JP3190947B2 - Viscosity controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscosity adjusting device suitable for adjusting the viscosity of ink for gravure printing or the like.

[0002]

2. Description of the Related Art In gravure printing, since the ink is exposed to the outside air during the printing process, the solvent volatilizes and the viscosity of the ink increases, which causes not only a large number of defects such as printing stains, but also causes a problem. However, waste due to an increase in the amount of raw ink used has occurred. Conventionally, in order to prevent the occurrence of this kind of defect, viscosity management was performed by relying on the intuition of a skilled worker, but the operation became complicated and high-precision viscosity management could not be performed. On the other hand, for the purpose of controlling the viscosity without relying on the intuition of such an operator, a device that detects the viscosity of the ink as a certain parameter and replenishes the solvent based on the detection result has been developed. However, the conventional device had to convert the detection data into viscosity using a complicated numerical table to numerically manage the viscosity of the ink, which was troublesome and liable to cause work errors and breakdowns. There were many.

[0003]

Recently, with the rapid growth of consumers in the food industry and the like, the printing of packaging materials has become extremely high in order to increase the added value of products and increase consumers' willingness to purchase. It is now required to be quality. For example, high quality printing has been rapidly advancing, for example, by using many thin lines, thin characters, and halftones. Severe conditions such as a depth of 7 to 15 microns are required for a gravure printing plate cylinder, and strict control of ink viscosity is required.

[0004] Therefore, the present invention provides an automatic viscosity control device capable of controlling the viscosity of a fluid such as ink with high precision by combining a precise hard portion and a soft portion using a computer. It is an object to provide an adjusting device.

[0005]

In order to solve the above-mentioned problems, the present invention has the following configuration. That is, the viscosity adjusting device according to the present invention is provided with a diaphragm pump arranged in a flow path of a fluid such as printing ink and flowing the fluid, a detector for detecting the number of pulsations of the diaphragm pump, and the detector Calculating means for obtaining the viscosity of the fluid from the detected number of pulsations per unit time ; display means for directly displaying the obtained viscosity; and detecting the viscosity based on the pulsation number at predetermined time intervals. And a control device for outputting a signal for opening a diluent supply valve for a set time when the determined viscosity is out of a preset viscosity range.

In the viscosity adjusting device of the present invention, a diaphragm pump driven by air is disposed in a flow path of a fluid such as ink, and a pulsation due to the flow is detected while the fluid is caused to flow by the diaphragm pump. The pulsation of the diaphragm pump changes depending on the viscosity of the fluid. The higher the viscosity, the smaller the number of pulsations within a certain period of time (unit time) , and the lower the viscosity, the greater the number of pulsations. You can know. The number of pulsations of the diaphragm pump can be detected by various detectors such as a proximity switch. However, it is preferable to detect fluctuations in air pressure caused by the pulsation with a pressure switch in order to maintain high accuracy.

The number of pulsations detected by the detector is
It is supplied to a calculating means, where it is converted into the viscosity of the fluid. For this purpose, the relationship between the viscosity of the target fluid and the pulsation number is determined in advance by experiments, and the viscosity is calculated from the pulsation number detected during the actual work using this relational expression.
The determined viscosity is directly displayed on the display means.

On the other hand, when the obtained viscosity is out of the set viscosity range, that is, when the viscosity is higher than the set value, a signal is output so as to keep the viscosity within the set range. Specifically, a signal for adding a diluent for diluting the concentration of the fluid is output. As a result, a predetermined amount of the diluent is added to the fluid, and its viscosity is reduced. The above control is repeated at predetermined time intervals, and the viscosity of the fluid is always maintained within the set range.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention shown in the drawings will be specifically described below. FIG. 1 shows a viscosity adjusting device according to the present invention.
Is composed of a hard section 2 and a control section 3 including a computer, and constitutes a fully automatic viscosity ink control system for printing ink.

In the casing 4 of the hard portion 2, there is provided a pipe 5 serving as a flow path of ink as a fluid, and a diaphragm pump 10 is interposed in an intermediate portion thereof. The diaphragm pump 10 includes a diaphragm 10a that is vibrated by air pressure. The diaphragm pump 10 is a pump that pumps a fluid by vibrating the diaphragm. Since there is no rotating portion, lubricating oil is not required for the portion, and maintenance is easy. is there.

The compressed air (air) introduced from the air supply port 15 a of the air pipe 15 is supplied to the cock 16 and the pressure controller 1.
7, the oil is supplied to the diaphragm pump 10 via the oil cup 18, the speed controller 19, etc., and then sent to the control unit 3 and then discharged to the atmosphere from the air discharge port 15b. During this time, the diaphragm is vibrated. Then, the ink in the pipe 5 flows in the direction of the arrow. 5a is an ink inlet, and 5b is an ink outlet.

A solvent tank 20 is provided above the casing 4 and contains an ink solvent D as a diluent. A solvent pipe 21 is connected to the bottom of the solvent tank 20 via a solvent cock 23. A pressure-resistant explosion-proof electromagnetic valve 25 is provided at an intermediate portion of the solvent pipe 21.

The control section 3 is provided with a CPU (personal computer) 30 to which a pressure switch 32 as a pressure sensor is connected. The pressure switch 32 is connected to the air pipe 15.
, And detects a pressure fluctuation in the air pipe (air hose) 15 and outputs the detection signal to C.
Input to PU.

On the other hand, the CPU 30 has a viscosity range setting device 3
4. The solvent valve opening time setting device 35, the memory 36, the detection cycle setting device 37, etc. are connected to set the viscosity limit for starting the addition of the solvent, the setting of the time t for opening the solvent electromagnetic valve 25, the target ink. It is possible to store the relationship (preliminary test result) between the pulsation number and the actual viscosity when the fluid flows, set the control cycle, and the like.

The CPU 30 is connected to a solvent addition buzzer 40 for notifying that the solvent is being added and a digital counter 42 for displaying the obtained viscosity. In the drawing, 44 is a power switch, and 45 is a signal lamp indicating that the power is being turned on.

The viscosity adjusting device 1 is installed in a system for supplying ink L to a printing device 50, as shown in FIG. The ink in the ink tank 51 is circulated and supplied to the printing apparatus 50 by the pump 53. On the other hand, ink tank 5
The ink in 1 is sucked up by the diaphragm pump 10 of the viscosity adjusting device 1, and the number of pulsations per unit time at that time is detected by the pressure switch 32.

The detection result is input to the CPU 30 and is expressed by a relational expression (stored in the memory) based on the result of the preliminary experiment.
Is converted into a viscosity. The obtained viscosity value (centipoise) is displayed by the digital counter 42 to one decimal place.

On the other hand, the control limit (upper limit) of the viscosity is set by the viscosity range setting device 34, and when the measured viscosity exceeds this range, the electromagnetic valve 25 is opened for a set time t. For this reason, the solvent in the solvent tank is added to the ink and the concentration of the ink is reduced, resulting in a decrease in viscosity. During the addition of the solvent, Buzzer-40 reports this.
The set time t is generally set to about several seconds to several tens of seconds, but may be set appropriately depending on the size of the apparatus, the type of ink, and the like.

Although the shorter the cycle of viscosity detection, that is, the shorter the control cycle, the higher the accuracy, a time of several seconds to several tens of seconds is usually sufficient. The management data, that is, the measured viscosity value and the addition time (amount) of the solvent are continuously recorded on a recording paper by a printer (not shown).

In the above description, the viscosity of the fluid is detected by the pulsation of the diaphragm pump. However, if the viscosity of the fluid can be detected while circulating using a pump other than the diaphragm pump, Other methods may be employed. Further, the amount of the solvent to be added may be controlled by a method in which the valve is opened for a certain time as described above, or the valve opening degree and the opening time may be controlled according to the viscosity value.

[0021]

As is apparent from the above description, the viscosity adjusting apparatus according to the present invention measures the viscosity of a fluid such as ink, and adds a diluent when the viscosity of the fluid reaches a set viscosity limit. Since the operation of lowering the viscosity is performed automatically, it is possible to control the viscosity of ink and the like with high accuracy, and to maintain the quality of products such as printed materials using this kind of fluid at high quality. Became possible. Further, since the viscosity of the fluid is directly displayed, it is convenient for quality control. It goes without saying that this viscosity adjusting device can be used for adjusting the viscosity of a fluid in various industrial fields such as the chemical industry and the food industry.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view showing an example of a viscosity adjusting device of the present invention.

FIG. 2 is a perspective view seen from the front side.

FIG. 3 is a perspective view seen from the back side.

FIG. 4 is an explanatory diagram of the usage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Viscosity adjustment device 2 Hard part 3 Control part 5 Ink piping 10 Diaphragm pump 15 Air piping 20 Solvent tank 25 Electromagnetic valve for solvent 30 CPU 32 Pressure switch (pressure detector) 42 Digital counter (display device) 50 Printing device

Claims (2)

(57) [Claims] 1. A diaphragm pump disposed in a flow path of a fluid such as printing ink for flowing the fluid, a detector for detecting the number of pulsations of the diaphragm pump, and a unit time detected by the detector. Calculating means for obtaining the viscosity of the fluid from the pulsation number, display means for directly displaying the obtained viscosity, and detecting the viscosity based on the pulsation number at predetermined intervals, and the obtained viscosity is preset. A viscosity controller that outputs a signal that opens a diluting liquid supply valve for a set time when the viscosity is out of the set viscosity range. 2. The viscosity adjusting device according to claim 1, wherein the detector for detecting the number of pulsations comprises a pressure switch for detecting the air pressure of the diaphragm pump.