Air compressor

Abstract

To provide an air compressor capable of reliably stopping functions of the air compressor when a user is in the proximity for transport.SOLUTION: An air compressor is for supplying compressed air to an external pneumatic tool, and comprises a detection unit that detects the proximity of a user, and a control unit that stops functions of the air compressor when the detection unit has detected the proximity.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an air compressor. [Background technology]

[0002] At construction sites and other worksites, pneumatic tools powered by compressed air are widely used to perform tasks such as cutting, nailing, and screwing. Well-known pneumatic tools include air drivers and nailers, which are used to drive fasteners such as staples, pins, screws, and nails. An air compressor supplies compressed air to these pneumatic tools.

[0003] In general, an air compressor is configured such that the rotational motion of a motor is converted via a crankshaft into the reciprocating motion of a piston in a cylinder, which compresses air drawn in through the cylinder's intake valve. The compressed air compressed in the cylinder is discharged through a pipe from the cylinder's exhaust valve into a tank, where it is stored. The user can then fine-tune the pressure of the compressed air stored in the tank by operating a pressure adjustment dial. The compressed air, once finely adjusted to the desired pressure, is then supplied to an external pneumatic tool through a compressed air supply port.

[0004] For such air compressors, mechanisms have been proposed to stop various functions of the air compressor, for example, in consideration of safety during transportation. For example, Patent Document 1 discloses an air compressor equipped with an installation detection means that detects whether the air compressor is installed or not installed on the installation surface. When the switch detects the not installed state, the air compressor stops functioning as an air compressor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-33969 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the air compressor described in the above patent document detects the installation state of the air compressor, but does not directly detect whether a user is approaching the air compressor for transportation, which poses a problem in that it cannot reliably shut down the air compressor when the user is approaching the air compressor for transportation.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an air compressor that can reliably stop functioning as an air compressor when a user is approaching for transportation. [Means for solving the problem]

[0008] An air compressor according to one aspect of the present invention is an air compressor that supplies compressed air to an external pneumatic tool, and includes a detector that detects the proximity of a user and a controller that stops the function of the air compressor when the detector detects the proximity. This stops the function of the air compressor when the proximity of a user is detected. Therefore, when a user is close to the air compressor, the function of the air compressor can be reliably stopped, improving safety for the user.

[0009] In the air compressor of the above aspect, the control unit may stop the function as an air compressor by stopping the operation of the electric motor that generates compressed air, which makes it possible to easily and reliably stop the function as an air compressor.

[0010] In the air compressor of the above aspect, the control unit may stop the function as an air compressor by stopping the supply of power to the electric motor that generates compressed air, which makes it possible to easily and reliably stop the function as an air compressor.

[0011] The air compressor may further include a solenoid valve provided at a supply port for supplying compressed air to the pneumatic tool, and the control unit may stop the function as an air compressor by controlling the solenoid valve to stop the supply of compressed air to the pneumatic tool. This stops the function as an air compressor and stops the supply of compressed air to the pneumatic tool, thereby improving the safety of the user.

[0012] In the air compressor of the above aspect, the control unit may stop the function as an air compressor when the detection unit continuously detects proximity for a predetermined period of time or more. This allows the function as an air compressor to be continued even if the detection unit detects proximity for less than the predetermined period of time, thereby improving user convenience while ensuring user safety.

[0013] The air compressor of the above aspect may be configured so that the predetermined time can be set arbitrarily, thereby enabling the length of time required for detecting proximity to stop the function of the air compressor to be set, thereby further improving user convenience.

[0014] In the air compressor of the above aspect, the control unit may cancel the stop of the function as an air compressor when the detection unit does not detect proximity for a predetermined continuous time or more after the function as an air compressor is stopped. This eliminates the need for an operation to cancel the stop of the function as an air compressor, improving convenience for the user.

[0015] The air compressor of the above aspect may further include a reception unit that receives a command to cancel the function as an air compressor, and the control unit may cancel the function as an air compressor when the reception unit receives the command to cancel. This allows the user to cancel the function as an air compressor at a desired timing, improving user convenience.

[0016] In the air compressor of the above aspect, the control unit may cancel the stop of the function as the air compressor when the acceptance unit accepts the cancellation and when the detection unit has not detected proximity for a predetermined consecutive time or more after the acceptance of the cancellation. This improves user safety because the stop of the function as the air compressor is not canceled even when a cancellation operation by the user is accepted unless the detection unit detects proximity for a predetermined consecutive time or more.

[0017] In the air compressor of the above aspect, the control unit does not need to stop the function of the air compressor when the air compressor is connected to an AC power source, which improves user convenience in situations where the user is unlikely to carry the air compressor.

[0018] In the air compressor of the above aspect, the detection unit may detect the proximity of the user based on a change in capacitance, thereby making it possible to easily detect the proximity of the user.

[0019] In the air compressor of the above aspect, the detection unit may be provided in a part electrically isolated from the housing ground, thereby reducing false detections and improving user convenience because the user only needs to be in close proximity to the detection unit.

[0020] In the air compressor of the above aspect, the detector may be provided on or near the grip, which allows the proximity of the user to be detected at a part that is likely to come into contact with the user, thereby more reliably stopping the function of the air compressor.

[0021] In the air compressor of the above aspect, the detector may be provided on or near the pressure adjustment dial, thereby enabling detection of proximity to a part that is likely to be touched by the user, thereby more reliably stopping the function of the air compressor.

[0022] In the air compressor of the above aspect, the detector may be provided on the housing ground, which allows for proximity detection over a wide area, making it possible to more reliably stop the function of the air compressor.

[0023] In the air compressor of the above aspect, the detector may be provided in a tank that stores compressed air or in a compressed air supply port provided in the tank, thereby enabling proximity detection over a wide area, and thus enabling more reliable stopping of the air compressor function. [Effects of the Invention]

[0024] According to the air compressor of the present invention, when a user is close to the air compressor for transportation, the function as an air compressor can be reliably stopped, thereby improving safety for the user. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a perspective view showing an example of the external configuration of an air compressor 1 according to the present embodiment. [Figure 2] 1 is a block diagram showing an example of a functional configuration of an air compressor 1 according to the present embodiment. [Figure 3] FIG. 4 is a diagram showing an example of an operation flow of a function stop process performed by the air compressor 1 according to the present embodiment. [Figure 4] FIG. 4 is a diagram showing an example of an operation flow of processing for releasing a function stoppage by the air compressor 1 according to the present embodiment. [Figure 5] FIG. 10 is a diagram showing another example of the operational flow of the process for releasing the function stoppage of the air compressor 1 according to the present embodiment. [Figure 6] FIG. 10 is a block diagram showing an example of the functional configuration of an air compressor 1′ according to a modified example of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an air compressor according to the present invention will now be described with reference to the drawings.

[0027] <Air compressor schematic configuration> Fig. 1 is a perspective view showing an example of the external configuration of an air compressor 1 according to this embodiment. Fig. 2 is a block diagram showing an example of the functional configuration of the air compressor 1 according to this embodiment. The air compressor 1 includes a housing 50, grips 61 and 62, a motor 4, a compression mechanism 3 driven by the motor 4 to generate compressed air, a control unit 5 for controlling the motor 4, a tank 8 for storing the compressed air generated by the compression mechanism 3, a pressure sensor 12 for acquiring the internal pressure of the tank 8, an operation panel 30, etc. As will be described later, the air compressor 1 is also provided with a proximity sensor 40 for detecting the proximity of a user to the air compressor 1.

[0028] The air compressor 1 according to this embodiment provides compressed air to a pneumatic tool connected to the air compressor 1. The pneumatic tool may be, for example, an air screwdriver or a nailer for driving fasteners such as staples, pins, screws, and nails. The air compressor 1 is configured so that a user can lift the air compressor 1 by holding the grips 61, 62, for example, when transporting the air compressor 1.

[0029] The tank section 2 includes a tank 8 for storing compressed air to be supplied to the pneumatic tool. The tank 8 can store compressed air having a pressure of, for example, 4.4 MPa or less. The tank 8 is provided with air chucks (compressed air supply ports) 7 and 9 for supplying compressed air to the pneumatic tool. The air compressor 1 according to this embodiment includes an air chuck (with a purge mechanism) 9A for supplying high-pressure compressed air and an air chuck (with a purge mechanism) 9B for supplying low-pressure compressed air. The purge mechanism is a mechanism for purging (releasing) residual pressure in the air hose when the plug of the air hose is separated from the air chuck. The air compressor 1 according to this embodiment also includes an air chuck (without a purge mechanism) 7A for supplying high-pressure compressed air and an air chuck (without a purge mechanism) 7B for supplying low-pressure compressed air. The air chucks 7A, 7B, 9A, and 9B are configured to allow detachable hoses for supplying compressed air to the pneumatic tool. The high-pressure air chucks 7A and 9A are provided with a pressure adjustment dial 10A for operating a pressure adjustment valve. The low-pressure air chucks 7B and 9B are provided with a pressure adjustment dial 10B for operating a pressure adjustment valve. Pressure gauges 11A and 11B that indicate the pressure of the compressed air supplied to the pneumatic tool are provided near the pressure adjustment dials 10A and 10B (see Figure 1).

[0030] The pressure sensor 12 acquires the internal pressure of the tank 8 (see FIG. 2). The pressure sensor 12 is, for example, a piezo-resistive type whose resistance value varies depending on the air pressure, or a pressure sensor whose capacitance varies depending on the air pressure. A strain gauge type may also be used as the pressure sensor 12. The MPU 5F of the control unit 5 acquires information indicating the internal pressure of the tank 8 from the pressure sensor 12. The part including the tank 8, the pressure sensor 12, the air chucks 7A, 7B, 9A, and 9B, and the pressure adjustment dials 10A and 10B is called the tank unit 2.

[0031] The compression mechanism 3 is driven by a motor 4 to generate compressed air. The compression mechanism 3 includes, for example, a cylinder and a piston provided in the cylinder, and generates compressed air by causing the piston to reciprocate using the motor 4 to compress air supplied into the cylinder through an intake valve of the cylinder. The compressed air is supplied to the tank 8 via a connecting pipe 14 (see FIG. 2).

[0032] The motor 4 drives the compression mechanism 3. The motor 4 according to this embodiment generates a driving force for reciprocating a piston of the compression mechanism 3. The motor 4 is a three-phase brushless DC motor 4 and includes a stator 16 having windings 16A, 16B, and 16C of three phases, namely U, V, and W, and a rotor 17 having a permanent magnet. The rotor 17 is rotated by a rotating magnetic field formed by current flowing through the three-phase windings 16A, 16B, and 16C, causing the piston to reciprocate, the piston engaging with a rotor connected to the rotary shaft of the rotor 17.

[0033] The control unit 5 controls, for example, the motor 4. Furthermore, the control unit 5 supplies information necessary for display by the external terminal device 20 and the operation panel 30. The control unit 5 includes, for example, a power supply switching circuit 5A, a converter circuit 5B, an inverter circuit 5C, a current / voltage detection circuit 5D, a communication circuit 5E, and an MPU 5F.

[0034] The power supply switching circuit 5A switches on / off the power supply from the AC power source AC to the converter circuit 5B. For example, the power supply switching circuit 5A may be configured to include a relay that switches on / off the power supply from the AC power source AC to the converter circuit 5B, or may be configured to include a switchable semiconductor element such as an FET. The air compressor 1 may be powered not only by the AC power source AC but also by a DC power source. In this case, the power supply switching circuit 5A may be configured to switch on / off the power supply from the DC power source to the next circuit or the motor 4.

[0035] The converter circuit 5B converts the AC power supply AC into DC power supply having a predetermined voltage and supplies it to the inverter circuit 5C. The converter circuit 5B can employ a known configuration, and may include, for example, a rectifier circuit including a diode for converting the AC voltage into a DC voltage, a boost circuit including a switching element for controlling the DC voltage, and a smoothing circuit including a capacitor for smoothing the DC voltage.

[0036] The inverter circuit 5C switches the DC power supplied from the converter circuit 5B and supplies it to three-phase windings 16A, 16B, and 16C of the motor 4. The inverter circuit 5C may have a known configuration, and may include, for example, switching elements formed of IGBTs (Insulated Gate Bipolar Transistors) or FETs (Field Effect Transistors) connected in a three-phase bridge between a power supply line and a ground line. The MPU 5F can perform PWM (Pulse Width Modulation) control by controlling the switching elements of the inverter circuit 5C.

[0037] The current / voltage detection circuit 5D includes a current detection circuit (an example of a "load acquisition unit") and a voltage detection circuit. The current detection circuit is connected to at least one of the three-phase windings 16A, 16B, and 16C and detects the current flowing therethrough. Because the current flowing through the windings 16A, 16B, and 16C of the motor 4 varies depending on the load on the motor 4, the current detection circuit functions as a load acquisition unit that acquires information indicating the load on the motor 4. The MPU 5F acquires information indicating the load on the motor 4 from the current detection circuit and is able to control the converter circuit 5B and the inverter circuit 5C based on this information. The MPU 5F also transmits information indicating the load on the motor 4 to the external terminal device 20 via the communication circuit 5E. The voltage detection circuit detects the power supply voltage converted by the converter circuit 5B. The MPU 5F acquires information indicating the power supply voltage from the voltage detection circuit and is able to control the converter circuit 5B and the inverter circuit 5C based on this information. Furthermore, the MPU 5F transmits information indicating the power supply voltage to the external terminal device 20 via the communication circuit 5E.

[0038] The communication circuit 5E transmits and receives information to and from the external terminal device 20 via wireless communication. The wireless communication preferably complies with technical standards such as the Bluetooth (registered trademark) communication standard, the wireless LAN communication standard, or the Zigbee (registered trademark) communication standard. The communication circuit 5E includes an interface circuit for transmitting and receiving information to and from the external terminal device 20 in accordance with the Bluetooth communication standard, for example.

[0039] The MPU 5F controls the power supply switching circuit 5A, the converter circuit 5B, the inverter circuit 5C, etc., to control the function of the air compressor 1. Furthermore, when the proximity sensor 40 detects that a user is approaching the air compressor 1, the MPU 5F executes processing to stop the function of the air compressor 1 based on the detection result. The control to stop the function of the air compressor 1 will be described later.

[0040] The MPU 5F can switch on / off the power supply from the AC power supply AC to the converter circuit 5B by controlling the power supply switching circuit 5A. Specifically, for example, the MPU 5F can control on / off of relays and switchable semiconductor elements (FETs, etc.) included in the power supply switching circuit 5A.

[0041] The MPU 5F can perform PAM (Pulse Amplitude Modulation) control by controlling the switching elements of the boost circuit of the converter circuit 5B. The MPU 5F in this embodiment reads from a memory element included in the MPU 5F or receives from the external terminal device 20 a motor start pressure value (hereinafter sometimes referred to as the "ON pressure value") and a motor stop pressure value (hereinafter sometimes referred to as the "OFF pressure value") that are preset according to the operating mode of the air compressor 1, compares them with the current internal pressure of the tank 8 based on the internal pressure information, and if the internal pressure of the tank 8 is equal to or lower than the motor start pressure value, generates control signals for driving the motor 4 (a PAM signal for driving the switching elements of the converter circuit 5B and a PWM signal for driving the switching elements of the inverter circuit 5C) and supplies them to the converter circuit 5B and the inverter circuit 5C, thereby driving the motor 4 until the internal pressure of the tank 8 reaches the motor stop pressure value.

[0042] The MPU 5F acquires internal pressure information indicating the internal pressure of the tank 8 from the pressure sensor 12, acquires load information indicating the load on the motor 4 from the current detection circuit, and acquires power supply voltage information indicating the power supply voltage from the voltage detection circuit, and based on these, generates control signals for controlling the power supply switching circuit 5A, the converter circuit 5B, and the inverter circuit 5C, thereby controlling the motor 4.

[0043] The MPU 5F uses the communication circuit 5E to transmit internal pressure information, load information, and power supply voltage information to the external terminal device 20. Furthermore, the MPU 5F is configured to be able to control the motor 4 based on information for selecting an operation mode, information for selecting the rotation amount of the motor 4, and information indicating a motor start pressure value and a motor stop pressure value, which are received from the external terminal device 20 using the communication circuit 5E. The MPU 5F may also control a predetermined display unit.

[0044] The external terminal device 20 is a terminal device capable of operating the air compressor 1 from a location remote from the air compressor 1. The external terminal device 20 is a portable computer device, such as a smartphone or tablet, that has a display screen for displaying information and is capable of wireless communication. The external terminal device 20 can be configured by installing and running an application program (computer program) for executing the various processes according to this embodiment on this computer device. The external terminal device 20 of this embodiment includes a communication circuit 20D for receiving information, including internal pressure information of the tank 8, from the air compressor 1; a display unit 20B including a display screen for displaying information, including the internal pressure of the tank 8; an operation unit 20C for inputting at least one of a motor start pressure value and a motor stop pressure value; and an MPU 20A having a processor and a memory element for controlling the communication circuit 20D, the display unit 20B, and the operation unit 20C and for executing the various processes performed by the external terminal device 20 of this embodiment (see FIG. 2).

[0045] The operation panel 30 is provided on, for example, the top surface of the housing 50 as an information transmission means for receiving operation inputs from the operator and for informing the operator of predetermined information (see FIG. 1, etc.). The operation panel 30 may include a light-guiding member that guides light from an LED or the like provided inside the housing 50 to the outside, an operation switch, etc. The operation panel 30 may particularly function as an example of a reception unit, and may receive, for example, an operation to release the function as an air compressor.

[0046] <Air compressor operating mode> The air compressor 1 can be configured to operate in three modes: high-power mode, AI mode, and quiet mode. High-power mode is an operating mode suitable for tasks that consume large amounts of air, such as screwing with a pneumatic tool like an air driver or nailing without nails, and drives the motor 4 with relatively high power. AI mode automatically varies the ON and OFF pressure values and the output of the motor 4 according to the frequency of air use, and changes the drive according to the consumption of compressed air, achieving optimal automatic operation that is relatively gentle on the motor 4. This mode is suitable for tasks such as laying foundations with a super nailer or for construction work. Quiet mode is a power-saving operating mode suitable for tasks that require lower power than high-power mode, such as interior work, and drives the motor 4 with relatively low power.

[0047] The above-mentioned operation modes may be notified to the operator by lighting up a light-guiding member corresponding to each operation mode, which is arranged on or near the operation panel 30, for example.

[0048] <Proximity sensor 40>

[0049] The proximity sensor 40 is an example of a detection unit that detects the user's proximity to the air compressor 1 and supplies a detection signal to the control unit 5 (MPU 5F). Here, the proximity of the user may include the user touching the air compressor 1 or the user approaching the air compressor 1 within a predetermined distance. The predetermined distance that defines the user's proximity to the air compressor 1 may be, for example, 50 cm. However, the predetermined distance is not limited to this, and may be arbitrarily defined depending on the configuration and settings of the proximity sensor 40, and may be, for example, several millimeters, several centimeters, or several tens of centimeters. The proximity sensor 40 may be capable of quantitatively detecting the degree of the user's proximity (e.g., the distance from the proximity sensor 40 to the user). In this case, the proximity sensor 40 may be configured as a distance measurement sensor.

[0050] The configuration and detection principle of the proximity sensor 40 are not particularly limited as long as it can detect the proximity of a user. For example, the proximity sensor 40 may be configured as a capacitance-type sensor that detects a user by a change in capacitance when the user enters an electric field. The capacitance-type proximity sensor 40 is composed of, for example, an oscillation circuit incorporating a detection electrode and a detection circuit that detects changes in the oscillation frequency of the oscillation circuit. When a user enters the detection area, the capacitance increases due to an increase in charge of the detection electrode, and the oscillation frequency of the oscillation circuit changes. The proximity of the user is detected by the change in the oscillation frequency.

[0051] Furthermore, for example, the proximity sensor 40 may be configured as an infrared detection sensor that detects infrared rays emitted by the user. The proximity sensor 40 as an infrared sensor may be configured to include, for example, a light receiving element (infrared absorbing layer) that receives infrared rays emitted by the user and causes a temperature rise, and a temperature sensor that detects the temperature change of the light receiving element and converts it into an electrical signal.

[0052] Furthermore, for example, the proximity sensor 40 may be configured as a photoelectric sensor that detects a user by receiving a predetermined light. The proximity sensor 40 as a photoelectric sensor may be configured to include, for example, a light-emitting unit that emits light such as visible light or infrared light, and a light-receiving unit that receives the light emitted by the light-emitting unit. The proximity sensor 40 may be, for example, a reflective photoelectric sensor that detects a user by having the light emitted by the light-emitting unit reflected by the user and the light-receiving unit receive the reflected light. The proximity sensor 40 may be, for example, a transmissive photoelectric sensor that detects a user by having the light-receiving unit constantly receive the light emitted by the light-emitting unit detect that the light is blocked by the user.

[0053] Here, the location where the proximity sensor 40 is provided will be described with reference to FIG. 1. The proximity sensor 40 may be provided, for example, in a portion of the air compressor 1 that is electrically independent from the housing earth. This allows the entire air compressor 1 to detect the user's proximity, thereby reducing the occurrence of malfunctions due to erroneous detection, and making it possible to prioritize and improve user convenience. Here, the housing earth is a metal earth mechanism provided in the air compressor 1 to prevent electric shock, and may be configured to include, for example, the tank 8 and air chucks 7 and 9 of the air compressor 1.

[0054] For example, the proximity sensor 40 may be provided on or near the grips 61, 62 as a part electrically independent from the housing earth. The proximity sensor 40 may be provided on at least a part of the grips 61, 62 (which may be a part that the user grips or a part that does not come into contact with) or on the entire grips 61, 62. When the proximity sensor 40 is provided near the grips 61, 62, the nearby part may be, for example, a surface designed to face the user's body (hand, wrist, arm, etc.) within a predetermined distance when the user grips the grips 61, 62.

[0055] Furthermore, for example, proximity sensor 40 may be provided on or near pressure adjustment dials 10A, 10B as a part electrically independent from the housing earth. Proximity sensor 40 may be provided on at least a part or the entire pressure adjustment dials 10A, 10B. When proximity sensor 40 is provided near pressure adjustment dials 10A, 10B, the nearby part may be, for example, at least a part of a surface (e.g., the surface indicated by reference symbol 50A in FIG. 1) designed to face the user's body (hand, wrist, arm, etc.) within a predetermined distance when the user operates pressure adjustment dials 10A, 10B.

[0056] The proximity sensor 40 may be provided, for example, on the housing earth of the air compressor 1. This increases the sensitivity of the proximity sensor 40 to the proximity of a user, making it possible to more reliably shut down the function based on the proximity. For example, the proximity sensor 40 may be provided on at least a part or the entire tank 8. Furthermore, for example, the proximity sensor 40 may be provided on at least a part or the entire air chucks 7, 9. Note that the proximity sensor 40 is not limited to the above-mentioned position and may be provided at any position on the air compressor 1.

[0057] <Air compressor function stops> 3 is a diagram showing an example of the operational flow of the process of stopping the function of the air compressor 1 according to this embodiment. As described above, when the proximity sensor 40 detects that a user is approaching the air compressor 1, the MPU 5F executes control to stop the function of the air compressor 1 based on the detection result.

[0058] (S101) First, the MPU 5F determines whether or not the user is approaching the air compressor 1 based on the detection signal supplied from the proximity sensor 40. At this time, the MPU 5F may determine whether the user is in contact with or approaching the air compressor 1 (proximity sensor 40). Furthermore, the MPU 5F may obtain information quantitatively indicating the degree of proximity based on the detection signal output by the proximity sensor 40.

[0059] (S102) If it is determined that the user is not approaching the air compressor 1 (S101; No), the MPU 5F resets the timer. Then, the process returns to step S101. Note that the threshold value of the detection signal of the proximity sensor 40 for determining that the user is approaching may be arbitrarily set in advance, taking into consideration user convenience, safety, etc.

[0060] (S103) On the other hand, if it is determined that the user is approaching the air compressor 1 (S101; Yes), the MPU 5F counts up the timer.

[0061] (S104) Next, the MPU 5F refers to the timer and determines whether a predetermined time has elapsed. Here, the predetermined time is a time set as the time required for the user's proximity to the air compressor 1 to be continuously detected, which is necessary for the air compressor 1 to stop functioning. The predetermined time may be arbitrarily set in advance, taking into consideration user convenience, safety, etc., and may be set to, for example, 5 seconds. However, the predetermined time is not limited to this, and may be set in units of, for example, several milliseconds, several seconds, several tens of seconds, or several minutes. If it is determined that the predetermined time has not elapsed (S104; No), the processing returns to step S101.

[0062] (S105) If it is determined that the predetermined time has elapsed (S104; Yes), the MPU 5F executes a process to stop functioning as the air compressor 1. That is, the MPU 5F stops functioning as the air compressor 1 when the proximity sensor 40 detects the user's proximity to the air compressor 1 continuously for a predetermined time or more.

[0063] The process of stopping the function of the air compressor 1 may include, for example, a process of turning off the power supply switching circuit 5A. This stops the supply of power from the power supply switching circuit 5A to the converter circuit 5B, thereby rendering the motor 4 unable to drive (the motor 4 being driven stops). The process of stopping the function of the air compressor 1 may also include, for example, a process of stopping the function of the converter circuit 5B. This stops the supply of DC power having a predetermined voltage converted from the AC power source AC to the inverter circuit 5C, rendering the motor 4 unable to drive (the motor 4 being driven stops). The process of stopping the function of the air compressor 1 may also include, for example, a process of stopping the function of the inverter circuit 5C. This stops the supply of DC power from the converter circuit 5B to the three-phase windings 16A, 16B, and 16C by switching, rendering the motor 4 unable to drive (the motor 4 being driven stops). This completes the process.

[0064] The MPU 5F may detect, for example, whether the air compressor 1 is connected to the AC power supply AC. Here, the air compressor 1 being connected to the AC power supply AC may include, for example, a power plug of the air compressor 1 being connected to a supply port (outlet) for supplying the AC power supply AC. In this case, the power plug may supply the control unit 5 with a detection signal indicating whether it is connected to the supply port of the AC power supply AC. When the air compressor 1 is connected to the AC power supply AC, the MPU 5F may not stop the function of the air compressor 1, as specified in step S105 described above. In particular, when the air compressor 1 is connected to the AC power supply AC, the MPU 5F may not stop the function of the air compressor 1 even if the proximity sensor 40 detects proximity.

[0065] Furthermore, for example, if the proximity sensor 40 is configured to be able to detect the degree of proximity, the MPU 5F may change the type of process for stopping the function of the air compressor 1 depending on the degree of proximity. For example, the closer the user is to the proximity sensor 40, the more priority may be given to control that can more reliably stop the function of the air compressor 1. The MPU 5F may selectively execute a process for turning off the power supply switching circuit 5A, a process for stopping the function of the converter circuit 5B, and a process for stopping the function of the inverter circuit 5C depending on the degree of proximity based on preset information.

[0066] <Removing the air compressor function> 4 is a diagram showing an example of the operational flow of the process for canceling the function stoppage of the air compressor 1 according to this embodiment. In particular, in the process of FIG. 4, a condition for canceling the function stoppage as an air compressor includes that proximity is not detected continuously for a predetermined time or more after the function stoppage. This process is executed after the function as the air compressor 1 is stopped by the MPU 5F, for example, as in step S105 described above.

[0067] (S201) First, the MPU 5F determines whether or not the user is approaching the air compressor 1 based on the detection signal supplied from the proximity sensor 40. At this time, the MPU 5F may determine whether the user is in contact with or approaching the air compressor 1 (proximity sensor 40). Furthermore, the MPU 5F may obtain information quantitatively indicating the degree of proximity based on the detection signal output by the proximity sensor 40.

[0068] (S202) If it is determined that the user is approaching the air compressor 1 (S201; Yes), the MPU 5F resets the timer. Then, the process returns to step S201. Note that the threshold value of the detection signal of the proximity sensor 40 for determining that the user is approaching may be arbitrarily set in advance, taking into consideration the convenience and safety of the user, etc.

[0069] (S203) On the other hand, if it is determined that the user is not close to the air compressor 1 (S201; No), the MPU 5F counts up the timer.

[0070] (S204) Next, the MPU 5F refers to the timer and determines whether a predetermined time has elapsed. Here, the predetermined time is a time set as a period during which the user's proximity to the air compressor 1 is not continuously detected, which is necessary to release the function of the air compressor 1. The predetermined time may be set arbitrarily in advance, taking into consideration user convenience, safety, etc., and may be set to, for example, 5 seconds. However, the predetermined time is not limited to this, and may be set in units of, for example, several milliseconds, several seconds, several tens of seconds, several minutes, several tens of minutes, or several hours.

[0071] (S205) If it is determined that the predetermined time has not elapsed (S204; No), the MPU 5F determines whether or not an operation to cancel the function stop of the air compressor 1 has been accepted. The cancel operation may be, for example, a user operation on the operation panel 30 of the air compressor 1, or a user operation on the external terminal device 20 (accepted via the communication circuit 5E). Note that the determination process of step S205 (determination process of whether or not an operation to cancel the function stop has been accepted) does not necessarily have to be executed.

[0072] (S206) If it is determined in step S204 above that the predetermined time has elapsed (S204; Yes), or if it is determined in step S205 above that a release operation has been accepted (S205; Yes), the MPU 5F executes processing to release the suspension of function as the air compressor 1. That is, the MPU 5F releases the suspension of function as the air compressor 1 if the proximity sensor 40 does not detect the user's proximity to the air compressor 1 continuously for a predetermined time or longer.

[0073] The process of releasing the air compressor 1 from the stopped state may include, for example, turning on the power supply switching circuit 5A if the power supply switching circuit 5A is off. This releases the supply of power from the power supply switching circuit 5A to the converter circuit 5B, thereby enabling the motor 4 to be driven. The process of releasing the air compressor 1 from the stopped state may also include, for example, restoring the function of the converter circuit 5B if the function of the converter circuit 5B is stopped. This restores the supply of DC power having a predetermined voltage converted from the AC power source AC to the inverter circuit 5C, thereby enabling the motor 4 to be driven. The process of releasing the air compressor 1 from the stopped state may also include, for example, restoring the function of the inverter circuit 5C if the function of the inverter circuit 5C is stopped. This restores the supply of DC power from the converter circuit 5B to the three-phase windings 16A, 16B, and 16C by switching, thereby enabling the motor 4 to be driven. This completes the process.

[0074] 5 is a diagram showing another example of the operational flow of the process for canceling the function stop of the air compressor 1 according to this embodiment. In particular, in the process of FIG. 5, a condition for canceling the function stop as an air compressor is that proximity is not detected continuously for a predetermined time or more after the cancellation of the function stop is accepted. This process is executed after the function as the air compressor 1 is stopped by the MPU 5F, for example, as in step S105 described above.

[0075] (S301) First, the MPU 5F determines whether or not an operation to release the function stop of the air compressor 1 has been accepted. The release operation may be, for example, a user operation on the operation panel 30 of the air compressor 1, or a user operation on the external terminal device 20 (accepted via the communication circuit 5E). Step S301 is repeated until the operation is accepted (S301; No).

[0076] (S302) If it is determined that an operation to release the function stop of the air compressor 1 has been accepted (S301; Yes), the MPU 5F determines whether or not the user is approaching the air compressor 1 based on the detection signal supplied from the proximity sensor 40. At this time, the MPU 5F may determine whether the user is in contact with or approaching the air compressor 1 (proximity sensor 40). Furthermore, the MPU 5F may acquire information quantitatively indicating the degree of proximity based on the detection signal output by the proximity sensor 40.

[0077] (S303) If it is determined that the user is approaching the air compressor 1 (S302; Yes), the MPU 5F resets the timer. Then, the process returns to step S302. Note that the threshold value of the detection signal of the proximity sensor 40 for determining that the user is approaching may be arbitrarily set in advance, taking into consideration user convenience, safety, etc.

[0078] (S304) On the other hand, if it is determined that the user is not close to the air compressor 1 (S302; No), the MPU 5F counts up the timer.

[0079] (S305) Next, the MPU 5F refers to the timer and determines whether a predetermined time has elapsed. Here, the predetermined time is a time set as a period of time during which the user's proximity to the air compressor 1 is not continuously detected after the request to release the function is accepted, which is necessary to release the function of the air compressor 1. The predetermined time may be set arbitrarily in advance, taking into consideration user convenience, safety, and the like, and may be set to, for example, 5 seconds. However, the predetermined time is not limited to this, and may be set in units of, for example, several milliseconds, several seconds, several tens of seconds, several minutes, several tens of minutes, or several hours.

[0080] (S306) If it is determined in step S305 described above that the predetermined time has elapsed (S305; Yes), the MPU 5F executes a process to release the function suspension as the air compressor 1. That is, the MPU 5F releases the function suspension as the air compressor 1 if the proximity sensor 40 does not detect the user approaching the air compressor 1 for a predetermined time or more consecutively after the release of the function suspension is accepted.

[0081] The process of releasing the air compressor 1 from the stopped state may include, for example, turning on the power supply switching circuit 5A if the power supply switching circuit 5A is off. This releases the supply of power from the power supply switching circuit 5A to the converter circuit 5B, thereby enabling the motor 4 to be driven. The process of releasing the air compressor 1 from the stopped state may also include, for example, restoring the function of the converter circuit 5B if the function of the converter circuit 5B is stopped. This restores the supply of DC power having a predetermined voltage converted from the AC power source AC to the inverter circuit 5C, thereby enabling the motor 4 to be driven. The process of releasing the air compressor 1 from the stopped state may also include, for example, restoring the function of the inverter circuit 5C if the function of the inverter circuit 5C is stopped. This restores the supply of DC power from the converter circuit 5B to the three-phase windings 16A, 16B, and 16C by switching, thereby enabling the motor 4 to be driven. This completes the process.

[0082] <Modification> An air compressor 1' according to a modified example of this embodiment will be described with reference to Fig. 6. Fig. 6 is a block diagram showing an example of the functional configuration of an air compressor 1' according to a modified example of this embodiment.

[0083] The air compressor 1′ according to the modified example has solenoid valves 70A and 70B. More specifically, the high-pressure air chucks 7A and 9A are provided with the solenoid valve 70A, and the low-pressure air chucks 7B and 9B are provided with the solenoid valve 70B. The solenoid valves 70A and 70B are configured to be able to adjust the flow rate of compressed air supplied to the pneumatic tool from the air chucks 7 and 9, respectively. The solenoid valves 70A and 70B may include, for example, a plunger (a piece of iron) provided in a compressed air flow path in the air chucks 7 and 9, and a solenoid (electromagnet) configured to move the plunger between a position that opens the flow path and a position that closes the flow path.

[0084] The solenoid valves 70A and 70B adjust the flow rate of compressed air supplied to the pneumatic tool from the air chucks 7 and 9 in response to a control signal supplied from the MPU 5F, for example. In particular, the MPU 5F can control the solenoid valves 70A and 70B to stop the supply of compressed air to the pneumatic tool under predetermined conditions based on the proximity detection result of the proximity sensor 40. When the supply of compressed air to the pneumatic tool stops, the function as an air compressor stops.

[0085] In the air compressor 1′, solenoid valves do not necessarily have to be provided for all of the air chucks 7A, 7B, 9A, and 9B; they may be provided for only some of the air chucks 7A, 7B, 9A, and 9B. The MPU 5F may stop the supply of compressed air to the pneumatic tool by controlling the solenoid valves 70A and 70B as a process for stopping the function as an air compressor, for example, in step S105 described above. The MPU 5F may control the solenoid valves 70A and 70B in conjunction with other processes for stopping the function as an air compressor (e.g., a process for turning off the power supply switching circuit 5A, a process for stopping the function of the converter circuit 5B, and a process for stopping the function of the inverter circuit 5C), or may control the solenoid valves 70A and 70B instead of the other processes.

[0086] The above-described embodiment is one example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment and can be modified in various ways without departing from the spirit of the present invention. [Explanation of symbols]

[0087] 1, 1'...air compressor, 2...tank section, 3...compression mechanism, 4...motor, 5...control section, 5A...power supply switching circuit, 5B...converter circuit, 5C...inverter circuit, 5D...current / voltage detection circuit, 5E...communication circuit, 5F...MPU, 7, 7A, 7B, 9, 9A, 9B...air chuck, 8...tank, 10A, 10B...pressure adjustment dial, 11A, 11B...pressure gauge, 12...pressure sensor, 14...connecting pipe, 16...stator, 16A, 16B, 16C...three-phase winding, 17...rotor, 20...external terminal device, 30...operation panel, 40...proximity sensor, 50...casing, 61, 62...grip, 70A, 70B...solenoid valve

Claims

1. An air compressor that supplies compressed air to an external pneumatic tool, a detection unit that detects the proximity of a user; An air compressor comprising: a control unit that stops the function as an air compressor when the detection unit detects the proximity, and a control unit that does not stop the function as an air compressor when the air compressor is connected to an AC power source even when the detection unit detects the proximity.

2. The air compressor according to claim 1 , wherein the control unit stops the function as an air compressor by stopping operation of an electric motor that generates the compressed air.

3. 3. The air compressor according to claim 1, wherein the control unit stops the function of the air compressor by stopping the supply of power to an electric motor that generates the compressed air.

4. 4. The air compressor according to claim 1, further comprising: a solenoid valve provided at a supply port for supplying the compressed air to the pneumatic tool, wherein the control unit stops the function as an air compressor by controlling the solenoid valve to stop the supply of the compressed air to the pneumatic tool.

5. The air compressor according to claim 1 , wherein the control unit stops the function of the air compressor when the detection unit detects the proximity continuously for a predetermined time or longer.

6. 6. The air compressor according to claim 5, wherein the predetermined time can be set arbitrarily.

7. 7. The air compressor according to claim 1, wherein the control unit cancels the stop of the function as an air compressor when the detection unit does not detect the proximity for a predetermined time or more consecutively after the function as an air compressor is stopped.

8. Further, a reception unit is provided for receiving a cancellation of the stop of the function as an air compressor, The air compressor according to claim 1 , wherein the control unit cancels the stop of the function as an air compressor when the accepting unit accepts the cancellation.

9. The air compressor according to claim 8, wherein the control unit cancels the stop of the function as an air compressor when the acceptance unit accepts the cancellation and when the detection unit does not detect the proximity for a predetermined time or more consecutively after the acceptance of the cancellation.

10. The air compressor according to claim 1 , wherein the detection unit detects the proximity based on a change in capacitance.

11. The air compressor according to claim 1 , wherein the detection unit is provided in a portion electrically isolated from the housing ground.

12. The air compressor according to claim 11, wherein the detection unit is provided on or near a grip configured to be grippable for transporting the air compressor.

13. 13. The air compressor according to claim 11, wherein the detection unit is provided on or near the pressure adjustment dial.

14. The air compressor according to claim 1 , wherein the detection unit is provided to a housing earth.

15. 15. The air compressor according to claim 14, wherein the detection unit is provided in a tank that stores the compressed air or in a supply port of the compressed air provided in the tank.

Images