between various forces acting on an object to be measured.

FIG. 8 is a schematic perspective view showing a belt-conveying process of the belt-shaped material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Guide means 2 Load detection means 3 Output means 14a Positioning part 100 Buckling detection means H Load acting means P Pressing means

Claims (6)

[Claims] 1. A rectangular plate-shaped object to be measured is separately attached to opposite ends thereof, and when pressed in a direction approaching each other, a pressing load acting when the object is pressed is applied to an end of the object to be measured. Work over the entire length of the 2
Load applying means, guide means for guiding the two load applying means to move closer along a predetermined path, pressing means for pressing the two load applying means closer to each other, A buckling strength measuring device provided with a load detecting means for detecting a pressing load by a pressing means. 2. The guide means is configured to guide the two load applying means to move closer to each other along a predetermined vertical path, and the pressing means sets the two load applying means to each other. 2. The apparatus according to claim 1, wherein said pressing means is pressed to approach in a vertical direction.
The buckling strength measuring device according to the above. 3. The buckling strength measuring device according to claim 1, wherein the load acting means is configured to hold and hold an end of the object to be measured over its entire length. 4. A buckling detecting means for detecting a buckling time when the object to be measured buckles due to the action of the pressing load; and the load at the buckling time detected by the buckling detecting means. The buckling strength measuring device according to any one of claims 1 to 3, further comprising an output unit that outputs a detection value of the detection unit. 5. The buckling strength according to claim 4, wherein the buckling detecting means is configured to detect, as the buckling time, a time point at which the detected value of the load detecting means becomes maximum in a change with time. Measuring device. 6. A jig used in the buckling strength measuring device according to claim 1, wherein the two load acting means are attached to the object to be measured. A jig provided with a positioning portion for positioning so as to be positioned at a corresponding interval and in a posture parallel to each other.