JPS63218825A - Weight detector - Google Patents

Abstract

PURPOSE:To enhance the detection accuracy of the wt. value of an object, by constituting the title detector of a turntable for mounting an object, a wt. detection element for detecting the wt. of the object placed on the turntable and a circuit part for processing the signal from the wt. detection element. CONSTITUTION:This detector is constituted of a turntable mounting an object 2, a wt. detection element 5 detecting the wt. of the object mounted on the turntable and a circuit part 6 for detecting the wt. of the object on the turntable n-times during one revolution of the turntable by the wt. detection element to successively average (n)-detected wt. values. By this constitution, the wt. of the object on the turntable can be detected while the turntable is rotated. The wt. of the object is detected n-times during one revolution of the turntable and (n)-detected wt. values are successively averaged to obtain a wt. value. By this method, even when there is an intercardinal error in a weighing mechanism, the wt. of the object can be accurately detected. Further, since (n)-accurate wt. values per one revolution are obtained, an S/N ratio is high and wt. change can be instantaneously detected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a weight detector, and more particularly to a weight detector that has a rotating weighing platform and detects changes in the weight of an object placed thereon.

Conventional technology Conventionally, weight detectors with this type of rotating weighing table (carousel) detect the weight during one rotation of the weighing table, and detect the maximum and minimum values. The value or average value was calculated as the weight value.

Problems to be Solved by the Invention However, in the above-mentioned weight detector, since the detected weight value is as small as one per revolution of the weighing platform, it is susceptible to noise and has a poor S/N ratio of the N quantity value.

Another problem is that even if a weight change occurs in the object on the weighing platform, the weight change cannot be detected until the weighing platform rotates once.

The present invention solves these conventional problems,
Even if there are errors in the four corners of the weighing mechanism, high accuracy and high S/N,
Another object of the present invention is to provide a weight detector that can immediately detect a change in weight of an object on a weighing platform.

Means for Solving the Problems In order to solve the above problems, the weight detector of the present invention includes:
The structure consists of a rotating table (weighing table) for placing an object, a weight sensing element for detecting the weight of the object placed on the rotating table, and a circuit section for processing signals from the weight sensing element. It is prepared.

Operation Since the present invention has the above configuration, it is possible to detect the weight of an object on the rotary table while rotating the rotary table on which the object is placed. During one revolution of the turntable, the weight of the object is n
The weight of the object can be accurately detected even if the weighing mechanism has errors in the four corners by averaging the n detected weight values in sequence and determining the weight value. Furthermore, since n accurate weight values can be obtained per -rotation, the S/N is high and changes in weight can be detected immediately.

Example Embodiments of the present invention will be described below based on the drawings.

In Fig. 1, 1 is a rotary table on which an object 2 is placed (
Weighing platform). 3 indicates a rotating shaft of the rotating table 1, and 4 indicates a motor attached to the rotating shaft 3 for driving the rotating table. Reference numeral 5 designates a weight sensing element for detecting the weight of the object 2 on the rotary table 1, and 6 represents a circuit unit for processing a signal from the weight sensing element 5. 7 indicates a power source.

FIG. 2 shows the time change of the signal from the weight sensing element 5 when the rotary table 1 is rotated by the motor 4 at a cycle of 1°. In the figure, the horizontal axis represents time t, and the vertical axis represents detector Ex W.
(t) is shown. The detected weight W (t) had an average weight of 250 g due to errors in the four corners of the weighing mechanism, and the apparent weight change due to rotation of the rotary table was ±7.5 g. The figure shows a case where the weight of the object decreases by about 9.9% between about 90 seconds and 150 seconds after the start of detection. Weight detection is
At a rate of 1 flash per second, i.e. 1 revolution, 10 flashes (n
= 10).

In Fig. 3, the detected weight W (t) from the weight sensing element is shown as
The results of processing in the circuit section 6 are shown. That is, in the circuit section 6,
The process shown in the following formula was performed.

In the above formula, τ indicates the rotation period (=10 seconds).

The symbol on the left side of equation (1) indicates the sequential average value of one rotation (time τ). During the first rotation, from 1=0 to t=τ, the average value is calculated as the weight value W□ (approximately 2
51 g) was used.

Even though there was a weight fluctuation of ±7.5 g due to the rotation of the weighing table due to the four-corner error of the weighing mechanism (see Figure 2), we were able to accurately detect the slight weight loss of 9 g that occurred after 90 seconds. . (See Figure 3). That is, in FIG. 3, it can be seen that when there is no change in the weight of the object 2, the weight value is very stable (within ±1 g) from time 0 to 90 seconds.

Also, compared to conventional weight detectors, for example, the weight value of one point per rotation, such as the maximum value, minimum value, or average value of one rotation, the weight value of n points (n = 10) per rotation is It can be seen that it has a high S/N and is resistant to noise.

As described in detail, the weight detector of the present invention provides the following effects.

(1) Since weight detection is performed n times per rotation and the average value of n points is sequentially taken as the weight value, it is possible to accurately detect the weight value of the object even if a four-corner error occurs in the weighing mechanism.

Shun) If a weight change occurs in an object, it can be detected immediately.

(3) Since weight values of n points can be obtained per revolution, S
/N is high, making it more resistant to noise.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a weight detector according to an embodiment of the present invention, and FIG.
3 and 3 are characteristic diagrams of the same weight detector, respectively. 1... Rotating table (weighing table), 2... Object, 3... Rotating shaft, 4... Motor, 5...
...Weight detector, 6...Circuit section, 7...
····power supply. Name of agent: Patent attorney Toshio Nakao and one other person
Rotating table? -Object 3-Rotating shaft 4-±-Event 5-King device 6-Circuit section 7-Power source Fig. 1? Figure 2 Q Xi u 91) r?
D IEn碍 Time (seconds) Figure 3 Time (sha)

Claims (1)

[Claims] A rotary table on which an object is placed; a weight detection element that detects the weight of the object placed on the rotary table; A weight detector comprising a circuit unit that detects n times and sequentially averages the n detected weight values.