JPH02678Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a device for measuring the volume and specific gravity of rubber test pieces of various rubber products.

[Conventional example]

Volume measurement and specific gravity measurement using rubber test pieces are performed as a means of process control for various rubber products.
There is an "automatic specific gravity measuring device" published in Publication No. 165253. In other words, this conventional device includes a sample holding means for holding a sample for specific gravity measurement, a container lifting means for lifting and lowering a container containing a specific gravity liquid with respect to the sample, and converting the weight of the sample into an electrical signal. The specific gravity of the sample is automatically calculated from the sample weight signal in the air and the sample weight signal in the specific gravity liquid detected by the weight detecting means.

[Problem that the invention attempts to solve]

However, when the sample is immersed in the specific gravity liquid,
Air bubbles often adhere to the surface, which causes measurement errors. In addition, when a sample is immersed in a specific gravity liquid, the sample does not enter vertically but sinks into the liquid due to its surface tension, so the sample undergoes a damping motion two to three times in the specific gravity liquid. It tends to come to rest after a while. For this reason, in the conventional example above, the weight signal of the sample is read after a preset period of time has passed after immersion, taking into consideration the time it takes for the damping motion to subside. Since the time for this is undefined depending on its size, shape, etc., there is a risk that the weight signal will be read during the damping movement, and there have been problems with overall reliability.

Furthermore, using ceramic materials as an example in JP-A No. 51-136446, it was found that due to the mechanical relationship due to the wet state, the microscopic conditions change and the value of buoyancy is affected and fluctuates, and this error causes weight measurement. It is stated that the values are affected and variations occur.
In this prior example, it was proposed to wash the ceramic material with a surfactant prior to immersion in water or to add a surfactant to the water to reduce the surface tension of the ceramic material and stabilize the weight measurement. ing. However, this method not only requires an additional material, the surfactant, but also requires separate control means for adding the appropriate amount of surfactant.

On the other hand, the inventor of the present invention focused on the fact that air bubbles do not adhere to the test sample when the test sample is immersed in water, pulled out, and then immersed again in water. By adapting it to the above-mentioned Japanese Utility Model Application Laid-Open No. 55-16525, the drawbacks of the automatic specific gravity measuring device can be improved, and accurate measurements can be made without adding additional parts as in the above-mentioned Japanese Unexamined Utility Model Application No. 51-136446. It is an object of the present invention to provide a volume specific gravity measuring device that can perform the following measurements.

[Means for solving problems]

In order to solve the problems of the conventional examples as described above, this invention includes a weighing device with a hanging hook for suspending a test sample such as rubber, a container containing pure water, and a mechanism for raising the container. A container lifting means is provided with a limit switch that defines the position and a lowering position, and a container lifting means is provided to raise and lower the container to immerse the test sample in pure water, and a signal from the limit switch controls the driving of the container raising and lowering driving means to perform weighing. A rubber having a calculation control device that stores the air weight and underwater weight of a test sample measured by a device and calculates the volume and specific gravity of the test sample from these weights, and a recording display device that records and displays the calculation results. In a device for measuring the volume and specific gravity of test pieces, etc., when the limit switch for determining the ascending position operates for the first time, the arithmetic and control unit immediately outputs a control signal for lowering the container to the drive means for raising and lowering the container, and then the limit switch for determining the descending position is activated. A control signal for raising the container again is output to the container lifting/lowering drive means by the operation of , and when the lifting position regulation limit switch is operated again, the container is held at the lifting position for a preset time, and then The device is characterized in that it has a control section that outputs a signal for lowering.

[Effect]

In this way, the control section of the arithmetic and control unit, when measuring weight in water, first immerses the test sample in pure water in the container to wet the entire test sample, then lowers the container and raises it again. Since the test piece is immersed in pure water for a certain amount of time, there are almost no air bubbles attached to the test piece, and the test piece is less likely to undergo damping motion as in conventional methods. Since it is immersed in the liquid relatively quietly, highly reliable measurement data can be obtained.

〔Example〕

Hereinafter, embodiments of this invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, this measuring device comprises a vertically configured frame 1,
A weighing device 2 is placed on the upper part. A known weighing device 2 is used, which has a weighing pan 3 at the top and a hanging hook 4 at the bottom for hanging weighing.In this case, the weighing pan 3 can be opened and closed. It is surrounded by a transparent cover 5. Further, the frame 1 is provided with a mounting table 7 on which a container 6 such as a beaker is placed. in this case,
The mounting table 7 has a support shaft 8 extending downward, and is moved in the vertical direction by a motor 9 installed in the lower part of the frame 1 via a gear mechanism including a pinion and a rack (not shown) provided on the support shaft 8. It is becoming more and more driven by Therefore, if the test sample S made of rubber is hooked onto the needle 13 of the hanging rod 12 and suspended from the hanging hook 4 in the illustrated state in which the mounting table 7 is hung downward, the test sample S is suspended. The weight in air is measured, and the weight in water is measured by raising the mounting table 7 by the motor 9 and immersing the test sample S in the test liquid (pure water) in the container 6. In addition, reference numeral 1
0 is an upper limit switch that determines the upper limit position of the mounting table 7 in cooperation with the arm 19 attached to the support shaft 8, and 11 is a lower limit switch that determines the lower limit position. In some cases, a pair of limit switches may be further provided as shown by dotted lines in the figure for higher safety.

Further, this measuring device is equipped with an arithmetic/control device 14 shown in FIG. This arithmetic/control device 14 includes a measured value storage circuit that stores measured values supplied from the weighing device 2, an arithmetic circuit that performs predetermined calculations based on the measured values, and an upper limit switch 10 and a lower limit switch 11. It includes a motor control circuit that is connected to the motor 9 and outputs a rise signal, a fall signal, or a stop signal to the motor 9. Note that each of these circuits can be implemented as a microcomputer. Also, this calculation
The control device 14 includes a needle 13 for hooking the test sample S.
A digital switch 15 for setting the weight in the air of the needle 13, a digital switch 16 for setting the underwater weight of the needle 13, and a digital switch 17 for setting the specific gravity of the pure water to be placed in the container 6 are provided. . Note that reference numeral 18 is a printer that records each measured value of the sample to be tested and the calculation output of the calculation circuit.

Next, the operation of this measuring device will be explained with reference to the flowchart shown in FIG.

First, as a preparation step, the test sample S is hooked onto the needle 13 of the hanging rod 12 and suspended from the hanging hook 4 of the weighing device 2, and the container 6 containing pure water is placed on the mounting table 7. Then, the digital switches 15 and 16 are operated to set the air weight w and underwater weight w' of the needle 13, and the digital switch 17 is operated to preset the specific gravity d of the pure water in the container 6.

When a start switch (not shown) is turned on, the arithmetic/control device 14 receives the measurement value signal supplied from the weighing device 2 and calculates the air weight W of the test sample S by subtracting [measurement weight - w], This is printed out on the printer 18, for example. Next, a rising signal is output to the motor 9, and the mounting table 7 is thereby raised to a position where the test sample S is immersed in the pure water in the container 6. In this case, the present invention is programmed so that when the upper limit switch 10 is turned on, a lowering signal is output to the motor 9 and the mounting table 7 is immediately lowered. Therefore, the test sample S is once immersed in pure water before entering the underwater weight measurement. When the mounting table 7 is lowered and the lower limit switch 11 is pressed, a rising signal is given to the motor 9. As a result, the mounting table 7 rises again and stops when it comes into contact with the upper limit switch 10. When the upper limit switch 10 is turned on, a timer circuit (not shown) operates, and the mounting table 7 is held at that position for a certain period of time (for example, about 5 seconds). That is, the test sample S is immersed in pure water in the container 6 for a certain period of time. After the timer circuit is activated, an arithmetic circuit (not shown) performs a subtraction of [measured weight - w'] to determine the underwater weight W' of the test sample S. Next, (W-W')/d=V (volume of test sample S) and (W-W')=D (specific gravity of test sample S)
are calculated, and these values W', V, and D are printed out on the printer 18, respectively. Thereafter, a lowering signal is output to the motor 9, the mounting table 7 is lowered, and the lower limit switch 11 is turned on with a signal, and the series of operations ends. In this embodiment, automatic measurement is performed according to a program set in the arithmetic/control device 14, but a print switch and a switch for raising and lowering the mounting table, etc., may be separately provided. It can also be operated manually. In the above embodiment, the test piece is immersed in the liquid only once before the actual weight measurement in water, but this may be repeated several times as the case may be.

〔effect〕

As is clear from the description of the above embodiments, according to this invention, in the process of moving from weight measurement in the air to weight measurement in water, the test sample is immersed in the test liquid, wetted entirely, and then immersed in the test liquid again. Immersion improves wetting of the test sample in pure water. Therefore, there are almost no air bubbles attached to the surface of the sample, and the test sample is not accompanied by damping motion as in the case of conventional methods, and is immersed into the liquid relatively quietly, making it more accurate. It is possible to obtain accurate measurement data.

[Brief explanation of the drawing]

Figure 1 is a partial sectional view of the volume/specific gravity measuring device based on this invention, and Figure 2 is a partial cross-sectional view of the volume/specific gravity measuring device based on this invention.
FIG. 3 is a block diagram of the control circuit arrangement and a flowchart thereof. In the figure, 1 is a frame, 2 is a scale, 4 is a hanging hook, 6 is a container, 7 is a container mounting table, 9 is a motor, 10 and 11 are limit switches, 14 is a calculation/control device, and 18 is a printer. .

Claims (1)

[Scope of utility model registration request] A weighing device has a hanging hook for suspending a test sample such as rubber, a container containing pure water, and a limit switch that determines the raising and lowering positions of this container. A driving means for raising and lowering a container that immerses the test sample in pure water, and a drive means for driving the driving means for raising and lowering a container is controlled by a signal from the limit switch, and the air weight of the test sample is measured by the weighing device. In a volume/specific gravity measuring device for a rubber test piece, etc., which has an arithmetic control device that stores the weight and weight in water and calculates the volume and specific gravity of the test sample from these weights, and a recording and display device that records and displays the calculation results, When the ascending position regulating limit switch is operated for the first time, the arithmetic and control unit immediately outputs a control signal to the container lifting/lowering driving means to lower the container, and the operation of the descending position regulating limit switch causes the container to be lowered again. A control signal for raising the container is output to the container lifting/lowering driving means, and when the lifting position regulating limit switch is operated again, the container is held at the raised position for a preset time and then lowered. An apparatus for measuring the volume and specific gravity of a rubber test piece, etc., characterized by having a control section that outputs a signal for measuring the volume and specific gravity of a rubber test piece.