JP2001219338A - Method and device for controlling degree of pollution of working fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a proper method and a device for controlling the degree of pollution of a working fluid by efficiently changing the working fluid so that a replacement interval is not varied without applying a burden to a worker. SOLUTION: A pressure sensor 5 is installed in a return pipe 1 for the working fluid discharged from a machine tool M at a position where the working fluid falls down by itself and, when the impact pressure of the working fluid detected by the pressure sensor 5 reaches the impact pressure equivalent to a preset pollution on level, it is determined that a working fluid switching time has come, or an optical sensor 6 is installed instead of the pressure sensor 5 and, when the light transmission amount of the working fluid lowers to a light transmission amount equivalent to a preset pollution level, the working fluid is determined to be switched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling the turbidity of a machining fluid for controlling the turbidity of a machining fluid (coolant) supplied for lubrication and cooling of a machining point when machining a workpiece with a machine tool. And a pollution control device.

[0002]

2. Description of the Related Art When a workpiece is ground or cut by a machine tool, a machining fluid (coolant) is poured into a machining point to enhance workability by a lubricating action and a cooling action of the machining fluid, and at the same time a chip at the machining point. Is smoothly eliminated. Since such a working fluid is generally expensive, it is used again after removing foreign matter such as chips.

A conventional circulation path of a machining fluid will be described with reference to FIG. 6. First, a machining fluid supplied to a machine tool M is dropped on a table of the machine tool M after being poured into a work, and chips are cut off. Such foreign substances are collected in the dirty tank 2 via the return pipe 1 while being mixed. Then, the working fluid collected in the dirty tank 2 passes through the filter 3. At this time, foreign substances such as chips are removed, and the processing liquid from which the foreign substances have been removed (filtered) is collected in the clean tank 4 and then sent again to the processing point of the machine tool M by a supply pump (not shown). .

[0004]

By the way, a magnet separator or a fine filter is used for the filter 3. However, since foreign substances such as chips cannot be completely recovered, the working fluid increases as the frequency of use increases. Pollutant increases. The use of the machining liquid having a high degree of contamination causes adverse effects such as deterioration in the finishing accuracy of the work surface, and when the degree of contamination reaches a predetermined degree of contamination, replacement with a new machining liquid is performed. Conventionally, the determination of the degree of contamination of the working fluid has been made visually by an operator.However, since the criteria for determining the degree of contamination by visual observation are difficult and unclear, there is a problem that the timing of replacement may vary. Was. Another problem is that it is difficult to set a replacement time for a machine tool such as a machining center that handles a plurality of workpieces.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is an efficient and appropriate method for contaminating a working fluid without placing a burden on an operator and having no variation in replacement time. A management method and an apparatus therefor are provided.

[0006]

A method for managing the degree of contamination of a working fluid which has been made to achieve the above object is to purify a working fluid containing foreign matter collected from a machine tool and supply the same to the machine tool again. The circulation pressure of the machining fluid that collides with the pressure sensor provided in the piping of the circulation path is measured, and the impact pressure reaches a predetermined impact pressure corresponding to a set pollutant level. Sometimes, it is determined that it is time to switch the working fluid.

In the above-mentioned method for controlling the degree of contamination of a working fluid, attention is paid to the fact that the specific gravity of the working fluid increases in accordance with the degree of contamination of the working fluid, and the impact force colliding with the pressure sensor increases in proportion thereto. When the impact pressure reaches a predetermined impact pressure corresponding to the set turbidity level, it is determined that it is time to switch the working fluid.

In order to achieve the above object, a method for controlling the degree of contamination of a machining fluid, which is provided with a circulating path for the machining fluid, which purifies the machining fluid containing foreign matter collected from the machine tool and supplies the machine fluid to the machine tool again, The optical sensor provided in the pipe of the circulation path measures the light transmission amount of the processing liquid, and when the light transmission amount decreases to a predetermined light transmission amount corresponding to the set contamination level, the processing liquid It is characterized by determining that it is time to switch.

In the above-mentioned method for controlling the degree of contamination of the working fluid, attention is paid to the fact that the light transmittance of the working fluid is reduced in accordance with the degree of contamination of the working fluid, and the light transmission amount is determined by a predetermined level corresponding to the set pollution level. When the light transmission amount has decreased to the above, it is determined that it is time to switch the working fluid.

In order to achieve the above-mentioned object, a working fluid pollution control apparatus provided with a working fluid circulating path for purifying a working fluid containing foreign matter collected from a machine tool and supplying the working fluid to the machine tool again, In the pipe of the circulation path, a downflow pipe section in which the machining fluid flows by its own weight is provided, and a pressure sensor against which the machining liquid collides in the downflow pipe section is provided, and the pressure sensor of the pressure sensor is provided outside the pipe of the circulation path. It is characterized in that a pollution degree indicator is provided for displaying whether or not the measured pressure has decreased to a predetermined pressure corresponding to the pollution level at the time of switching the working fluid.

In the above-mentioned apparatus for controlling the degree of contamination of a machining fluid, the downflow pipe section through which the machining fluid flows under its own weight is provided in the pipe of the circulation path, so that the passing speed of the machining fluid flowing through the downflow pipe section is constant. Becomes Therefore, the impact force colliding with the pressure sensor installed in the downflow pipe portion is proportional to the weight of foreign matter such as cutting chips. The impact force when the pollutant level to be replaced is reached is measured in advance, and when the pressure sensor reaches the impact force (pressure), it is determined that the working fluid is to be switched, and the result is displayed on the pollutant indicator. With such a configuration, there is no variation in the determination of the timing of switching the machining fluid.

In order to achieve the above-mentioned object, a working fluid pollution control device is provided with a working fluid circulation path for purifying a working fluid containing foreign substances collected from a machine tool and supplying the working fluid to the machine tool again. An optical sensor is provided in the piping of the circulation path, and a predetermined light transmission amount outside the piping of the circulation path, wherein the light transmission amount of the machining fluid measured by the optical sensor corresponds to the contamination level at the time of switching the machining fluid. It is characterized in that a pollution degree indicator for displaying whether or not the amount has decreased is provided.

In the apparatus for controlling the degree of contamination of a working fluid, an optical sensor is provided in the piping of the circulation path. Therefore, when foreign matters such as cutting chips of the working fluid increase, the light transmission amount of the working fluid decreases. Then, when the light transmission amount is reduced to a predetermined light transmission amount corresponding to a preset contamination level, it is determined that it is time to switch the working fluid, and the result is displayed on a contamination display. Therefore, there is no variation in the determination of the timing of switching the working fluid.

In order to achieve the above-mentioned object, the apparatus for controlling the degree of turbidity of a working fluid comprises a main dirty tank for recovering the working fluid and a working fluid which has passed through a filter from the main dirty tank. A main circulation path having a main clean tank for storing and supplying the machine fluid to the machine tool, a sub-dirty tank for collecting the machining fluid, and a sub-clean tank for storing the machining fluid passing through the filter from the sub-dirty tank and supplying the machine fluid to the machine tool And a switching valve for switching from the main circulation path to the sub-circulation path when the machining fluid flowing through the main circulation path reaches the contamination level. And

In the above-mentioned apparatus for controlling the degree of contamination of the working fluid, when the sensor (pressure sensor or optical sensor) detects that the working fluid gradually becomes polluted and reaches the level of contamination to be replaced, the main circulation is performed by the switching valve. The path is switched to the auxiliary circulation path, and a new machining fluid is used. By this switching, the machining fluid flows through the sub-circulation route supplied to the machine tool through the sub-dirty tank, the filter, and the sub-clean tank, so that during the period when the machining fluid is circulating in the sub-circulation route, Can be exchanged, and the workpiece can be machined without stopping the machine tool.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a processing fluid contamination management device according to the present invention, FIG. 2 is a cross-sectional view of a return pipe provided with a pressure sensor, and FIG. 4 is a longitudinal section showing a main part of a return pipe provided with an optical sensor, and FIG. 5 is a schematic configuration diagram of a working fluid pollution degree management device provided with two working fluid circulation paths. The apparatus for controlling the degree of contamination of a machining fluid according to the present invention shown in FIG. 1 is provided with a pressure sensor 5 in the return pipe 1 of the conventional circulation path of the machining fluid shown in FIG. Display 7
Is provided.

The pressure sensor 5 is, as shown in FIG.
Downflow pipe section 8 that falls almost vertically in the middle of return pipe 1
And the downflow pipe section 9. That is, as shown in FIG. 2, the support member 10 on which the pressure sensor 5 is mounted is inserted into the flange 8a of the downflow pipe section 8 and the flange 9a of the downflow pipe section. The support member 10 is formed by connecting a ring-shaped portion (not shown) sandwiched between the flanges 8a and 9a and a sensor fixing surface 10a substantially at the center with three support arms 10b. 1
The pressure sensor 5 is fixed to the upper surface of Oa. Also,
The support member 10 has a gap S formed between the three support arms 10b so as not to hinder the passage of the working fluid.

The pollution degree display 7 indicates to the operator that the impact pressure detected by the pressure sensor 5 has reached a predetermined impact pressure. Is provided at a position where it can be easily confirmed, or at a machine tool operation panel surface. The pollution degree indicator 7 may display the current impact pressure in comparison with a predetermined impact pressure notifying the replacement timing of the working fluid, or the present impact pressure has reached a predetermined impact pressure. May be transmitted to the worker by an alarm or an electric light display.

The method for controlling the degree of contamination by the above-configured apparatus for controlling the degree of contamination will now be described. The working fluid mixed with foreign matter discharged from the machine tool M is supplied to the downflow pipe section 8 provided in the return pipe 1, 9 flows down at a constant speed. After applying the impact pressure corresponding to the degree of contamination to the pressure sensor 5, the working fluid passes through the filter 3 to remove most of the foreign matter and is sent to the clean tank 4. It is supplied to the machine tool M.

At this time, since the filter 3 cannot completely remove the foreign matter in the working fluid, the working fluid gradually becomes turbid. As the degree of contamination of the working fluid increases, the collision pressure received by the pressure sensor 5 increases, and when the working fluid reaches the degree of contamination to be replaced, the detection signal from the pressure sensor 5 causes the pollution degree indicator 7 to change the working fluid. Inform the worker that the time has been reached. As described above, it is possible to automatically and accurately know that the switching time of the working fluid has been reached by the turbidity indicator 7, thereby preventing the work surface from being damaged due to excessive working fluid. It is possible,
The uneconomical problem of exchanging the working fluid earlier than necessary can be prevented.

Further, instead of the pressure sensor 5, an optical sensor 6 may be used as shown in FIG. In the pollution control apparatus shown in FIG. 4, a transparent window glass 12 is provided on the opposite side wall of the connecting short pipe 11 attached between the downflow pipe sections 8 and 9, and a light projector is provided outside the both window glasses. An optical sensor 6 including a light receiver 6a and a light receiver 6b is provided. In the optical sensor 6, light emitted from the light projector 6a passes through the inside of the connection short pipe 11, and is received by the light receiver 6b. At this time, the amount of light received by the light receiver 6b decreases in accordance with the increase in the degree of contamination of the working fluid flowing through the connecting short pipe 11, so that the light transmission of the optical sensor 6 when the degree of contamination of the working fluid comes to the switching time. When the degree is detected, if the worker is made to recognize by the pollution indicator 7, the same effect as the pressure sensor 5 can be obtained.

Next, a description will be given of a pollution degree control device capable of switching a polluted working fluid with reference to FIG. In this device, the circulation path of the machining fluid is constituted by two closed loops of a main circulation path 14 and a sub circulation path 15, and a switching valve 16 installed downstream of the pressure sensor 5 causes the main and sub circulation paths 14, It is configured to close one of the 15 while releasing the other. The main circulation path 14 has a main dirty tank 2 a in a pipe 17 connected to one outlet port of the switching valve 16,
The filter 3a and the main clean tank 4a are sequentially provided, and the processing liquid in the main clean tank 4a is supplied to the machine tool M. On the other hand, a sub-circulation path 15 is connected to a pipe 18 connected to the other outlet port of the switching valve 16 by a sub-dirty tank 2b, a filter 3b, and a sub-clean tank 4b.
Are sequentially provided, and the machining liquid in the sub-clean tank 4b is supplied to the machine tool M.

A description will be given of a management method by the pollution degree management device configured as described above. When the outlet port of the switching valve 16 is connected to the main circulation path 14, the machining fluid discharged from the machine tool M After passing through the return pipe 1, the impact pressure is detected by the pressure sensor 5 and supplied to the machine tool M via the main dirty tank 2a, the filter 3a, and the main clean tank 4a. Then, while the machining fluid circulates, foreign matters such as cutting chips gradually increase, and when the contamination reaches a predetermined contamination level, the detection signal of the pressure sensor 5 causes the contamination indicator 7 to switch the machining fluid. Show that.

The operator operates the switching valve 16 to close the main circulation path 14 and release the sub circulation path 15 according to the display on the pollution degree indicator 7. As a result, the machining fluid circulates in the sub-circulation route 15, and the machining fluid in the main circulation route 14 can be replaced with a non-contaminated one without stopping the machine tool M. In the above embodiment, the case where the switching valve 16 is manually operated has been described. However, an automatic switching valve that automatically operates according to a command from the pollution degree indicator 7 may be used. The pressure sensor 5
Although the description has been given of the case where the optical sensor is used, a similar effect can be obtained by using an optical sensor.

[0025]

Since the present invention has the above-described structure, it is not necessary to perform a troublesome visual inspection for determining the degree of contamination of the working fluid, and there is a possibility that the timing of changing the working fluid may vary. In addition, the working fluid can be efficiently and appropriately changed. Further, when the circulation path of the machining fluid is switched by the switching valve, there is an effect that the machining fluid can be exchanged without stopping the machine tool.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a processing liquid pollution degree management device according to the present invention.

FIG. 2 is a cross-sectional view of a return pipe provided with the pressure sensor shown in FIG.

FIG. 3 is a view taken in the direction of arrows XX in FIG. 2;

FIG. 4 is a longitudinal sectional view showing a main part of a return pipe provided with an optical sensor.

FIG. 5 is a schematic configuration diagram of a pollution control apparatus provided with two working fluid circulation paths according to the present invention.

FIG. 6 is a schematic configuration diagram of a conventional pollution control device.

[Explanation of symbols]

 M Machine tool 1 Return pipe 2 Dirty tank 2a Main dirty tank 2b Secondary dirty tank 3 Filter 3a Filter 3b Filter 4 Clean tank 4a Main clean tank 4b Secondary clean tank 5 Pressure sensor 6 Optical sensor 7 Pollution degree indicator 8 Downstream piping section 9 Downflow pipe section 10 Support member 14 Main circulation path 15 Secondary circulation path 16 Switching valve

Claims (5)

[Claims] 1. A process for purifying a machining fluid containing foreign matter collected from a machine tool and recirculating the machining fluid to be supplied to the machine tool again, wherein the machining fluid collides with a pressure sensor provided in a pipe of the circulation route. Measuring the impact pressure of the liquid, and when the impact pressure reaches a predetermined impact pressure corresponding to the set contamination level, determining that it is time to switch the machining fluid, and a method for managing the degree of contamination of the machining fluid. . 2. A machining fluid circulation path for purifying a machining fluid mixed with foreign matters collected from a machine tool and supplying the machining fluid to the machine tool again. Measuring the amount of light transmission, and when the amount of light transmission decreases to a predetermined amount of light transmission corresponding to the set level of contamination, determining that it is time to switch the processing liquid; Method. 3. A down-flow pipe for circulating a processing fluid containing foreign matter collected from a machine tool and recirculating the processing fluid to be supplied to the machine tool again, wherein the machining fluid flows by its own weight in the pipe of the circulation path. And a pressure sensor with which a machining fluid collides in the downflow pipe portion, and a predetermined pressure corresponding to a contamination level at a machining fluid switching time, wherein a measurement pressure of the pressure sensor is provided outside the piping of the circulation path. A pollution control device for a working fluid, comprising a pollution indicator for displaying whether or not the pressure has decreased. 4. A circulating path for purifying the working fluid mixed with foreign substances collected from the machine tool and supplying the working fluid to the machine tool again, and an optical sensor is provided in a pipe of the circulating path. Provided outside the pipe is a pollution degree indicator that indicates whether or not the light transmission amount of the processing fluid measured by the optical sensor has decreased to a predetermined light transmission amount corresponding to the contamination level at the time of switching the processing fluid. A pollution control device for a working fluid. 5. A main circulation system comprising: a main dirty tank for collecting a working fluid; and a main clean tank for storing a working fluid that has passed through a filter from the main dirty tank and supplying the working fluid to a machine tool in a circulation path of the working fluid. A sub-circulation path including a sub-dirty tank that collects a machining fluid, and a sub-clean tank that stores the machining fluid that has passed through the filter from the sub-dirty tank and supplies the machining fluid to the machine tool. When the flowing machining fluid reaches the turbidity level,
The apparatus according to claim 3 or 4, further comprising a switching valve for switching from the main circulation path to the sub circulation path.