JP2606536B2 - Material testing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material testing machine for loading a test piece by rotating a screw rod, and more particularly to a material tester which facilitates centering of the test piece on a load shaft.

[0002]

2. Description of the Related Art Conventionally, a crosshead (first load frame) is mounted on a pair of screw rods erected on a table (second load frame).
A material testing machine is known in which both ends of a material are screwed together and a pair of grips are coaxially attached to a crosshead and a table. In this material testing machine, after the both ends of the test piece are respectively gripped by the pair of gripping tools, the screw rod is rotated to raise the crosshead with respect to the table, thereby applying a tensile load to the test piece.

[0003]

In such a tensile test, in order to improve the test accuracy, the test piece is held on the grip so that the center of the test piece coincides with the center (load axis) of the upper and lower grips. Conventionally, it is necessary to grasp the test piece, and an operator has performed centering work by visual observation of the test piece and intuition. However, there is a problem that the visual centering work is troublesome and lacks accuracy.

The object of the present invention is to
Moreover, it is an object of the present invention to provide a material testing machine capable of accurately aligning the center of a test piece with a load axis.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a first load frame screwed to a screw rod is separated from and connected to a second load frame in an axial direction of the load by rotating the screw rod. It is applied to a material testing machine that loads a test piece having both ends fixed to a frame.
A pedestal which is screwed to the screw rod between the first and second load frames and moves in the direction of the load axis following the first load frame as the screw rod rotates; And a camera for photographing the test piece and a monitor device for displaying an image of the test piece taken by the camera and displaying an auxiliary display for clearly indicating whether or not the center of the test piece coincides with the load axis. To solve the above-mentioned problem.

[0006]

The monitor device outputs an image of the test piece taken by the camera and an auxiliary display indicating whether or not the center of the test piece matches the load axis. If the centering operation is performed while viewing this screen, the center of the test piece can be quickly and accurately aligned with the load axis. Here, the test piece is
When attaching to the second load frame, the interval between the first and second load frames is adjusted according to the length of the test piece, and the pedestal of the camera is screwed to the screw rod. Therefore, when the screw rod is rotated to move the first load frame, the camera moves following the first load frame. Therefore, it is not necessary to adjust the position of the camera again after the movement of the first load frame.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front partial sectional view of a material testing machine (tensile testing machine) according to the present invention. Reference numeral 100 denotes a material testing machine main body. Both ends of a table 2 are respectively supported on a lower portion of a pair of columns 1 erected on a floor surface, and a cross yoke 3 is horizontally mounted on an upper portion. At both ends of the table 2, a pair of screw rods 4 (only one is shown) are erected inside each column 1, and nuts 5 a built into both ends of the crosshead 5 are screwed onto these screw rods 4, respectively. Have been combined. Therefore, the crosshead 5 moves up and down with respect to the table 2 according to the rotation of the pair of screw rods 4.

Bellows 6 are provided on upper and lower portions of the crosshead 5 on the surfaces of the columns 1 facing each other, and the bellows 6 expand and contract as the crosshead 5 moves up and down. These bellows 6 are for preventing dust from entering the inside of the column. Upper and lower grips 7 and 8 are coaxially attached to the lower surface of the crosshead 5 and the upper surface of the table 2, respectively, and both ends of the test piece TP are gripped by these grips 7 and 8.

A screw head 4 on the left side of FIG.
Between the TV and the table 2
2 attached. As shown in FIG. 2, a nut 13 is rotatably fixed to the camera mount 12 via a bearing 14, and the nut 13 is screwed to the screw rod 4. The TV camera 11 is attached to the top end of the mounting base 12.
Is fixed, and the TV camera 11 photographs a substantially central portion in the vertical direction of the test piece TP. Here, a bellows 6 provided below the crosshead 5 is provided with a long hole 6a near the camera mounting portion as shown in FIGS. 2 and 3, and a bellows 9 is provided so as to cover the long hole 6a. Have been. The lens barrel 11a of the TV camera 11 penetrates a substantially central portion of the bellows 9 and protrudes toward the test piece TP.

A motor 15 is mounted on the base end of the lower surface of the camera mounting base 12, and its output shaft 15a projects upward through the mounting base 12, and a gear 15 mounted on the distal end thereof.
b is engaged with a gear portion 13a formed on the upper portion of the nut 13. Therefore, when the motor 15 is rotated,
The nut 13 rotates via the gear 15b and the gear 13a. As shown in FIG. 4, the rear portion of the camera mount 12 is chamfered at both corners, and the chamfered portions 12a are respectively brought into contact with a pair of machine pillars 16 erected on the table 2, whereby the screws of the mount 12 are screwed. Rotation with respect to the rod 4 is prevented. Therefore, when the nut 13 is rotated by the motor 15, the camera mount 12, that is, the TV camera 1 is rotated.
1 can be moved up and down along the screw rod 4 to adjust its photographing position. On the other hand, when the motor 15 is stopped, the rotation of the nut 13 is prevented via the output shaft 15a, the gear 15b and the gear portion 13a. At this time, when the screw rod 4 rotates, the TV camera 11 Crosshead 5
Up and down following the ascent and descent of.

Here, the chamfered portion 12 of the camera mount 12 is
“a” always slides on the machine column 16 when the mounting table 12 is moved up and down. Therefore, in order to prevent abrasion of the machine column 16 that is difficult to replace, it is desirable that the mounting base 12 be made of a member that is easily worn, and that the mount 12 be replaced when it has worn out by a predetermined amount or more.

In FIG. 1, a control device 200 including a monitor device 51 is provided beside the tester main body 100 configured as described above. FIG. 5 shows the configuration of the control device 200. The controller 52 that controls the entire sequence of the tester includes the above-described television camera 11, the motor 15 and the motor driving circuit 5 for driving the screw rod driving motor 53.
4 and the interface circuit 55
The monitor device 51 is connected via the. Further, a setting switch 56 for setting the test strip display mode and a switch group 57 including various other switches are also connected to the controller 52.

When the test strip display mode is set, the controller 52 captures a video signal from the TV camera 11 and
As shown in FIG. 6, an image (a shaded portion) T of the test piece is displayed on the screen of the monitor device 51 via the interface circuit 55.
Visualize and output P '. At this time, a line L indicating the central axis of the upper and lower grips 7 and 8 (this corresponds to the load axis)
Then, a plurality of lines L1 and L2 in the load axis direction arranged at predetermined pitches P on the left and right from the line L are also displayed on the screen of the monitor device 51. From these lines L, L1, L2, it can be determined whether the center of the test piece TP coincides with the load axis. By operating a predetermined switch constituting the switch group 57, the test piece T is replaced with the test piece image TP '.
The deformation amount of P and the like can be graphed and displayed on a monitor screen.

Next, the operation of the embodiment will be described. Prior to the tensile test, the test piece photographing mode is first set by the switch 56, and if necessary, the vertical position of the TV camera 11 is finely adjusted as follows. When the test strip shooting mode is set,
The image from the TV camera 11 and the lines L, L1, L2 are displayed on the screen of the monitor device 51. In this state, for example, when an up switch constituting the switch group 57 is turned on, the motor 15 is rotated in a predetermined direction via the motor drive circuit 54, and the nut 13 is rotated in a predetermined direction via the gear 15b and the gear portion 13a. Thereby, the camera mount 12, that is, the TV camera 11, rises along the screw rod 4. When the TV camera 11 moves to a position where the vicinity of the vertical center of the test piece TP is photographed, the up switch is turned off to stop the motor. When the down switch constituting the switch group 57 is turned on, the motor 15 rotates in the opposite direction to the above, and the TV camera 11 can be lowered. Here, when the TV camera 11 moves up and down, the bellows 9 expands and contracts up and down via the lens barrel 11a.

When the position adjustment of the TV camera 11 is completed,
The test piece TP is inserted between the upper and lower grips 7 and 8. At this time, an image TP 'of the test piece is displayed on the screen of the monitor device 51. While watching the monitor screen in this state, the lines L, L
The test piece TP is centered using 1, L2. In the example of FIG. 6, if the test piece TP is moved and positioned in the direction A so that the left and right protrusion amounts P1 of the test piece TP from the line L1 are the same, the test piece TP can be centered with respect to the load axis. . Thereafter, when the gripping teeth of the upper and lower grips 7 and 8 are closed, both ends of the centered test piece TP are gripped by the grips 7 and 8.

Next, the motor 53 is driven via a motor drive circuit 54 to perform a tensile test, and the pair of screw rods 4 is rotated in a predetermined direction. As a result, the crosshead 5, that is, the upper grip 7 is raised, and a tensile load is applied to the test piece TP. At this time, the gear 15b and the gear 1
Since rotation of the nut 13 is prevented via 3a,
By the rotation of the screw rod 4, the TV camera 11 rises following the crosshead 5 via the camera mount 12.
The bellows 6 expands and contracts up and down as the crosshead 5 rises. Here, after the test piece TP is centered as described above, there is no need to display an image of the test piece TP on the monitor screen. The amount of deformation or the like may be displayed as a graph.

As described above, in this embodiment, the image TP 'of the test piece and the lines L, L1, L2 indicating whether or not the center of the test piece TP coincides with the load axis are displayed on the monitor screen. Therefore, the test piece TP can be easily and accurately centered while looking at the screen of the monitor device 51. Also,
When the screw rod 4 is rotated, the TV camera 11 also moves up and down following the up and down movement of the crosshead 5, so that the following effects can be obtained. That is, the test piece TP is held by the upper and lower grips 7, 8
When the cross head 5 is to be gripped, it is necessary to change the vertical position of the crosshead 5 in accordance with the length of the test piece TP.
As described above, once the position of the TV camera 11 is adjusted by operating the motor 15 as described above, the position of the TV camera 11 is moved again after the crosshead 5 is moved according to the length of the test piece TP. There is no need to adjust. In particular, in this embodiment, since the long hole 6a of the bellows 6 is covered by the bellows 9 which expands and contracts in accordance with the elevation of the TV camera 11, dust can be prevented from entering the inside of the column 1 through the long hole 6a.

In the configuration of the above embodiment, the crosshead 5 serves as the first load frame, the table 2 serves as the second load frame,
The camera mount 12 forms a pedestal, and the lines L, L1, L2 form auxiliary displays.

The installation position of the monitor device is not limited to the embodiment, but may be any position that is easy to see when the test piece is mounted. In particular, for example, a thin monitor device using a liquid crystal can be attached to the material testing machine main body side.
Although the position of the TV camera 11 can be finely adjusted by the motor 15, this fine adjustment mechanism does not have to be particularly provided as long as the TV camera can be moved up and down at least following the elevation of the crosshead. Further, the configuration of the tester main body is not limited to the embodiment as long as the test piece is loaded by rotation of the screw rod, and for example, a type in which the lower load frame is moved up and down with respect to the upper load frame may be used. Although the description has been given of the vertical type material testing machine main body, a horizontal type may be used. Furthermore, the auxiliary display indicating whether or not the center of the test piece coincides with the load axis is not limited to the embodiment, and may be, for example, the one shown in FIG. 6 from which the line L indicating the load axis is removed, or vice versa. Alternatively, only the line L may be used. Alternatively, a band-shaped display having a predetermined width around the load axis may be used.

[0020]

According to the present invention, an image of a test piece photographed by a camera and an auxiliary display indicating whether or not the center of the test piece coincides with the load axis are displayed on the monitor device. Therefore, if the centering operation is performed while watching the monitor screen, the center of the test piece can be quickly and accurately aligned with the load axis. In addition, since the camera is mounted on the pedestal screwed to the first load frame driving screw rod, the camera moves following the first load frame when the screw rod rotates, and thus the length of the test piece is increased. It is not necessary to adjust the position of the camera again when the position of the first load frame is changed according to
The test efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing the overall configuration of a material testing machine according to the present invention.

FIG. 2 is an enlarged view showing a mounting mechanism of the TV camera.

FIG. 3 is a view as seen from a direction III in FIG. 2;

FIG. 4 is a view as seen from a direction IV in FIG. 2;

FIG. 5 is a block diagram illustrating a configuration of a control device.

FIG. 6 is a diagram showing a display state of a monitor screen.

[Description of Signs] 1 support 2 table 4 screw rod 5 cross head 6, 9 bellows 7 upper grip 8 lower grip 11 TV camera 11a lens barrel 12 camera mount 13 nut 14 bearing 15 motor 16 body 51 monitor device 52 Controller 53 Screw rod drive motor

Claims (1)

(57) [Claims] 1. A test in which a first load frame screwed to a screw rod by rotation of the screw rod is separated from and brought into contact with a second load frame in a load axis direction, and both ends are fixed to both load frames. In the material testing machine for loading a piece, the first and second load frames are screwed to the screw rod, and the first rod is rotated with the rotation of the screw rod.
A pedestal that moves in the direction of the load axis following the load frame, a camera that is fixed to the pedestal and captures the test piece, and displays an image of the test piece captured by the camera.
A material testing machine comprising: a monitor device that displays an auxiliary display indicating whether or not the center of a test piece is coincident with a load axis.