HK1068683A - Method and apparatus for measuring a variable in lubricant/coolant system - Google Patents

Description

Method and device for determining variables in a lubricant/coolant system

Technical Field

The present invention relates generally to methods and apparatus for determining a variable in a fluid system, and more particularly to methods and apparatus for determining a fluid variable in a lubricant or coolant system, and for cleaning and performing calibration checks on the determination apparatus to ensure accurate determinations.

Background

Most metal removing machine tools, including automatic screw machines and computer controlled machining center machines, rely on cooling and lubricating fluids supplied to the machining site to extend tool life, improve surface finish of the machined part, increase cutting speed and remove heat generated by the machining to reduce part distortion and disturbances or degradation of performance caused by heat treatment.

Maintaining optimum concentrations and fluid characteristics of the cooling or lubricating fluid is necessary from the standpoint of maintaining optimum machining conditions, extending coolant and lubricant service life, and thus reducing overall operating costs.

Various devices and methods have been developed for optimal utilization of cutting equipment and cooling and lubricating fluids. For example, U.S. patent 4757307 discloses a method of detecting the heat generated by a tool in order to determine the condition of the tool.

Us patent 6134930 discloses a system in which separate or separate lubricating and cooling fluids are used to achieve separate operational advantages.

Typically, the system operating conditions may be monitored at the workplace and the relevant information provided by the land line to a remote location where decisions regarding adjusting fluid parameters are made and transmitted to the operating location. Such a system is disclosed in us patent 5244051.

In us patent 6336362, a method and system for determining, and reporting the level of, liquid in a container is disclosed. The system is particularly useful for detecting and reporting the level of liquid propane in industrial, commercial and residential spaces to avoid depletion of the gas supply at specific locations.

As can be seen from the above description, the monitoring and control systems related to the fluid, the amount of fluid and the condition of the fluid are various. In addition, it can be seen that methods and apparatus have not been fully developed to address specific operational issues, such as the accurate determination of fluid variables, such as pH, concentration, conductivity or temperature. For example, many sensors become dirty after contacting the coolant and lubricant, particularly when the coolant and lubricant become contaminated. The present invention addresses and solves the problems described.

Disclosure of Invention

An automated system for monitoring/controlling a variable of a machine tool or metalworking fluid system that also enables cleaning and selective targeted inspection of the sensors of the variable. The system includes one or more sensors for sensing variables such as pH, fluid concentration, conductivity, and temperature, a source of cleaning reagents, and associated valves and conduits connecting the automated system to the fluid to be sensed. The cleaning cycle may be set to clean and/or check calibrate the one or more sensors, as desired, and ensure accurate determination of the sensed variables. The inlet of the system and the outlet of the system may be connected to separate manifolds having a corresponding plurality of inputs and outputs, if necessary. In addition, data on the sensed variables can be used for real-time calibration operations, if necessary. Finally, the detection and operation data may be transmitted over telephone lines, the internet, or other means to a remote location where the variables and operations may be monitored and recorded.

It is therefore an object of the present invention to provide a method for monitoring at least one variable of a machine tool coolant or lubricant.

It is a further object of the present invention to provide a device for monitoring at least one variable of a machine tool coolant or lubricant.

It is a further object of the present invention to provide an apparatus and method for monitoring and controlling at least one variable of a machine tool coolant or lubricant.

It is another object of the present invention to provide a method and apparatus for cleaning and checking a calibrated fluid variable sensor.

It is another object of the present invention to provide a method and apparatus for cleaning and inspecting fluid variable sensors that calibrate machine coolant and lubricant.

It is a further object of the present invention to provide for monitoring at least one variable of machine coolant and lubricant and providing that information to a remotely located location.

Other objects and advantages of the present invention will be understood by reading the following description of the preferred embodiments and the accompanying drawings, in which like reference numerals refer to the same parts, elements or features.

Drawings

FIG. 1 is a schematic view of an automatic screw machine employing the present invention;

FIG. 2 is a block diagram of the components of the apparatus of the present invention having sensors for monitoring variables of the machine tool coolant or lubricant, and components for cleaning and providing a calibration check of the sensors;

FIG. 3 is a schematic view of inlet and outlet manifolds for use in combination with the coolant and lubricant monitoring assembly of the present invention; and

FIG. 4 is a schematic view of the coolant and lubricant monitoring assembly of the present invention located remotely from the monitoring site.

Detailed Description

Referring to fig. 1, an automatic screw machine 10 includes a plurality of tool posts 12 and a work library 14 of workpieces, as well as tools that cooperate to produce a variety of machine components (not shown). It should be understood that the automatic threading machine 10 is merely illustrative and that the apparatus and method of the present invention may be and is intended for use with the automatic threading machine 10, Computer Numerical Control (CNC) devices and machining centers, lathes, grinders, iron beds, and all common forms of equipment for cutting, forming, boring, milling, drilling, and forming, but not exclusively, metal parts, wherein such machining is facilitated by the use of the cooling and/or lubricating fluid 16.

The cooling and lubricating fluid 16 is typically stored in a reservoir 18 and may be delivered to the machine tool 10 via a pipe 22 by the pressure of a pump 20. The cooling and lubricating fluid 16 is returned directly to the reservoir 18 by a return line 24. The cooling and lubrication fluid 16 is provided to the coolant and lubricant monitoring assembly 30 by a second return line and inlet or delivery line 26. Fluid 16 exiting the coolant and lubricant monitoring assembly 30 returns to the reservoir 18 through the outlet tube 32 and is thus recirculated.

Referring to FIG. 2, the input or delivery tube 26 includes a first pressure gauge 36, which may be an eye-readable device, such as a conventional Bourdon tube pressure gauge, or may be a sensor capable of providing a signal to a remote location. At the end of the input or delivery tube 26 is a normally closed, two-position first solenoid valve 38 that can be opened or closed by a controller 40 to deliver or inhibit cooling or lubrication fluid 16 to the coolant and lubrication monitoring assembly 30. When the solenoid valve 38 is open, the cooling or lubrication fluid 16 is provided to the high pressure pump 42. A pump 42 driven by a motor 43 may increase the pressure of the fluid 16 to approximately 80 p.s.i.. The actual operating pressure is regulated by the restriction provided by the flow regulating or restricting device 44. The restriction provided by the flow regulating device 44 increases, raising the pressure in the delivery pipe 46 to a higher pressure, and decreases, here, to a lower pressure. The preferred or selected operating pressure in the delivery tube 46 is influenced by the type of cooling and lubricating fluid 16. A second pressure gauge 48 reads and indicates the pressure at the outlet of the high pressure pump 40 on the delivery pipe 46. Likewise, the second pressure gauge 48 may be a conventional (visible to the naked eye) pressure gauge or a sensor that provides a signal to a remote location.

As described above, the flow regulating device 44 may control the pressure of the fluid 16 moving in the delivery tube 46. The high pressure cooling and lubricating fluid 16 is provided into the sensor assembly housing 50 through an orifice 51 having a diameter on the scale of 0.125 inches (3 millimeters). Fluid 16 that passes through the flow adjustment device 44 and thus does not pass through the delivery tube 46 also flows into the sensor assembly housing 50. The sensor assembly housing 50 can removably receive a refractive concentration sensor 52, such as those sold by several manufacturers, including K-Patents, Naperville, Illinois, AFAB Enterprises, Eustis, Florida, and Misco, Cleveland, Ohio. The concentration sensor 52 includes a surface upon which the fluid flow of cooling and lubrication fluid 16 through the orifice 51 impinges under high pressure conditions. The output signal or data from the concentration sensor 52 is provided through an output lead 54. The fluid 16 flows from the sensor assembly housing 50 and may impinge upon, engage, or pass through additional or alternative sensors 56, such as temperature sensors, pH sensors, conductivity sensors, turbidity sensors, or other sensors capable of providing information about various variables and conditions of the cooling or lubricating fluid 16.

The cooling or lubrication fluid 16 then travels to the normally closed second solenoid valve 58, which is activated and causes the metered cooling or lubrication fluid 16 to flow out of the monitoring assembly 30 through the second flow regulator 62. The second flow adjustment device 62 provides an adjustable restriction that ensures that the proper pressure is maintained in the monitoring assembly 30. The cooling or lubricating fluid 16 is returned to the reservoir 18 and associated equipment via an output pipe 32.

Described above are components of the coolant and lubricant monitoring assembly 30 that are associated with monitoring variables under normal operating conditions. The components constitute a passage for a small percentage of the cooling or lubricating fluid 16 that circulates in the system of fig. 1 to bypass the monitoring assembly 30.

The cooling and lubrication monitoring assembly 30 also includes components that accommodate and are used to clean the concentration sensor 52 and any optional sensors 56. Thus, the monitoring assembly 30 includes a source of concentrated cleaning agent contained in a storage container 72 that is supplied to a chemical metering pump 74. The concentrated cleaning agent is preferably and acts as a solvent for the components and contaminants of the particular cooling and lubricating fluid 16 being used so as to facilitate softening, emulsifying and removal of contaminants from the monitoring assembly 30 by the addition of such cleaning agent.

The chemical metering pump 74 is activated for a predetermined time by the timing function of the controller 40. When the controller 40 commands operation, the chemical metering pump 74 is operated for a predetermined time to inject a controlled amount of concentrated cleaning solution through the check valve 78 into the sensor assembly housing 50. The time may be adjusted to accommodate and compensate for different cooling and lubrication fluids 16 and different concentrated cleaning agents.

Also associated with the purge function is a bypass or purge circuit 80 having a normally open third solenoid valve 82 and a check valve 84. The third solenoid valve is operated by the controller 40 and in fluid communication with the outlet of the third solenoid valve 82 is a check valve 84. A fourth solenoid valve 86, which is normally closed, is also operated by the controller 40 and opens to dump the concentrated cleaning agent or any other fluid contained in the coolant and lubrication monitoring assembly 30 into a waste container 88.

The operation of the coolant and lubricant monitoring assembly 30 in two operating states, namely a monitoring mode and a cleaning mode, will now be described.

The first solenoid valve 38 is normally closed and, when it is activated, receives cooling and lubricating fluid 16 from the external system through the pipe 26. At the same time, a second normally closed solenoid valve 58 may also be activated to provide an outlet for the input fluid 16. The pressure of the delivered cooling and lubrication fluid 16 is monitored by a first pressure gauge 36. By deactivating the normally open third solenoid valve 82, fluid 16 may flow through the bypass or purge circuit 80 at intervals, purging and draining previously contained fluid in the bypass or purge circuit 80.

When the flush interval is over, the normally open third solenoid valve 82 is activated and the bypass or return 80 is closed. This action directs all of the incoming fluid 16 to the high pressure pump 42. The motor 43 of the pump 42 is activated so as to suck the cooling and lubricating fluid 16 to be detected and to fill the various components of the coolant and lubricant monitoring system 30, flushing and discharging the previously contained fluid. Thus, fluid 16 is provided to sensor assembly housing 50, concentration sensor 52, and other optional sensors 56 for ease of understanding. The normally closed second solenoid valve 58 remains activated and therefore opens and allows fluid 16 to return to main system through flow regulator 62 and return line 32.

When a test cycle is complete, the high pressure pump 42 is shut down and the controller 40 signals the chemical metering pump 74 to inject a metered amount of concentrated cleaning solution into the system through the check valve 78. The operating time of the metering pump 74, and the amount of concentrated cleaning agent injected, can be controlled and adjusted by software in the tuning controller 40. The normally closed first solenoid valve 38 is then deactivated to close it. The second solenoid valve 58, which is normally closed, is deactivated to close it. And the third solenoid valve 82, which is normally open, is deactivated to open it. The high pressure pump 42 is activated and the fluid 16, now containing concentrated cleaning agent, is forced at high pressure against the surface of the concentration sensor 52 to clean the sensor and any optional sensors 56. The bypass or purge circuit described above now functions as a fluid circuit to the high pressure pump 42 so that the cooling and lubricating fluid 16 containing the purge concentrate can be recirculated through the sensor.

Under the control of controller 40, the cleaning cycle is conducted for a period of time determined by prior experimentation or inspection that is sufficient to properly clean concentration sensor 52 and any selected sensors 56. The cooling and lubricating fluid 16 containing the cleaner concentrate can be left in the system 30, if necessary, and circulated at intervals until a new measurement is needed or it is drained. To release the fluid 16 containing the cleaning concentrate, the first solenoid valve 38 is activated to provide the incoming fluid 16 and the second solenoid valve 58 is activated to remove the fluid 16 present in the assembly 30. In this state, fluid is facilitated to flow through the bypass or purge loop 80 at intervals to remove the fluid 16 containing concentrated purge. When the interval is over, the normally open third solenoid valve is activated and the bypass or purge circuit 80 is closed. This action directs all of the incoming fluid to the pump 42. The motor 43 of the high pressure pump 42 is activated to assist in drawing in the fluid 16 to be tested and to fill the various components of the coolant and lubricant monitoring system 30 other than the bypass to remove the fluid 16 containing the concentrated cleaning agent back to the main system 32. Additionally, the normally closed second solenoid valve 58 is deactivated, while the normally closed fourth solenoid valve 86 is activated to allow fluid 16 to flow into a waste container 88.

Referring to fig. 3, the coolant and lubricant monitoring assembly 30 may also be used with input and output manifolds to enable simultaneous monitoring of fluids in several independent systems and to provide a variety of special fluids having other functions. Thus, at the return and input lines 26, which provide fluid to the coolant and lubricant monitoring assembly 30, is an input manifold 90 having a plurality of independently operated input solenoid valves, the outlets of which are in fluid communication with the input manifold. Also in fluid communication with the output conduit 32 is a second output manifold 100 having a plurality of independently operated output solenoid valves.

For the input manifold 90, a plurality of solenoid operated valves 92A, 92B, 92C, 92D and 92E are provided with various fluids from various independent drilling, cutting, grinding and other manual and CNC machines having cooling or lubricating fluids 16 that need to be monitored. The solenoid valves 92A, 92B, 92C, 92D and 92E are controlled by the controller 40 (or by an optional controller 94 that is connected to the controller 40 to effect proper sequencing and system identification) to coordinate with the multiple output valves 102A, 102B, 102C, 102D and 102E, rather than operate simultaneously. That is, the controller 94 activates the input valve 92A to receive the fluid 16, and may then operate the output valve 102A so that the fluid 16 may be returned to the same system 1. Accordingly, valves 92A and 102A may be closed and valves such as 92C and 102C may be opened to provide cooling and lubrication fluid 16 from the third system to the coolant and lubricant monitoring assembly 30 and back thereto.

It should be understood that while 5 input valves 92A, 92B, 92C, 92D and 92E and corresponding 5 output valves 102A, 102B, 102C, 102D and 102E are shown, the number 5 is merely illustrative and a greater or lesser number of valves and associated systems may be conveniently housed and employed on the cooling and lubrication monitoring assembly 30.

In addition, a cleaning fluid, such as deionized water, or a calibration fluid may be provided to the assembly 30 through the input manifold 90 and exhausted through the output manifold 100. In particular, the input solenoid valve 96 may be supplied with deionized water from a suitable source. The input solenoid valve 96 is operated to supply deionized water to the module 30. Similarly, calibration or other fluid may be provided to the input solenoid 98. The calibration fluid may be used with the coolant and lubricant monitoring assembly 30 to perform calibration checks on the various sensors 52 and 56 or to obtain desired operating or control functions. In this context, calibration check means that a standard reference or calibration fluid is used in the monitoring assembly 30. The current calibration signal or value is provided to the controller 40 or other associated device by a reading from either of the sensors 52 or 56. The current calibration signal may then be compared to a known, stored, reference value, and the current accuracy of the sensor 52 or 56 may be determined. If the current signal or value differs from the stored reference value, an error compensation signal sufficient to compensate for the error may be generated and used to normalize or correct the output values of sensors 52 and 56. Calibration fluid may then be discharged from the monitoring assembly 30 through the corresponding output valve 108 and provided to the waste container 88.

Referring to fig. 4, an apparatus having the capability of real-time control and remote monitoring of at least one variable in the cooling and lubricating fluid system 110 is shown. In addition, the system employs an automatic screw machine 10 or other device, such as a Computer Numerically Controlled (CNC) device, machining center, lathe, grinder, milling machine or similar cutting, forming, boring, drilling or truing device, including a reservoir 18 and a pump 20 in the cooling and lubricating fluid circuit of the coolant and lubricant monitoring assembly 30 of the present invention. The system 110 also includes providing one or more coolant and lubricant compositions contained in reservoirs or containers 112 and 114. The storage containers 112 and 114 may contain concentrated coolant, lubricant, pH adjuster, or any other fluid or component of the cooling and lubricating fluid 16 necessary to provide the enhancement or adjustment to the fluid characteristics. The reservoirs 112 and 114 preferably include electrically controlled solenoid output valves 116 and 118, respectively, which are controlled by the controller 40, which receives signals from the various coolant and lubricant sensors 52 and 56 shown in FIG. 2.

The absence or exceeding of certain detected characteristics or variables of the cooling and lubricating fluid 16 to the allowable operating conditions can be quickly and accurately corrected by activating one or both of the solenoid valves 116 and 118 to provide the appropriate amount of necessary fluid to correct the detected defects. It should be understood that the two tanks or containers 112 and 114 of ingredients in the above description are illustrative only, and that one container holding an ingredient or mixture of ingredients or multiple (more than two) containers holding a single ingredient are also within the scope of the invention.

The first interface module 120 is connected to the controller 40 by a line 121 and a land line 122A, such as a telephone line, an internet connection, a fiber optic line, or wirelessly, by a microwave or satellite transmission device 122B to a remotely located second interface module 124. The second interface assembly 124 is preferably connected to a computer 126 having a display 128, such as a cathode ray tube or plasma display, a keyboard 132 for inputting data, and a printer 134, and/or other electronic media or optical read/write storage devices for providing permanent records of operations and conditions.

With this design, data detected by the sensors 52 and 56 of the coolant and lubricant monitoring assembly 30 is provided to the controller and interface assembly 120 for transmission to the interface assembly 124 and computer 126. The data is then stored in a computer or displayed on a display device 128 or printed out by a printer 134. Thus, an operator at a remote location may monitor one or more remote locations and manipulate conditions or events occurring at the remote location and receive data or information regarding operating parameters of various systems in real time. In addition, permanent records of various fluid characteristics may be generated by the printer 134 and/or other electronic media or optical storage devices. In addition, the recording of corrective actions performed on the collected data may also be accomplished.

It should be understood that the system of the present invention, and in particular the coolant and lubricant monitoring assembly 30, may employ any currently used cooling and/or lubricating fluid. That is, soluble oils consisting of oil, emulsifier and typically 10% to 90% water; synthetic fluids that do not use oil, and semi-synthetic fluids that use oil, are suitable for the monitoring assembly 30. Thus, as noted above, the concentrated cleaning fluid must be selected based on the solubility of the particular type of coolant and lubrication fluid 16 used in the particular system.

Accordingly, the foregoing detailed description is to be regarded as illustrative rather than limiting, and it is understood that all claims, including all equivalents, that are intended to define the spirit and scope of this invention.

Claims (20)

1. An apparatus for monitoring fluid system parameters generally comprising:

a fluid circuit is arranged in the fluid loop,

an input valve for controlling the flow of fluid from such a system into the circuit,

a pump for circulating this fluid in said circuit,

at least one sensor for detecting such a fluid parameter in the circuit,

an outlet valve for controlling the release of such fluid from the circuit,

a source of functional material, and

a metering device for injecting the functional material into the fluid circuit.

2. The apparatus of claim 1, wherein the fluid is a metalworking fluid and the parameter is a concentration of a constituent of the metalworking fluid.

3. The apparatus of claim 1, wherein the at least one sensor is a refractometer.

4. The device of claim 1, wherein the functional material is a solvent for such fluid.

5. The apparatus of claim 1, wherein the functional material is selected from the group consisting of a cleaning fluid, deionized water, and a calibration fluid.

6. The apparatus of claim 1, further comprising a controller that sequentially operates the valve, the pump, and the metering device.

7. The apparatus of claim 1, further comprising a valve for establishing a recirculation path in the fluid circuit.

8. The apparatus of claim 1, further comprising an input manifold having a plurality of fluid inlets and input valves, and an output manifold having a plurality of output valves and fluid outlets.

9. An apparatus for monitoring fluid system parameters generally comprising:

a fluid circuit is arranged in the fluid loop,

an input valve for controlling the flow of fluid from such a system into the circuit,

a pump for circulating fluid in said circuit,

at least one sensor for detecting such a fluid parameter in the circuit,

an output valve for controlling the release of said fluid from said circuit,

a metering device for injecting a selected amount of functional material into said fluid circuit, and

a controller for sequentially operating said valve, said pump and said metering device.

10. The apparatus of claim 9, further comprising a valve for forming a recirculation path in the fluid circuit.

11. The apparatus of claim 9, wherein the functional material is selected from the group consisting of a cleaning fluid, deionized water, and a calibration fluid.

12. The apparatus of claim 9, wherein the parameter is a concentration of a metal working fluid constituent.

13. The apparatus of claim 9, wherein the at least one sensor is a refractometer.

14. The device of claim 9, wherein the functional material is a solvent for the fluid.

15. A method of monitoring fluid parameters in a fluid system, comprising the steps of:

a fluid circuit is provided to be connected to the fluid circuit,

providing a fluid flow from the fluid system into the fluid circuit,

exposing a fluid parameter sensor to the fluid to determine a fluid parameter,

injecting a quantity of functional material into the fluid circuit, and

circulating the fluid and the functional material in the fluid circuit.

16. The method of monitoring a fluid parameter of claim 15, wherein the parameter is a concentration of a component of a metalworking fluid.

17. The method of monitoring a fluid parameter of claim 15, wherein the fluid parameter sensor is a refractometer.

18. A method of monitoring a parameter of a fluid as claimed in claim 15 wherein the functional material is a solvent for the fluid.

19. A method of monitoring fluid parameters according to claim 15, wherein said functional material is selected from cleaning fluids, de-ionized water and calibration fluids or any other functional material needed to perform cleaning and/or calibration check functions.

20. The method of monitoring a fluid parameter of claim 15, further comprising providing a valve for forming a recirculation path in the fluid circuit and recirculating fluid in the circuit.