JP2011220288A - Tank incorporated type air compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tank incorporated type air compressor capable of materializing high reliability of a compressor on a low voltage by changing operation-stopping and recovering pressures upon the low voltage.SOLUTION: The tank incorporated type air compressor comprises: a compressor body for compressing air; a storage tank for storing the gas compressed by the compressor body; a motor for rotating a rotative shaft and driving the compressor body; a cooling fan which is disposed on the end part of the rotative shaft; and a control part for controlling the drive of the motor, wherein the control part lowers the operation-stopping pressure of the compressor when the voltage value supplied to the motor comes equal to or less than a first voltage value.

Description

  The present invention relates to a tank-integrated air compressor.

  The tank-integrated air compressor described in Patent Document 1 automatically stops power supply to the motor in order to reduce the load on the motor when a voltage drop is detected.

JP 2003-254252 A

  For example, in the air compressor described in Document 1, when used at a construction site or a temporary facility or outdoors where power is not stably supplied, the low voltage state is detected, the compressor stops, and the user's work is stopped. There has been a problem that the number of rotations of the motor is reduced and the reliability of the compressor is lowered.

  In view of the above problems, an object of the present invention is to achieve high reliability of a compressor at a low voltage by changing the operation stop and return pressure at a low voltage in a tank-integrated compressor.

  In the present invention, a compressor main body that compresses air, a storage tank that stores gas compressed by the compressor main body, a motor that rotates the rotary shaft to drive the compressor main body, and an end of the rotary shaft A cooling fan provided in the unit, and a control unit that controls driving of the motor, wherein the control unit is configured to control the motor when a voltage value supplied to the motor is equal to or lower than a first voltage value. The tank-integrated air compressor is characterized in that the operation stop pressure, which is the upper limit pressure for driving is reduced.

  In another aspect of the present invention, a compressor main body that compresses air, a storage tank that stores gas compressed by the compressor main body, a motor that rotates the rotating shaft and drives the compressor main body, A cooling fan provided at an end of the rotating shaft, an operating unit, a cover covering the compressor body and the motor, and operating the operating unit to switch the operation mode, And a controller that changes a rotational speed and a pressure driven by the motor. The controller drives the motor when a voltage value supplied to the motor becomes equal to or lower than a first voltage value. There is provided a tank-integrated air compressor characterized by forcibly changing to an operation mode in which an operation stop pressure that is an upper limit pressure is the lowest.

  According to the present invention, in a small and light tank-integrated air compressor, the high reliability of the compressor at low voltage is realized by changing the operation stop and return pressure at low voltage in the tank-integrated compressor. can do.

It is a sectional side view of the compressor main body which concerns on the Example of this invention. 1 is a perspective view of a tank-integrated air compressor according to an embodiment of the present invention. It is an operation part of the tank integrated air compressor which concerns on the Example of this invention. It is a control flow of the normal mode at the time of the low voltage which concerns on the Example of this invention, and a silent mode. It is a control flow of the powerful mode at the time of the low voltage which concerns on the Example of this invention.

  Hereinafter, a tank integrated air compressor and low voltage detection control according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  First, the structure of the compressor body 1 that compresses air in the tank-integrated air compressor according to the present embodiment will be described below with reference to FIG.

  Reference numeral 1 denotes a compressor body that compresses air. The compressor body 1 includes a crankcase 1A and a cylinder 18 attached to the crankcase 1A. A shaft (rotary shaft) 6A of the motor 6 passes through the crankcase 1A.

  A crankcase 1A covers the compressor body 1 and the motor 6. A stator 2 is directly fixed to one end side of the crankcase 1A and a bearing 3 is mounted. A bearing box 5 to which a bearing 4 is mounted is fitted on the opposite side of the stator 2 from the mounting side. ing. A key 12 is provided at the center of the shaft 6A penetrating the crankcase 1A. Further, a connecting rod assembly 14 having a piston ring 13 for sealing and compressing air is inserted together with a balance 17 through an eccentric 16 eccentric with a bearing 15. The connecting rod assembly 14 and the balance 17 are supported from both sides by two bearings 3 and 4 attached to the crankcase 1A and the bearing housing 5.

  Reference numeral 6 denotes a motor for driving the compressor body 1. The motor 6 includes a stator 2, a bearing 3, a shaft 6A, a key 7, a rotor 8, and a washer 9. A cooling fan 10 is provided at an end of the shaft 6A. A rotor 8 is attached to one end side of the shaft 6A via a key 7. The rotor 8 is fixed in the axial direction by a fan shaft 11 for attaching a washer 9 and a cooling fan 10.

  Reference numeral 10 denotes a cooling fan for supplying cooling air to the interior of a cover 26, which will be described later, and cooling components of the tank-integrated air compressor such as the compressor body 1 and the air tanks 24 and 25. The cooling fan 10 is provided at the end of the shaft 6 </ b> A by the fan shaft 11 and is driven by the motor 6.

  Reference numeral 18 denotes a cylinder attached to the crankcase. In this embodiment, two cylinders 18 are provided, and the pair of cylinders 18 are attached so as to face each other with the crankcase interposed therebetween. The cylinder 18 includes a flange 19, an air valve 20, and a through bolt 22. The cylinder head 21 is provided with a flange 19 for attaching the cylinder 18 to the crankcase 1A. The cylinder 19, the air valve 20, and the cylinder head 21 are fixed to the flange 19 by through bolts 22 to form a compression chamber 23. is doing.

  The operation of the compressor body 1 in this embodiment will be described. In the compressor main body 1 according to this embodiment, when the shaft 6 </ b> A is rotated by driving the rotor 8, the connecting rod assembly 14 and the piston ring 13 reciprocate in the compression chamber 23 by the eccentric 16. The piston ring 13 sucks air into the compression chamber 23 through the cylinder head 21 and the air valve 20 in the suction process from the top dead center to the bottom dead center, and conversely compresses the sucked air in the discharge process toward the top dead center. On the other hand, the air is discharged through the air valve 20 and the cylinder head 21. The air discharged through the cylinder head 21 is stored in storage tanks 24 and 25 described later. In this embodiment, air is efficiently compressed by performing two-stage compression in which the air compressed by one cylinder 18 is further compressed by the other cylinder 18.

  Next, the external appearance and operation unit of the tank-integrated air compressor according to the present embodiment will be described below with reference to FIGS.

  Reference numerals 24 and 25 denote storage tanks which are substantially cylindrical and are arranged in parallel to each other, and store compressed air compressed by the compressor body 1 described above. A resin cover 26 integrally formed so as to cover the compressor main body 1 and the motor 6 is attached to the upper portions of the storage tanks 24 and 25. In front of the resin cover 26, pressure reducing valves 27 and 28 are provided for decompressing and taking out the compressed air stored in the storage tanks 24 and 25 according to the purpose. The pressure reducing valves 27 and 28 have a high pressure compatible pressure reducing valve 27 that can extract a pressure from about 2.0 MPa to about 2.5 MPa and a low pressure compatible pressure that can extract a pressure from 0 MPa to about 1.0 MPa in order to widen the pressure range for taking out. The pressure reducing valve 28 is classified. Further, in order to make it possible to confirm the pressure taken out of the pressure reducing valves 27 and 28, each is provided with a pressure gauge 29 for high pressure and a pressure gauge 30 for low pressure. In addition, as the compressed air outlet, each of the pressure reducing valves 27 and 28 is provided with two high-pressure couplers 31 and two low-pressure couplers 32.

  Reference numeral 33 denotes an operation unit of the tank-integrated air compressor, which controls the operation, stop, return from abnormality, etc. of the compressor by operating the operation switch 34, the mode changeover switch 35, and the return switch 36. The operation of (not shown) can be changed. The state of the compressor such as operation, stop, mode, and abnormality can be determined by the LEDs 37, 38, 39, 40, 41, and 42. LED 37 displays operation and stop, LEDs 38, 39, and 40 display modes, LED 41 displays abnormalities such as temperature abnormality and overcurrent abnormality, and LED 42 displays maintenance time. Further, the tank internal pressure in the storage tanks 24 and 25 can be discriminated by the LEDs 43, 44, 45, 46 and 47 provided in the operation unit 33. The operation mode indicates the operation state of the compressor, and is classified by the operation stop pressure, the operation return pressure, and the rotation speed. For example, in the normal mode, the operation stop pressure is 4.2 MPa, the operation return pressure is 3.2 MPa, and the rotation speed is about 2800 min−1 at the maximum. In the powerful mode, the operation stop pressure is 4.2 MPa, and the operation return pressure is 3 The operation is performed at a maximum speed of about 3500 min-1, and the low speed mode is operated at an operation stop pressure of 4.2 MPa, an operation return pressure of 3.2 MPa, and a rotation speed of about 1500 min-1. The operator selects the mode for each application and operates the compressor. Here, an example in which three types of operation modes can be selected will be described, but the operation mode is not limited to this, and there may be two types or four or more types. Further, although an example has been described in which the operation stop pressure, the operation return pressure, and the rotation speed are all changed by changing the operation mode, only one or two of them may be changed. In addition, an operation mode for changing the operation stop pressure and the operation return pressure and an operation mode for changing the rotation speed may be provided separately.

  Next, the control flow at the time of low voltage of the tank-integrated air compressor according to the present embodiment will be described below with reference to FIGS.

  The controller that controls the drive of the motor monitors the pressure in the tank, drives the motor until the pressure in the tank reaches the upper limit pressure value (operation stop pressure), and fills the tank with compressed air. When the pressure reaches the upper limit pressure value (operation stop pressure), the motor is temporarily stopped. When the pressure in the tank drops to the lower limit pressure value (operation return pressure), the motor is started again and compressed air is supplied to the tank. Fill.

  For example, in a construction site or the like, the number of outlets is limited, and an extension cord is used to secure a power source at a place where the nailer is used. However, when the distance from the outlet position to the place where the nailer is used is long, a plurality of extension cords may be connected in series.

  However, in addition to the nailing machine, other power tools (for example, an electric drill or an electric saw) may be connected to the extension cord. As described above, when the cords of a plurality of power tools are connected to the extension cord at the same time, the voltage supplied to each power tool and the air compressor (motor 6) may decrease.

  In this way, if the control determines that the voltage is 75 V or less when the voltage supplied to the motor 6 decreases due to simultaneous use of other electrical products during operation, it is compulsory regardless of which operation mode is used. Thus, the operation mode becomes the low voltage mode. In the low voltage mode, the operation stop pressure is set to 3.2 MPa and the operation return pressure is set to 2.5 MPa. That is, among the plurality of modes, the operation mode having the lowest operation stop pressure, operation return pressure, and rotation speed is forcibly selected. Here, the example in which the lowest operation mode is selected for all of the operation stop pressure, the operation return pressure, and the rotation speed has been described. However, the mode may be changed so as to be the lowest for any one or two. . Also, instead of changing the operation mode so that the operation stop pressure, the operation return pressure, and the rotation speed become the lowest when the voltage drops below a predetermined voltage value, the operation stop pressure and the operation return pressure are stepwise step by step. The operation mode may be changed so as to decrease the rotation speed.

  Further, when the voltage becomes 75 V or less, the LEDs 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47 are all blinked to warn the operator of the low voltage abnormality. Here, an example has been described in which an LED notifies a worker of a low voltage state. However, the display is not limited to an LED or the like, and an alarm may be used.

  Further, when the voltage drops further and the voltage becomes 65 V or less even in the low voltage mode, the operation is forcibly stopped. Thereby, when the voltage supplied to the motor 6 falls and the cooling efficiency of the cooling fan 10 falls, the temperature rise of the compressor main body 1 and the motor 6 can be prevented. When the operation stops, the forced stop of the operation is notified by an alarm or the like. For example, the operator can correctly recognize the cause of the decrease in the number of rotations and the forced stop by notifying the low voltage state with the LED and notifying with a different method such as notifying the forced stop with an alarm. It is possible to prevent the operator from mistaking it as a failure.

  When the voltage becomes 80 V or more during the low voltage mode, it is determined that the control is a normal voltage, and the mode is forcibly changed from the low voltage mode to each operation mode set before the low voltage mode. Further, when the voltage becomes 70 V or more during the forced stop state, it is determined that the operation may be performed in the low voltage mode, and the operation is restored in the low voltage mode.

  Note that the operation stop pressure and operation return pressure in the low voltage mode depend on the eigenvalues of the air compressor motor torque and moment of inertia, and thus are not limited to the values described above, but are values other than 3.2 MPa and 2.5 MPa. Also good.

  In addition, the voltage that switches to the low voltage mode when a voltage drop occurs is not limited to the value described above, and may be other than 75V. Further, the voltage value at which the low voltage mode is canceled may be other than 80V.

  Further, the voltage for forcibly stopping the operation when a voltage drop occurs is not limited to the value described above, and may be other than 65V.

  Further, as a modification of the present embodiment, when the current exceeds a certain current value, the operation stop pressure and the operation return pressure may be changed from normal values.

According to the present embodiment described above, before the air compressor is forcibly stopped when the supply voltage to the motor is reduced during high-pressure air compression in a low voltage state, the operation stop pressure, operation Since the operation is continued in a state where the return pressure and the number of revolutions are reduced, the compressor can be used without the user interrupting the work. In addition, by forcibly reducing the shutdown pressure to 3.2 MPa, it is possible to prevent overcurrent from flowing to the motor and the inverter control device when the current flows at a low voltage higher than the normal voltage. And the temperature rise of the heat generating element in the inverter control device can be suppressed, and high reliability can be ensured. (When generating high-pressure compressed air, since the motor torque is required, the current value increases accordingly.)
In addition, when generating high-pressure compressed air in a low voltage state, there has been a method of adding a flywheel as a method of reducing the current applied to the motor and the inverter control device. By adding the flywheel, the moment of inertia increases and the rotation of the motor can be assisted. Therefore, the current value applied to the motor can be reduced. However, adding a flywheel requires weight and mounting space. According to the present embodiment, since it is not necessary to add a flywheel, the product can be reduced in weight and the product can be reduced in size.

  In many cases, the air compressor is intermittently driven for a relatively long time as compared with other electric tools (for example, an electric drill or an electric saw). When other power tools that are intermittently driven are used, the supply voltage to the motor is temporarily changed such as when the air compressor switches from the standby state where the motor is stopped to the compression operation state driven by the motor. Even when a low state occurs, it is possible to prevent the operation of the compressor from being stopped in a high pressure region where the compression load is large, and it is possible to continuously generate compressed air even in a low voltage state. Accordingly, by operating the compressor even in a low voltage state, it is possible to improve the reliability without stopping the work of the user who uses the compressor.

  The embodiments described so far are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention is not limitedly interpreted by these. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

DESCRIPTION OF SYMBOLS 1 Compressor main body 1A Crankcase 6 Motor 6A Shaft 10 Cooling fan 18 Cylinder 21 Cylinder head 26 Cover 27 High pressure corresponding pressure reducing valve 28 Low pressure corresponding pressure reducing valve 33 Operation unit 34 Operation switch 35 Mode switch 36 Return switch

Claims (17)

A compressor body for compressing air;
A storage tank for storing gas compressed by the compressor body;
A motor for driving the compressor body by rotating a rotary shaft;
A cooling fan provided at an end of the rotating shaft;
A control unit for controlling the drive of the motor,
The control unit lowers an operation stop pressure, which is an upper limit pressure at which the motor is driven, when a voltage value supplied to the motor is equal to or lower than a first voltage value. Air compressor.   When the voltage value supplied to the motor becomes equal to or lower than the first voltage value, the control unit lowers an operation return pressure that is a pressure for starting the motor again when the motor stops. The tank-integrated air compressor according to claim 1.   2. The control unit according to claim 1, wherein the control unit forcibly stops the motor when a voltage value supplied to the motor becomes equal to or lower than a second voltage value lower than the first voltage value. The tank-integrated air compressor described.   2. The tank-integrated air compression according to claim 1, wherein when the voltage value supplied to the motor becomes equal to or less than the first voltage value, the control unit issues a warning for notifying a low voltage. Machine.   5. The tank-integrated air compressor according to claim 4, wherein the control unit reports a low voltage by an LED of an operation unit provided on a cover that covers the compressor main body and the motor.   4. The tank integrated unit according to claim 3, wherein the control unit issues an alarm for notifying a forced stop of the motor when a voltage value supplied to the motor becomes equal to or less than the second voltage value. Air compressor.   The tank integrated air compressor according to claim 6, wherein the control unit notifies the forced stop of the motor by an alarm.   2. The tank-integrated air compressor according to claim 1, wherein the operation stop pressure of the compressor is changed when the current supplied to the motor becomes a predetermined value or less in the air compressor.   2. The tank-integrated air compressor according to claim 1, wherein in the air compressor, when the current supplied to the motor becomes a predetermined value or less, the operation return pressure of the compressor is changed. A compressor body for compressing air;
A storage tank for storing gas compressed by the compressor body;
A motor for driving the compressor body by rotating a rotary shaft;
A cooling fan provided at an end of the rotating shaft;
A cover that includes an operation unit and covers the compressor body and the motor;
A controller that changes the number of rotations of the motor and the pressure that the motor drives by switching the operation mode by operating the operation unit;
When the voltage value supplied to the motor becomes equal to or lower than the first voltage value, the control unit forcibly changes the operation mode to the lowest operation stop pressure, which is the upper limit pressure at which the motor drives. A tank-integrated air compressor.   When the voltage value supplied to the motor becomes equal to or lower than the first voltage value, the control unit forces the operation mode in which the operation return pressure, which is a pressure for starting the motor again when the motor is stopped, is the lowest. The tank-integrated air compressor according to claim 10, wherein the tank-integrated air compressor is changed.   The control unit forcibly changes to an operation mode in which the rotation speed of the compressor is the lowest when a voltage value supplied to the motor becomes equal to or lower than a first voltage value. The tank-integrated air compressor described in 1.   The said control part forcibly stops the said motor when the voltage value supplied to the said motor becomes below 2nd voltage value lower than 1st voltage value. The tank-integrated air compressor described.   11. The tank-integrated air compression according to claim 10, wherein when the voltage value supplied to the motor becomes equal to or less than the first voltage value, the control unit issues an alarm for notifying a low voltage. Machine.   The tank-integrated air compressor according to claim 14, wherein the control unit notifies a low voltage by an LED of an operation unit provided on a cover that covers the compressor body and the motor.   The tank integrated unit according to claim 13, wherein the control unit issues an alarm for notifying a forced stop of the motor when a voltage value supplied to the motor becomes equal to or less than the second voltage value. Air compressor.   The tank-integrated air compressor according to claim 16, wherein the control unit notifies the forced stop of the motor by an alarm.

Images