JPS6310373B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention applies a load to a test piece to cause elongation, and detects the load and elongation of the test piece using a load detector and an elongation detector. The present invention relates to a material testing machine designed to perform the test, and particularly relates to a load-elongation curve recording device for recording the load-elongation curve of a test piece.

(b) Prior art In a material testing machine, when a load is applied to a test piece to cause elongation, and at the same time, the load-elongation curve of the test piece is recorded in real time, the color, shape, etc. of the test piece can be measured. It is possible to compare the change in the state of the curve with the load-elongation curve at that time.
Materials can be tested from a wide perspective.
When recording a load-elongation curve, conventionally the load and elongation of the specimen were detected by a load detector and elongation detector, and the detected values of load and elongation were sent directly from each detector to the recorder. . However, when performing a high-speed load test by applying a load to a test piece with a large elastic constant at a high speed, the load on the test piece increases rapidly immediately after the start of the test, and the amount of change in load per unit time is the maximum of the recorder. The response value is often exceeded. For this reason, there was a problem that the load-elongation curve could not be accurately recorded. FIG. 1 shows the actual load-elongation curve of the specimen and the load-elongation curve recorded by a conventional recorder.
Actual load-elongation curve (A) unit time (tn ₊₁ −tn)
When the amount of change in the load (Ltn ₊₁ − Ltn) exceeds the maximum response value (LM) of the recorder, the recorder responds to the amount of change (Ltn ₊₁ − Ltn) within the unit time (tn ₊₁ − tn).
Ltn) cannot be responded to. The recorder has a load determined by its maximum response value (LM).
Just record the elongation curve (B). Therefore,
The recorded load-elongation curve (B) does not follow or match the actual load-elongation curve (A). On the other hand, the same thing happened when the amount of change in elongation per unit time exceeded the maximum response value of the recorder, and the load-elongation curve could not be accurately recorded.

(c) Purpose This invention solves the conventional problems described above, applies a load to a test piece to cause elongation, and at the same time records the load-elongation curve of the test piece in real time, and also records this accurately. This was done with the aim of matching the load-elongation curve with the actual load-elongation curve.

(D) Configuration This invention detects the load and elongation of a test piece using a load detector and an elongation detector, and reads the detected values of the load and elongation at each sampling time by a central processing unit. Sequentially store the sampling values at the sampling times in the data buffer. At the same time, the sampling values stored in the data buffer are sequentially taken out from the data buffer by the central processing unit and applied to the recorder. This records the load-elongation curve of the specimen in real time. When the amount of change in load or elongation within the time from sampling time to sampling time exceeds the maximum response value of the recorder, the next data from the data buffer is processed until the recorder completely responds to the change in load or elongation. The extraction of the sampling value at the sampling time is interrupted, and the extraction of the sampling value at the next sampling time is started after the recorder has completely responded to the amount of change in load or elongation within the said time.

(E) Examples Examples of the present invention will be described below. FIGS. 2 and 3 show an embodiment of the invention. The material testing machine 1 applies a load to the test piece 2 to cause it to elongate. The load on the test piece 2 is detected by a load detector 3, and the elongation is detected by an elongation detector 4. Each detector 3, 4 is connected to a central processing unit 5, and the processing unit 5 is connected to a recorder 6. The recorder 6 is for recording the load-elongation curve. The central processing unit 5 is also connected to a data buffer 7 suitable for storing a large amount of data. The operation of the central processing unit 5 will be described later.

In this load-elongation curve recording device, each detector 3, 4 detects the load and elongation of the test piece 2,
The detected values of load and elongation are given to the central processing unit 5. The central processing unit 5 reads and samples the detected values of the load and elongation given from each of the detectors 3 and 4 at every sampling time (t ₁ , t _{2 .} . . ). Then, the sampling value at each sampling time, that is, the sampling value of the load (Lt ₁ , Lt ₂ ...
…) and elongation sampling values (Et ₁ , Et ₂ …
...) are sequentially transmitted to the data buffer 7. Sampling values at each sampling time (Lt ₁ and Et ₁ , Lt ₂
and Et _{2 .} . .) are sequentially and individually stored by the data buffer 7. The central processing unit 5 sequentially stores the sampled values in the data buffer 7, and at the same time sequentially extracts the sampled values stored in the data buffer 7 from the data buffer 7, and provides the sampled values to the recorder 6. The recorder 6 records the load-elongation curve based on the sampling values given from the central processing unit 5. Therefore, when a load is applied to the test piece 2 and elongation occurs, the load-elongation curve of the test piece 2 can be recorded in real time.

When performing a high-speed load test on a test piece with a large elastic constant, the load on the test piece increases rapidly immediately after the start of the test, and the amount of change in load per unit time often exceeds the maximum response value of the recorder. As mentioned above. The time from sampling time to sampling time, for example, the time from sampling time (tn) to sampling time (tn ₊₁ ) (tn ₊₁ −
When the amount of change in load (Ltn ₊₁ - Ltn) within tn) exceeds the maximum response value (LM) of the recorder 6, the central processing unit 5 informs the recorder 6 of the sampling time (tn ₊₁ ).
Even if sampling values (Ltn ₊₁ , Etn ₊₁ ) are given _, the recorder 6 calculates the time ( _{tn +2 −tn + 1} ) The amount of change in load (Ltn ₊₁ −Ltn)
unable to respond. In order for the recorder 6 to completely respond to the amount of change in load (Ltn ₊₁ - Ltn), the time (tn ₊₂ - Ltn) until the next sampling time (tn ₊₂ ) is required.
tn ₊₁ ). Therefore, when the amount of change in load (Ltn ₊₁ - Ltn) exceeds the maximum response value (LM) of the recorder 6, the central processing unit 5 causes the recorder 6 to detect the amount of change in load (Ltn ₊₁ - Ltn). Ltn)
The extraction of the sampling value at the next sampling time (tn ₊₂ ) from the data buffer 7 is interrupted until the response is completely received. Therefore, the recorder 6 can completely respond to the amount of change in load (Ltn ₊₁ - Ltn) and can accurately record the load-elongation curve. Recorder 6 measures the amount of change in load (Ltn ₊₁ −
Ltn), the central processing unit 5 starts retrieving the sampling values (Ltn ₊₂ , Etn ₊₂ ) at the next sampling time (tn ₊₂ ).

Similarly, the extraction of the sampling value at the next sampling time from the data buffer 7 is interrupted according to the amount of change in the load within the time from each sampling time to the sampling time, and the recorder 6 is recorded from each sampling time to the sampling time. fully responds to changes in load and accurately records the load-elongation curve.

The same holds true when the amount of change in elongation from sampling time to sampling time exceeds the maximum response value of recorder 6, and central processing unit 5 continues to control data from data buffer 7 until the recorder completely responds to the amount of change in elongation. The retrieval of the sampling value at the next sampling time is interrupted. Therefore, the load -
Elongation curves can be accurately recorded.

Note that since the retrieval of sampling values from the data buffer 7 is interrupted, the recording of the load-elongation curve lags behind the actual load and elongation of test piece 2, but the time lag is small and the There is no problem in comparing the change in state and the load-elongation curve at that time. Therefore, materials can be tested from a wide range of perspectives.

(f) Effects As explained above, according to the present invention, in the material testing machine 1 configured to detect the load and elongation of the test piece 2 using the load detector 3 and the elongation detector 4, the load and elongation are detected. The detected elongation value is read by the central processing unit 5 at each sampling time ₍ t ₁ , t ₂ ...), _and
The sampling values (Lt ₁ and Et ₁ , Lt ₂ and Et _{2 . .} . ) are sequentially stored in the data buffer 7. At the same time, the sampling values (Lt ₁ and Et ₁ , Lt ₂ and Et _{2 . .} . ) stored in the data buffer 7 are sequentially taken out from the data buffer 7 by the arithmetic unit 5 and given to the recorder 6. 6 records the load-elongation curve of specimen 2. Therefore, when a load is applied to the test piece 2 and elongation occurs,
The load-elongation curve of the test specimen 2 can be recorded in real time. Furthermore, according to this invention,
Amount of change in load or elongation within the time (tn+ ₁ - tn) from sampling time (tn) to sampling time (tn+ ₁ ) (Ltn+ ₁ - Ltn), (Etn+ ₁ - Etn)
exceeds the maximum response value (LM) of recorder 6,
The recorder 6 records the amount of change in load or elongation (Ltn+ ₁
−Ltn), until it fully responds to (Etn+ ₁ −Etn).
The extraction of the sampling value at the next sampling time (tn+ ₂ ) from the data buffer 7 is interrupted. Therefore, the recorder 6 can completely respond to changes in load or elongation (Ltn+ ₁ -Ltn), (Etn+ ₁ -Etn). Then, after the recorder 6 completely responds to the amount of change (Ltn+ ₁ -Ltn) and (Etn+ ₁ -Etn), extraction of the next sampling value is started. Therefore, the load-elongation curve can be accurately recorded.

[Brief explanation of the drawing]

FIG. 1 is a graph of the load-elongation curve of a test piece, FIG. 2 is an explanatory diagram showing an embodiment of the present invention, and FIG. 3 is an enlarged view of the data buffer in FIG. 2. 1... Material testing machine, 2... Test piece, 3... Load detector, 4... Elongation detector, 5... Central processing unit, 6... Recorder, 7... Data buffer.

Claims (1)

[Claims] 1. In a material testing machine that applies a load to a test piece to cause elongation and also detects the load and elongation of the test piece using a load detector and an elongation detector, the detected values of the load and elongation are A central processing unit reads the sampling values at each sampling time, and sequentially stores the sampling values at each sampling time in a data buffer, and at the same time, the processing unit sequentially extracts the sampling values stored in the data buffer from the data buffer and supplies them to the recorder. , when the load-elongation curve of the test piece is recorded by the recorder, and the amount of change in load or elongation within the time from sampling time to sampling time exceeds the maximum response value of the recorder; suspending the retrieval of sampling values at the next sampling time from the data buffer until the recorder fully responds to the change in load or elongation, and after the recorder fully responds to the change in load or elongation; A load-elongation curve recording device, characterized in that it starts taking out the next sampling value.