JP6476702B2 - Hydraulic unit or oil cooling unit - Google Patents

Description

  The present invention relates to a hydraulic unit or an oil cooling unit.

  Conventionally, a fluid pressure unit that drives a machine tool or the like by feeding a fluid with a fluid pressure pump is known. As this type of fluid pressure unit, for example, there is a hydraulic unit disclosed in Patent Document 1. The hydraulic unit of Patent Document 1 includes a passage for returning a part of discharged oil from the discharge side of the hydraulic pump to the tank. The passage is provided with a throttle valve for limiting the flow rate and a radiator fan for cooling the oil that has passed through the throttle valve. In this hydraulic unit, only a predetermined amount of the oil discharged from the hydraulic pump always flows into the passage without being supplied to the machine tool or the like. The oil flowing in this passage flows into the tank after being cooled by the radiator fan. Thereby, the temperature rise of the oil in a tank is suppressed.

JP2004-162860

  By the way, in the hydraulic unit of Patent Document 1, when the temperature of the motor rises and the temperature of the motor becomes an abnormal temperature, the hydraulic unit stops urgently. In particular, when internal leakage of the pump or leakage on the chuck side occurs, the motor temperature is likely to rise, and there is a high possibility of an emergency stop due to the motor temperature rising to an abnormal temperature. Are known. In this way, when the hydraulic unit stops urgently, the machine tool not only stops in the middle of the machining process, but the entire processing line temporarily stops to repair that one hydraulic unit. It takes a lot of damage. In other words, the hydraulic unit suddenly stopped unexpectedly, and there was a problem that it was impossible to take measures.

  Such a problem is caused not only when the hydraulic unit suddenly stops due to the motor temperature rising to an abnormal temperature in the hydraulic unit, but also due to, for example, the temperature of the electrical component rising to an abnormal temperature. This also occurs when the hydraulic unit comes to an emergency stop. Further, in the oil cooling unit, the same applies to the case where the oil cooling unit is brought to an emergency stop due to the rise in the condenser temperature to an abnormal temperature.

  Therefore, an object of the present invention is to provide a hydraulic unit or an oil cooling unit capable of notifying an emergency level of maintenance for preventing an emergency stop.

The hydraulic unit or oil cooling unit according to the first invention is a hydraulic unit or oil cooling unit whose operation is stopped when the temperature of the component rises to an abnormal temperature, and the temperature of the component has risen to the abnormal temperature. Before the operation is stopped due to the above, the notification means for notifying the urgency of maintenance for preventing the temperature of the component from rising to an abnormal temperature , the temperature detection means for detecting the temperature of the component, A failure rate calculating means for calculating a component failure rate based on the temperature detected by the temperature detecting means, an operating condition determining means for determining an operating condition affecting the temperature rise of the component, and the operating condition determining means. Correction means that corrects the component failure rate calculated by the failure rate calculation means based on the operating state, and the notification means corrects the component failure rate after being corrected by the correction means. Based on, characterized in that it informs the urgency of maintenance.

  With this hydraulic unit or oil cooling unit, it is possible to notify the user of the urgency of maintenance. Therefore, the user can continue the operation of the unit in consideration of the urgency of maintenance, and can make a maintenance plan.

  In this hydraulic unit or oil cooling unit, when operating in an operating state that affects the temperature rise of the component, the temperature of the component is likely to rise. Can inform the user. Therefore, when the operation state is such that the temperature of the component is likely to rise, the user is informed that the failure rate of the component is corrected to be larger than the current failure rate, so that the user knows that the urgency of maintenance is high. Can do.

The hydraulic unit or oil cooling unit according to a second aspect of the invention is the hydraulic unit or oil cooling unit according to the first aspect of the invention, wherein the notification means includes a component failure rate calculated by the failure rate calculation means, and the correction means. The component failure rate after being corrected in the step is notified.

  In this hydraulic unit or oil cooling unit, when operating under severe operating conditions due to temperature rise of parts, the more severe the operating conditions, the larger the failure rate is corrected. Therefore, the failure rate before correction and the corrected failure rate Based on the difference, the user can know how severe the driving state is.

Hydraulic unit or oil cooling unit according to the third invention, in the hydraulic unit or oil cooling unit according to the first or second one of the invention, based on the change of the component failure rate after being corrected by said correcting means And a predicting means for predicting a time when the operation is stopped due to the temperature of the component rising to an abnormal temperature when the operation is continued without performing maintenance. In addition, the time predicted by the prediction means is notified.

  In this hydraulic unit or oil cooling unit, based on the change in the component failure rate, it is predicted and notified when the operation is stopped due to the temperature of the component rising to an abnormal temperature when maintenance is not performed. Thus, the user can know when the maintenance needs to be performed.

A hydraulic unit or an oil cooling unit according to a fourth aspect of the present invention is the hydraulic unit or the oil cooling unit according to the first aspect of the invention, further comprising an operating state determination means for detecting an operating state that affects the temperature rise of the component. The means reports the driving state detected by the driving state determination means.

  In this hydraulic unit or oil cooling unit, when operating in an operating state that affects the temperature rise of the parts, the operating state is notified, so the user can determine the operating state based on the notified operating state. It is possible to know that a problem that causes the problem has occurred.

  As described above, according to the present invention, the following effects can be obtained.

  In the first invention, the user can be informed of the urgent level of maintenance. Therefore, the user can continue the operation of the unit in consideration of the urgency of maintenance, and can make a maintenance plan.

In the first aspect of the invention, when operating in an operating state that affects the temperature rise of the component, the temperature of the component is likely to rise, so the user is informed of the urgency of maintenance in consideration of the operating state. be able to. Therefore, when the operation state is such that the temperature of the component is likely to rise, the user is informed that the failure rate of the component is corrected to be larger than the current failure rate, so that the user knows that the urgency of maintenance is high. Can do.

In the second aspect of the invention, when operating in an operating condition that is severe with respect to the temperature rise of the part, the more severe the operating condition, the larger the failure rate is corrected, so the difference between the failure rate before correction and the corrected failure rate Based on the above, the user can know how severe the driving state is.

In the third invention, based on the change in the component failure rate, when the maintenance is not performed, the time when the operation is stopped due to the temperature of the component rising to the abnormal temperature is predicted and notified. The user can know when the maintenance needs to be performed.

In the fourth aspect of the invention, when operating in an operating state that affects the temperature rise of components, the operating state is notified, so the user can determine the cause of the operating state based on the notified operating state. It is possible to know that a malfunction has occurred.

It is a circuit diagram showing the composition of the hydraulic unit concerning a 1st embodiment of the present invention. It is a characteristic view of the discharge pressure-discharge flow rate of a hydraulic pump. It is a figure explaining the calculation method of the failure rate of a motor. It is a figure explaining the driving | running state which affects the temperature rise of a motor. It is a figure explaining the prediction method of the time of emergency stop resulting from the temperature of a motor rising to abnormal temperature. It is a flowchart which shows the display operation of the emergency level of a maintenance. It is a circuit diagram which shows the structure of the oil cooling unit which concerns on 2nd Embodiment of this invention. It is a figure explaining the change of the capability command value of a compressor. It is a figure explaining the calculation method of the failure rate of a condenser. It is a figure explaining the driving | running state which affects the temperature rise of a condenser.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the hydraulic unit 1 of this embodiment is used for machine tools, such as a lathe, a grinding machine, a surface finishing machine, a shaving machine, and a machining center. Although not shown, the machine tool has a plurality of hydraulic actuators (hereinafter simply referred to as actuators) for fixing a work and a tool, such as a tailstock clamp, a tool post clamp, and a chuck, and these actuators are hydraulic units. 1 driven.

  The hydraulic unit 1 includes a hydraulic circuit 10 and a control unit 2 for controlling the hydraulic circuit 10.

  The hydraulic circuit 10 includes an oil tank 11, a hydraulic pump 13, a pump motor 14 that drives the hydraulic pump 13, a throttle passage 21, a radiator 23, and a radiator fan 24.

  The hydraulic pump 13 constitutes a fluid pressure pump that sucks and discharges hydraulic oil in an oil tank 11 that is a fluid tank. The hydraulic pump 13 is, for example, a piston pump, and is a fixed displacement pump.

  The pump motor 14 is a variable speed motor that is connected to the hydraulic pump 13 and drives the hydraulic pump 13, and is provided with a temperature thermistor 14a that detects the temperature thereof. A pulse generator 15 that outputs a pulse signal corresponding to the rotational speed of the pump motor 14 is connected to the pump motor 14.

  An oil filter 12 is provided on the suction side of the hydraulic pump 13. The discharge pipe 18 of the hydraulic pump 13 is provided with a safety valve 16 so that the discharge pressure of the hydraulic pump 13 does not exceed a predetermined pressure. The discharge pipe 18 of the hydraulic pump 13 is provided with a pressure sensor 17 that detects the discharge pressure of the hydraulic pump 13. The discharge pipe 18 of the hydraulic pump 13 is connected to an actuator on the machine tool side via a direction switching valve (not shown).

  The throttle passage 21 is connected to the oil tank 11 and the discharge pipe 18 of the hydraulic pump 13. The throttle passage 21 is provided with a variable throttle valve 22 that is a flow rate adjusting valve. The throttle passage 21 is configured such that a part of the hydraulic oil discharged from the hydraulic pump 13 always returns to the oil tank 11 without flowing to the machine tool side. The return amount to the oil tank 11 is adjusted by the variable throttle valve 22. The throttle passage 21 constitutes a bypass passage.

  The radiator 23 is provided on the downstream side of the variable throttle valve 22 in the throttle passage 21. A radiator fan 24 is provided in the vicinity of the radiator 23. The radiator fan 24 cools the hydraulic oil that passes through the radiator 23. Thereby, the temperature of the hydraulic oil of the oil tank 11 falls. In other words, the radiator fan 24 is for cooling the hydraulic oil in the oil tank 11 and suppressing the temperature rise of the hydraulic oil. The radiator fan 24 is driven by a fan motor.

  As described above, the throttle passage 21, the variable throttle valve 22, the radiator 23 and the radiator fan 24 constitute oil cooling means for cooling the hydraulic oil in the oil tank 11. On the other hand, by providing the throttle passage 21, it is possible to reliably avoid operating the hydraulic pump 13 in the low rotation region. In general, the driving torque of a hydraulic pump becomes unstable in a low rotation range. In the present embodiment, part of the hydraulic oil discharged from the hydraulic pump 13 flows into the throttle passage 21, so that the discharge flow rate of the hydraulic pump 13 is greater than the flow rate required by the actuator of the machine tool. If it does so, the hydraulic pump 13 will be drive | operated in a comparatively high rotation area | region. Therefore, it is possible to avoid the hydraulic pump 13 being operated at a low rotation, and pressure control / flow rate control can be performed stably.

  A drain passage 25 is provided in the hydraulic pump 13. The drain passage 25 is connected between the variable throttle valve 22 and the radiator 23 in the throttle passage 21. In the drain passage 25, the hydraulic oil leaked in the hydraulic pump 13 flows into the throttle passage 21.

  The control unit 2 includes a PQ control unit 30, a speed control unit 31, an inverter 32, a speed detection unit 33, a failure rate calculation unit 34, an operating state determination unit 35, a correction unit 36, and a margin calculation unit. 37 and a prediction unit 38. In addition, a display unit 50 is connected to the control unit 2.

  The PQ control unit 30 receives the discharge pressure of the hydraulic pump 13 from the pressure sensor 17. The PQ control unit 30 outputs a speed command based on the input discharge pressure and the discharge pressure-discharge flow rate characteristic (hereinafter referred to as PQ characteristic) shown in FIG. The speed detector 33 receives a pulse signal from the pulse generator 15 and detects the rotation speed (rotational speed) of the pump motor 14 as a current speed by measuring the interval between the pulse signals. The speed controller 31 receives a speed command from the PQ controller 30 and a current speed from the speed detector 33. Then, the speed control unit 31 performs a speed control calculation using the speed command and the current speed, and outputs a current command. The inverter 32 receives a current command from the speed controller 31 and controls the rotational speed of the pump motor 14 based on the current command.

  In the present embodiment, the PQ control unit 30, the speed control unit 31, and the inverter 32 are configured so that the flow control operation (constant flow control) and the pressure control operation (constant pressure) of the hydraulic pump 13 based on the PQ characteristics shown in FIG. Control). In the flow rate control operation, the rotational speed (rotational speed) of the pump motor 14 is controlled so that the discharge flow rate of the hydraulic pump 13 becomes the flow rate set value Qa. In the pressure control operation, the rotation speed (rotation speed) of the pump motor 14 is controlled so that the discharge pressure of the hydraulic pump 13 becomes a predetermined dead head pressure Pa (pressure set value Pa).

<Flow control operation and pressure control operation>
Next, the control operation in the hydraulic unit 1 will be described with reference to FIG.

  The control unit 2 controls the hydraulic circuit 10 based on the PQ characteristic shown in FIG. At point B in FIG. 2, the rotational speed of the pump motor 14 is controlled so that the discharge flow rate of the hydraulic pump 13 becomes the flow rate set value Qa (constant flow rate control). When controlling the flow rate at point B, for example, a hydraulic cylinder as an actuator performs an expansion operation or a contraction operation at a constant speed, and the workpiece or tool moves to a predetermined position. At that time, the discharge pressure of the hydraulic pump 13 becomes a relatively low value.

  At point A in FIG. 2, the rotational speed of the pump motor 14 is controlled so that the discharge pressure of the hydraulic pump 13 becomes the dead head pressure Pa (constant pressure control). At the time of pressure control at point A, for example, the hydraulic cylinder does not expand and contract, and the workpiece and tool are clamped and held with a predetermined force. In this state, the discharge flow rate of the hydraulic pump 13 is almost zero and is in a dead head state.

  Here, the cause (mechanism) of the rotational speed of the pump motor 14 in the dead head state increasing / decreasing to exceed / below the “normal rotation” range will be described.

  When dust or the like is clogged in the motor shaft portion of the radiator fan 24, the rotational speed of the motor decreases. If it does so, the cooling effect by the radiator fan 24 will fall, and the hydraulic fluid of the throttle passage 21 will return to the oil tank 11 without being cooled very much. Therefore, the oil temperature of the oil tank 11 rises. Since the viscosity of the hydraulic oil decreases as the temperature rises, the hydraulic pump 13 increases the amount of hydraulic oil leakage and lowers the volumetric efficiency. As a result, in the dead head state, the discharge pressure of the hydraulic pump 13 decreases and falls below the dead head pressure Pa. Then, since the discharge pressure of the hydraulic pump 13 is returned to the dead head pressure Pa, the rotational speed of the pump motor 14 is increased. As a result, the rotation speed of the pump motor 14 in the dead head state exceeds the “normal rotation” range.

  Further, when dust or the like is mixed into the hydraulic oil in the oil tank 11 or the like, dust or the like mixed into the hydraulic oil enters the sliding portion of the hydraulic pump 13, and the sliding portion is worn and internal leakage increases. Thereby, the volumetric efficiency of the hydraulic pump 13 decreases. Then, as described above, since the discharge pressure of the hydraulic pump 13 is lower than the dead head pressure Pa, the rotation speed of the pump motor 14 is increased. As a result, the rotation speed of the pump motor 14 in the dead head state exceeds the “normal rotation” range.

  Further, if dust or the like is clogged in the seat portion of the safety valve 16 when the safety valve 16 is opened, the safety valve 16 may not be completely closed. Then, hydraulic oil is always bypassed through the safety valve 16. That is, hydraulic oil leaks in the safety valve 16. As a result, in the dead head state, the discharge pressure of the hydraulic pump 13 decreases and falls below the dead head pressure Pa. Then, as in the case of the radiator fan 24 described above, the rotational speed of the pump motor 14 is increased. As a result, the rotation speed of the pump motor 14 in the dead head state exceeds the “normal rotation” range.

  Further, when dust or the like is clogged in the variable throttle valve 22, the amount of oil flowing to the throttle passage 21 decreases. As a result, the amount of oil supplied to the actuator increases. Thereby, in the dead head state, the discharge pressure of the hydraulic pump 13 rises and exceeds the dead head pressure Pa. Then, since the discharge pressure of the hydraulic pump 13 is returned to the dead head pressure Pa, the rotation speed of the pump motor 14 is reduced. As a result, the rotation speed of the pump motor 14 in the dead head state falls below the “normal rotation” range.

  For the above reasons, the rotational speed of the pump motor 14 exceeds or falls below the “normal rotation” range in the dead head state.

The failure rate calculation unit 34 calculates the failure rate of the pump motor 14 based on the temperature of the pump motor 14 (temperature detected by the temperature thermistor 14a). As shown in FIG. 3, for example, when the temperature of the pump motor 14 is the lower limit value of the use range (for example, 0 ° C.), the failure rate is 0%, and the temperature at which the motor temperature is abnormal (for example, 80 ° C., hydraulic unit 1 Temperature at which the emergency stop occurs)
And the failure rate of the temperature during that time is calculated.
Failure rate (%) = motor temperature / 80 (° C.) × 100

  The operation state determination unit 35 determines the operation state of the hydraulic unit 1 based on the discharge pressure of the hydraulic pump 13 detected by the pressure sensor 17 and the rotational speed of the pump motor 14 detected by the speed detection unit 33. . In the present embodiment, the operating state determination unit 35 determines whether the rotational speed of the pump motor 14 is in a normal state range, increased from a normal state, or decreased from a normal state during constant pressure control. to decide. As shown in FIG. 4, the operating state determination unit 35 determines whether the motor rotation speed is in the normal state, the rising state 1, the rising state 2, or the decreasing state.

The correction unit 36 corrects the failure rate calculated by the failure rate calculation unit 35 based on the operation state determined by the operation state determination unit 36. When the operating state determination unit 36 determines whether the motor rotation speed is in the normal state, the rising state 1, the rising state 2, or the decreasing state, the correction coefficient corresponding to each driving state is determined. The In the present embodiment, the correction coefficients for the normal state, the rising state 1, the rising state 2, and the decreasing state are 1.2, 1.1, 1.0, and 1.0, respectively, and the correction coefficient is larger. This indicates that the motor temperature is likely to rise.
Corrected failure rate (%) = Failure rate (%) x Correction factor

The margin calculation unit 37 calculates a maintenance margin for preventing the temperature of the pump motor 14 of the hydraulic unit 1 from rising to an abnormal temperature. In the present embodiment, not the corrected failure rate is displayed as the maintenance emergency level, but a margin corresponding to the corrected failure rate is displayed. Accordingly, the margin calculation unit 37 is calculated based on the corrected failure rate corrected by the correction unit 36, and indicates that the smaller the margin, the more urgent maintenance is required.
Margin (%) = 100−corrected failure rate (%)

  Based on the change in the margin calculated by the margin calculation unit 37, the prediction unit 38 is urgent due to the temperature of the motor rising to an abnormal temperature when the operation is continued without performing maintenance. Predict when to stop.

  An example of a prediction method in the prediction unit 38 will be described with reference to FIG. The prediction unit 38 uses the margin when maintenance is performed as a reference value, compares the reference value with the latest margin, and predicts when the margin is 0% based on the difference. As the reference value, the daily margin is stored individually, and when a predetermined period is stored, this is used as the reference value. Thereafter, every time a predetermined period elapses, a decrease in the margin in that period is calculated, and assuming that the margin continues to decrease at the same slope as the decrease, a time when the margin becomes 0% is predicted. As the margin for the predetermined period, the margin is periodically calculated in the predetermined period, compared with the current margin, and the smaller one is stored as the current margin. When the predetermined period has elapsed, the current margin is reset to the initial value of 100%. For example, assuming that the reference value of the margin in the predetermined period is 30%, the margin in period 1 to period 5 is 30% as shown in FIG. Thereafter, if the margin in period 6 is reduced to 25%, the margin is reduced by 5% in period 6, and thereafter, assuming that the margin is reduced by 5% for each predetermined period, after period 6, a predetermined period × When the period of 6 elapses, the margin is predicted to be 0%. The prediction method in the prediction unit 38 may be other methods.

  The display unit 50 displays the urgency level of maintenance for preventing the operation of the hydraulic unit 1 from being urgently stopped due to the motor temperature rising to an abnormal temperature in the hydraulic unit 1. In the present embodiment, the display unit 50 includes a motor failure rate calculated by the failure rate calculation unit 34, a corrected failure rate corrected by the correction unit 36, a margin calculated by the margin calculation unit 37, The time when the driving predicted by the prediction unit 38 is urgently stopped is displayed.

<Emergency display operation>
Next, the emergency level display operation in the hydraulic unit 1 will be described with reference to FIG.

  It is determined whether or not constant pressure control is being performed in the hydraulic unit 1 (step S1). When the constant pressure control is being performed (S1: YES), the failure rate of the pump motor 14 is calculated based on the temperature of the pump motor 14 (step S2). Thereafter, the operating state of the hydraulic unit 1 is determined based on the rotational speed of the pump motor 14 detected by the speed detector 33 (step S3), and the correction coefficient is determined based on the operating state (step S4). . When the correction coefficient is determined, the failure rate calculated by the failure rate calculation unit 35 is corrected, and the corrected failure rate is calculated (step S5). Thereafter, a margin is calculated based on the corrected failure rate (step S6). In this way, by calculating the margin every predetermined period, by grasping the change in the margin every predetermined period, when the operation of the hydraulic unit 1 is continued without performing the maintenance, The time when the operation is urgently stopped due to the temperature rising to the abnormal temperature is predicted (step S7), and then the failure rate, the corrected failure rate, and the margin are given to inform the user of the maintenance urgency level. Are displayed on the display unit 50 (step S8).

<Characteristics of hydraulic unit of this embodiment>
The hydraulic unit 1 of the present embodiment has the following features.

  In the hydraulic unit 1 of the present embodiment, it is possible to notify the user of the urgent level of maintenance for preventing the motor temperature from rising to an abnormal temperature. Therefore, the user can continue the operation of the hydraulic unit 1 in consideration of the urgency of maintenance, and can make a maintenance plan.

  In the hydraulic unit 1 according to the present embodiment, when the motor unit is operated in an operation state that affects the motor temperature increase, the motor temperature is likely to rise. Can inform the user. Therefore, when the motor is in an operating state in which the temperature of the motor is likely to rise, the correction is made so that the motor failure rate is larger than the current failure rate, so that the user knows that the maintenance urgency is high. Can do.

  In the hydraulic unit 1 of the present embodiment, when the motor is operated in an operation state that is severe with respect to the temperature rise of the motor, the failure rate is corrected to be larger as the operation state is severe. Therefore, the failure rate before correction and the corrected failure after correction Based on the difference from the rate, the user can know how severe the driving state is.

  In the hydraulic unit 1 according to the present embodiment, based on the change in the margin, the time when the operation is urgently stopped due to the temperature of the motor rising to an abnormal temperature when maintenance is not performed is predicted and notified. Thus, the user can know when the maintenance needs to be performed.

(Second Embodiment)
An oil cooling unit 101 according to a second embodiment of the present invention will be described. The oil cooling unit 101 according to the second embodiment is greatly different from the hydraulic unit 1 according to the first embodiment in that the oil cooling unit 101 is a device that cools the oil supplied to the main machine, and the condenser temperature reaches an abnormal temperature. It is a point which notifies the emergency degree of the maintenance which prevents an emergency stop resulting from having risen.

  As shown in FIG. 7, the oil cooling unit 101 of the present embodiment has a refrigerant circuit to which a variable capacity compressor 102, a condenser 103, an expansion valve 104, and an evaporator 105 are connected. The evaporator 105 has a refrigerant pipe through which refrigerant flows and an oil pipe through which oil flows, and performs heat exchange between the refrigerant in the refrigerant pipe and the oil in the oil pipe. In this refrigerant circuit, a condenser 103 is connected to the discharge port of the compressor 102, and an expansion valve 104 is connected to the condenser 103. One end of the evaporator 105 is connected to the expansion valve 104, and the suction port of the compressor 102 is connected to the other end of the evaporator 105. In this way, a refrigerant discharged from the compressor 102 flows in order to the condenser 103, the expansion valve 104, and the evaporator 105, and a cooling cycle returning to the compressor 102 is formed. This refrigerant circuit has a bypass circuit that bypasses between the compressor 102 and the condenser 103, and between the expansion valve 104 and the evaporator 105, and an open / close valve 104a is disposed in the bypass circuit. The The oil cooling unit 101 has a fan 107 facing the condenser 103 and an air filter 108 disposed between the condenser 103 and the fan 107 to remove dust contained in the air supplied to the condenser 103. doing. A room temperature thermistor 101a is disposed around the oil cooling unit 101, a condenser temperature thermistor 103a is disposed in the condenser 103, and an oil inlet temperature thermistor 105a and a hydraulic outlet temperature thermistor 105b are disposed in the evaporator 105. The

  The oil cooling unit 101 supplies oil cooled by the evaporator 105 to the main machine, and includes a control unit 110 for controlling the refrigerant circuit.

  The control unit 110 includes a temperature control unit 111, a frequency command calculation unit 112, an inverter 113, a failure rate calculation unit 114, an operation state determination unit 115, a correction unit 116, a margin calculation unit 117, and a prediction unit. 118. In addition, a display unit 150 is connected to the control unit 110.

  In this embodiment, when the target value of the set oil outlet temperature and the oil outlet temperature detected by the oil outlet temperature thermistor 105b are input to the temperature controller 111, the temperature controller 111 receives the input. Based on the target value of the oil outlet temperature and the oil outlet temperature, the capability command value of the oil cooling unit is calculated and output. The frequency command calculation unit 112 outputs a compressor frequency command value to the inverter 113 based on the capability command value output by the temperature control unit 111. Thus, since the minimum frequency and the maximum frequency of the compressor differ depending on the model, in order to absorb the difference between the models, the temperature control unit 111 calculates the capability command value (0-100%) of the oil cooling unit, The frequency command calculation unit 112 calculates a frequency command value suitable for the compressor mounted on the oil cooling unit, and outputs it to the inverter 113.

  Next, the control operation in the oil cooling unit 101 will be described.

  When clogging of the condenser 103 and the air filter 108 progresses, the heat dissipation capacity in the condenser 103 decreases and the capacity command value of the compressor 102 increases (FIG. 8). Therefore, the load on the compressor 102 increases and the condensation temperature (the high-pressure saturation temperature of the refrigerant detected by the condensation temperature thermistor 103a) increases. Therefore, the temperature of the condenser 103 is likely to rise, and the operating state is such that the temperature of the condenser 103 is likely to rise to an abnormal temperature.

The failure rate calculation unit 114 calculates the failure rate of the condenser 103 based on the temperature of the condenser 103 (temperature detected by the condensation temperature thermistor 103a). As shown in FIG. 9, for example, when the temperature of the condenser 103 is the lower limit value of the use range (for example, 5 ° C.), the failure rate is 0%, and the temperature at which the condensation temperature becomes abnormal (for example, 60 ° C., oil cooling unit 101 Is the emergency stop temperature), the failure rate is 100%, and the failure rate of the temperature during that time is calculated.
Failure rate (%) = (condensation temperature−5 (° C.)) / 55 × 100

  The operation state determination unit 115 determines the operation state of the oil cooling unit 101 based on the oil outlet temperature detected by the oil outlet temperature thermistor 105b, the oil inlet temperature detected by the oil inlet temperature thermistor 105a, and the capability command value. To do. In the present embodiment, the operation state determination unit 115 determines how far the relationship between the difference between the oil inlet temperature and the oil outlet temperature and the capability command value is out of the normal state range. As shown in FIG. 10, the driving state determination unit 115 determines whether the capability command value is in the normal state, the rising state 1, the rising state 2, or the rising state 3.

The correction unit 116 corrects the failure rate calculated by the failure rate calculation unit 114 based on the operation state determined by the operation state determination unit 115. The operating state determination unit 115 determines whether the relationship between the difference between the oil inlet temperature and the oil outlet temperature and the capacity command value is in the normal state, the rising state 1, the rising state 2, or the rising state 3. Then, the correction coefficient corresponding to each operation state is determined. In the present embodiment, the correction coefficients for the normal state, the rising state 1, the rising state 2 and the rising state 3 are 1.0, 1.1, 1.2 and 1.3, respectively, and the correction coefficient is large. It shows that the operating state is such that the temperature of the condenser 103 is likely to rise.
Corrected failure rate (%) = Failure rate (%) x Correction factor

The margin calculation unit 117 calculates a maintenance margin for preventing the temperature of the condenser 103 of the oil cooling unit 101 from rising to an abnormal temperature. In the present embodiment, not the corrected failure rate is displayed as the maintenance emergency level, but a margin corresponding to the corrected failure rate is displayed. Accordingly, the margin calculation unit 117 is calculated based on the corrected failure rate corrected by the correction unit 116, and indicates that the maintenance needs to be performed urgently as the margin is smaller.
Margin (%) = 100−corrected failure rate (%)

  The predicting unit 118 operates based on the change in the margin calculated by the margin calculating unit 117 because the condenser temperature rises to an abnormal temperature when the operation is continued without performing maintenance. Predict when emergency stop will occur. Since the prediction method in the prediction unit 118 is the same as the prediction method of the prediction unit 38 in the first embodiment, detailed description thereof is omitted.

  The display unit 150 displays the urgent level of maintenance for preventing the operation of the oil cooling unit 101 from being urgently stopped due to the temperature of the condenser rising to an abnormal temperature in the oil cooling unit 101. . In the present embodiment, the display unit 150 includes the condenser failure rate calculated by the failure rate calculation unit 114, the corrected failure rate corrected by the correction unit 116, and the margin calculated by the margin calculation unit 117. The time when the operation is urgently stopped due to the rise in the condenser temperature predicted by the prediction unit 118 to the abnormal temperature is displayed.

<Emergency display operation>
The urgent level display operation in the oil cooling unit 101 is the same as the display operation of the first embodiment shown in FIG.

<Characteristics of oil cooling unit of this embodiment>
The oil cooling unit 101 of this embodiment has the following features.

  In the oil cooling unit 101 of the present embodiment, it is possible to notify the user of the urgent level of maintenance for preventing the condenser temperature from rising to an abnormal temperature. Therefore, the user can continue the operation of the oil cooling unit 101 in consideration of the urgency of maintenance, and can make a maintenance plan.

  In the oil cooling unit 101 of the present embodiment, when operating in an operating state that affects the temperature rise of the condenser, the temperature of the condenser tends to rise. The user can be notified of the degree of urgency. Therefore, when the condenser is in an operating state in which the temperature of the condenser is likely to rise, the condenser failure rate is corrected and notified so as to be larger than the current failure rate, so that the user must confirm that the maintenance urgency is high. I can know.

  In the oil cooling unit 101 of the present embodiment, when operating in an operation state that is severe with respect to the temperature rise of the condenser, the failure rate is largely corrected as the operation state is severe. Therefore, the failure rate before correction and the value after correction are corrected. Based on the difference from the corrected failure rate, the user can know how severe the operating state is.

  In the oil cooling unit 101 of the present embodiment, based on the change in the margin, when the maintenance is not performed, the time when the operation is urgently stopped due to the temperature of the condenser rising to an abnormal temperature is predicted. Therefore, the user can know when it is necessary to perform maintenance.

(Third embodiment)
A hydraulic unit according to a third embodiment of the present invention will be described. The hydraulic unit according to the third embodiment is greatly different from the hydraulic unit 1 according to the first embodiment in that it is informed that the operating state affects the temperature rise of the motor. Since the other configuration of the hydraulic unit according to the third embodiment is the same as that of the hydraulic unit 1 according to the first embodiment, detailed description thereof is omitted.

  In the hydraulic unit according to the third embodiment, the display unit 50 displays the urgent level of maintenance for preventing the operation of the hydraulic unit from being stopped urgently due to the temperature of the motor rising to an abnormal temperature. To do. In the present embodiment, the display unit 50 displays the operation state determined by the operation state determination unit 35. That is, it is displayed whether the operating state of the hydraulic unit is a normal state, a rising state 1, a rising state 2, or a decreasing state. Therefore, when the operation state of the hydraulic unit is either the rising state 1 or the rising state 2, there is a high possibility that internal leakage of the pump 13 or leakage on the chuck side has occurred. 13 is informed that an internal leak or a chuck side leak has occurred.

<Characteristics of hydraulic unit of this embodiment>
The hydraulic unit of the present embodiment has the following characteristics.

  In the hydraulic unit of the present embodiment, it is possible to notify the user of the urgent level of maintenance for preventing the motor temperature from rising to an abnormal temperature. Therefore, the user can continue the operation of the hydraulic unit 1 in consideration of the urgency of maintenance, and can make a maintenance plan.

  In the hydraulic unit of the present embodiment, when operating in an operating state that affects the temperature rise of the motor, the operating state is notified, so the user can change the operating state based on the notified operating state. It is possible to know that the cause of the problem (for example, internal leakage of the pump 13 or leakage on the chuck side) has occurred.

  As mentioned above, although embodiment of this invention was described based on drawing, it should be thought that a specific structure is not limited to these embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  In the first and third embodiments described above, the urgency of maintenance for preventing an emergency stop due to the temperature of the motor rising to an abnormal temperature is notified, and in the second embodiment, a condenser is used. Although the case where the emergency level of maintenance to prevent an emergency stop due to the temperature of the engine rising to the abnormal temperature has been described, the temperature of the other parts has increased to the abnormal temperature has been explained. Thus, the emergency level of maintenance for preventing an emergency stop may be notified.

  Therefore, for example, when the hydraulic unit 1 of the first embodiment includes an electrical component and a fan that supplies an air flow to the electrical component, if dust or the like is clogged in the motor shaft portion of the fan, the motor The number of rotations decreases. If it does so, the cooling effect by a fan will fall, the temperature of an electrical component will rise without the electrical component being cooled very much, and there is a high possibility of an emergency stop due to the temperature of the electrical component rising to an abnormal temperature. In such a case, it is conceivable to notify the urgency of maintenance for preventing an emergency stop due to the temperature of the electrical component rising to an abnormal temperature. At this time, the temperature of the electrical component is detected, the failure degree of the electrical component is calculated based on the temperature of the electrical component, the temperature of the fan motor is detected, and the temperature of the electrical component is increased based on the temperature of the fan motor. It is possible to determine whether or not the driving state has an influence. The urgent level display operation in the hydraulic unit is the same as the display operation of the first embodiment.

  In the first and second embodiments described above, the display unit has a component failure rate calculated by the failure rate calculation unit, a corrected failure rate corrected by the correction unit, and a margin calculated by the margin calculation unit. In addition, the case where the operation predicted by the prediction unit is displayed when the emergency stop is described has been described, but the display unit has a component failure rate, a corrected failure rate, a margin, as an emergency level of maintenance, At least one of the emergency stop time may be displayed.

  In the above-described third embodiment, in the hydraulic unit, the operating state determination is performed as the urgent level of maintenance for preventing the hydraulic unit from being urgently stopped due to the temperature of the motor rising to an abnormal temperature. In the oil cooling unit according to the second embodiment, the temperature of the condenser is abnormal in the oil cooling unit according to the second embodiment, but the operation state (for example, the occurrence of internal leakage of the pump or leakage on the chuck side) has been described. As the urgency level of maintenance to prevent the oil cooling unit from being stopped due to an increase in temperature, the operation state determined by the operation state determination unit (for example, the condenser and air filter eyes) That clogging is in progress).

  In the above-described first to third embodiments, the case has been described in which the maintenance emergency level is notified by being displayed on the display unit, but may be notified by other methods such as voice.

  By using the present invention, it is possible to notify the urgency of maintenance for preventing an emergency stop.

1 Hydraulic unit 14 Fan motor (parts)
14a Temperature thermistor (temperature detection means)
34 Failure rate calculation unit (failure rate calculation means)
35 Driving state determination unit (driving state determination means)
36 Correction unit (correction means)
37 Margin calculation unit 38 Prediction unit (prediction means)
50 Display section (notification means)
101 Oil cooling unit 103 Condenser (parts)
103a Condensation temperature thermistor (temperature detection means)
114 Failure rate calculation unit (failure rate calculation means)
115 Operation state determination unit (operation state determination means)
116 Correction unit (correction means)
117 Margin calculation unit 118 Prediction unit (prediction means)
150 Display (notification means)

Claims (4)

A hydraulic unit or oil cooling unit that stops operation when the temperature of a component rises to an abnormal temperature,
Informing means for informing the urgency of maintenance for preventing the temperature of the component from rising to the abnormal temperature before the operation is stopped due to the temperature of the component rising to the abnormal temperature ;
Temperature detecting means for detecting the temperature of the component;
A failure rate calculation means for calculating a component failure rate based on the temperature detected by the temperature detection means;
An operation state determination means for determining an operation state that affects the temperature rise of the component;
Correction means for correcting the component failure rate calculated by the failure rate calculation means based on the operating state detected by the operating state determination means;
The notifying means notifies the urgency of maintenance based on the component failure rate corrected by the correcting means, or a hydraulic unit or an oil cooling unit. 2. The hydraulic unit or oil according to claim 1 , wherein the notifying unit notifies the component failure rate calculated by the failure rate calculating unit and the component failure rate after being corrected by the correcting unit. Cooling unit. Based on the change in the component failure rate after being corrected by the correction means, the time when the operation is stopped due to the temperature of the component rising to an abnormal temperature when the operation is continued without performing maintenance. A prediction means for predicting,
The notification means, in conjunction with the urgency of the maintenance, the hydraulic unit or oil cooling unit according to claim 1 or 2, characterized in that notifying the timing that was predicted by the predicting means. Provided with an operation state determination means for detecting an operation state that affects the temperature rise of the component,
The hydraulic unit or oil cooling unit according to claim 1, wherein the notification unit notifies the operation state detected by the operation state determination unit.

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