JPH03264088A - Dehydrator - Google Patents

Abstract

PURPOSE:To enhance degree of accuracy for detection of abnormal vibration, irrespective of the rotational speed of a drum, so as to obtain effective dehydration by providing a comparing means for comparing a measured value by a vibration detecting means and a reference value stored in a memory means, and a control means for delivering an instruction to a drive means so as to lower the rotational speed of the drum if the measured value is greater than the reference value in accordance with the comparison by the comparing means. CONSTITUTION:A microcomputer 16 controls the operation of a load 19 such as a drive motor 7, a solenoid or the like, and the operation of a display unit 20 and so forth in accordance with data from an input key circuit 17 composed of several kinds of manipulating keys, a water level sensor 18, an acceleration sensor 10, a reed switch 14 and the like. When a sensor output is greater than its reference value, it is determined that abnormal vibration caused by unbalance in dehydration occurs, and accordingly, the time counting is interrupted and the drum 5 is stopped. Further, after two seconds elapses from the time at which the drum 2 is completely stopped, the time counting is reinitiated, and the dehydration is carried out from the first for the remaining time.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a dehydrator.

(b) Conventional technology As a conventional example, in order to prevent continuation of dewatering operation under abnormal vibration conditions caused by unbalance of the material to be dehydrated in the drum, an outer tank elastically supported within a frame is subjected to abnormal vibrations. A dehydrator equipped with a detection device was developed in 1983-2023.
It is shown in Publication No. 5 (D06F37/04).

The abnormal vibration detection device has a case that has mercury inside and a contact point attached to the outer tank at a predetermined angle. Abnormal vibrations are detected by contacting the contacts and making them conductive.

(C) In the structure of the conventional structure that the invention aims to solve, abnormal vibrations are detected based on the amplitude and swing speed of the outer tank.For example, if the amplitude is large but the swing speed is low (slow and large swings (This is often the case when abnormal vibrations occur at the beginning of spin-off), the amount of mercury movement may be small and the abnormal vibrations may not be detected.

That is, in the conventional structure, there is a problem in that the abnormal vibration detection accuracy varies depending on the number of dehydration rotations.

The present invention relates to an improvement of a dehydrator and is intended to solve these problems.

(d) Means for Solving the Problems The dewatering machine of the present invention includes an outer tank elastically supported within a frame, a drum rotatably supported within the outer tank and containing objects to be dehydrated, and a drum. a rotational drive means, a vibration detection means for outputting an electric signal proportional to the vibration of the outer tank, a rotation speed detection means for outputting a signal for detecting the rotation speed of the drum, and a rotation speed of the drum is increased. storage means for storing reference values obtained based on signals from the vibration detecting means at each of the plurality of rotational speeds during the process; and the vibration detecting means each time the drum reaches the plurality of rotational speeds. a comparison means for comparing the actual measurement value and the reference value stored in the storage means, and based on the comparison result by the comparison means, if the actual measurement value is larger than the reference value, the rotation speed of the drum is and control means for instructing the drive means to lower the drive means.

(e) Since the reference value for abnormal vibration determination is set according to the operation, that is, the spin speed, the detection accuracy is almost constant at all times.

(f) Example Embodiments of the present invention will be described based on the drawings.

In FIG. 2, l is a frame, 2 is a spring 3, a shock absorber 4, etc. inside this frame 1.
The outer tank 5 is elastically supported by the outer tank 1'12
It is a horizontally narrow drum that is rotatably supported inside and has many through holes around its circumference (not shown). 6 is a drive pulley fixed to the rotating shaft of the drum drum 5 described in WiJ, and 7 is the outer tank 2.
A drive motor I2 is fixed to the outer bottom of the drive pulley 6, and is connected to the drive pulley 6 via a small boot 8 and a belt 9. Reference numeral 10 denotes an acceleration sensor fixed to the upper part of the outer tank 2, and as shown in FIGS. 3 and 4, a thin disc-shaped piezo plastic film 11 is used as a vibrator to vibrate the outer tank 2. When acceleration is applied to the acceleration sensor 1o, the vibrator shakes and converts the displacement into an electrical signal. 1
2 is an impedance converter, and 13 is an amplifier. As shown in FIG. 4, this acceleration sensor 10 can take out an output voltage of ±0.2 V per acceleration IG from the output terminals VO and T when a voltage of ±6 V is applied thereto. That is,
According to this acceleration sensor 10, as shown in FIG. 5, an output voltage proportional to acceleration can be obtained.

14 is a reed switch attached to the outer WI 2, and a magnet 15 attached to the drive early 6
-Turned off. That is, each time the drive pulley 6 rotates once, the reed switch 14 is turned ON-OFF. This 0
The N-OFF signal is input to a microcomputer (described later) via a monostable multivibrator, and the microcomputer receives this QN-OFF signal.
By counting the OFF signals, the number of rotations of the drive motor 7 (drum 5) per unit time can be determined.

Now, FIG. 6 shows a control mechanism centered on a microcomputer 16 (hereinafter referred to as microcomputer) in this embodiment.
Based on information from the input key circuit 17, the water level sensor 18, the acceleration sensor 10, the reed switch 14, etc., the operation of the drive motor 7, load 19 such as a solenoid, display device 20, etc. is controlled.

Since the configuration of the microcomputer 16 is well known, it will be briefly explained based on FIG. 7.

The microcomputer 16 has a cpji 21 (central
processing unit), RAM 22
(random access memory), R
OM 23 (read only memory)
, timer 24, system bus 25 and input/output device 26
．． It consists of 27 pieces.

The CP 21 is composed of a control unit 28 and a calculation unit 29. The control unit 28 takes out and executes instructions, and the calculation unit 29 receives control from the control unit 28 during the instruction execution stage. It performs arithmetic processing such as binary addition, logical operation, increase/decrease, and ratio V on data given from input devices and memory by signals. The RAM 22 is for storing data related to the equipment, and the ROM 2S
In this method, the means for operating the device, the settings for conditions for judgment, the rules for processing various information, etc. are loaded in advance.

In this embodiment, if the distribution of the material to be dehydrated in the drum 5 is unbalanced, the drum 5 will not rotate smoothly and the outer tank 2 will vibrate abnormally. The table below shows that the dehydration rotation is steady from startup (600r, p,
At each rotation speed up to m), the allowable amplitude of the outer tank, the acceleration at this time, and the output of the acceleration sensor 10 are shown. Then, each sensor output G is the RO
It is stored in advance in M23.

The allowable acceleration is first determined at a drum rotational speed of 60 rpm, and those below that are determined in inverse proportion to the square of the rotational speed.

The dewatering operation based on such a configuration will be explained with reference to FIG.

Dehydration time measurement (S-1), drum rotation (drive motor 7)
ON) (S-2), and at the same time, measurement of the rotation speed data A of the drum 5 and the output data G of the acceleration sensor 10 is started (S-F) (S-4).

As time passes, the rotational speed A of the drum 5 gradually begins to rise, and at the time when 100<A≦2°O, the sensor output G and the rotational speed 20 Orpm stored in the ROM 23 Standard output (120mV) corresponding to
5-5), if G≧120, it is determined that abnormal vibration is occurring due to dehydration imbalance,
At the same time as interrupting the time measurement (C5-6), the drum 5 is stopped (S7>. Then, two seconds after the drum 5 has completely stopped, the time measurement is restarted (S8), and the liquid is removed for the remaining time. Run from the beginning.

Similarly, when 200<A≦300, the rotation speed is 30
The reference output (240mV) corresponding to Orpm and 30
When 0<A≦400, the reference output (360 mV) corresponding to the rotation speed 400 rp pressure, and when 400 A≦500, the reference output (360 mV) corresponding to the rotation speed 500 rpc.
mV), and when 500<A, the reference output corresponding to the rotation speed 60 Orpm, and 5-9) to (S-1
2) If the standard output is exceeded, (S-6) to (S-
Execute the same operation as in 8).

When the time measurement ends, the drum 5 is stopped.S-13)
, A≦10, the draining operation is terminated.

In this embodiment, when abnormal vibration is detected, the time measurement is interrupted, but the time measurement may be reset.

(G) Effects of the Invention According to the structure of the dehydrator of the present invention, the detection accuracy of abnormal vibrations is high regardless of the rotational speed of the drum, so that efficient dewatering can be performed.

[Brief explanation of drawings]

Figures 1 (a) and (b) are flowcharts showing the operation of the dehydrator of the present invention, Figure 2 is an internal mechanism diagram, Figure 3 is an internal structure diagram of the acceleration sensor, and Figure 4 is an electric circuit diagram.
FIG. 5 is a similar output characteristic diagram, FIG. 6 is a block circuit diagram of the control mechanism, and FIG. 7 is a block diagram of the microcomputer. ■... Frame, 2... Outer tank, 5 7... Drive motor (drive means), 1 Sensor (vibration detection means), 14. Isochi, 15... Magnet (14, 1, means), 23... ROM (memory means)...Drum, O...Acceleration/reeds: rotation speed detection, 28...Control section stage (control means) -Calculation section (comparator)

Claims (1)

[Claims] (1) an outer tank that is elastically supported within the frame; a drum that is rotatably supported within the outer tank and accommodates the material to be dehydrated;
A rotation driving means for the drum, a vibration detection means for outputting an electric signal proportional to the vibration of the outer tank, a rotation speed detection means for outputting a signal for detecting the rotation speed of the drum, and a rotation speed detection means for outputting a signal for detecting the rotation speed of the drum. storage means for storing reference values obtained based on signals from the vibration detection means at a plurality of rotational speeds during the increasing process; a comparison means for comparing an actual value measured by the detection means with a reference value stored in the storage means, and a rotation of the drum when the actual measurement value is larger than the reference value based on the comparison result by the comparison means; 1. A dehydrator, comprising: control means for instructing the drive means to reduce the number of dehydrators.