JPH0939205A - Viscosity adjusting unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform viscosity adjustment for fluid such as ink accurately, by providing a control unit which outputs signals which open a valve for supplying a diluent for a preset time when required viscosity deviates from a predetermined range of viscosity. SOLUTION: Ink within an ink tank is sucked by a diaphragm pump 10 of a viscosity adjusting unit 1, and the number of pulsations during a unit time is detected by a pressure switch 32. The result of detection is inputted to a CPU 30, and viscosity is calculated by a relational expression based on the result of preliminary experiments. The control limit (upper limit) of viscosity is set by a viscosity range definer 34, if measured viscosity exceeds the range, an electromagnetic valve 25 opens for a preset time. Thus a solvent within a solvent tank 20 is added to ink and dilutes the concentration of the ink and lowers its viscosity. During this solvent addition, it is signaled by a buzzer 40.

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 use in adjusting the viscosity of ink such as gravure printing.

[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 rises, causing not only frequent defects such as printing stains that are believed to be the cause. However, there was waste due to an increase in the amount of raw ink used. In order to prevent the occurrence of this kind of defect, conventionally, the viscosity control was performed by relying on the feeling of a skilled worker, but the work was complicated and it was not possible to perform highly accurate viscosity control. On the other hand, for the purpose of managing the viscosity without depending on the feeling of the operator, a device for detecting the viscosity of the ink as a certain parameter and supplying the solvent based on the detection result has been developed. However, in the conventional device, in order to numerically control the viscosity of the ink, it was necessary to convert the detection data into the viscosity by using a complicated numerical table, so it is complicated and prone to work mistakes and breakdowns, and eventually it is manual. I often depended on it.

[0003]

Recently, with the high growth of consumers such as the food industry, the printing of packaging materials is extremely high in order to increase the added value of the products and increase the motivation of consumers to purchase. There is a demand for quality. For example, the high quality of printing is rapidly progressing, for example, by frequently using thin lines, thin letters, and halftones. Even in the case of a gravure printing plate cylinder, the severe condition that the depth is 7 to 15 microns is required, and strict control of the viscosity of the ink is required.

Therefore, in the present invention, by combining a precise hard portion and a soft portion using a computer, an automatic viscosity capable of highly accurately controlling the viscosity of a fluid such as ink. It is an object to provide an adjusting device.

[0005]

In order to solve the above problems, the present invention has the following constitution. That is, the viscosity adjusting device according to the present invention includes a diaphragm pump that is disposed in a flow path of a fluid such as printing ink and causes the fluid to flow, a detector that detects the pulsation number of the diaphragm pump, and the detector. The calculation means for obtaining the viscosity of the fluid from the detected pulsation number, the display means for directly displaying the obtained viscosity, and the detection of the pulsation number at every predetermined time, the obtained viscosity is preset. And a control device that outputs a signal for opening the valve for supplying the diluting liquid for a set time when the viscosity is out of the range.

In the viscosity adjusting device of the present invention, a diaphragm pump driven by air is arranged in the flow path of a fluid such as ink, and the pulsation due to the flow is detected while the fluid is flowed 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 pulsation number within a certain period of time, and the lower the viscosity, the larger the pulsation number. Therefore, the viscosity can be known from this pulsation number. . The pulsation number of the diaphragm pump can be detected by various detectors such as a proximity switch, but it is preferable to detect the fluctuation of the air pressure caused by the pulsation with a pressure switch in order to maintain high accuracy.

The pulsation number detected by the above detector is
It is supplied to the calculation means and converted into the viscosity of the fluid there. For this purpose, the relationship between the viscosity of the target fluid and the pulsation number is obtained in advance by experiments, and the viscosity is calculated from the pulsation number detected during the actual work using this relational expression.
The calculated 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 that the viscosity is 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 diluting liquid is added to the fluid, and its viscosity decreases. The above control is repeated every predetermined time, 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 control system for printing ink.

Inside the casing 4 of the hard part 2, a pipe 5 is provided which serves as a flow path for ink which is a fluid, and a diaphragm pump 10 is interposed in the middle part thereof. The diaphragm pump 10 is a pump that includes a diaphragm 10a that can be vibrated by air pressure, and pumps a fluid by the vibration of the diaphragm. Since there is no rotating part, lubricating oil for that part is not required and maintenance is simple. is there.

Compressed air (air) introduced from the air supply port 15a of the air pipe 15 is used for the cock 16 and the pressure regulator 1.
7, is supplied to the diaphragm pump 10 via the oil cup 18, the speed controller 19, etc., is sent to the control unit 3 from there, and is then discharged into the atmosphere from the air discharge port 15b. During this time, the diaphragm is vibrated. The ink in the pipe 5 is caused to flow in the direction of the arrow. Reference numeral 5a is an ink suction port, and 5b is its discharge port.

A solvent tank 20 is installed above the casing 4, and an ink solvent D, which is a diluting liquid, is stored in the solvent tank 20. A solvent pipe 21 is connected to the bottom of the solvent tank 20 via a solvent cock 23. An explosion-proof explosion-proof electromagnetic valve 25 is provided in the middle of the solvent pipe 21.

The control unit 3 is provided with a CPU (personal computer) 30, to which a pressure switch 32 which is a pressure sensor is connected. The pressure switch 32 is the air pipe 15
Is attached so as to come into contact with the air pipe (air hose) 15 and detects the pressure fluctuation in the air pipe (air hose) 15
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, the limit setting of the viscosity for starting the addition of the solvent, the setting of the time t for opening the solvent electromagnetic valve 25, the target ink The relationship (preliminary test result) between the pulsation number and the actual viscosity when fluidized is stored, the control cycle can be set, and the like.

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

As shown in FIG. 4, the viscosity adjusting device 1 is installed in a system for supplying the ink L to the printing device 50. The ink in the ink tank 51 is circulated and supplied to the printing device 50 by the pump 53. On the other hand, the ink tank 5
The ink in 1 is sucked up by the diaphragm pump 10 of the viscosity adjusting device 1, and the pulsation number per unit time at that time is detected by the pressure switch 32.

This detection result is input to the CPU 30 and a relational expression (stored in the memory) based on the result of the preliminary experiment.
Is converted into viscosity. The obtained viscosity value (centipoise) is displayed by the digital counter 42 to the first 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 the set time t. For this reason, the solvent in the solvent tank is added to the ink, and the concentration of the ink is diluted, resulting in a decrease in viscosity. During the addition of this solvent, the buzzer-40 notifies this.
The set time t is usually set to several seconds to several tens of seconds, but it may be set appropriately depending on the size of the apparatus, the type of ink, and the like.

Further, the shorter the viscosity detection cycle, that is, the control cycle, the higher the accuracy, but normally, several seconds to several tens of seconds are sufficient. The control data, that is, the measured viscosity value and the addition time (amount) of the solvent are continuously recorded on the 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 can also be adopted. Further, the amount of the solvent added may be controlled by the method of opening the valve for a fixed time as described above, or the valve opening and the opening time may be controlled according to the viscosity value.

[0021]

As is apparent from the above description, the viscosity adjusting device according to the present invention measures the viscosity of a fluid such as ink and, when it reaches the limit of the set viscosity value, adds a diluent. Since the operation of lowering the viscosity automatically is performed, it is possible to control the viscosity of ink etc. with high accuracy, and to maintain the quality of products such as printed matter using this type of fluid at high quality. Became possible. In addition, the viscosity of the fluid is directly displayed, which 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 drawings]

FIG. 1 is a structural 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 thereof.

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

FIG. 4 is an illustration of how to use it.

[Explanation of symbols]

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

Claims (2)

[Claims] 1. A diaphragm pump which is arranged in a flow path of a fluid such as printing ink to flow the fluid, a detector for detecting the pulsation number of the diaphragm pump, and a pulsation number detected by the detector. The calculating means for obtaining the viscosity of the fluid, the displaying means for directly displaying the obtained viscosity, the detection of the pulsation number at predetermined time intervals, and the obtained viscosity deviates from the preset viscosity range. And a controller for outputting a signal for opening a valve for supplying the diluent for a set time. 2. The viscosity adjusting device according to claim 1, wherein the detector for detecting the pulsation number is composed of a pressure switch for detecting the air pressure of the diaphragm pump.