JPH05162017A - Ion exchange device - Google Patents

Abstract

(57) [Abstract] [Purpose] To achieve reliable and effective use of the ion-exchange resin in the ion-exchange device with an inexpensive and simple structure, to extend the life of the ion-exchange resin and reduce the running cost. [Structure] A hermetic container 21 of the ion exchange resin 16 is provided with a stirring plate 26 for stirring the ion exchange resin 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion exchange apparatus for adjusting the specific resistance of a working fluid by using an ion exchange resin,
In particular, the present invention relates to an ion exchange device for adjusting the specific resistance of a machining fluid used in an electric discharge machine.

[0002]

2. Description of the Related Art FIG. 10 is a sectional view showing a machining liquid circulation path of an electric discharge machine including a conventional ion exchange device. In the figure, 1 is an electrode, 2 is a workpiece, 3 is a machining liquid, and 4 is a machining liquid. Is a DC power source, 5 is a current limiting resistor, 6 is a switching element,
7 is a processing power source, 8 is a processing tank, 9 is a drain pipe connected to the processing tank 8, 10 is a processing liquid supply device, 11 is a waste liquid tank of the processing liquid supply device 10, 12 is a filtration pump for pumping the waste liquid, and 13 is A filter for filtering the processed powder, 14 a clean liquid tank of the processing liquid supply device 10, 15 a supply pump for supplying the processing liquid 3 to the processing portion, 16 an ion exchange resin, 17 a specific resistance control device, 18 a specific resistance Sensor, 19 is ion exchange resin 1
An ion exchange pump for sending the working fluid 3 to 6, 20 an ion exchange device, 21 a closed container, 22 a supply pipe for the working fluid 3, 2
3 is a discharge pipe for the ion-exchanged working fluid 3.

Next, the operation will be described. In the electric discharge machining, the electrode 1 and the work piece 2 are opposed to each other with a minute gap therebetween via the machining liquid 3, and the electric discharge energy generated by the voltage applied between the electrode 1 and the work piece 2 is used for machining. The voltage is supplied from a processing power supply 7 including a DC power supply 4, a current limiting resistor 5 and a switching element 6.

The machining liquid 3 supplied to the machining section contains machining powder generated by electric discharge machining, and is collected in the waste liquid tank 11 of the machining liquid supply device 10 through the machining tank 8 and the drain pipe 9. The waste liquid is pressure-fed to the filter 13 by the filtration pump 12, and the processed powder is removed to become a clean liquid, which is stored in the clean liquid tank 14. The clean liquid is supplied to the processing section by the supply pump 15, and again contains the processed powder and is collected in the waste liquid tank 11. In this way, the working fluid 3 is recycled and used again.

The working fluid 3 includes insulating oil and electrically conductive water-based working fluid. This is not a problem in the case of an insulating working fluid, but in the case of a conductive working fluid with a low specific resistance (high electrical conductivity), depending on the voltage applied between the electrode 1 and the workpiece 2, the working fluid 3 or the positive electrode side Electrolysis of the material occurs,
The voltage appearing between the electrode 1 and the workpiece 2 is reduced, and the occurrence of electric discharge does not occur. When the distance between the electrode 1 and the workpiece 2 becomes short or the facing area becomes large, it becomes more remarkable.

For this reason, when using a water-based processing liquid,
Ions in the working fluid 3 must be removed so that the resistivity is high. Ions in the working fluid 3 include carbonate ions that are melted from the air, chlorine ions contained in tap water, and metal ions generated by electric discharge machining. In addition,
The reason why the water-based processing liquid is used is that it has advantages such as higher processing speed than oil and no fear of fire.

Ions are removed by bringing the working fluid 3 into contact with the ion exchange resin 16. Specific resistance is 1 × 10 ⁴ to 1 × 1
It is necessary to maintain a value suitable for machining within the range of about 0 ^6, but ions are generated one after another due to contact of machining fluid 3 with air, electrical discharge machining, etc. Must be continuously removed.

The control of the specific resistance is executed by the specific resistance control device 17. Resistivity sensor 1 provided in working fluid 3
When it is detected that the specific resistance of the working fluid 3 is equal to or less than the set value by 8, the ion exchange pump 19 is operated and the working fluid 3 is sent to the ion exchange device 20. When the specific resistance returns to the set value, the ion exchange pump 19 is stopped.

The ion exchange apparatus 20 is a closed vessel 21 filled with a mixture of a cation exchange resin and an anion exchange resin in an appropriate ratio. Ion exchange pump 19
While the working fluid 3 is made to flow in from the upper supply pipe 22 by the pressure of the ion exchange pump 19 and the working fluid 3 is discharged from the lower discharge pipe 23, the ion exchange resin 16 and the working fluid 3 come into contact with each other. Exchange will take place. In the figure, the ion exchange is performed by circulation in the clean liquid tank 14.

Each of the ion-exchange resins (hereinafter referred to as ion-exchange resin particles) has a spherical shape with a diameter of 1 to several mm and adsorbs ions on the surface thereof. If ions are adsorbed on the entire surface, the ion exchange capacity will be lost and the life will end.
The specific resistance control device 17 can determine whether or not the life has expired. That is, as shown in FIG.
Is operated to determine whether the specific resistance of the working fluid 3 has risen after a predetermined time. If the specific resistance does not increase even after the lapse of a predetermined time and it is determined that the life has expired, this is displayed and the ion exchange resin 16 is replaced with a new one.

[0012] In addition, as a reference technical document related to the present invention, there is an "electromachining liquid circulating supply device" disclosed in JP-A-60-135128.

[0012]

Since the conventional ion exchange apparatus is constructed as described above, the position of each ion exchange resin particle is fixed in the container. Therefore, if a constant working liquid flow path is created due to the density of the ion exchange resin particles (density), the ion exchange resin particles in contact with the working liquid will be limited, and the entire ion exchange resin will not be effectively used, There is a problem that the life of the ion exchange resin is shortened.

Further, even if the surface of the ion-exchange resin particles in contact with other ion-exchange resin particles or the surface of the ion-exchange resin particles on which dirt is attached for some reason is present in the machining liquid flow path. There is a problem that it is not effectively used for ion exchange and the life of the ion exchange resin is shortened.

Further, in the above-mentioned Japanese Patent Application Laid-Open No. 60-135128, the "electro-machining liquid circulating and supplying device" ultrasonically vibrates the ion-exchange device to make the contact area of the machining liquid and the ion-exchange resin /
Although it is disclosed that the contact time is substantially increased, the ion exchange resin actually used is at least 10
Since 201 is required, the mechanism for vibrating the device becomes large and the device becomes expensive accordingly.

The present invention has been made in order to solve the above-mentioned problems, and ensures reliable and effective use of the ion exchange resin in the ion exchange device with an inexpensive and simple structure, thereby performing ion exchange. An object of the present invention is to obtain an ion exchange device that can extend the life of the resin and reduce the running cost.

[0016]

In order to achieve the above object, the present invention provides an ion exchange apparatus for adjusting the specific resistance of a working fluid by using an ion exchange resin, which comprises a stirring means for stirring the ion exchange resin. It is provided.

Further, in the ion exchange apparatus for adjusting the specific resistance of the working fluid by using the ion exchange resin, a stirring means for stirring the ion exchange resin and a driving means for driving the stirring means are provided. .

Further, the driving means is constantly operating during ion exchange.

Further, the drive means is repeatedly operated / stopped during ion exchange.

Further, in an ion exchange apparatus for adjusting the specific resistance of the working fluid by using an ion exchange resin, a specific resistance detecting means for detecting the specific resistance of the working fluid, a stirring means for stirring the ion exchange resin, and Drive means for driving the stirring means and control means for controlling the drive means according to the specific resistance detected by the specific resistance detection means are provided.

Further, the tip of the discharge pipe for discharging the ion-exchanged working fluid is constantly immersed in the working fluid.

[0022]

The stirring means according to the present invention changes the relative position between the ion exchange resin particles and the relative position between the ion exchange resin particles and the working liquid supply pipe.

The drive means according to the present invention automatically drives the ion-exchange resin stirring means in synchronization with the operation of the ion-exchange pump.

Further, the control apparatus according to the present invention operates the ion exchange pump by comparing the specific resistance of the working fluid with a preset reference, and when the specific resistance does not rise even when the ion exchange pump operates. Drives the stirring means of the ion exchange resin.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a sectional view showing an embodiment of the present invention. In the figure, 24 is a handle, 25 is a gear, 26
Is a stirring plate, 27 is a rotary shaft to which the stirring plate 26 is attached, 2
Reference numerals 8 and 29 are bearings that support the rotating shaft 27, and 30 is a seal. Further, FIG. 1B is an explanatory view showing the shape of the stirring plate 26.

Next, the operation will be described. Similar to the conventional example, the specific resistance control device 17 operates when the ion exchange pump 19 is operated.
Displays that 6 has reached the end of its life. When the display appears,
The operator rotates the handle 24 in a predetermined direction. The handle 24 is provided with a stirring plate 2 via a gear 25 for deceleration / increase.
6 is attached to a rotating shaft 27, and the stirring plate 26 is rotated in the ion exchange device 20 by turning the handle 24. The rotating shaft 27 is supported by bearings 28 and 29 at the top and bottom, and a seal 30 is provided at the top. The number of rotations is appropriate and does not matter.

The rotation of the stirring plate 26 moves the ion-exchange resin particles from the original position, and the density in the closed container 21 changes. Further, the contact position with other ion-exchange resin particles is changed and the particles are rubbed against each other to remove the dirt attached to the surface. As a result, a new machining liquid flow path is formed, and the ion-exchange resin particles and the surface, which have not been effectively acting until then, are effectively actuated, and the effective life of the ion-exchange resin 16 is extended.

FIG. 2 is a sectional view showing a second embodiment of the present invention. In this embodiment, a plurality of stirring plates 26 are installed on the rotating shaft 27 in a blade shape. The operation is similar to that of the first embodiment.

FIG. 3 is a sectional view showing a third embodiment of the present invention. In FIG. 3A, reference numeral 31 is a cylindrical container having a mesh smaller than the diameter of the ion-exchange resin particles and having a stirring plate 26 inside. The cylindrical container 31 is installed laterally in the closed container 21 and is configured to be rotatable by bearings 28, 29 and the like, and the deceleration / enhancement gear 2 is provided.
A handle 24 for rotation is connected via 5.
Further, as shown in FIG. 3B, approximately half of the ion exchange resin 16 is filled in the cylindrical container 31 in the height direction.

Ion exchange resin 1 in the cylindrical container 31
When stirring 6, the cylindrical container 31 is rotated by the handle 24 in a predetermined direction. The ion-exchange resin particles lifted up to a certain height by the stirring plate 26 eventually fall to the bottom surface of the cylindrical container 31 due to their own weight, and change their position.

FIG. 4 is a sectional view showing a fourth embodiment of the present invention. A gear 25 is provided on the outer circumference of the cylindrical container 31, and a configuration is adopted in which the gear is meshed with the gear provided on the rotating shaft of the handle 24. The operation is similar to that of the third embodiment.

FIG. 5 is a sectional view showing a fifth embodiment of the present invention. In the figure, reference numeral 32 is a motor, which is controlled so as to interlock with the operation of the ion exchange pump 19 and is connected to the rotary shaft 27. Has been done. When the specific resistance of the working fluid 3 is lowered and the ion exchange pump 19 operates, the motor 3 is interlocked with each other.
2 rotates. The motor 32 is constantly rotating at a low speed. Since the motor 32 is connected to the rotating shaft 27 and the stirring plate 26, the position of the ion-exchange resin particles is constantly changed during the operation of the ion-exchange pump 19, and a new machining liquid flow path is formed.

FIG. 6 shows a sixth embodiment of the present invention,
It is a timing chart which shows another operation timing by the motor in the said 5th Example. That is, the inside of the specific resistance control device 17 is set to the motor 3 so as to periodically start / stop.
Control 2 First, at the same time when the operation of the ion exchange pump 19 starts, the motor 32 also starts to operate, and the ion exchange resin 1
Stir 6 After a lapse of a certain time (T1), the operation of the motor 32 is stopped and the stirring is stopped. Then, if the ion exchange pump 19 continues to operate after the elapse of a certain time (T2), the operation of the motor 32 is restarted and the ion exchange resin 16 is agitated. This operation is repeated. Even if the motor 32 rotates and the ion exchange resin 16 is being stirred, if the specific resistance increases and the ion exchange pump 19 stops, the motor 32 also stops. This control processing can be realized by a relay having a timer function, software, or the like.

FIG. 7 is a flow chart showing the operation in the seventh embodiment. The operation of stopping / operating the motor 32 is controlled by the specific resistance control device 17. The resistivity control device 17 determines whether or not the resistivity of the working fluid 3 is the lower limit (S
1) If the lower limit is determined, the counting of the stirring determination time is started (S2), and the ion exchange pump 19
Is operated (S3), and ion exchange is executed. afterwards,
It is judged whether or not the stirring judgment time is counted up (S
4) If it is determined that the count has been incremented, the counting of the stirring time is started (S5), the motor 32 is operated to stir the ion exchange resin 16 (S6), and then the counting of the stirring determination time is reset (S7). ). Then, it is determined whether or not the stirring time has counted up (S8), and when it is determined that the stirring time has counted up, the motor 32 is stopped (S9), and counting up of the life time is started (S10). , The count of the stirring time is reset (S11). Then, it is determined whether or not the life time has counted up (S12), and when it is determined that the life time has counted up, the ion exchange pump 19 is stopped (S13) and the stirring life time count is reset ( S14).

If it is determined in step S4 that the stirring determination time has not counted up, it is determined whether the specific resistance is the upper limit (S15). If it is determined that the specific resistance is the upper limit, the stirring is determined. Reset the judgment time count (S
16) Start counting the stirring judgment time (S1
7) and returns to step S1. In addition, the above step S
If it is determined in 8 that the stirring time has not counted up, it is determined whether the specific resistance is the upper limit (S18), and if it is determined that it is the upper limit, the motor 32 is stopped (S1).
9) After resetting the stirring time count (S2
0), start counting the stirring judgment time (S1
7) and returns to step S1. In addition, the above step S
When it is determined that the life time has not counted up in 12, it is determined whether the specific resistance is the upper limit (S21),
When it is determined that the upper limit is reached, the stirring life time count is reset (S22), the stirring determination time count is started (S17), and the process returns to step S1.

As described above, after the motor 32 is stopped, if the specific resistance does not increase even after the ion exchange is continued for a predetermined time, it means that the ion exchange resin 16 has reached the end of its life and a message prompting the exchange is displayed.
Further, the above-mentioned predetermined time is appropriately determined depending on the flow rate of ion exchange, the total amount of processing liquid, and the like. FIG. 8 shows the relationship between the passage of time and the specific resistance value.

FIG. 9 is an explanatory view showing the eighth embodiment of the present invention. That is, after the ion exchange, when the machining fluid 3 having an increased specific resistance passes through the air and falls into the clean fluid, the carbonate ions in the air are mixed due to the entrainment of air during the fall and due to splashing on the surface of the clean fluid during the fall. Easy to do. This means that the ion exchange resin 16 is wasted. In the eighth embodiment, the tip of the discharge pipe 23 is fixed in the clean liquid. As a result, the ion-exchanged working fluid 3 can prevent a decrease in the specific resistance without entraining air on the way.

[0038]

According to the present invention, since the ion exchange resin can be used by stirring in the ion exchange device, the ion exchange resin in the ion exchange device can be reliably and effectively utilized with a low cost and a simple structure. This makes it possible to extend the life of the ion exchange resin, maintain the processing accuracy, and reduce the running cost. Further, there is an effect that the ion exchange resin can be automatically stirred.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an ion exchange device according to the present invention.

FIG. 2 is an explanatory diagram showing another schematic configuration of the ion exchange device according to the present invention.

FIG. 3 is an explanatory diagram showing another schematic configuration of the ion exchange device according to the present invention.

FIG. 4 is an explanatory diagram showing another schematic configuration of the ion exchange device according to the present invention.

FIG. 5 is an explanatory diagram showing another schematic configuration of the ion exchange device according to the present invention.

FIG. 6 is a timing chart showing another operation example of the ion exchange device shown in FIG.

FIG. 7 is a flowchart showing an operation example of the ion exchange device according to the present invention.

FIG. 8 is a graph showing the relationship between elapsed time and specific resistance value.

FIG. 9 is an explanatory diagram showing another schematic configuration of the ion exchange device according to the present invention.

FIG. 10 is an explanatory view showing a machining fluid circulation path including a conventional ion exchange device.

[Explanation of symbols]

 16 Ion exchange resin 17 Specific resistance control device 18 Specific resistance sensor 19 Ion exchange pump 20 Ion exchange device 21 Closed container 22 Supply pipe 23 Discharge pipe 24 Handle 25 Gear 26 Stirring plate 27 Rotating shaft 31 Cylindrical container 32 Motor

Claims (6)

[Claims] 1. An ion exchange device for adjusting the specific resistance of a working fluid by using an ion exchange resin, wherein an ion exchange device is provided with stirring means for stirring the ion exchange resin. 2. An ion exchange apparatus for adjusting the specific resistance of a working fluid by using an ion exchange resin, wherein an agitation means for agitating the ion exchange resin and a drive means for driving the agitation means are provided. Ion exchange device. 3. The ion exchange apparatus according to claim 2, wherein the drive means is constantly operating during ion exchange. 4. The ion exchange apparatus according to claim 2, wherein the driving means repeats operation / stoppage periodically during ion exchange. 5. An ion exchange apparatus for adjusting the specific resistance of a working fluid by using an ion exchange resin, a specific resistance detecting means for detecting the specific resistance of the working fluid, a stirring means for stirring the ion exchange resin, and Drive means for driving the stirring means,
An ion exchange apparatus comprising: a control unit that controls the driving unit according to the specific resistance detected by the specific resistance detection unit. 6. The ion exchange apparatus according to claim 1, wherein a tip of a discharge pipe for discharging the ion-exchanged working fluid is constantly immersed in the working fluid.