JP2004160617A - High-pressure coolant feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coolant feeder which detects an abnormal condition without mounting a special sensor. <P>SOLUTION: With the revolution speed of a motor being one between a minimum one and a maximum one and an on-load valve turned on, the abnormal condition is detected under the condition that a load torque is lower than a minimum load torque, namely, the abnormal condition can be detected if the load torque is lower than a normal range under the condition that a delivery coolant pressure is controlled by the on-load valve. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a high-pressure coolant supply device, and more particularly, to a high-pressure coolant supply device having an abnormality detection function.
[0002]
[Prior art]
Conventionally, as a high-pressure coolant supply device, coolant is sucked from a tank by a pump driven by a motor, sent to an attachment through a pipe, and discharged through the attachment, lubrication of friction parts, smooth discharge of cutting chips, etc. Those that achieve this have been proposed.
[0003]
In addition, this type of high-pressure coolant supply device is provided with an on-load valve for controlling the discharge coolant pressure as required. Further, a relief valve may be provided for safety, and a pressure sensor for detecting a discharge coolant pressure may be provided.
[0004]
[Problems to be solved by the invention]
The above-mentioned conventional high-pressure coolant supply device is configured to start and stop by turning on / off the power supply, and detects that the high-pressure coolant supply device is in an abnormal state until a secondary trouble such as burn-in occurs. I can't.
[0005]
As a result, when the liquid level falls below the suction port of the pump due to, for example, a decrease in the coolant liquid, the pump cannot suck the coolant liquid and the pump runs idle.
[0006]
The pump ensures lubricity by sending coolant to the sliding surface.If the pump continues to operate with the coolant running out, damage due to seizure on the sliding surface or machining failure due to poor chip discharge may occur. generate.
[0007]
Even when the attachment is forgotten to be attached to the end of the discharge port of the pump, or when the pipe is ruptured, it cannot be detected, and a problem due to a shortage of the coolant occurs.
[0008]
Even if the pump deteriorates due to abrasion and the volumetric efficiency decreases, the deterioration is extremely advanced and cannot be detected until the discharge amount is visibly reduced. Occurs. In particular, in the case of unmanned operation, these deteriorations and the like are not known until inconveniences caused by coolant shortage occur.
[0009]
Then, if a problem caused by running out of the coolant liquid occurs, the production line or the like is stopped for a considerably long time.
[0010]
[Object of the invention]
The present invention has been made in view of the above problems, and has as its object to provide a high-pressure coolant supply device capable of detecting an abnormal state without providing a special sensor.
[0011]
[Means for Solving the Problems]
The high-pressure coolant supply device according to claim 1 drives a fixed displacement pump by a motor to supply coolant from the tank to the attachment, and controls supply of the discharge coolant to the attachment by the on-load valve,
Controlling the motor with a command value and a feedback value as inputs, and control means for controlling an on-load valve,
Abnormal state detecting means for detecting an abnormal state by inputting a command value and a feedback value.
[0012]
The high-pressure coolant supply device according to claim 2, wherein, as the abnormal state detecting means, in a state where the rotation speed of the motor is a rotation speed between a minimum rotation speed and a maximum rotation speed, and an on-load valve is turned on, An apparatus that detects an abnormal state on condition that the load torque is lower than the minimum load torque is employed.
[0013]
The high-pressure coolant supply device according to claim 3, wherein, as the abnormal state detecting means, in a state where the rotation speed of the motor is a rotation speed between a minimum rotation speed and a maximum rotation speed, and an on-load valve is turned on, An apparatus that detects an abnormal state on condition that the pressure feedback value remains below the predetermined pressure is employed.
[0014]
The high-pressure coolant supply device according to claim 4 employs, as the abnormal state detecting means, a unit that detects an abnormal state on condition that the load torque exceeds a maximum load torque.
[0015]
The high-pressure coolant supply device according to claim 5, wherein, as the abnormal state detecting means, a load characteristic in a normal state of the attachment for discharging the high-pressure coolant is stored, and an abnormal state is detected on the condition that the load characteristic deviates from the load characteristic. To adopt.
[0016]
The high-pressure coolant supply device according to claim 6 is a high-pressure coolant supply device that supplies a coolant from a tank to an attachment by driving a fixed displacement pump by a motor,
Control means for controlling the motor using a command value and a feedback value as input,
Abnormal state detecting means for detecting an abnormal state by inputting a command value and a feedback value.
[0017]
The high-pressure coolant supply device according to claim 7, wherein, as the abnormal state detecting means, when the rotation speed of the motor is between the minimum rotation speed and the maximum rotation speed, the load torque is lower than the minimum load torque. A condition for detecting an abnormal state is employed as a condition.
[0018]
In the high-pressure coolant supply device according to claim 8, as the abnormal state detecting means, in a state where the number of rotations of the motor is between the minimum number of rotations and the maximum number of rotations, the pressure feedback value remains below a predetermined pressure. A system that detects an abnormal state on condition that there is a certain condition is adopted.
[0019]
The high-pressure coolant supply device according to a ninth aspect employs, as the abnormal state detecting means, a unit that detects an abnormal state on condition that the load torque exceeds a maximum load torque.
[0020]
The high-pressure coolant supply device according to claim 10, wherein the abnormal condition detecting means stores a load characteristic of the attachment for discharging the high-pressure coolant in a normal state, and detects an abnormal condition on condition that the load characteristic deviates from the load characteristic. To adopt.
[0021]
[Action]
In the high-pressure coolant supply device according to claim 1, while supplying a coolant to the attachment from the tank by driving the fixed displacement pump by the motor, in controlling supply of the discharge coolant to the attachment by the on-load valve,
The control means controls the motor with the command value and the feedback value as inputs, and controls the on-load valve,
The abnormal state can be detected by the abnormal state detecting means by inputting the command value and the feedback value.
[0022]
Therefore, an abnormal state can be detected at an early stage, and necessary measures can be taken before a catastrophic failure occurs.
[0023]
In the high-pressure coolant supply device according to claim 2, as the abnormal state detecting means, a state in which the rotation speed of the motor is a rotation speed between a minimum rotation speed and a maximum rotation speed and an on-load valve is turned on. In the above, a method for detecting an abnormal state on condition that the load torque is lower than the minimum load torque is employed, so that idle operation, forgetting to attach an attachment, and pipe rupture can be detected as an abnormal state.
[0024]
In the high-pressure coolant supply device according to claim 3, a state in which the rotational speed of the motor is a rotational speed between a minimum rotational speed and a maximum rotational speed, and the on-load valve is turned on, as the abnormal state detecting means. In the above, a method of detecting an abnormal state on condition that the pressure feedback value remains lower than the predetermined pressure is employed, so that idle operation, forgetting to attach an attachment, and pipe rupture can be detected as an abnormal state.
[0025]
In the high-pressure coolant supply device according to the fourth aspect, since the abnormal state detecting means employs a means for detecting an abnormal state on condition that the load torque exceeds the maximum load torque, the seizure of the fixed displacement pump is performed. Can be detected as an abnormal state.
[0026]
In the high-pressure coolant supply device according to the fifth aspect, as the abnormal state detecting means, a load characteristic in a normal state of the attachment for discharging the high-pressure coolant is stored, and an abnormal state is detected on condition that the load characteristic deviates from the load characteristic. Since such a pump is employed, deterioration with time of the fixed displacement pump can be detected as an abnormal state.
[0027]
In the case of the high-pressure coolant supply device according to claim 6, in supplying a coolant from the tank to the attachment by driving the fixed displacement pump by the motor,
The control unit controls the motor by inputting a command value and a feedback value,
The abnormal state detecting means can detect the abnormal state by inputting the command value and the feedback value.
[0028]
Therefore, even when there is no on-load valve, an abnormal state can be detected early, and necessary measures can be taken before a catastrophic failure occurs.
[0029]
In the high-pressure coolant supply device according to claim 7, the load torque is lower than the minimum load torque when the rotation speed of the motor is between the minimum rotation speed and the maximum rotation speed as the abnormal state detection means. Therefore, even when there is no on-load valve, idle operation, forgetting to attach an attachment, and rupture of a pipe can be detected as an abnormal state.
[0030]
In the high-pressure coolant supply device according to claim 8, as the abnormal state detecting means, the pressure feedback value is lower than a predetermined pressure in a state where the rotation number of the motor is between the minimum rotation number and the maximum rotation number. Since a device that detects an abnormal condition is adopted on condition that the device remains as it is, even if there is no on-load valve, idle operation, forgetting to attach an attachment, and piping rupture can be detected as an abnormal condition. .
[0031]
In the high-pressure coolant supply device according to the ninth aspect, since the abnormal condition detecting means employs a device that detects an abnormal condition on condition that the load torque exceeds the maximum load torque, there is no on-load valve. Even in this case, the seizure of the fixed displacement pump can be detected as an abnormal state.
[0032]
In the high-pressure coolant supply device according to the tenth aspect, as the abnormal state detecting means, a load characteristic in a normal state of the attachment for discharging the high-pressure coolant is stored, and an abnormal state is detected on condition that the load characteristic deviates from the load characteristic. Therefore, even if there is no on-load valve, the deterioration with time of the fixed displacement pump can be detected as an abnormal state.
[0033]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a high-pressure coolant supply device of the present invention will be described in detail with reference to the accompanying drawings.
[0034]
FIG. 1 is a schematic diagram showing one embodiment of a high-pressure coolant supply device of the present invention.
[0035]
This high-pressure coolant supply device has a fixed displacement pump 2 that discharges coolant from a tank 1 and supplies the coolant to an attachment 4 such as a drill. An on-load valve 8 that controls the supply of coolant discharged from the fixed displacement pump 2 to the attachment, and a controller 7 that receives an AC power source 6, an external operation command signal, an external on-load command, and a detected pressure are input. The motor 5 is connected directly to the motor 5 and the fixed displacement pump 2. Further, if necessary, a relief valve 3 for returning the coolant discharged from the fixed displacement pump 2 to the tank 1 is provided, and a pressure sensor 9 for detecting the pressure of the coolant discharged from the fixed displacement pump 2 is provided. Provided.
[0036]
FIG. 2 is a block diagram showing an example of the configuration of the controller 7 in detail.
[0037]
The controller 7 includes a converter unit 11 that generates DC power by using the AC power source 6 as an input, an inverter unit 12 that generates AC power by using the generated DC power as an input, and supplies the AC power to the motor 5, A difference calculation unit 13 that calculates a difference from pressure, a pressure control unit 14 that performs a PI control operation using the calculated difference as an input and outputs a speed command, and a pulse generator 5a connected to the motor 5 A speed detection unit 16 that detects a speed by inputting a pulse signal to be input, a speed control unit 15 that performs a PI control operation with a speed command and a detected speed as inputs and outputs a current command, and a current command and a current detection unit 5b. A switching command is generated by performing a PI control operation using the input motor current as an input, a current control unit 17 that supplies the switching command to the inverter unit 12, a command value and And a abnormality detecting section 18 for detecting an abnormal state to feedback values as input.
[0038]
If the high-pressure coolant supply device having the above configuration is adopted, the rotation speed of the motor 5 can be controlled so as to secure a pump discharge amount that always generates a required pressure.
[0039]
Further, while the high-pressure coolant is being supplied, the abnormal state detecting unit 18 can detect the abnormal state by using the command value and the feedback value as inputs. Therefore, an abnormal state can be detected before a fatal inconvenience occurs, and necessary measures can be taken at an early stage.
[0040]
Next, the processing in the abnormal state detection unit 18 will be further described.
[0041]
In the abnormal state detection unit 18, for example, when the rotation speed of the motor 5 is between the minimum rotation speed and the maximum rotation speed and the on-load valve 8 is turned on, the load torque (motor Abnormal condition can be detected on the condition that the value of (current current) can be lower than the minimum load torque. That is, in a state where the discharge coolant pressure is controlled by the on-load valve 8, if the pressure falls below the normal range shown in FIG. 3, it can be detected that the state is abnormal.
[0042]
FIG. 4 is a schematic diagram showing the configuration of the abnormal state detecting unit 18 corresponding to this operation.
[0043]
The abnormal state detecting unit 18 includes a predetermined value holding unit 21 for holding the maximum rotation speed, the minimum rotation speed, and the minimum load torque, a failure-free data holding unit 23 for holding data indicating that there is no failure, and an input of the motor current. A load torque detection unit 25 that outputs a load torque by performing a conventionally known predetermined process, and the above-described abnormal state by inputting a maximum rotation speed, a minimum rotation speed, a minimum load torque, a load torque, and a motor rotation speed. A range determination processing unit for determining whether or not the determination is made, and a determination result from the range determination processing unit selected in response to an on-load signal operated by the on-load signal and instructing to turn on the on-load valve; And a switch unit 24 for selecting data indicating no abnormality in other cases.
[0044]
Further, in the abnormal state detecting section 18, when the rotation speed of the motor is between the minimum rotation speed and the maximum rotation speed, and the on-load valve is turned on, the pressure feedback value becomes a predetermined pressure. It is also possible to detect an abnormal condition on the condition that it remains less than.
[0045]
FIG. 5 is a schematic diagram showing the configuration of the abnormal state detecting unit 18 corresponding to this operation.
[0046]
The abnormal state detecting unit 18 includes a predetermined value holding unit 31 that holds a maximum rotation speed, a minimum rotation speed, and a predetermined pressure, a data storage unit 33 that stores data indicating no abnormality, and a maximum rotation speed and a minimum rotation speed. A range discriminating processing unit 32 for discriminating whether or not the above-mentioned abnormal condition is detected by inputting the number of revolutions, a predetermined pressure, a discharge pressure, and the number of revolutions of the motor; And a switch unit 34 for selecting a determination result from the range determination processing unit 32 in response to an on-load signal instructing the operation, and selecting data indicating no abnormality in other cases.
[0047]
Further, the abnormal state detecting section 18 can detect an abnormal state on condition that the load torque exceeds the maximum load torque.
[0048]
FIG. 6 is a schematic diagram showing the configuration of the abnormal state detecting unit 18 corresponding to this operation.
[0049]
The abnormal state detection unit 18 performs a conventionally known predetermined process using a motor current as an input, a predetermined value holding unit 41 for holding the maximum load torque, a data storage unit 43 for holding data indicating no abnormality, and a motor current. A load torque detecting unit 45 for outputting a load torque, a range discriminating processing unit 42 which receives the maximum load torque and the load torque as inputs, and determines whether or not the above-mentioned abnormal condition is present. And a switch unit 44 for selecting a determination result from the range determination processing unit 42 in response to an on-load signal instructing to turn on the switch 8, and selecting data indicating no abnormality in other cases. I have.
[0050]
When the abnormal state is detected as described above, it may be simply notified that the abnormal state has been detected, or a signal indicating that the motor 5 should be stopped may be output. . Further, the motor 5 may be stopped autonomously at the same time as the notification of the abnormal state.
[0051]
When the abnormal state is detected by the abnormal state detecting section 18, the abnormal state detection signal is output only when the abnormal state detection continues for a predetermined time or longer instead of immediately outputting the abnormal state detection signal. It is possible to eliminate the influence of noise and the like.
[0052]
Further, the abnormal state detecting section 18 can store the load characteristics of the attachment 4 that discharges the high-pressure coolant in a normal state, and detect an abnormal state on the condition that the load characteristics deviate from the load characteristics. The straight lines {circle around (1)} to {circle around (5)} shown in FIG. 3 indicate the load characteristics of five types of attachments 4 having different hole diameters. Therefore, by selecting a load characteristic corresponding to the actually mounted attachment 4 and determining whether or not the load characteristic is deviated from the selected load characteristic, an abnormal state (the abnormal state in this case is deterioration over time). Can be detected. Of course, it is preferable to detect the degree of deviation from the selected load characteristic, and it is possible to detect the replacement time of the fixed displacement pump 2.
[0053]
As a result, the occurrence of an abnormal state can be detected before a secondary problem occurs, and the stop period can be shortened as much as possible even when the production line needs to be stopped.
[0054]
FIG. 7 is a schematic diagram showing the configuration of the abnormal state detecting unit 18 corresponding to this operation.
[0055]
The abnormal state detecting unit 18 includes a predetermined value holding unit 51 for holding load characteristics and an allowable range, an abnormality-free data holding unit 53 for holding data indicating no abnormality, and a conventionally known predetermined A load torque detection unit 55 that performs processing and outputs a load torque, a range determination processing unit 52 that receives a load characteristic, an allowable range, a load torque, and a motor speed as input and determines whether or not the above-described abnormal state is present; The determination result from the range determination processing unit 52 is operated in response to the on-load signal and instructs the on-load valve 8 to be turned on. And a switch unit 54 for selection.
[0056]
FIG. 8 is a schematic diagram showing a state where the processes of FIGS. 4 and 6 are integrated.
[0057]
The abnormal state detecting unit 18 includes a predetermined value holding unit 61 that holds the maximum rotation speed, the minimum rotation speed, the maximum load torque, and the minimum load torque, an abnormality-free data holding unit 63 that holds data indicating that there is no abnormality, A load torque detecting unit 65 that performs a conventionally known predetermined process with a motor current as an input and outputs a load torque, and a maximum rotation speed, a minimum rotation speed, a maximum load torque, a minimum load torque, a load torque, and a motor rotation speed. As an input, a range determination processing unit 62 that determines whether or not the above-described abnormal state is present, and a range determination processing unit that is operated by an on-load signal and responds to an on-load signal that instructs to turn on the on-load valve 8 And a switch unit 64 for selecting the discrimination result from 62 and selecting data indicating no abnormality in other cases.
[0058]
【The invention's effect】
The invention according to claim 1 has a specific effect that an abnormal state can be detected at an early stage, and necessary measures can be taken before a catastrophic failure occurs.
[0059]
According to the second aspect of the present invention, it is possible to detect idle running, forgetting to attach an attachment, and a pipe rupture as an abnormal state, and also has the same effect as the first aspect.
[0060]
The invention according to claim 3 can detect idle running, forgetting to attach an attachment, and detecting a pipe rupture as an abnormal state, and has the same effect as that of claim 1.
[0061]
According to the fourth aspect of the invention, the seizure of the fixed displacement pump can be detected as an abnormal state, and the same effect as that of the first aspect can be obtained.
[0062]
According to the fifth aspect of the invention, the time-dependent deterioration of the fixed displacement pump can be detected as an abnormal state, and the same effect as that of the first aspect can be obtained.
[0063]
According to the invention of claim 6, even when there is no on-load valve, an abnormal state can be detected at an early stage, and necessary measures can be taken before a catastrophic failure occurs. It has the unique effect of being able to.
[0064]
According to the seventh aspect of the present invention, even when there is no on-load valve, idle operation, forgetting to attach an attachment, a pipe rupture can be detected as an abnormal state, and the same effects as those of the sixth aspect can be obtained.
[0065]
According to the invention of claim 8, even when there is no on-load valve, it is possible to detect an idle operation, forgetting to attach an attachment, a pipe rupture as an abnormal state, and has the same effect as in claim 6.
[0066]
According to the ninth aspect of the invention, even if there is no on-load valve, the seizure of the fixed displacement pump can be detected as an abnormal state, and the same effect as that of the sixth aspect can be obtained.
[0067]
According to the tenth aspect of the invention, even if there is no on-load valve, the time-dependent deterioration of the fixed displacement pump can be detected as an abnormal state, and the same effect as that of the sixth aspect can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing one embodiment of a high-pressure coolant supply device of the present invention.
FIG. 2 is a block diagram illustrating an example of a configuration of a controller in detail.
FIG. 3 is a diagram illustrating an example of a normal range and load characteristics.
FIG. 4 is a schematic diagram illustrating an example of a configuration of an abnormal state detection unit.
FIG. 5 is a schematic diagram showing another example of the configuration of the abnormal state detection unit.
FIG. 6 is a schematic diagram showing still another example of the configuration of the abnormal state detection unit.
FIG. 7 is a schematic diagram showing still another example of the configuration of the abnormal state detection unit.
FIG. 8 is a schematic diagram showing still another example of the configuration of the abnormal state detection unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tank 2 Fixed displacement pump 4 Attachment 5 Motor 8 On-load valve 18 Abnormal state detector

Claims (10)

A high-pressure coolant that drives a fixed displacement pump (2) by a motor (5) to supply coolant from the tank (1) to the attachment (4) and controls the supply of discharge coolant to the attachment by an on-load valve (8). A supply device,
Control means (7) for controlling the motor (5) using a command value and a feedback value as inputs and for controlling an on-load valve (8);
An abnormal state detecting means (18) for detecting an abnormal state by using a command value and a feedback value as inputs; The abnormal state detecting means (18) detects a load when the rotation speed of the motor (5) is between the minimum rotation speed and the maximum rotation speed and the on-load valve (8) is turned on. The high-pressure coolant supply device according to claim 1, wherein the abnormal state is detected on condition that the torque is lower than the minimum load torque. The abnormal state detecting means (18) detects the pressure when the motor (5) has a rotation speed between the minimum rotation speed and the maximum rotation speed and the on-load valve (8) is turned on. The high-pressure coolant supply device according to claim 1, wherein an abnormal state is detected on condition that the feedback value remains below a predetermined pressure. The high-pressure coolant supply device according to claim 1, wherein the abnormal state detecting means (18) detects an abnormal state on condition that the load torque exceeds a maximum load torque. The abnormal condition detecting means (18) stores a load characteristic in a normal state of the attachment (4) for discharging high-pressure coolant, and detects an abnormal condition on condition that the load characteristic deviates from the load characteristic. 2. The high-pressure coolant supply device according to 1. A high-pressure coolant supply device for supplying a coolant from a tank (1) to an attachment (4) by driving a fixed displacement pump (2) by a motor (5),
Control means (7) for controlling the motor (5) using a command value and a feedback value as inputs,
An abnormal state detecting means (18) for detecting an abnormal state by using a command value and a feedback value as inputs; The abnormal state detecting means (18) is configured to detect an abnormal state under a condition that the load torque is lower than the minimum load torque in a state where the rotation number of the motor (5) is between the minimum rotation number and the maximum rotation number. 7. The high-pressure coolant supply device according to claim 6, wherein the high-pressure coolant supply device detects the pressure. The abnormal condition detecting means (18) is provided for a condition that the pressure feedback value remains below a predetermined pressure in a state where the rotation speed of the motor (5) is between the minimum rotation speed and the maximum rotation speed. 7. The high-pressure coolant supply device according to claim 6, wherein the abnormal condition is detected as a condition. The high-pressure coolant supply device according to claim 6, wherein the abnormal state detecting means (18) detects an abnormal state on condition that the load torque exceeds a maximum load torque. 7. The abnormal state detecting means (18) stores a load characteristic of the attachment (4) for discharging high-pressure coolant in a normal state, and detects an abnormal state on condition that the load characteristic deviates from the load characteristic. 2. The high-pressure coolant supply device according to 1.

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