阅读说明：本技术 智能冷却剂泵 (Intelligent coolant pump ) 是由 保罗·斯克尔纳 于 2019-09-10 设计创作，主要内容包括：一种用于机器人或计算机控制的机器的智能冷却剂泵。该智能泵使用伺服电机而不是传统的工业电机(诸如感应电机)。智能泵具有固有的扭矩和速度感测,以及与计算机控制的机器的控制器集成的控制器。电机扭矩/速度感测和冷却剂压力/流量感测使能够立即检测任何异常状况,诸如冷却剂液位低或冷却剂端口堵塞。智能泵可以被配置以一定速度运行并且针对在工作站处执行的每个加工操作提供特定的冷却剂压力和流量,并且在各加工操作之间以非常低的速度运行。与传统的恒速冷却剂泵相比,这种速度配置节省能量并允许泵和冷却剂在更低的温度下运行。(An intelligent coolant pump for a robot or computer controlled machine. The smart pump uses a servo motor rather than a conventional industrial motor (such as an induction motor). Smart pumps have inherent torque and speed sensing, and controllers integrated with the controller of a computer controlled machine. Motor torque/speed sensing and coolant pressure/flow sensing enable immediate detection of any abnormal condition, such as low coolant level or blocked coolant ports. The smart pump may be configured to run at a speed and provide a specific coolant pressure and flow rate for each process operation performed at the workstation, and at a very low speed between process operations. This speed configuration saves energy and allows the pump and coolant to run at lower temperatures than conventional constant speed coolant pumps.)

1. A coolant pump system for a computer controlled machine, the system comprising:

the servo motor comprises a motor torque sensor and a motor speed sensor;

a pump body mechanically coupled to the servo motor, wherein the pump body comprises a pumping element that pumps coolant when actuated by rotation of the servo motor;

a coolant pressure sensor located at an outlet of the pump body;

a coolant flow sensor in the fluid circuit downstream of the pump body; and

a controller receiving signals from the motor torque and motor speed sensors, the coolant pressure sensor, and the coolant flow sensor, the controller providing control signals to the servo motor based on the received signals to achieve a predetermined coolant pressure or coolant flow specified for a particular machining operation of the computer controlled machine.

2. The system of claim 1, wherein the controller is further configured to take preemptive action when signals from the motor torque and motor speed sensors indicate a coolant supply problem.

3. The system of claim 2, wherein the coolant supply problem is indicated by a motor torque signal that is below a threshold for a given motor speed.

4. The system of claim 2, wherein the coolant supply problem is low coolant level, no coolant or coolant supply channel blockage.

5. The system of claim 2, wherein the preemptive action is issuing a warning alert.

6. The system of claim 2, wherein the preemptive action is stopping a machining operation on the computer controlled machine.

7. The system of claim 1, wherein the controller and the servo motor are configured to recover regenerated electrical energy when the controller signals the servo motor to reduce a rotational speed.

8. The system of claim 1, wherein the controller is configured to cause the servo motor to reduce the rotational speed, but not stop, when the machining operation is complete and before a next machining operation begins.

9. The system of claim 1, wherein the controller further controls the computer controlled machine, and the controller is configurable to provide control signals to the servo motors to achieve a different predetermined coolant pressure or coolant flow rate for each different machining operation of the computer controlled machine.

10. The system of claim 9, wherein the different machining operations include drilling, milling, and thread tapping, and the predetermined coolant pressure or coolant flow is determined based on a tool diameter, a rotational speed and a feed rate, and a workpiece material.

11. The system of claim 1, wherein the servo motor and the pump body are used as a main coolant pump in the computer controlled machine.

12. The system of claim 11, further comprising a second servo motor and a second pump body used as a center-through coolant pump in the computer-controlled machine, wherein the coolant is pumped through a center of a tool used in the computer-controlled machine.

13. An industrial processing station, comprising:

one or more machine tools disposed within the housing;

a machining station controller in communication with the one or more machine tools, the machining station controller configured to control the one or more machine tools to perform a prescribed sequence of machining operations on a workpiece to produce a part; and

a coolant subsystem for applying coolant to the workpiece and tool during the machining operation, the coolant subsystem including a coolant pump coupled to a network of coolant tubes, the coolant pump including;

the servo motor comprises a motor torque sensor and a motor speed sensor;

a pump body mechanically coupled to the servo motor and fluidly coupled to the coolant tube network, wherein the pump body comprises a pumping element that pumps coolant when actuated by rotation of the servo motor;

a coolant pressure sensor located at an outlet of the pump body;

a coolant flow sensor in the fluid circuit downstream of the pump body; and

a pump controller receiving signals from the motor torque and motor speed sensor, the coolant pressure sensor, and the coolant flow sensor, the pump controller providing control signals to the servo motor to achieve a predetermined coolant pressure or coolant flow prescribed for each process operation, wherein the predetermined coolant pressure or coolant flow is communicated from the process plant controller.

14. The processing station of claim 13, wherein the pump controller and the servo motor are configured to recover regenerative electrical energy when the pump controller signals the servo motor to reduce the rotational speed.

15. The processing station of claim 13, wherein the pump controller is configured to cause the servo motor to reduce the rotational speed, but not stop, upon completion of one processing operation and before the start of the next processing operation.

16. The machining station of claim 13, wherein the machining operations include drilling, milling, and thread tapping, and the predetermined coolant pressure or coolant flow is determined based on a tool diameter, a rotational speed and a feed rate, and a workpiece material.

17. The processing station of claim 13, further comprising a second servo motor and a second pump body that function as a central through coolant pump in the industrial processing station, wherein the coolant is pumped through the center of a tool used in the processing station.

18. A coolant pump for a computer controlled machine, the pump comprising:

the servo motor comprises a motor torque sensor and a motor speed sensor;

a pump body mechanically coupled to the servo motor, wherein the pump body comprises a pumping element that pumps coolant when actuated by rotation of the servo motor; and

a controller receiving signals from the motor torque and motor speed sensors, the controller providing control signals to the servo motor based on the signals from the motor torque and motor speed sensors to achieve a predetermined coolant pressure or coolant flow rate specified for a particular machining operation of the computer controlled machine.

19. The pump of claim 18, wherein the pump functions as a primary coolant pump in the computer controlled machine.

20. The pump of claim 18, wherein the pump is used as a center-through coolant pump in the computer-controlled machine, wherein the coolant is pumped through a center of a tool used in the computer-controlled machine.

Technical Field

The present invention relates to the field of coolant pumps, and more particularly to a coolant pump for a robot or computer controlled machine that uses a servo motor with a controller and sensors for measuring coolant pressure and flow during drilling/machining operations, which in turn enables early detection of any problems including low coolant levels or coolant flow blockage, and further enables automatic adjustment of pump speed based on real time coolant demand as indicated by the drilling/machining operation that is occurring.

Background

Automated robotic drilling/machining stations and Computer Numerical Control (CNC) machines are known in the art that perform complex, multi-axis, multi-tool machining operations upon touch of control screen buttons. For example, such computer controlled machines can machine parts having several different design variations, wherein the part is machined from a solid block of metal, and the finished part includes a number of through holes, non-through holes, chamfers, drilled and tapped holes, etc., and the holes and machined features are aligned along several different orientation axes relative to the part.

CNC and similar machines of the type described above require a coolant flow (e.g., machining oil) for the cutting operation. The coolant acts to cool the parts and tool and to flush "chips" of the cut metal out of the tool and out of any holes being machined. Existing CNC machines use a simple coolant pump that can be turned on or off depending on the operation performed by the workstation at a given time. For example, when the machine is drilling a hole in a part, the coolant pump is turned on and the coolant flow is directed to the drill bit in the hole. Conversely, after a drilling operation, the coolant pump is normally shut down when the machine is to be tool-changed in preparation for the next machining step.

While the simple coolant pumps described above are able to perform adequately, they typically pump more coolant than is required for a given operation, resulting in unnecessary energy usage. Furthermore, the frequent closing and opening of these pumps increases the wear of the pumps, which increases the amount of maintenance and repair required. Furthermore, simple coolant pumps fail to detect problems associated with low levels or flows of coolant, which can quickly lead to damage of parts and tools in CNC machines.

Accordingly, it is desirable to provide an intelligent coolant pump that is integrated with the machine controller and provides the proper coolant flow for any drilling/machining operation.

Disclosure of Invention

In accordance with the teachings of the present disclosure, an intelligent coolant pump for a computer controlled processing station is described. Smart pumps employ servo motors rather than traditional industrial motors (e.g., induction motors). The smart pump has inherent torque and speed sensing, and a controller integrated with the process plant controller. Motor torque/speed sensing and coolant pressure/flow sensing can immediately detect any abnormal condition such as low coolant level or blocked coolant ports. The smart pump may be configured to operate at a speed and provide a specific coolant pressure and flow rate for each process operation performed at the workstation, and at a very low speed between process operations. This speed configuration may save energy and allow the pump and coolant to operate at lower temperatures than conventional constant speed coolant pumps.

Additional features of the disclosed technology will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.

Drawings

FIG. 1 is a diagrammatic view of an intelligent coolant pump integrated with a computer controlled machine in accordance with an embodiment of the present disclosure;

FIG. 2 is a diagrammatic view of one of the intelligent coolant pumps coupled to a coolant manifold, showing a partial implementation of a coolant subsystem in the computer controlled machine of FIG. 1, in accordance with an embodiment of the present disclosure; and

FIG. 3 is an illustration of a plurality of user interface screens for configuring and monitoring the intelligent coolant pump of FIGS. 1-2, in accordance with an embodiment of the present disclosure.

Detailed Description

The following discussion of the embodiments of the present disclosure directed to an intelligent coolant pump integrated with a robotic or computer-controlled machine is merely exemplary in nature, and is in no way intended to limit the disclosed devices or their applications or uses.

FIG. 1 is a diagrammatic view of a flexible manufacturing facility including two computer-controlled machines 100. The computer controlled machine 100 may be any type of CNC or computer controlled machine or robotic drilling/machining station and is capable of automatically producing many different preprogrammed designs of machined parts at great speed and quality. The computer controlled machine 100 includes a fixture for holding a workpiece in place, and a machine tool for performing operations such as drilling, milling, and thread tapping along any axis arbitrarily oriented with respect to the workpiece. According to an embodiment of the present disclosure, the machine 100 of fig. 1 is equipped with a new intelligent coolant pump 10.

In fig. 1, the intelligent coolant pump 10 is shown external to the computer controlled machine 100 for visual impact only. In practice, one of the intelligent coolant pumps 10 is disposed inside each of the computer controlled machines 100, as discussed in detail below. The intelligent coolant pump 10 in each computer controlled machine 100 provides coolant flow to the machining operation, directing the coolant through one or more nozzles to the workpiece and tool, where the coolant is recirculated to the tank and returned to the intelligent coolant pump 10.

Each computer controlled machine 100 includes a controller 110 and a display unit 120. Each of the computer controlled machines 100 further includes a robotic device (not shown) including a gripping tool configured to select and hold workpieces in fixed positions from a supply inventory during machining operations, and interchangeable machine tools, such as milling cutters, drill bits, drilling holes, taps, etc., for performing machining operations on the workpieces according to predefined programs running on the controller 110.

Existing computer controlled processing stations using conventional coolant pump motors suffer from several limitations. For example, conventional coolant pumps do not provide feedback of motor torque or speed. Without motor torque or speed feedback, it is not readily apparent whether the pump is operating properly, pumping a desired volume of coolant, etc. Conventional coolant pumps also do not provide coolant temperature feedback. The coolant temperature is important and may indicate a need for more or less coolant flow. Furthermore, conventional coolant pumps are not capable of changing speed or adjusting the pressure and flow of coolant. In addition, conventional coolant pumps consume more electrical energy than necessary because they are frequently stopped and restarted and operated at a fixed speed that provides a coolant flow rate that is typically higher than that required for a given machining operation.

According to an embodiment of the present disclosure, the computer controlled machine 100 includes an intelligent coolant pump 10, which intelligent coolant pump 10 overcomes the limitations of the conventional coolant pump described above. The intelligent coolant pump 10 is driven by a servo motor 12 (fig. 2), which servo motor 12 is fully controllable in terms of pump rotational speed and ramp up and ramp down speed profiles. The sensors and control logic discussed below enable the behavior of the intelligent coolant pump 10 to be tailored to any combination of tools, operations, and conditions that the computer controlled machine 100 may experience.

For purposes of the following discussion, it is contemplated that the controller 110 in the computer controlled machine 100 controls the operation of the machine itself (positioning the work piece and performing all machining operations on the work piece to produce the desired part) and also controls the operation of the intelligent coolant pump 10. A separate controller for the smart pump 10 may also be provided, in which case the pump controller would be in communication with the controller 110 of the computer controlled machine 100.

As mentioned above, the intelligent coolant pump 10 is driven by the servo motor 12. The servo motor 12 is equipped with sensors that inherently provide speed and torque signals to the pump controller (in this case, the machine controller 110). For example, the servo motor 12 may include a position encoder, a rotational speed sensor, and a torque sensor. Signals from the torque, speed and position sensors are provided to the controller 110 or other pump controller, which enables real-time feedback of speed control and torque measurements.

The motor torque signal may be used by the controller 110 to determine whether an appropriate supply of coolant is provided to the inlet of the pump 10. Low coolant levels, blocked coolant filters or inlets, or no coolant at all may result in an insufficient supply of coolant. If one of these conditions is detected by a low torque value, the controller 110 may prevent the computer-controlled machine 100 from cutting or performing any other machining operation; in this case, it is also preferable to provide an alarm signal to the operator. Preventing the computer controlled machine 100 from inadvertently dry cutting reduces the cost of tool repair and replacement and reduces the number of parts that are returned.

The motor speed signal enables real-time feedback of coolant flow as a function of pump speed. This allows the machine controller 110 to ensure that the motor speed corresponds to the coolant flow rate selected by the operator for any particular tool, operation, and condition. For example, much less coolant is required to drill a small diameter hole in aluminum than is required to drill a large diameter hole in steel. The intelligent coolant pump 10 may be configured (see FIG. 3) to provide a desired amount of coolant for each operation selected by the operator, and this coolant control is then included in the operation of the computer controlled machine 100 via the motor speed signal. No additional hardware is required to control the speed of the pump; the servo motor 12 already comprises sensors and controllability features. The controller 110 allows for selection of a particular volumetric flow rate (and corresponding speed) of coolant for each individual operation performed by the computer-controlled machine 100, as discussed further below.

Another advantage of the intelligent coolant pump 10 is that the coolant subsystem can be operated at lower temperatures. The ability to vary the pump speed means that the temperature of the electric motor 12 and the coolant can be reduced by slowing the electric motor 12 without requiring a maximum flow of coolant from the intelligent coolant pump 10. Operating the motor 12 at a lower speed reduces the temperature of the coolant subsystem and also saves energy.

The servo motor 12 in the intelligent coolant pump 10 is also capable of decelerating the motor 12 during times when coolant flow is not required (e.g., when changing tools between machining operations). Decelerating the electric motor 12 and pump 10 to an "idle" speed, rather than stopping the electric motor as in conventional coolant pumps, not only reduces the number of stop/start cycles of the electric motor 12, but also enables the electric motor 12 and controller 110 to capture energy during deceleration to provide regenerative power — further reducing energy costs.

FIG. 2 is a diagrammatic view of one of the intelligent coolant pumps 10 coupled to a coolant manifold 130, representing a partial implementation of the coolant subsystem in the computer controlled machine 100. The intelligent coolant pump 10, including the servo motor 12 and pump body 14, is shown in the upper left inset. The upper part of the intelligent coolant pump 10 (including the upper part of all the servo motors 12 and the pump body 14) is visible in the main large image of fig. 2.

The coolant manifold 130 includes a plurality of servo or solenoid controlled valve bodies, each of which is controlled by an electrical signal line 132. Each valve controls flow through one branch of the coolant circuit, where each branch includes a conduit and nozzle (not shown) to deliver coolant to a specific location inside the computer controlled machine 100. For example, one valve may be configured to control coolant flow to a nozzle for a milling station located on top of the workpiece, another valve may be configured to control coolant flow to a nozzle for a drilling station located on the end of the workpiece, and so on. The manifold 130 is connected (fluidly coupled) to the pump body 14 by a fluid coupler 134, the fluid coupler 134 being visible near the bottom center of fig. 2.

As described above, by simply using the servo motor's 12 natural speed and torque sensors, the intelligent coolant pump 10 can detect and react to conditions such as improper coolant flow, low coolant levels, or insufficient coolant, and thereby prevent tool wear/breakage and ensure part dimensional accuracy. Furthermore, the intelligent coolant pump 10 may be equipped with coolant pressure and flow sensors, and pressure and flow signals provided to the controller 110 or other pump controllers. By directly measuring coolant pressure and flow, the controller 110 can more accurately control the speed of the smart pump 10 to achieve a desired coolant pressure and/or flow, which can be specified for a particular tool or operation in the computer controlled machine 100. The coolant pressure and flow signals may also be monitored for values outside of prescribed ranges (e.g., too high or too low a pressure, or too low a flow), and the controller 110 may stop operation in the computer-controlled machine 100, if appropriate.

The coolant pressure and flow values, and the relationship therebetween, may also be used to make other determinations regarding maintenance of the computer controlled machine 100. For example, it may be desirable to change or treat the coolant after a particular total volume flow rate, rather than simply changing or treating the coolant after a particular number of operating hours, in view of the actual coolant usage. The volumetric flow may be integrated to obtain a cumulative volumetric flow that may be compared to a predefined threshold, wherein an operator may be signaled that a coolant and filter change is required when the cumulative volumetric flow exceeds the threshold.

Another advantage of the intelligent coolant pump 10 is that a smaller coolant tank can be used than with a standard pump. This is because the intelligent coolant pump 10 is often operated at a speed less than full speed, whereas conventional coolant pumps are always operated at full speed even when less coolant flow is required.

Using the intelligent coolant pump 10 also reduces pump maintenance, as the reduced speed profile also reduces pressure on all pump components. The use of the intelligent coolant pump 10 also reduces power consumption due to the lower average pump speed compared to conventional pumps, and due to the regenerative power capture capability of the servo motor 12 used in the intelligent coolant pump 10.

FIG. 3 is an illustration of a plurality of user interface screens 122 and 128 for configuring and monitoring the intelligent coolant pump 10. User interface screens 122-128 are displayed on display unit 120 (shown in FIG. 1) of computer-controlled machine 100.

Interface screen 122 and 128 provide the user with the ability to fully configure coolant flow for each tool, operation and condition in computer controlled machine 100. For example, a drilling operation using a 30mm drill bit rotating at 500 Revolutions Per Minute (RPM) to drill a hole in cast aluminum at a bit feed rate of 1 mm/second represents a particular combination of tools, operations, and conditions. Each such combination (tool, operation, condition) may be configured with a coolant arrangement that includes "center-through-coolant" (CTC-discussed below), cutting (coolant flow to tool tip), wall-cleaning, bed-cleaning, and flow/volume. Each of these different coolant flows is controlled by a separate valve/nozzle of the coolant manifold 130 shown in fig. 2.

Interface screens 122 and 124 are general setup screens for computer controlled machine 100, including control of workholding fixtures, drilling/machining operations, and control of other features such as blowers and debris conveyors. The interface screens 122 and 124 also provide access to interface screens 126 and 128 that configure the coolant system parameters.

The interface screen 126 includes coolant configuration controls for specific combinations of tools, operations, and conditions. Configuration options include the location (cutting operation, wall, bed and/or CTC) where the coolant flow is directed, and the corresponding flow rates. Based on the selected coolant flow position and flow rate, the total flow rate of the coolant pump may be determined. Other configuration options include a delay timer for shutting down or reducing the speed of the pump 10 after operation.

Interface screen 128 is a configuration control screen for each nozzle in the coolant system. Interface screen 128 is referred to as a spider cooling setting screen because the individual pipes and nozzles may be oriented at specific angles to provide coolant flow at locations and amounts required for proper cooling and lubrication of the cutting operation. The user may communicate coolant during configuration to visually verify flow for a particular machine tool and location.

Interface screens 126 and 128 are shown here to illustrate the configurability of the coolant system, which results in optimized flow and placement of coolant for specific tools, operations, and conditions. With the total flow thus defined, the intelligent coolant pump 10 provides the ability to operate at the speed required to deliver the required coolant flow, and verifies the proper coolant flow through servo motor feedback and sensor measurements.

Certain machining operations require "center-through-coolant" (CTC), wherein coolant is provided directly through the center of the tool (e.g., a milling head). CTCs require relatively low coolant flow rates, but require much higher pressures (e.g., 1000psi) than used for nozzle flow to normal cutting operations, wall cleaning, etc. (which can operate at, for example, 100 psi). For this reason, CTCs are typically provided by a separate coolant pump and separate coolant loop, rather than by the main coolant system. The CTC coolant system may be powered by another intelligent coolant pump, where the CTC pump has the same characteristics (servo motor drive, inherent torque and speed sensing and control) as the intelligent coolant pump 10, but the CTC pump is smaller than the intelligent coolant pump 10.

In the foregoing discussion, various controllers are described and implied for controlling the motion and tasks of the computer controlled machine 100, the smart pump 10, and the like. It should be understood that the software applications and modules of these controllers are executed on one or more computing devices having a processor and memory modules. In one non-limiting embodiment, each computer controlled machine 100 has a machine controller (110), and the smart pump 10 may be controlled by the machine controller 110 or its own dedicated pump controller. Communication between the machine controller 110, the pump controller, and the factory master controller can be over a hard-wired network, or any suitable wireless technology can be used — e.g., cellular phone/data network, Wi-Fi, broadband internet, bluetooth, etc.

As mentioned above, the disclosed intelligent coolant pump with integrated servo motor drive and integrated control with a robot or computer controlled machine provides several advantages over the prior art. The ability to control pump speed and coolant flow for each particular machining tool/operation/condition, as well as the ability to identify coolant flow problems before part or tool damage, is far superior to typical "on or off" coolant pumps. The features of the intelligent coolant pump result in lower maintenance costs, lower energy consumption, and better detection of problems such as low coolant levels or flow blockage.

While various exemplary aspects and embodiments of an intelligent coolant pump integrated with a robotic or computer-controlled machine have been discussed above, those skilled in the art will recognize modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.