JP4448254B2 - Material testing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a material testing machine, and more particularly to a material testing machine that measures the amount of elongation of a thin material such as metal or plastics.
[0002]
[Prior art]
As a testing machine for measuring the amount of elongation of material, for example, in Utility Model Registration No. 3019347, a guide column supported upright so as to be parallel to the column, and one end side along the longitudinal axis of the guide column is A pair of spring plate-like upper and lower clamp arms supported so as to be movable up and down and facing each other, and provided on the other end of the upper and lower clamp arms, respectively, There has been proposed a material testing machine including a clamping tool for clamping and an opening / closing means for upper and lower clamp arms.
[0003]
In the material testing machine according to this utility model registration, the clamp arm is moved along the guide rod in a state where the test piece is sandwiched between the pair of upper and lower clamp arm clamps in the vertical direction. Then, measure the elongation of the test piece.
[0004]
In the material testing machine having such a configuration, when the test piece is held by the holding tool, the upper and lower clamp arms are opened by the opening / closing means. In the case of the utility model, the opening / closing means is A rotating protrusion shaft provided with a conical protrusion protruding perpendicularly to the axial direction is installed so as to penetrate the center of each clamp arm, and the rotating protrusion shaft is rotated to place the conical protrusion on the side surface of the clamp arm. When being engaged with the long hole formed through, the interval between the clamp arms is widened and opened so that the test piece can be attached to and detached from the holding tool.
[0005]
On the other hand, when the rotating protrusion shaft is rotated backward from such an open position and returned to the original position, the cone-shaped protrusion is separated from the side surface of the clamp arm, the interval between the clamp arms is reduced, and the test piece is placed on the holding tool. Is held in a non-detachable manner.
[0006]
However, in the material testing machine having such a configuration, there is a technical problem described below particularly in the opening / closing means of the clamp arm.
[0007]
[Problems to be solved by the invention]
That is, in the above-described material testing machine, the engagement relationship between the conical projection provided on the rotary projection shaft and the long hole provided on the clamp arm is changed by changing the rotation of the rotary projection shaft. The test piece can be attached to and detached from the tool, or can be clamped.
[0008]
However, in such a configuration, if the engagement relationship between the conical protrusion and the elongated hole is shifted, the opening and closing operations cannot be performed. Therefore, in order to accurately align the two, high-precision processing is performed. There was a problem that it was necessary.
[0009]
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a material testing machine that can smoothly perform opening and closing operations without performing accurate positioning. It is in.
[0010]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a support body having a base and a shelf-like portion arranged opposite to each other with a predetermined interval in the vertical direction, and both ends supported between the base and the shelf-like portion. A guide rod suspended on the base, and a pair of upper and lower portions, one end of which is supported so as to be vertically movable along the longitudinal axis of the guide rod and arranged to face each other. A clamp arm, a clamp that is disposed on the other end of each of the upper and lower clamp arms, and clamps the test piece; and an opening / closing means for the upper and lower clamp arms, and the test strip is placed on the clamp. In the material testing machine that measures the amount of elongation of the test piece by moving the clamp arm along the guide rod in a sandwiched state, the opening / closing means has both ends between the base and the shelf. Supported rotatably A cross-sectional shape of a portion corresponding to a vertical movement region of at least the upper and lower clamp arms of the cam rod, comprising a cam rod disposed substantially parallel to the guide rod so as to pass through the centers of the upper and lower clamp arms The cross-section has a long diameter that allows the test piece to be attached / detached by opening the holding tool and a short diameter that closes the holding tool and makes the test piece undetachable. .
[0011]
According to the material testing machine configured as described above, the opening / closing means is rotatably supported at both ends by the base and the shelf, and is substantially parallel to the guide rod so as to pass through the centers of the upper and lower clamp arms. The cross-sectional shape of the part corresponding to the vertical movement area of the upper and lower clamp arms, the long diameter that allows the specimen to be attached and detached, and the clamping tool are closed Thus, since the cross section has a different diameter with a short diameter that makes it impossible to attach and detach the test piece, the accuracy of the mutual positional relationship between the cam rod and the upper and lower clamp arms does not need to be high.
[0012]
The opening / closing means includes a drive motor that rotationally drives the cam rod, and a proximity sensor that is disposed at an end of the cam rod and detects the opening and closing positions of the clamping tool, and the rotation of the cam rod causes the Each test piece clamping part of a clamping tool can be opened and closed automatically.
[0013]
According to this configuration, the test piece can be continuously measured.
[0014]
The clamping tool has a clamping force assisting spring that urges the clamping part that clamps the test piece in a direction close to each other, and the elastic force adjusting parts can be provided on both ends of the spring. .
[0015]
According to this configuration, when holding the test piece with the holding portion, it is possible to easily adjust the resilience of the holding force assisting spring while observing the holding state.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 1 to 8 show an embodiment of a material testing machine according to the present invention. As shown in FIG. 1, the material testing machine shown in FIG. 1 includes a support 10, a pair of upper and lower clamp arms 12 and 14, a guide rod 15, and each clamp arm 12 and 14. The provided clamping tools 16 and 18 and the cam rod (opening / closing means) 20 are provided.
[0017]
The support body 10 includes a base 10a, a shelf-like portion 10b, and a column portion 10c. The base 10a and the shelf-like portion 10b are arranged so as to face each other in the vertical direction, and a column portion 10c is fixed to one end thereof, and the base 10a is installed on the support surface.
[0018]
The shelf-shaped portion 10b includes a shelf plate 100b and a cover 101b, and a pair of encoders 22 for detecting the amount of extension of the test piece A and the gravity of the clamp arms 12 and 14 are cancelled. A balance unit 24 is installed.
[0019]
An automatic opening / closing mechanism 26 for the cam rod (opening / closing means) 20 is also installed in the shelf-like portion 10b. Both ends of the guide rod 15 are supported by the base 10a and the shelf-like portion 10b, are on the front side of the column portion 10c, and are suspended so as to be parallel thereto.
[0020]
Each of the pair of clamp arms 12 and 14 has substantially the same configuration, and as shown in a top view in FIG. 2, the mounting bases 12a and 14a, the two leaf springs 12b and 14b, It has hollow cylindrical bearing sleeves 12c and 14c, and interval adjusting portions 12d and 14d.
[0021]
The mounting bases 12a and 14a are formed in a substantially L shape having a stepped portion, and sleeves 12c and 14c are fixedly provided at the center of the stepped portion. The sleeves 12c and 14c are inserted through the guide rods 15, respectively, so that one end sides of the pair of clamp arms 12 and 14 are supported so as to be movable up and down.
[0022]
One end of two leaf springs 12b and 14b is fixed to the side surfaces of the mounting bases 12a and 14a, and the flat surfaces of these leaf springs 12b and 14b face each other.
[0023]
The distance adjusting portions 12d and 14d are disposed on the inner surface of the central portion in the longitudinal axis direction of each leaf spring 12b and 14b, and a pair of spacer blocks 120d and 140d are screwed to 121d and 141d on the side surface of each leaf spring 12b and 14b. The distance between the opposing spacer blocks 120d and 140d is adjusted by adjusting the screwing amount of the screws 121d and 141d.
[0024]
On the other hand, the holding tools 16 and 18 are respectively arranged on the opposite sides of the support portions of the upper and lower clamp arms 12 and 14, and in the case of this embodiment, the clamp arms 12 and 14 have substantially the same configuration. Are arranged respectively.
[0025]
The holding tools 16 and 18 include a pair of spacers 16a and 18a, a pair of holding parts 16b and 18b for holding the test piece A, holding force assisting springs 16c and 18c, and resilience adjusting parts 16d and 18d. have.
[0026]
The pair of spacers 16a and 18a includes main bodies 160a and 180a and mounting screws 161a and 181a, and are located on the free ends (tips) of the leaf springs 12b and 14b of the upper and lower clamp arms 12 and 14, respectively. The fixing screws 161a and 181a are fixed so that 160a and 180a face each other.
[0027]
The pair of main bodies 160a and 180a are provided with through holes 162a and 182a located on the same axis. The pair of sandwiching portions 16b and 18b that sandwich the test piece A have substantially the same configuration with respect to the leaf springs 12b and 14b of the clamp arms 12 and 14, respectively.
[0028]
In the present embodiment, the sandwiching portions 16b and 18b are a pair of sandwiching pieces 160b and 180b that contact the side surface of the test piece A, and the sandwiching pieces 160b and 180b can be swung freely toward the distal end side of the spacers 16a and 18a. Locking pins 161b and 181b to be attached are provided.
[0029]
The clamping force assisting spring 16c is attached via the elasticity adjusting portions 16d and 18d so that part of both ends thereof are inserted into the through holes 162a and 182a provided in the spacer main bodies 160a and 180a. It has been.
[0030]
The elastic force adjusting portions 16d and 18d of the present embodiment have butterfly-shaped plates 160d and 180d provided with a narrow width portion at the center for engaging the ends of the springs 16c, and both ends of the plates 160d and 180d as main bodies. Adjustment springs 161d and 181d fixed to 160a and 180a. By adjusting the screwing amount of each adjustment screw 161d and 181d, the elastic force of the spring 16c is controlled. As a result, the clamping portions 16b and 18b The clamping force of the specimen A being clamped is adjusted.
[0031]
In this case, the elastic force adjusting parts 16d and 18d are located in the vicinity of the holding parts 16b and 18b. Therefore, when holding the test piece A with the holding parts 16b and 18b, It is possible to easily adjust the resilience of 16c.
[0032]
3 and 4 is a shock absorbing buffer that functions when the clamp arms 12 and 14 suddenly move and collide when the specimen A is broken. It is a spring.
[0033]
The balance portion 24 is supported by the guide rod 15 so as to be movable up and down, and erases the gravity acting on the lower clamp arms 12 and 14, and as shown in FIG. 2, can rotate to the shelf-like portion 10b. The pulley 24a is supported by the balance 24, the balance weight 24b, and the wire 24c.
[0034]
One end of the wire 24c is locked to the mounting bases 12a and 14a of the upper and lower clamp arms 12 and 14, and the balance weight 24b is locked to the other end wound around the pulley 24a.
[0035]
The balance weight 24b has a weight corresponding to the weight of the upper and lower clamp arms 12 and 14, and the balance weight 24b and the upper and lower clamp arms 12 and 14 are suspended from both ends of the wire 24c. The upper and lower clamp arms 12 and 14 are smoothly moved up and down with a very small force without being affected by gravity.
[0036]
The encoder 22 for detecting the extension amount is mounted coaxially with the pulley 24a, and detects the extension amount of the test piece A as the upper and lower clamp arms 12 and 14 move up and down.
[0037]
The opening / closing means is rotatably supported at both ends by the base 10a and the shelf-like portion 10b of the support 10 via bearings 19 and is disposed on the central axis of the upper and lower clamp arms 12 and 14, that is, opposed to each other. The cam rod 20 is disposed substantially parallel to the guide rod 15 so as to pass through the centers of the pair of leaf springs 12b and 14b.
[0038]
The cam rod 20 has a long diameter R1 that allows the test piece A to be attached and detached by widening the interval between the holding portions 16b and 18b of the holding tools 16 and 18 of the upper and lower clamp arms 12 and 14, and the upper and lower clamp arms. The interval between the holding parts 16b and 18b of the holding tools 16 and 18 of 12 and 14 is narrowed, and an elliptical cross section (different diameter cross section) provided with a short diameter R2 that makes the test piece A incapable of being attached and detached. ing.
[0039]
In addition, although the different diameter cross-sectional area | region of this cam rod 20 may be made into a different diameter over the full length, it is good also considering only the part corresponding to the up-and-down moving area | region of the upper and lower clamp arms 12 and 14 as a different diameter cross section.
[0040]
In the case of the present embodiment, an automatic opening / closing mechanism 26 is attached to the cam rod 20. Details of the automatic opening / closing mechanism 26 are shown in FIGS.
[0041]
The automatic opening / closing mechanism 26 shown in these drawings includes a drive motor 26a that rotates the cam rod 20 and a proximity sensor 26b that is provided on the upper end side of the cam rod 20a and detects the opening and closing positions of the holding tools 16 and 18. The holding parts 16b and 18b of the holding tools 16 and 18 are automatically opened and closed as the cam rod 20a rotates.
[0042]
As shown in FIG. 5, the drive motor 26 a has a drive shaft connected to a cam rod 20 that is rotatably supported via a bearing 19, and drives the cam rod 20 to rotate.
[0043]
The proximity sensor 26b has a sensor plate 260b connected to the end of the cam rod 20, and a proximity switch 261b that contacts and separates from the sensor plate 260b.
When the long diameter R1 side of the cam rod 20 contacts the sensor plate 260b so as to be orthogonal to the longitudinal direction of the leaf springs 12b and 14b, the clamping portions 16b and 18b are opened (shown in FIG. 7A). And the short diameter R2 side of the cam rod 20 corresponds to the closed state (shown in FIG. 7 (B)) of the clamping portions 16b and 18b when they become perpendicular to the longitudinal direction of the leaf springs 12b and 14b. The groove portions 262b are provided at predetermined angular intervals.
[0044]
In the case of this embodiment, the switch 261b is turned off while the proximity switch 261b is in contact with the groove 262b, and the switch 261b is in contact with the portion other than the groove 262b. Is turned on.
[0045]
As shown in FIG. 6, the drive motor 26a is driven by a commercial power source, and a proximity switch 261b is interposed between the drive source and the motor 26a, and the proximity switch 261b is in parallel with this. A push button type start switch 26c is provided.
[0046]
When measuring the elongation amount of the test piece A with the tensile tester configured as described above, the upper and lower sides of the thin test piece A having the shape shown in FIG. 8 are held between the holding portions 16b and 18b. .
[0047]
At the time of this clamping, both ends of the test piece A are positioned between the opened clamping parts 16b and 18b, and the start switch 26c is turned on. When the start switch 26c is turned on and the drive motor 26a is operated, the cam rod 20 is rotated accordingly, and the short diameter R2 of the cam rod 20 becomes perpendicular to the leaf springs 12b and 14b. The upper and lower sides of A are clamped by the clamping parts 16b and 18b.
[0048]
This clamping state is continued until the cam rod 20 further rotates and the proximity switch 261b is fitted into the concave groove 262b of the next sensor plate 261b and is turned OFF. Start the head and start the test.
[0049]
When the test is started, the upper and lower clamp arms 12 and 14 move in the direction of pulling the test piece A. In this case, the upper clamp arm 12 moves upward at substantially the same speed as the pulling speed, and the lower clamp arm 14 moves in the same direction at a considerably slower speed.
[0050]
When the test is further continued, the test piece A is broken and the movement of the crosshead is stopped. The amount of movement of the upper and lower clamp arms 12 and 14 at that time is read by the encoder 22, and the amount of elongation of the test piece A is obtained from the read value.
When such a test is completed and the proximity switch 261b is turned OFF, the long diameter R1 of the cam rod 20 becomes orthogonal to the leaf springs 12b and 14b, the clamping portions 16b and 18b are opened, and the measurement is performed. The completed test piece A can be taken out, and preparation for the next test is completed.
[0051]
Now, according to the material testing machine configured as described above, the opening / closing means is rotatably supported at both ends by the base 10a and the shelf 10b, and passes through the centers of the upper and lower clamp arms 12, 14. The cam rod 20 is arranged substantially in parallel with the guide rod 15, and the cross-sectional shape of the cam rod 20 is set such that the clamps 16 and 18 of the upper and lower clamp arms 12 and 14 are opened and the test piece A is attached and detached. The cross section has a different diameter cross section with a long diameter that allows the clamp 16 and 18 to be closed and a short diameter that makes the test piece A unmountable, so that the cam rod 20 and the upper and lower clamp arms 12, The accuracy of the mutual positional relationship of 14 need not be high.
[0052]
In the above-described embodiment, the cam rod 20 as the opening / closing means has an elliptical cross-sectional shape, but the present invention is not limited to this. It may be an eyeglass-like cross section in which two circular cross sections are connected.
[0053]
【The invention's effect】
As described above in detail, according to the material testing machine according to the present invention, the opening / closing operation can be smoothly performed without performing the alignment accurately.
[Brief description of the drawings]
FIG. 1 is an overall perspective view showing an embodiment of a material testing machine according to the present invention.
FIG. 2 is a top view of the clamp arm of FIG.
FIG. 3 is a side view of FIG. 2;
4 is a front view of FIG. 2;
FIG. 5 is an enlarged view of the automatic opening / closing mechanism shown in FIG. 1;
6 is an electric circuit diagram of a drive motor of the automatic opening / closing mechanism shown in FIG. 5;
7 is an operation explanatory diagram of the automatic opening / closing mechanism shown in FIG. 5;
8 is an explanatory view showing a state in which a test piece is clamped by the testing machine shown in FIG. 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Support 10a Base 10b Shelf-shaped part 12 Upper clamp arm 12b Leaf spring 14 Lower clamp arm 14b Leaf spring 16 Clamping tool 16a Spacer 16b Clamping part 18 Clamping tool 18a Spacer 18b Clamping part 20 Cam rod (opening / closing means)
22 Encoder

Claims (3)

A support body having a base and a shelf-like portion arranged opposite to each other with a predetermined interval in the vertical direction;
Both ends are supported between the base and the shelf, and a guide rod suspended on the base;
A pair of upper and lower clamp arms, which are supported so that one end side thereof is vertically movable along the longitudinal axis of the guide rod and are opposed to each other,
A clamp that is disposed on the other end of each of the upper and lower clamp arms and clamps the test piece;
Opening and closing means for the upper and lower clamp arms,
In a material testing machine that measures the amount of elongation of the test piece by moving the clamp arm along the guide rod in a state where the test piece is held in the holding tool,
The opening / closing means includes a cam rod that is rotatably supported at both ends by the base and the shelf, and is arranged substantially parallel to the guide rod so as to pass through the centers of the upper and lower clamp arms,
At least the cross-sectional shape of the cam rod corresponding to the vertical movement area of the upper and lower clamp arms, the long diameter that allows the test piece to be attached and detached by opening the clamping tool, and the clamping tool is closed. A material testing machine characterized by having a different-diameter cross section having a short diameter that makes it impossible to attach and detach the test piece. The opening / closing means includes a drive motor that rotationally drives the cam rod, and a proximity sensor that is disposed at an end of the cam rod and detects the opening and closing positions of the clamping tool, and the rotation of the cam rod causes the 2. The material testing machine according to claim 1, wherein each test piece holding portion of the holding tool is automatically opened and closed. The clamping tool has a clamping force assisting spring that biases the clamping part that clamps the test piece in a direction close to each other, and the elastic force adjusting parts are provided on both ends of the spring. The material testing machine according to claim 1 or 2, characterized in that:

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