JPH06167433A - Testing machine - Google Patents

Abstract

PURPOSE:To enable correct alignment of the center of a test piece with a load axis without requiring much time, by displaying an image of the test piece picked up by a camera and an auxiliary indication showing whether the center of the test piece is aligned with the load axis or not. CONSTITUTION:The opposite ends of a table 2 are supported respectively at the lower parts of a pair of supports 1 erected on a floor surface, and in the opposite end parts of the table 2, a pair of threaded poles 4 are erected respectively inside the supports 1. A crosshead 5 moves up from and down toward the table 2 in accordance with the rotation of these poles 4. Besides, a TV camera 11 is fitted between the crosshead 5 and the table 2, through the intermediary of a camera fitting stage 12. When regulation of the position of the camera 11 is finished, a test piece TP is inserted through between upper and lower grips 7 and 8. At this time, an image TP' of the test piece is displayed on the screen of a monitoring device 51. With the monitoring screen watched, centering of the test piece TP is executed in this state, using lines L, L1 and L2.

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 testing machine for facilitating centering of the test piece with respect to 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).
There is known a material testing machine in which both ends of the above are screwed together and a pair of grips are coaxially attached to the crosshead and the table. In this material testing machine, after the pair of grippers grips both ends of the test piece, respectively, 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 clamped so that the center of the test piece coincides with the center (load axis) of the upper and lower grips. It is necessary to hold the test piece, and in the past, an operator performed a centering operation by directly visually inspecting the test piece. However, there is a problem that the visual centering work is troublesome and lacks accuracy.

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

[0005]

SUMMARY OF THE INVENTION According to the present invention, the first load frame screwed to the screw rod by the rotation of the screw rod is brought into contact with and separated from the second load frame in the load axis direction, and both loads are loaded. It is applied to a material testing machine that loads a test piece whose both ends are fixed to a frame.
A pedestal that is screwed into the above-mentioned screw rod between the first and second load frames and moves in the load axis direction following the first load frame as the screw rod rotates, and is fixed to this pedestal. And a monitor device for displaying a camera for photographing the test piece and an image of the test piece photographed by this camera, and for displaying an auxiliary display clearly indicating whether or not the center of the test piece coincides with the load axis. And to solve the above problems.

[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 coincides with the load axis. If the centering operation is performed while looking at this screen, the center of the test piece can be quickly and accurately aligned with the load axis. Here, the test piece is
When mounting on the second load frame, the interval between the first and second load frames is adjusted according to the length of the test piece, but the pedestal of the camera is screwed onto 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 EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front partial cross-sectional view of a material testing machine (tensile testing machine) according to the present invention. Reference numeral 100 indicates a material testing machine main body, and a pair of columns 1 standing on the floor surface support both ends of a table 2 on the lower part, and a cross yoke 3 is horizontally mounted on the upper part. At both ends of the table 2, a pair of screw rods 4 (only one is shown) are erected inside each of the columns 1, and nuts 5a incorporated at both ends of the crosshead 5 are screwed into 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 the 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, 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, 8.

A crosshead 5 is attached to the screw rod 4 on the left side of the drawing.
The TV camera 11 is mounted on the camera mount 1 between the table and the table 2.
It is attached via 2. 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 mount 12.
Is fixed, and the TV camera 11 takes an image of a substantially central portion of the test piece TP in the vertical direction. Here, in the bellows 6 provided below the crosshead 5, a long hole 6a is formed in the vicinity of 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. Has been. The lens barrel 11 a of the TV camera 11 penetrates the substantially central portion of the bellows 9 and projects toward the test piece TP.

A motor 15 is attached to the bottom end of the camera mount 12, and an output shaft 15a thereof penetrates through the mount 12 and projects upward, and a gear 15 attached to the tip thereof.
The gear 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 portion 13a. Further, as shown in FIG. 4, both corners of the rear part of the camera mount 12 are chamfered, and the chamfered parts 12a are brought into contact with a pair of machine columns 16 erected on the table 2, respectively. The rotation with respect to the rod 4 is blocked. Therefore, when the nut 13 is rotated by the motor 15, the camera mount 12, that is, the TV camera 1
1 moves up and down along the screw rod 4, and its shooting position can be adjusted. On the other hand, when the motor 15 is stopped, the rotation of the nut 13 is blocked through 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 is moved through the camera mount 12 and the above-mentioned camera. Cross head 5
It goes up and down by following up and down.

Here, the chamfered portion 12 of the camera mount 12
The a slides on the machine pillar 16 at all times when the mount 12 is moved up and down. Therefore, in order to prevent wear of the machine column 16 that is difficult to replace, it is desirable that the mounting base 12 be made of a member that easily wears and that the mount 12 be replaced when it is worn by a predetermined amount or more.

In FIG. 1, a control device 200 including a monitor device 51 is provided on the side of 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 sequence of the entire testing machine includes the above-described television camera 11, the motor 15 and the motor drive circuit 5 for the screw rod drive motor 53.
4 is connected and the interface circuit 55
The monitor device 51 is connected via. Further, a setting switch 56 for setting the test piece display mode and a switch group 57 including other various switches are also connected to the controller 52.

When the test strip display mode is set, the controller 52 takes in the video signal from the TV camera 11,
As shown in FIG. 6, the image of the test piece (hatched portion) T is displayed on the screen of the monitor device 51 through the interface circuit 55.
Visualize and output P '. At this time, a line L indicating the central axes 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, which are arranged to the left and right of the line L at predetermined pitches P, are also displayed on the screen of the monitor device 51. From these lines L, L1, L2, it can be determined whether or not the center of the test piece TP and the load axis match. By operating a predetermined switch that constitutes the switch group 57, the test piece T is replaced with the test piece image TP ′.
The amount of deformation of P and the like can be graphed and displayed on the monitor screen.

Next, the operation of the embodiment will be described. Prior to the tension test, first, the test piece photographing mode is set by the switch 56, and the vertical position of the TV camera 11 is finely adjusted as necessary as follows. When the test piece shooting mode is set,
The image by 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. As a result, the camera mount 12, that is, the TV camera 11 ascends along the screw rod 4. When the TV camera 11 has moved 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. Further, when the down switch that constitutes 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 is vertically expanded and contracted 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, 8. At this time, an image TP ′ of the test piece is displayed on the screen of the monitor device 51. While looking at the monitor screen in this state, the above lines L, L
The test piece TP is centered using 1 and L2. In the example of FIG. 6, the test piece TP can be centered with respect to the load shaft by moving and positioning the test piece TP in the A direction so that the left and right protrusion amounts P1 of the test piece TP from the line L1 are the same. . Then, when the gripping teeth of the upper and lower grips 7, 8 are closed, both ends of the centered test piece TP are gripped by the grips 7, 8.

Next, the motor 53 is driven through the motor drive circuit 54 to perform the tension test, and the pair of screw rods 4 are rotated in a predetermined direction. As a result, the crosshead 5, that is, the upper grip 7 rises, and a tensile load is applied to the test piece TP. Further, at this time, the gear 15b and the gear portion 1
Since the rotation of the nut 13 is blocked via 3a,
Due to the rotation of the screw rod 4, the TV camera 11 follows the crosshead 5 and ascends via the camera mount 12.
The bellows 6 expands and contracts vertically as the crosshead 5 rises. Here, after the test piece TP is centered as described above, it is not necessary to display the image of the test piece TP on the monitor screen. Therefore, by operating a predetermined switch forming the switch group 57, The amount of deformation and 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 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 observing the screen of the monitor device 51. Also,
When the screw rod 4 is rotated, the TV camera 11 also moves up and down in accordance with the up and down movement of the crosshead 5, so that the following effects are also obtained. That is, the test piece TP is held by the upper and lower grips 7, 8
When gripping the crosshead 5, the vertical position of the crosshead 5 needs to be changed according to the length of the test piece TP. In the present embodiment, the TV camera 11 follows the vertical movement of the crosshead 5.
Also, since the motor 15 is once actuated to adjust the position of the TV camera 11 as described above, the position of the TV camera 11 is re-adjusted after the crosshead 5 is moved according to the length of the test piece TP. Does not need to be adjusted. In particular, in this embodiment, since the long hole 6a of the bellows 6 is covered with the bellows 9 which expands and contracts according to the up and down movement of the TV camera 11, it is possible to prevent dust from entering the column 1 through the long hole 6a.

In the structure of the above embodiment, the crosshead 5 is the first load frame, the table 2 is the second load frame,
The camera mount 12 constitutes a pedestal, and the lines L, L1 and L2 constitute auxiliary displays.

The installation position of the monitor device is not limited to the embodiment, and may be any position as long as it is easy to see when the test piece is attached. In particular, for example, a thin monitor device using liquid crystal can be attached to the material testing machine body side.
Further, although the position of the TV camera 11 can be finely adjusted by the motor 15, this fine adjustment mechanism may not be provided in particular, as long as the TV camera moves up and down at least in accordance with the up and down movement of the crosshead. Further, the structure of the tester main body is not limited to that of the embodiment as long as the test piece is loaded by the rotation of the screw rod. For example, the lower load frame may be lifted up and down with respect to the upper load frame. Further, the vertical type material testing machine has been described, but 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 with the line L indicating the load axis removed, or vice versa. The line L alone may be used. Alternatively, a band-shaped display having a predetermined width centered on the load axis may be used.

[0020]

According to the present invention, an image of a test piece taken 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 work is performed while looking at this monitor screen, the center of the test piece can be quickly and accurately aligned with the load axis. Further, since the camera is attached to the pedestal screwed to the screw rod for driving the first load frame, the camera moves following the first load frame when the screw rod rotates, and therefore the length of the test piece is reduced. There is no need 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 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 TV camera mounting mechanism.

FIG. 3 is a view seen from the direction III in FIG.

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

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

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

[Explanation of symbols]

 1 prop 2 table 4 screw rod 5 crosshead 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 machine pillar 51 monitor 52 controller 53 screw Drive motor

Claims (1)

[Claims] 1. A test in which both ends are fixed to both load frames by causing a first load frame screwed to the screw rod by rotation of the screw rod to separate from and contact with a second load frame in a load axis direction. In a material testing machine for loading a piece, the screw rod is screwed between the first and second load frames, and the first rod is rotated as the screw rod rotates.
A pedestal that moves in the load axis direction by following the load frame of No. 1, a camera fixed to this pedestal and photographing the test piece, and an image of the test piece photographed by this camera is displayed,
A material testing machine, comprising: a monitor device for displaying an auxiliary display indicating whether or not the center of the test piece coincides with the load axis.