WO2015194425A1

WO2015194425A1 - Liquid discharge device

Info

Publication number: WO2015194425A1
Application number: PCT/JP2015/066695
Authority: WO
Inventors: 智明須藤; 一彦船橋; 和隆岩田
Original assignee: 日立工機株式会社
Priority date: 2014-06-20
Filing date: 2015-06-10
Publication date: 2015-12-23

Abstract

In the present invention, in order to provide a high pressure washing device for which it is possible to mitigate an increase in cost, a high pressure washing device (10) is provided with a pump (12) that takes in and discharges a washing fluid, and a brushless motor (14) that drives the pump (12). The high pressure washing device is further provided with a control unit (15) that detects a load on the brushless motor (14) when driving the pump (12) and estimates the amount of washing fluid that the pump (12) has taken in on the basis of the detected load on the brushless motor (14), and the control unit (15) stops the brushless motor (14) if it is estimated that there is no more washing fluid to be taken in by the pump (12).

Description

Liquid ejection device

The present invention relates to a liquid discharge apparatus including a pump that discharges liquid.

2. Description of the Related Art Conventionally, a liquid ejecting apparatus including a pump that ejects liquid is known, and the liquid ejecting apparatus is described in Patent Document 1. The liquid ejection device described in Patent Document 1 is a high-pressure washing machine that cleans an object by spraying liquid onto the object. This high-pressure washing machine includes an apparatus main body, a pump provided in the apparatus main body, a tank attached to the apparatus main body for storing liquid to be supplied to the pump, a motor for driving the pump, and a battery pack for supplying electric power to the motor. And. A connection plug is attached to the discharge port of the pump, and the connection plug is connected to the cleaning gun via a hose. When the motor is driven, the pump sucks and discharges the cleaning liquid in the tank, and the cleaning liquid discharged from the pump is sprayed from the nozzle of the cleaning gun through the hose so that the cleaning operation can be performed.

The high pressure washer described in Patent Document 1 drives the motor with the hose removed from the connection plug after the cleaning operation, and drains the cleaning liquid remaining in the pump from the connection plug to the outside. It can be carried out. Further, in Patent Document 1, a cleaning liquid detection sensor for detecting the presence or absence of cleaning liquid in the tank is provided at the lower end of the tank, and when the cleaning liquid detection sensor detects that the cleaning liquid in the tank has run out, a draining operation is performed. It is described.

JP 2014-46282 A

However, the liquid ejection device described in Patent Document 1 needs to provide a dedicated cleaning liquid detection sensor in order to detect the presence or absence of the cleaning liquid in the tank, and there is a problem that the cost of the liquid ejection apparatus increases.

An object of the present invention is to provide a liquid ejection device capable of suppressing an increase in cost.

The liquid discharge apparatus of the present invention is a liquid discharge apparatus including a pump for sucking and discharging liquid, and a motor for driving the pump, and detects a load of the motor for driving the pump; and A liquid amount detection unit that estimates the amount of liquid sucked by the pump based on the load of the motor, and a motor that stops the motor when it is estimated that the amount of liquid sucked by the pump is equal to or less than a predetermined amount And a control unit.

A liquid discharge apparatus according to another embodiment is a liquid discharge apparatus including a pump that sucks and discharges liquid, a motor that drives the pump, and a tank that stores the liquid sucked by the pump. A load detection unit that detects a load of the motor; detects the amount of the liquid in the tank based on the load of the motor; and stops the motor when the amount of the liquid is equal to or less than a predetermined amount A motor control unit.

In another embodiment, a liquid discharge apparatus includes a pump that sucks and discharges liquid, a motor that drives the pump, a tank that stores the liquid sucked by the pump, and a flow of the liquid discharged from the pump. A liquid ejection device having a trigger for opening and closing a path, and a cleaning gun for discharging the liquid to the outside, wherein the liquid is ejected from the cleaning gun when the flow path is opened In addition, a motor control unit is provided for stopping the motor when the load of the motor becomes a predetermined value or less.

According to the present invention, the amount of liquid sucked by the pump can be estimated based on the load of the motor when the pump is being driven. Therefore, it is not necessary to provide a dedicated sensor for detecting the amount of liquid sucked by the pump, and it is possible to suppress an increase in the cost of the liquid ejection device.

It is a schematic diagram which shows the high-pressure washing machine which is embodiment of the liquid discharge apparatus of this invention, and a washing | cleaning gun. It is a block diagram which shows the control system of the high pressure washer shown in FIG. It is a flowchart which shows the example of control which can be performed with the high pressure washer of FIG. It is a time chart corresponding to the flowchart of FIG.

Hereinafter, an embodiment in which a liquid discharge apparatus of the present invention is applied to a high pressure washer will be described with reference to the drawings. The high-pressure washing machine 10 according to the present embodiment includes a washing machine main body 11, a pump 12 provided in the washing machine main body 11, a tank 13 that stores a cleaning liquid supplied to the pump 12, and a brushless motor 14 that drives the pump 12. And a control unit 15 that controls the brushless motor 14 and a battery pack 16 that supplies power to the brushless motor 14. Further, a hose 18 for supplying the cleaning liquid discharged from the pump 12 to the cleaning gun 17 is provided.

The tank 13 is disposed on the upper part of the cleaning machine main body 11, and the tank 13 is detachable from the cleaning machine main body 11. The cleaning liquid injected into the tank 13 may be either water or water containing a surfactant. The pump 12 includes an operating member that is operated by the power of the brushless motor 14, a suction port 12a connected to the tank 13, and a discharge port 12b connected to the flow path 12c. The flow path 12 c is connected to the hose 18. As the pump 12, for example, a plunger pump can be used. In the pump 12, the plunger reciprocates to suck and discharge the cleaning liquid.

The cleaning gun 17 is an injection device that injects the cleaning liquid discharged from the pump 12. The cleaning gun 17 includes a gun main body 19, a nozzle 20 attached to the gun main body 19, a flow path 21 provided in the gun main body 19 and connecting the hose 18 and the nozzle 20, and a flow path 21. And a trigger 23 for opening and closing the valve 22. The trigger 23 is operated by an operator. When no operating force is applied to the trigger 23, the valve 22 is closed and no cleaning liquid is ejected from the nozzle 20. When an operating force is applied to the trigger 23, the valve 22 is opened and the cleaning liquid is sprayed from the nozzle 20 to the outside of the cleaning gun 17.

The battery pack 16 is detachable from the washing machine body 11, and the battery pack 16 has a plurality of battery cells housed in a housing case. The battery cell includes a secondary battery that can be repeatedly charged and discharged, for example, a lithium ion battery.

The brushless motor 14 is a type of DC motor, and the brushless motor 14 includes a stator 14a and a rotor 14b. The stator 14a includes three coils U1, V1, and W1 corresponding to the U phase, the V phase, and the W phase, and the stator 14a does not rotate. The stator 14a is annularly arranged, and the rotor 14b is rotatably arranged inside the stator 14a. A plurality of permanent magnets 14c are attached to the outer peripheral surface of the rotor 14b at intervals in the circumferential direction. The plurality of permanent magnets 14c include a plurality of types of permanent magnets 14c having different polarities, and the permanent magnets 14c having different polarities are alternately arranged. Furthermore, a power transmission mechanism that transmits the rotational force of the rotor 14b to the plunger is provided.

FIG. 2 is a block diagram showing a control system of the high pressure washer 10. An operation panel 24 is provided in the cleaning machine main body 11, and the operation panel 24 includes a pressure setting dial 25, a remaining amount display unit 26, and a main power switch 27. An operator can set the discharge pressure of the cleaning liquid by operating the pressure setting dial 25. The remaining amount display unit 26 displays the remaining amount of the battery pack 16, that is, the voltage. The operator switches between turning on and off the main power switch 27 and selects starting and stopping of the high-pressure washing machine 10. As the main power switch 27, a known tactile switch can be used.

In addition, Hall ICs 28a to 28c for detecting the rotational position of the rotor 14b of the brushless motor 14 are provided. Three Hall ICs 28a to 28c are provided at different positions in the rotational direction of the rotor 14b, corresponding to the U phase, V phase, and W phase. The Hall ICs 28a to 28c are non-contact sensors that do not contact the rotor 14b, and the Hall ICs 28a to 28c detect a magnetic field formed by the permanent magnet 14c attached to the rotor 14b and correspond to the magnitude of the magnetic field. It is a magnetic sensor that outputs a signal.

The control unit 15 has an inverter circuit 29 for controlling the drive current supplied to the three coils U1, V1, W1 constituting the stator 14a. The inverter circuit 29 controls the drive current supplied to the coils U1, V1, and W1. The inverter circuit 51 is a three-phase full-bridge inverter circuit, and includes two

switching elements

29a and 29b connected in series, two

switching elements

29c and 29d connected in series, and two switching elements connected in series. It has

elements

29e and 29f. The three

switching elements

29a, 29c, and 29e are connected to the positive electrode 16a of the battery pack 16, and the three switching

elements

29b, 29d, and 29f are connected to the negative electrode 16b of the battery pack 16. The three

switching elements

29a, 29c, 29e connected to the positive electrode 16a of the battery pack 16 are on the high side, and the three switching

elements

29b, 29d, 29f connected to the negative electrode 16b of the battery pack 16 are It is on the low side.

One connection terminal of the coil U1 is connected between the switching element 29a and the switching element 29b. One connection terminal of the coil V1 is connected between the switching element 29c and the switching element 29d. One connection terminal of the coil W1 is connected between the switching element 29e and the switching element 29f. The other connection terminals of the coils U1, V1, and W1 are connected to each other, and the coils U1, V1, and W1 are star-connected. In addition, the connection system of the coils U1, V1, and W1 may be delta connection. For example, when a gate signal is turned on to the switching element 29a on the high side and the switching element 29d on the low side, current is supplied to the coils U1 and V1. By adjusting the timing of the gate signal supplied to each of the switching elements 29a to 29f, the direction and current value of the current passing through the coils U1, V1, and W1 are controlled.

Further, the control unit 15 includes a driver circuit 30, and the driver circuit 30 outputs gate signals for turning on and off the switching elements 29a to 29f of the inverter circuit 29, respectively. Further, the control unit 15 includes a microcomputer 31. The microcomputer 31 includes an input port and an output port, a storage unit, and a calculation unit, and a signal output from the pressure setting dial 25 and a signal output from the Hall ICs 28a, 28b, and 28c are input to the microcomputer 31. The

Further, a pressure detection switch 32 for detecting the pressure in the flow path 12c is provided. The pressure detection switch 32 is provided in the cleaning machine body 11. The pressure detection switch 32 is, for example, a switch provided with a diaphragm. The pressure detection switch 32 is turned on when the pressure in the flow path 12c is lower than the first predetermined pressure, and the pressure in the flow path 12c increases to increase the first pressure. When the pressure exceeds a predetermined level, the switch is switched from on to off.

On the other hand, the pressure detection switch 32 is switched from off to on when the pressure in the flow path 12c decreases to be equal to or lower than the second predetermined pressure. The first predetermined pressure is higher than the second predetermined pressure. For example, the first predetermined pressure is 5 [MPa], and the second predetermined pressure is 3.5 [MPa]. The difference between the first predetermined pressure and the second predetermined pressure is hysteresis. The reason why the pressure detection switch 32 has hysteresis in the characteristic of switching between on and off is to prevent the pressure in the flow path 12c from fluctuating by a minute amount and frequently switching between on and off. The pressure detection switch 32 outputs a detection signal corresponding to ON or OFF, and the signal output from the pressure detection switch 32 is input to the microcomputer 31.

The control unit 15 includes a current detection resistor 33 provided in the electric circuit E <b> 1 that supplies power from the battery pack 16 to the inverter circuit 29. The control unit 15 includes a current detection circuit 34. The current detection circuit 34 detects the current value supplied to the coils U1, V1, W1 of the stator 14a from the voltage drop of the current detection resistor 33, and according to the detection result. The signal is output to the microcomputer 31. Further, the control unit 15 includes a control system power circuit 35 connected between the battery pack 16 and the inverter circuit 29, and the control system power circuit 35 converts the voltage of the battery pack 16 into a drive voltage of the microcomputer 31. And supply.

The control unit 15 further includes a power on / off circuit 36 to which a signal output from the main power switch 27 is input. The power on / off circuit 36 controls the control system power circuit 35 based on the input signal. The microcomputer 31 receives a signal for maintaining a signal input from the power on / off circuit 36 to the control system power circuit 35. The microcomputer 31 detects the voltage of the battery pack 16 and outputs a signal indicating the result of detecting the voltage of the battery pack 16 to the remaining amount display unit 26.

Further, the control unit 15 includes a motor operation stop circuit 37 provided between the battery pack 16 and the inverter circuit 29 in the electric circuit E1. The motor operation stop circuit 37 includes a semiconductor switch, and the motor operation stop circuit 37 turns on or off the electric circuit E1 that supplies the power of the battery pack 16 to the brushless motor 14 according to a signal input from the control system power supply circuit 35. To do. The motor operation stop circuit 37 is switched on and off by a signal input from the pressure detection switch 32 without passing through the microcomputer 31 in addition to a signal input from the control system power supply circuit 35. The motor operation stop circuit 37 is turned off by an off signal input from the pressure detection switch 32, and the motor operation stop circuit 37 is turned on by an on signal input from the pressure detection switch 32.

Further, the electric circuit E 1 connects the battery pack 16 and the brushless motor 14, and a fuse 38 is provided between the motor operation stop circuit 37 and the battery pack 16. The fuse 38 is an electronic component that protects the electric circuit E1 from a large current exceeding the rating. Various types of data are stored in the storage unit of the microcomputer 31. The data stored in the storage unit includes a map representing the relationship between the target pressure set by operating the pressure setting dial 25 and the rotational speed of the rotor 14b of the brushless motor 14.

The data stored in the storage unit includes a map representing the relationship between the rotational speed of the rotor 14b of the brushless motor 14 and the duty ratio that is the ON ratio of the switching elements 29a to 29f. Further, the data stored in the storage unit includes a map representing the relationship between the target pressure set by operating the pressure setting dial 25 and the current value supplied to the brushless motor 14.

When the main power switch 27 is turned on in the high pressure washer 10 having the above configuration, the power of the battery pack 16 is supplied to the microcomputer 31 via the control system power circuit 35, and the microcomputer 31 is activated. Further, a signal is input from the control system power supply circuit 35 to the motor operation stop circuit 37, and the motor operation stop circuit 37 is turned on.

Further, a signal is input from the microcomputer 31 to the driver circuit 30, and the switching elements 29 a to 29 f of the inverter circuit 29 are turned on / off by the signal output from the driver circuit 30, and the power of the battery pack 16 is passed through the inverter circuit 29. Is supplied to the coils U1, V1, W1 of the stator 14a to form a rotating magnetic field, and the rotor 14b rotates. Thus, the brushless motor 14 is driven.

When the main power switch 27 is turned on and no operating force is applied to the trigger 23, the control unit 15 once sets the pressure in the flow path 12c detected by the pressure detection switch 32 to 5.0 [MPa]. The rotational speed of the rotor 14b is controlled so as to increase to the above. The control unit 15 obtains the target rotational speed of the rotor 14b so that the flow path 12c is 5.0 [MPa] or more, and the actual rotational speed of the rotor 14b is brought close to the target rotational speed. Feedback control. Specifically, the duty ratio that is the ratio of turning on the plurality of switching elements 29a to 29f constituting the inverter circuit 29 is controlled. Increasing the duty ratio increases the actual rotational speed of the rotor 14b. When the duty ratio is lowered, the actual rotational speed of the rotor 14b is lowered. Further, the control unit 15 determines the timing for turning on the switching elements 29a to 29f based on the rotational position of the rotor 14b. In this way, the control unit 15 controls the current value supplied to the brushless motor 14 so that the pressure in the flow path 12c once becomes 5.0 [MPa].

Further, when the pressure in the flow path 12c detected by the pressure detection switch 32 becomes 5.0 [MPa] or higher, the control unit 15 stops supplying power to the coils U1, V1, W1 of the stator 14a, and the brushless motor. 14 rotors 14b are temporarily stopped.

Thereafter, when an operating force is applied to the trigger 23 and the valve 22 is opened, the cleaning liquid is discharged from the nozzle 20. When the cleaning liquid is discharged from the nozzle 20, the pressure in the flow path 12c detected by the pressure detection switch 32 decreases. When the pressure detected by the pressure detection switch 32 becomes 3.5 [MPa] or less, the control unit 15 supplies current to the stator 14a and rotates the rotor 14b of the brushless motor 14.

The controller 15 controls the brushless motor 14 so that the pressure detected by the pressure detection switch 32 is maintained at the target pressure set by operating the pressure setting dial 25 while the cleaning liquid is being discharged from the nozzle 20. The number of rotations of the rotor 14b is controlled. In this case, the control unit 15 obtains the target rotational speed of the rotor 14b according to the target pressure set by operating the pressure setting dial 25, and the brushless motor 14 so as to bring the actual rotational speed of the rotor 14b closer to the target rotational speed. Feedback control of the current value supplied to.

Further, when the operation force applied to the trigger 23 is released after the cleaning liquid is ejected from the nozzle 20, the control unit 15 once detects the pressure detected by the pressure detection switch 32 at 5.0 [MPa]. The rotational speed of the rotor 14b is controlled so that it becomes above. Thereafter, when the operating force is again applied to the trigger 23, the control unit 15 executes the same control as described above. When the main power switch 27 is turned off, the control unit 15 causes the control system power supply circuit 35 to move to the motor. The operation stop circuit 37 is turned off and the brushless motor 14 is stopped.

In the high pressure washer 10 of the present embodiment, the control unit 15 can execute control to stop the brushless motor 14 when the brushless motor 14 is in an idle state, and refer to the flowchart of FIG. 3 for an example of the control. To explain. Here, “the brushless motor 14 is in an idle state” means that the rotor 14b of the brushless motor 14 rotates when the amount of the cleaning liquid in the tank 13 is equal to or less than a predetermined amount. The amount of the cleaning liquid in the tank 13 is equal to or less than the predetermined amount when the cleaning liquid is not in the tank 13 and when the amount of the cleaning liquid in the tank 13 can maintain the target pressure set by operating the pressure setting dial 25. And the following cases.

In the flowchart of FIG. 3, when the main power switch 27 is turned on in step S <b> 1, the control unit 15 performs processing for setting “idle detection time setting flag = 0” in step S <b> 2. Furthermore, the “idle rotation detection time” is an elapsed time from when the control unit 15 determines that “the brushless motor 14 is in the idling state” until the control unit 15 stops the brushless motor 14.

In step S3 following step S2, the control unit 15 determines whether or not the pressure detection switch 32 is on. For example, if the main power switch 27 is turned on and before the first driving of the brushless motor 14, the pressure in the flow path 12c is lower than the first predetermined pressure, and the pressure detection switch 32 is turned on. . Then, the control part 15 determines Yes in step S3, and performs control of step S4. In step S 4, the motor operation stop circuit 37 is turned on by a signal from the control system power supply circuit 35, and the microcomputer 31 controls on / off of the switching elements 29 a to 29 f of the inverter circuit 29 to supply current to the brushless motor 14. Is done. When the brushless motor 14 is driven for the first time, if the trigger 23 is turned off, the current value of the brushless motor 14 is controlled so that the pressure in the flow path 12c once becomes 5.0 [MPa] or more. Is done.

In step S5 following step S4, the control unit 15 determines whether or not the current value supplied to the brushless motor 14 is equal to or less than a predetermined value. The control unit 15 detects the current value supplied to the brushless motor 14 based on the signal from the current detection circuit 34. The predetermined value used in the determination in step S5 is a threshold value for indirectly determining whether or not the brushless motor 14 is idling from the current value. Data representing the relationship between the target rotational speed and the current value supplied to the brushless motor 14 in order to set the pressure in the flow path 12 c as the target pressure is stored in the storage unit of the microcomputer 31. For example, the control unit 15 can use a current value for satisfying the target rotational speed as a predetermined value.

The control unit 15 feedback-controls the current value so that the actual rotational speed of the brushless motor 14 approaches the target rotational speed. If the current value of the brushless motor 14 is the same, when the amount of cleaning liquid sucked by the pump 12 decreases, the load decreases and the rotation speed increases. For this reason, in controlling the actual number of revolutions of the brushless motor 14, if the amount of the cleaning liquid sucked into the pump 12 decreases, the load of the brushless motor 14 decreases and the current value decreases.

That is, if the current value supplied to the brushless motor 14 is equal to or less than a predetermined value corresponding to the target pressure, the control unit 15 can determine that “the brushless motor 14 is idling”. If it is determined No in step S5, the control unit 15 returns to step S3. If the determination is Yes in step S5, the control unit 15 proceeds to step S6 and determines that “the brushless motor 14 is in an idle state”.

In step S7 subsequent to step S6, the controller 15 determines whether or not “idle time setting flag = 0”. If the control unit 15 determines Yes in step S7, the control unit 15 proceeds to step S8 and performs a process of “predetermined time t = t1”. The control unit 15 proceeds to step S9 and determines whether or not the predetermined time t [s] has elapsed after determining that the brushless motor 14 is in the idling state. When the control unit 15 proceeds to step S9 via step S8, the “predetermined time t = t1” is used in the determination of step S9.

If the controller 15 determines No in step S9, it returns to step S3. When the control unit 15 determines Yes in step S9, the control unit 15 proceeds to step S10, turns off all the switching elements 29a to 29f of the inverter circuit 29, and stops the supply of current to the brushless motor 14. The process of step S10 is expressed as “microcomputer power supply OFF” in the flowchart of FIG. As described above, when the brushless motor 14 is driven for the first time, the control unit 15 stops the brushless motor 14 when the process proceeds from step S9 to step S10 via step S8.

On the other hand, after the main power switch 27 is turned on, the brushless motor 14 is driven for the first time, and the pressure in the flow path 12c once becomes equal to or higher than the first predetermined pressure (5.0 [MPa]). If the pressure detection switch 32 is turned off, the control unit 15 determines No in step S3 and proceeds to step S11. In step S11, the motor operation stop circuit 37 is turned off so that no current is supplied to the brushless motor 14, and the brushless motor 14 stops. Further, the control unit 15 executes a process of setting “idle detection time setting flag = 1” in step S12, and returns to step S3.

Further, after the brushless motor 14 is stopped in step S11, when the trigger 23 is operated and the cleaning liquid is discharged, the pressure in the flow path 12c decreases. And if the pressure of the flow path 12c becomes below 2nd predetermined pressure (3.5 [MPa]), the pressure detection switch 32 will switch from OFF to ON. For this reason, it is judged as Yes in Step S3, and it progresses to Step S4, and the drive after the 2nd time of brushless motor 14 is performed.

When the control unit 15 proceeds to step S7 via steps S11 and S12, it determines No in step S7, executes the process of step S13, and proceeds to step S9. The controller 15 executes a process of setting “predetermined time t = t2” in step S13. Here, the predetermined time t2 is shorter than the predetermined time t1. Then, when the control unit 15 proceeds to step S9 via step S13, the control unit 15 performs the determination of step S9 using “predetermined time t = t2”.

An example of a time chart corresponding to the flowchart of FIG. 3 will be described with reference to FIG. First, before time t10, the main power switch 27 is turned off, and the motor operation stop circuit 37 is turned off. For this reason, the current value supplied to the brushless motor 14 is 0 [A]. The trigger 23 is turned off and the valve 22 is closed.

When the main power switch 27 is turned on at time t10, the motor operation stop circuit 37 is turned on by the control system power supply circuit 35, and current is supplied to the brushless motor 14 by the control of the inverter circuit 29. Start driving. When the brushless motor 14 starts the first driving, the pump 12 sucks and discharges the cleaning liquid, and the pressure in the flow path 12c increases.

The current value supplied to the brushless motor 14 is not more than a predetermined value between time t10 and time t11, and the current value exceeds the predetermined value after time t11. The time chart of FIG. 4 shows an example in which the predetermined value is 5 [A]. The current value supplied to the brushless motor 14 is not more than a predetermined value from time t10 to time t11. The elapsed time from time t10 to time t11 is less than the predetermined time t1. For this reason, the control part 15 supplies an electric current to the brushless motor 14 from the time t10 to the time t11.

The value of the current supplied to the brushless motor 14 increases after time t11. When the pressure in the flow path 12c becomes equal to or higher than the first predetermined pressure at time t12, the pressure detection switch 32 is switched from on to off. Then, the motor operation stop circuit 37 is turned off, and the current value supplied to the brushless motor 14 becomes 0 [A].

Thereafter, the pressure in the flow path 12c is lowered due to leakage of the cleaning liquid. When the trigger 23 is turned on at time t13, the cleaning liquid is discharged from the nozzle 20, and the pressure in the flow path 12c is further decreased. The control unit 15 feedback-controls the current value supplied to the brushless motor 14 in order to maintain the actual pressure in the flow path 12c above the target pressure after time t13. For this reason, the current value exceeds the predetermined value after time t13.

When the amount of the cleaning liquid in the tank 13 becomes equal to or less than the predetermined amount at time t14, the cleaning liquid is not ejected from the nozzle 20. That is, the pump 12 does not perform the pressurizing operation, and the current value supplied from the battery pack 16 to the brushless motor 14 decreases. Furthermore, the current value supplied to the brushless motor 14 is 5 [A] or less, which is a predetermined value at time t15. Then, the control unit 15 determines that “the brushless motor 14 is idling” at time t15. Then, when “predetermined time t = t2” has elapsed from time t15 and time t16 has elapsed, the control unit 15 turns off all the switching elements 29a to 29f of the inverter circuit 29 after time t16, and the current to the brushless motor 14 is reduced. Shut off the supply.

In the time chart of FIG. 4, the current value supplied to the brushless motor 14 fluctuates microscopically with a predetermined width, but the control unit 15 compares the peak of the current value with the predetermined value, Step 3 of step S5 is determined.

As described above, the control unit 15 estimates the presence / absence of the cleaning liquid in the tank 13 based on the current value supplied to the brushless motor 14, determines that there is no cleaning liquid in the tank 13, and then determines the predetermined value. When the predetermined time t has elapsed, the supply of current to the brushless motor 14 is cut off. Therefore, it is possible to prevent the brushless motor 14 from spinning, and it is possible to suppress wasteful power consumption by the brushless motor 14. In addition, the controller 15 automatically stops the brushless motor 14 when a predetermined time has elapsed after determining that there is no cleaning liquid in the tank 13. For this reason, the operator does not have to turn off the main power switch 27 after he / she notices that there is no cleaning liquid in the tank 13, and the operation burden on the operator can be reduced.

Further, the controller 15 indirectly determines the presence or absence of the cleaning liquid in the tank 11 from the current value supplied to the brushless motor 14. For this reason, it is not necessary to provide a dedicated sensor for detecting the presence or absence of the cleaning liquid in the tank 13. Therefore, the number of parts of the high pressure washer 10 can be reduced, and an increase in manufacturing cost can be suppressed.

Further, the predetermined time t = t1 is longer than the predetermined time t = t2. For this reason, at the time of the 1st drive of the brushless motor 14, when progressing to step S9 via step S8, it can suppress that the brushless motor 14 is stopped carelessly. Therefore, the pressure in the flow path 12c can be quickly increased to 5.0 [MPa].

Another determination example in which the control unit 15 determines that “the brushless motor 14 is in the idling state” in steps S5 and S6 illustrated in FIG. 3 will be described. In the first determination example, the control unit 15 determines that “the brushless motor 14 is idling” based on the number of rotations of the rotor 14 b of the brushless motor 14. The rotation speed of the rotor 14b is the rotation speed per unit time. If the cleaning liquid disappears and the load on the brushless motor 14 decreases, the actual rotational speed of the rotor 14b increases. That is, the determination content of step S5 of the flowchart can be “whether or not the actual rotational speed of the rotor 14b is equal to or greater than a predetermined value”. In this case, data representing the relationship between the target pressure of the flow path 12c and the actual rotational speed of the rotor 14b is stored in advance in the storage unit of the microcomputer 31. Thus, the control unit 15 can also detect the load of the pump 12 based on the rotation speed of the rotor 14b of the brushless motor 14.

Then, since the actual rotational speed of the rotor 14b is equal to or greater than the predetermined value, the control unit 15 determines Yes in step S5, and the state where the actual rotational speed of the rotor 14b is equal to or greater than the predetermined value is the predetermined time t [ s] When the time has elapsed, it is determined Yes in step S9, and the brushless motor 14 is stopped. That is, the control unit 15 estimates that the amount of the cleaning liquid in the tank 13 is equal to or less than a predetermined amount when the rotation speed of the rotor 14b is continuously equal to or greater than the predetermined value, and stops the brushless motor 14.

Next, in the second determination example, the control unit 15 determines that “the brushless motor 14 is idling” based on the rotational speed of the rotor 14 b of the brushless motor 14. If the cleaning liquid disappears and the load on the brushless motor 14 decreases, the actual rotational speed of the rotor 14b increases. That is, the determination content of step S5 in FIG. 4 can be “whether or not the actual rotational speed of the rotor 14b is equal to or higher than a predetermined value”. In this case, data representing the relationship between the target pressure of the flow path 12c and the actual rotational speed of the rotor 14b is stored in advance in the storage unit of the microcomputer 31. Thus, the control unit 15 can also detect the load of the pump 12 based on the rotational speed of the rotor 14b of the brushless motor 14. The microcomputer 31 can process the signals from the Hall ICs 28a to 28c to obtain the actual rotational speed and the actual rotational speed of the rotor 14b.

A correspondence relationship between the configuration described in this embodiment and the configuration of the present invention will be described. The cleaning liquid corresponds to the liquid of the present invention, the pump 12 corresponds to the pump of the present invention, the brushless motor 14 corresponds to the motor and the electric motor of the present invention, and the high-pressure cleaning machine 10 corresponds to the liquid discharge of the present invention. It corresponds to the apparatus, and the presence or absence of the cleaning liquid in the tank 13 corresponds to the “amount of liquid sucked by the pump” in the present invention. The control unit 15 corresponds to a liquid amount detection unit, a load detection unit, a motor control unit, and a motor load control unit of the present invention. Further, the case where there is no cleaning liquid in the tank 13 corresponds to “the amount of liquid is equal to or less than a predetermined amount” in the present invention, and the predetermined time t = t1 and the predetermined time t = t2 correspond to the predetermined time of the present invention, The predetermined time t = t1 corresponds to the first predetermined time of the present invention, and the predetermined time t = t2 corresponds to the second predetermined time of the present invention. The pressure setting dial 25 corresponds to a pressure setting unit of the present invention, and “the current value is equal to or less than a predetermined value” corresponds to “the motor load is equal to or less than a value corresponding to the target pressure” according to the present invention.

Further, proceeding to step S4 without driving steps S11 and S12 in FIG. 3 and driving the brushless motor 14 corresponds to the “first driving” in the present invention. Further, the process proceeds to step S4 via steps S11 and S12 in FIG. 3 to drive the brushless motor 14 corresponds to the “second drive” in the present invention. Furthermore, the pressure detection switch 32 corresponds to the pressure detection unit of the present invention, and the tank 13 corresponds to the tank of the present invention.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the motor operation stop circuit 37 may not be provided. In this case, the microcomputer 31 turns off all the switching elements 29a to 29f of the inverter circuit 29 when the main power switch 27 is turned off.

The liquid discharge apparatus according to the present invention includes a structure for sucking water supplied from a water tap with a pump in addition to a structure for sucking liquid in a tank with a pump. A liquid discharge device that sucks water discharged from a water tap with a pump. The water discharged from a water pump is disconnected when the water supply is cut off or the hose connecting the water tap and the pump is disconnected. The presence or absence can be determined based on the current value, and the supply of current to the motor can be stopped based on the determination result.

Further, a hydraulic motor, a pneumatic motor, and an engine can be used as the motor for driving the pump instead of the electric motor. In this case, a sensor for detecting the rotational speed or rotational speed of the output shaft of the hydraulic motor, a sensor for detecting the rotational speed or rotational speed of the output shaft of the pneumatic motor, and a sensor for detecting the engine rotational speed or rotational speed are provided. When the flow chart of FIG. 3 is executed in the hydraulic discharge device having the structure in which the pump is driven by the power of the hydraulic motor, the pneumatic motor, or the engine, in step S5, the rotational speed or rotational speed of the output shaft of the hydraulic motor, The idle rotation of the brushless motor is determined using the rotation speed or rotation speed of the output shaft and the engine rotation speed or rotation speed. Further, in step S10, a process for stopping the hydraulic motor, a process for stopping the pneumatic motor, or a process for stopping the engine is executed.

The liquid discharge device of the present invention is a device that pressurizes and discharges the liquid sucked into the pump, and the liquid discharge device of the present invention makes water mist in addition to a high-pressure washing machine that removes dirt on an object. Spraying device for spraying on the field, spraying device for spraying chemicals in the form of mist and spraying on vegetables or planted trees to control pests. That is, in the present invention, the liquid discharged from the pump includes water, a cleaning liquid, and a chemical liquid.

In this invention, the secondary battery which supplies electric power to an electric motor is provided. That is, the cleaning machine according to the embodiment is portable. The secondary battery may be a battery other than a lithium ion battery, for example, a nickel cadmium battery, a nickel hydrogen battery, or a lithium ion polymer battery. The liquid discharge apparatus of the present invention includes a structure capable of supplying power to the electric motor from both the secondary battery and the commercial power source. In addition, the liquid ejection device of the present invention includes a structure that can supply power to the electric motor only from a commercial power source.

The electric motor may be either a direct current brushless motor or an alternating current brushless motor. It is also possible to provide a power supply mechanism that supplies power from the AC power source to the electric motor. The pressure detection switch may be provided in the cleaning gun. In this case, a signal cable is provided for transferring signals between a pressure detection switch provided in the cleaning gun and a control unit provided in the cleaning machine main body. For example, the signal cable may be bundled together with a hose. Furthermore, you may employ | adopt the structure which transmits a signal wirelessly.

The pressure setting unit includes a dial, a touch panel, and a lever. The pressure detection unit includes a pressure sensor including a diaphragm, a pressure sensor including a Bourdon tube, and a pressure sensor including a bellows. The pressure detection unit may be configured to be turned on when the pressure of the cleaning liquid is equal to or higher than the first predetermined pressure and turned off when equal to or lower than the second predetermined pressure. The first predetermined pressure is higher than the second predetermined pressure. That is, the pressure detection unit only needs to output different signals depending on whether the pressure of the cleaning liquid is equal to or higher than the first predetermined pressure and lower than the second predetermined pressure, and can turn on and off the motor operation stop circuit. .

DESCRIPTION OF SYMBOLS 10 ... High pressure washing machine, 11 ... Washing machine main body, 12 ... Pump, 12a ... Suction port, 12b ... Discharge port, 12c, 21 ... Flow path, 13 ... Tank, 14 ... Brushless motor, 14a ... Stator, 14b ... Rotor, 14c ... Permanent magnet, 15 ... Control unit, 16 ... Battery pack, 16a ... Positive electrode, 16b ... Negative electrode, 17 ... Cleaning gun, 18 ... Hose, 19 ... Gun body, 20 ... Nozzle, 22 ... Valve, 23 ... Trigger, 24 , Operation panel, 25 pressure setting dial, 26 remaining amount display section, 27 main power switch, 29 inverter circuit, 29a to 29f switching element, 30 driver circuit, 31 microcomputer, 32 pressure detection switch , 33 ... current detection resistor, 34 ... current detection circuit, 35 ... control system power supply circuit, 36 ... power supply on / off circuit, 37 ... motor operation stop circuit, 38 Fuse, 51 ... inverter circuits, 28a ~ 28c ... Hall IC, E1 ... electrical circuits, U1, V1, W1 ... coils.

Claims

A liquid discharge apparatus comprising: a pump that sucks and discharges liquid; and a motor that drives the pump,
A liquid amount detection unit that detects a load of the motor that drives the pump and estimates an amount of liquid sucked by the pump based on the load of the motor;
When it is estimated that the amount of liquid sucked by the pump is equal to or less than a predetermined amount, a motor control unit that stops the motor;
A liquid ejection apparatus comprising:
The liquid ejecting apparatus according to claim 1, wherein the motor control unit stops the motor after a predetermined time has elapsed from a time when it is estimated that the amount of liquid sucked by the pump is equal to or less than a predetermined amount.
A pressure setting unit that sets a target pressure of the liquid discharged from the pump, and a motor load control unit that controls a load of the motor based on the target pressure,
The said liquid amount detection part estimates that the quantity of the liquid which the said pump suck | inhales below a predetermined amount when the load of the said motor is below the value according to the said target pressure. Liquid discharge device.
The motor control unit drives the motor for the first time, sucks and discharges liquid with the pump, and then uses the first predetermined time to stop the motor;
A second predetermined time that is used when stopping the motor after the stopped motor is driven a second time and the pump sucks and discharges the liquid, and is shorter than the first predetermined time;
The liquid ejection device according to any one of claims 1 to 3, wherein:
A pressure detector for detecting the pressure of the liquid discharged from the pump;
The said motor control part judges whether the said motor is the 1st drive or the 2nd drive based on the detection result of the pressure detected by the said pressure detection part. Liquid discharge device.
The motor is an electric motor that rotates when supplied with an electric current,
6. The liquid ejection device according to claim 1, wherein the liquid amount detection unit detects a load of the electric motor based on a current value supplied to the electric motor.
The liquid discharge apparatus according to claim 1, wherein the pump sucks the liquid from a tank in which the liquid is stored.
A liquid discharge apparatus comprising: a pump that sucks and discharges liquid; a motor that drives the pump; and a tank that stores the liquid sucked by the pump,
A load detection unit that detects a load of the motor; detects the amount of the liquid in the tank based on the load of the motor; and stops the motor when the amount of the liquid is equal to or less than a predetermined amount A liquid ejection device comprising: a motor control unit;
The motor is an electric motor that rotates when supplied with an electric current,
The load detection unit detects a load of the electric motor based on a current supplied to the electric motor,
The liquid according to claim 8, wherein the motor control unit estimates that the amount of the liquid in the tank is equal to or less than a predetermined amount when a current supplied to the electric motor is continuously equal to or less than a predetermined value. Discharge device.
The load detection unit detects the load of the motor based on the number of rotations of the motor,
The liquid ejecting apparatus according to claim 8, wherein the motor control unit estimates that the amount of the liquid in the tank is equal to or less than a predetermined amount when the rotation speed of the motor is continuously equal to or greater than a predetermined value. .
A pump for sucking and discharging liquid, a motor for driving the pump, a tank for storing the liquid sucked by the pump, a trigger for opening and closing the flow path of the liquid discharged from the pump, and A liquid discharge device comprising a cleaning gun for discharging the liquid to the outside,
A liquid ejecting apparatus, comprising: a motor control unit that stops the motor when a load of the motor becomes a predetermined value or less when the flow path is opened and the liquid is ejected from the cleaning gun.
The motor is an electric motor that rotates when supplied with an electric current,
When the flow rate is opened and the liquid is discharged from the cleaning gun, the motor control unit reduces the load of the motor to a predetermined value or less when the current value supplied to the motor becomes a predetermined value or less. The liquid ejection device according to claim 11, wherein the motor is stopped when it is determined that the motor has become.
The motor control unit determines that the load of the electric motor has become a predetermined value or less and stops the electric motor when a state in which a current value supplied to the electric motor is a predetermined value or less has elapsed for a predetermined time; The liquid ejection apparatus according to claim 12.