JP2020094562A - air compressor - Google Patents

Abstract

To improve visibility of a display part for digitally displaying a tank pressure and a discharge pressure while avoiding an increase in size of an air compressor.SOLUTION: An air compressor 1 comprises a compressed air generation part 3 for generating compressed air, a tank 4 for storing compressed air at a first pressure, a normal-pressure decompression valve 7 for decompressing the compressed air at the first pressure and generating compressed air at a second pressure, a normal-pressure coupler 9 for discharging the compressed air at the second pressure, a high-pressure decompression valve 10 for decompressing the compressed air at the first pressure and generating compressed air at a third pressure, a high-pressure coupler 12 for discharging the compressed air at the third pressure, and a digital display part 25 for digitally displaying the first pressure, the second pressure, and the third pressure in turn repeatedly.SELECTED DRAWING: Figure 1

Description

The present invention relates to an air compressor.

For example, in a construction site, a portable air tool for driving a nail or a screw into wood or the like by the pressure of compressed air is used. Compressed air, which is a power source for portable air tools used indoors and outdoors, is generated by, for example, a portable air compressor.

The air compressor includes a compressed air generation unit, a tank that stores compressed air, and an operation panel that operates and stops the air compressor. The air compressor includes a pressure reducing valve, a pressure gauge, and a coupler that is an outlet for compressed air.The compressed air in the tank is adjusted to an appropriate pressure by the pressure reducing valve, and then the air is supplied from the coupler through the air hose. Supplied to pneumatic tools. Pneumatic tools include those operated at high pressure and those operated at normal pressure, depending on the application. Therefore, the air compressor includes a high pressure reducing valve, a high pressure manometer, and a high pressure coupler, and a normal pressure reducing valve, a normal pressure manometer, and a normal pressure coupler. Further, analog type pressure gauges are used as the high pressure pressure gauge and the normal pressure pressure gauge. That is, the high-pressure pressure gauge displays the high-pressure discharge pressure in an analog manner, and the normal-pressure pressure gauge displays the normal-pressure discharge pressure in an analog manner. The operation panel also includes a power switch for operating and stopping the air compressor, an operation mode switch for switching operation modes, and a digital display section for displaying the air pressure of the tank.

Japanese Patent Laying-Open No. 2016-102478 (Patent Document 1) discloses a technique for displaying the air pressure of a tank and an operation mode (power mode, energy saving mode, etc.) on a digital display panel (the above-mentioned digital display unit). ing. In normal operating conditions, the digital display panel displays the air pressure inside the tank.When the operation mode switch is operated, the pressure display on the digital display panel is switched to the operation mode display, and the selected operation mode is selected. The indicated English letters are displayed, and then the display switches to the pressure display again.

JP, 2016-102478, A

According to a study by the inventor of the present application, an analog pressure gauge has a problem that visibility is low. Therefore, when working with an air tool at a position away from the air compressor, an analog display discharge is displayed. It is difficult to confirm the pressure. For example, in the case where there is no abnormality in the discharge pressure and there is a defect in the air tool, if the discharge pressure can be confirmed on the spot, the defect in the air tool can be immediately dealt with. Therefore, in order to digitally display not only the air pressure in the tank but also the discharge pressure for high pressure and the discharge pressure for normal pressure, a study example was considered in which three independent digital display units were provided on the operation panel. However, when three independent digital display units are provided on the operation panel having a limited size (area), the size of each digital display unit becomes small, and the visibility (in other words, the readability of the display value) is reduced. descend. Further, in order to improve the visibility, it is necessary to arrange the individual digital display units at a predetermined distance, which is also a factor that reduces the size of the individual digital display units. In addition, when the size of each digital display unit is increased and three independent digital display units are arranged at a predetermined interval, the size of the operation panel increases, and the air compressor increases accordingly. There is a problem.

An object of the present invention is to improve the visibility of a digital display unit that displays tank pressure and discharge pressure while avoiding an increase in the size of an air compressor.

The air compressor of the present invention generates a compressed air, a compressed air generator, a tank that stores compressed air at a first pressure, a compressed air at a first pressure, and a compressed air at a second pressure. A first pressure reducing valve, a first outlet for discharging compressed air of a second pressure, a second pressure reducing valve for reducing the pressure of the compressed air of the first pressure to generate compressed air of a third pressure, and a third pressure of the third pressure It has a second outlet for discharging the compressed air, and a first display unit capable of digitally displaying the pressure values of three portions including the tank, the first outlet, and the second outlet sequentially and digitally.

According to the present invention, the visibility of the discharge pressure can be improved while avoiding an increase in the size of the air compressor.

It is a block diagram of the air compressor of this embodiment. It is a top view which shows the internal structure of the air compressor shown in FIG. It is a perspective view which shows the external appearance of the air compressor shown in FIG. It is a top view which shows the operation panel of the air compressor shown in FIG. It is a flowchart which shows operation|movement of the air compressor shown in FIG. 6 is a graph showing the relationship between time and pressure at the atmospheric pressure outlet during pressure adjustment. It is a graph which shows the relationship between time and pressure in an atmospheric pressure outlet at the time of a pneumatic tool operation.

The air compressor according to the present embodiment is not particularly limited, but for example, supplies compressed air to an air tool that drives nails or screws into wood or the like by the pressure of compressed air. Hereinafter, an example of an embodiment of the air compressor of the present invention will be described.

As shown in FIG. 1, the air compressor 1 operates by receiving power from an external AC power source 31 (for example, a temporary power source, a household power source, etc.) via a power cord 32, and air tools 33 and 34. Supply compressed air to. The air compressor 1 includes a motor 2, a compressed air generator 3, a tank 4, a controller 5, a tank pressure sensor 6, a normal pressure reducing valve 7, a normal pressure sensor 8, a normal pressure coupler 9, and a high pressure reducing valve 10. A high pressure sensor 11, a high voltage coupler 12, and an operation panel 20 are provided.

The controller 5 includes a power device that controls the rotation of the motor 2 by an inverter and electronic components such as a microcomputer that comprehensively controls the air compressor 1. An operation panel 20 for externally operating the air compressor 1 is connected to the control unit 5 by, for example, an electric cable, and the operation panel 20 includes a power switch 21, an operation mode switch 23, and a digital display unit 25. And an information display unit 26 and the like.

Electric power is supplied from the AC power supply 31 to the control unit 5, and the control unit 5 drives the motor 2. The control unit 5 supplies electric power to the motor M and controls the rotation of the motor 2. Although not shown, the compressed air generating unit 3 includes a crankshaft, a piston, and a cylinder, and the rotational movement of the motor 2 is converted into the reciprocating movement of the piston via the crankshaft. Then, the reciprocating motion of the piston in the cylinder generates compressed air in the cylinder, and the generated compressed air is sent from the inside of the cylinder to the tank 4 through the pipe and is stored in the tank 4. That is, the compressed air generator 3 is driven by the motor 2 to generate compressed air. A tank pressure sensor 6 that detects the pressure of the compressed air stored in the tank 4 is installed in the tank 4, and the detected pressure value is input to the operation panel 20 via the control unit 5 as an electric signal. It The maximum pressure of the compressed air in the tank 4 is 4.4 MPa, for example. When the maximum pressure is reached, the driving of the motor 2 is stopped. When the pressure in the tank 4 drops due to the use of a pneumatic tool or the like, the motor 2 operates again. The pressure in the tank 4 is kept in the range of 4.0 MPa to 4.4 MPa, for example. However, this pressure range is an example in the "power mode" and the "auto mode", which will be described later. Is also good.

The normal pressure coupler 9 is an outlet for compressed air, and the tank 4 and the normal pressure coupler 9 are connected by a pipe joint or piping via the normal pressure reducing valve 7, and the air tool 33 is It is connected to the atmospheric pressure coupler 9 via an air hose. The atmospheric pressure reducing valve 7 is provided to adjust the pressure of the compressed air discharged from the atmospheric pressure coupler 9. A pressure sensor 8 for normal pressure is installed in the pressure reducing valve 7 for normal pressure, the pressure sensor 8 for normal pressure detects the pressure of the compressed air discharged from the coupler 9 for normal pressure, and the detected pressure value is controlled as an electric signal. It is input to the operation panel 20 via the unit 5. That is, the discharge pressure of the compressed air discharged from the normal pressure coupler 9 can be adjusted while confirming the pressure value displayed on the digital display unit 25 of the operation panel 20. The discharge pressure of the compressed air discharged from the normal pressure coupler 9 is in the range of 0 to 0.8 MPa, for example, and is lower than the pressure of the compressed air stored in the tank 4.

The high-pressure coupler 12 is an outlet for compressed air, and the tank 4 and the high-pressure coupler 12 are connected by a pipe joint or piping via the high-pressure reducing valve 10, and the air tool 34 is It is connected to the high-voltage coupler 12 via an air hose. The high pressure reducing valve 10 is provided to adjust the pressure of the compressed air discharged from the high pressure coupler 12. A pressure sensor 11 for high pressure is installed in the pressure reducing valve 10 for high pressure. The pressure sensor 11 for high pressure detects the pressure of the compressed air discharged from the coupler 12 for high pressure, and the detected pressure value is controlled as an electric signal. It is input to the operation panel 20 via the unit 5. That is, the discharge pressure of the compressed air discharged from the high-pressure coupler 12 can be adjusted while checking the pressure value displayed on the digital display unit 25 of the operation panel 20. The discharge pressure of the compressed air discharged from the high-pressure coupler 12 is, for example, in the range of 0 to 2.5 MPa, which is lower than the pressure of the compressed air stored in the tank 4. Further, the discharge pressure of the compressed air discharged from the high pressure coupler 12 is used in a range higher than the discharge pressure of the compressed air discharged from the normal pressure coupler 9.

The tank pressure sensor 6 may be installed in a pipe joint or a pipe that communicates the tank 4 with the atmospheric pressure reducing valve 7 and the high pressure reducing valve 10. Further, the pressure sensor 8 for normal pressure may be installed in a pipe joint or a pipe that connects the pressure reducing valve 7 for normal pressure and the coupler 9 for normal pressure, and the high pressure sensor 11 includes the high pressure reducing valve 10 and the high pressure coupler. You may install in the piping which connects 12 and.

As shown in FIG. 2, the tank 4 is composed of two tanks 4a and 4b, and the two tanks 4a and 4b are connected by piping. Each of the two tanks 4a and 4b is made of a metal such as aluminum, has a cylindrical shape with both ends closed, and is arranged so that its axes are parallel to each other, and is fixed to a frame (not shown). Has been done. Then, on the tank 4, the motor 2, the compressed air generation unit 3, the control unit 5, the tank pressure sensor 6, the normal pressure reducing valve 7, the normal pressure pressure sensor 8, the normal pressure coupler 9, the high pressure reducing valve 10, the high pressure. A pressure sensor 11 and a high pressure coupler 12 are arranged.

As shown in FIG. 3, a resin cover (housing) 30 is arranged on the tank 4, and the cover 30 includes the motor 2, the compressed air generating unit 3, the control unit 5, the tank pressure sensor 6, and the normal pressure sensor. 8 and the high pressure sensor 11 and the like. The cover 30 is provided with a plurality of openings and notches, from which the normal pressure reducing valve 7, the normal pressure coupler 9, the high pressure reducing valve 10, the high pressure coupler 12, and the power cord are taken out. The operation panel 20 is attached to the front surface (upper surface) of the cover 30.

As shown in FIG. 4, the operation panel 20 includes a power switch 21, an LED (Light Emitting Diode) 22, an operation mode switch 23, an LED 24, a digital display unit 25, and an information display unit 26. Further, the information display unit 26 includes LEDs 27, 28 and 29 and character information corresponding to them. The power switch 21 is a switch that switches between operating and stopping the air compressor 1. The LED 22 lights up during operation (switch: ON). The operation mode switch 23 is a switch for switching the operation mode, and for example, the operation mode is sequentially switched each time the button is pressed. The operation modes include, for example, “power mode”, “auto mode”, “silent mode”, and “energy saving mode”, and an appropriate mode can be selected depending on the work content or work environment of the pneumatic tools 33 and 34. Further, the selected mode is distinguished by turning off the LED 24 and emitting colors (red, green, yellow).

The digital display unit 25 is composed of a 7-segment LED display and can digitally display a 2-digit number. Further, the digital display unit 25 can be configured by a 9, 14, 16 segment LED display or a matrix LED display. The digital display unit 25 can display the pressure (pressure value) at the following three sites. That is, the pressure of the compressed air in the tank 4 (hereinafter referred to as “tank pressure Pt”), the pressure of the compressed air at the normal pressure outlet (the normal pressure coupler 9) (hereinafter referred to as “discharge pressure Pn”), and the high pressure. It is the pressure of the compressed air at the outlet (high-pressure coupler 12) (hereinafter referred to as “discharge pressure Ph”). The tank pressure Pt, the discharge pressure Pn, and the discharge pressure Ph are sequentially and repeatedly displayed on one digital display unit 25. Further, the information display unit 26 specifies one target site (target site) of the pressure value displayed on the digital display unit 25. The target of the pressure value displayed on the digital display unit 25 by turning on the LEDs 27, 28 and 29 arranged next to the "tank pressure", "normal pressure outlet" and "high pressure outlet" which are character information A site (target site) can be specified. That is, the target parts of the tank pressure Pt, the discharge pressure Pn, and the discharge pressure Ph are the “tank internal pressure”, the “normal pressure outlet”, and the “high pressure outlet”, respectively, and the LEDs 27, 28, and 29 are the tanks, respectively. It corresponds to the pressure Pt, the discharge pressure Pn, and the discharge pressure Ph. Incidentally, in FIG. 4, the LED 27 corresponding to “tank internal pressure” is turned on in the information display unit 26, and the numerical value of the digital display unit 25 is 4.4, so the tank pressure Pt is 4.4 MPa. It is shown that. The discharge pressure Pn and the discharge pressure Ph are also displayed in the same manner as the tank pressure Pt.

As a modification, the target portion may be specified by displaying the pressure value of the digital display unit 25 in different colors. In that case, the LEDs 27, 28 and 29 of the information display unit 26 can be omitted. Further, character information may be omitted. For example, the pressure values of "tank pressure", "normal pressure outlet" and "high pressure outlet" are displayed in "red", "green" and "yellow" respectively, but the color combination is limited to this. Not done.

5 is a flow chart showing the operation of the air compressor shown in FIG. 1, FIG. 6 is a graph showing the relationship between time and pressure at the atmospheric pressure outlet during pressure adjustment, and FIG. 7 is atmospheric pressure during operation of the air tool. 7 is a graph showing the relationship between time and pressure at the outlet.

In FIG. 5, the normal pressure sensor 8 is referred to as the pressure sensor 8, the high pressure sensor 11 is referred to as the pressure sensor 11, and the tank pressure Pt, the discharge pressure Pn, and the discharge pressure Ph are referred to as Pt, Pn, and Ph. There is. S13, S15, S16, S19, S21, S23 and S24 indicate display targets of the digital display unit 25 of FIG. In addition, Y means Yes and N means No.

<When starting up the air compressor>
First, the case where “the pressure sensor 8 or 11 senses a pressure change” (S11) is N after the power of the air compressor 1 is turned on will be described. That is, S13, S15, and S16 represent display targets of the digital display unit 25 when the atmospheric pressure reducing valve 8 and the high pressure reducing valve 10 are not operated, and the pneumatic tools 33 and 34 are not operated. When the power is turned on, the tank pressure Pt gradually increases and reaches the maximum pressure (for example, 4.4 MPa). If the normal pressure reducing valve 8 and the high pressure reducing valve 10 are closed, the discharge pressures Pn and Ph are zero, but if the normal pressure reducing valve 8 and the high pressure reducing valve 10 are completely open, the tank pressure Pt is The discharge pressure Pn increases to a maximum value (for example, 0.8 MPa) and the discharge pressure Ph increases to a maximum value (for example, 2.5 MPa) and becomes constant. The characteristic point here is that the display target of the digital display unit 25 is changed depending on whether or not the tank pressure Pt reaches the threshold value P1 or P2 in the process of increasing the tank pressure Pt. This is because even if the pneumatic tools 33 and 34 (see FIG. 1) are used when the tank pressure Pt is low, the original performance cannot be obtained. The threshold value P1 is, for example, the maximum value of the discharge pressure of the normal pressure coupler 9 (for example, 0.8 MPa), and the threshold value P2 is, for example, the maximum value of the discharge pressure of the high pressure coupler 11 (for example, 2.5 MPa). To do.

When “Pt≧threshold value P1” (S12) is N, only the detected value of “tank pressure Pt” (S13) is displayed on the digital display unit 25. That is, it indicates that the "normal pressure outlet" and the "high pressure outlet" are unusable (being prepared). It should be noted that the LED 27 of the information display unit 26 of FIG. 4 is turned on in correspondence with the display target of the digital display unit 25, indicating that the target portion of the tank pressure Pt corresponds to the “tank internal pressure”.

When “Pt≧threshold value P1” is Y and “Pt≧threshold value P2” is N, the detected values of “tank pressure Pt and discharge pressure Pn” (S15) are sequentially and repeatedly displayed on the digital display unit 25. In other words, it indicates that the "normal pressure outlet" is usable and the "high pressure outlet" is not usable (being prepared). It should be noted that the LEDs 27 and 28 of the information display unit 26 of FIG. 4 are sequentially turned on in correspondence with the display target of the digital display unit 25, the "tank pressure Pt" corresponds to the "tank internal pressure", and the "discharge pressure Pn" is " It corresponds to "normal pressure outlet".

When “Pt≧threshold value P1” and “Pt≧threshold value P2” are Y, the detected values of “tank pressure Pt, discharge pressure Pn, discharge pressure Ph” (S16) are sequentially and repeatedly displayed on the digital display unit 25. That is, it indicates that the "normal pressure outlet" and the "high pressure outlet" can be used. Of course, the LEDs 27, 28 and 29 of the information display unit 26 of FIG. 4 are sequentially turned on in correspondence with the display target of the digital display unit 25, the “tank pressure Pt” corresponds to the “tank internal pressure”, and the “discharge pressure Pn”. Indicates that the “normal pressure outlet” corresponds, and the “discharge pressure Ph” corresponds to the “high pressure outlet”.

When a plurality of detection values are sequentially and repeatedly displayed like "tank pressure Pt, discharge pressure Pn, discharge pressure Ph" (S16), each detection value should be displayed for a fixed time (for example, 5 to 10 seconds). Therefore, the detection value can be read easily. Similarly, in the case of "tank pressure Pt and discharge pressure Pn" (S15), each detected value is displayed for a fixed time (for example, 5 to 10 seconds).

<When adjusting the discharge pressure>
Next, the case where “the pressure sensor 8 or 11 senses a pressure change” (S11) and “the pressure change per unit time≦threshold value P3” (S17) are Y will be described. The threshold value (threshold pressure) P3 is a pressure drop of the discharge pressure Pn or Ph due to the driving of the air tool 33 or 34. That is, in S19, S21, S23, and S24, the pressure reducing valve 7 for normal pressure or the pressure reducing valve 10 for high pressure is operated and the discharge pressure Pn or Ph is adjusted in a state where the pneumatic tools 33 and 34 are not used. The display target of the digital display unit 25 in this case is shown.

When “Pt≧threshold value P1” (S18) is N, only the detected value of “tank pressure Pt” (S19) is displayed on the digital display unit 25. That is, it means that the discharge pressures Pn and Ph cannot be adjusted yet. The reason why the discharge pressures Pn and Ph are not displayed on the digital display unit 25 is that the change in the discharge pressure Pn or Ph is due to the operation of the normal pressure reducing valve 7 or the high pressure reducing valve 10 or the change in the tank pressure Pt. This is because it cannot be distinguished whether it is a thing or not.

When “Pt≧threshold value P1” (S18) is Y and “What sensed the pressure sensor 11?” (S20) is N, the detected value of “discharge pressure Pn” (S21) is displayed on the digital display unit 25. .. This is because the pressure sensor 8 for normal pressure has a pressure change and the discharge pressure Pn can be adjusted. While confirming the discharge pressure Pn displayed on the digital display unit 25, the normal pressure reducing valve 7 is operated to adjust the discharge pressure Pn to a desired value. FIG. 6 shows how the discharge pressure Pn changes from the initial value Pn1 to the set value Pn2. The display period of the digital display unit 25 includes “transition” and “stable state” of the discharge pressure Pn. The "transition" is the pressure change of the discharge pressure Pn from the initial value Pn1 to the set value Pn2, and the "stable state" is the state where the pressure of the set value Pn2 is stable for a certain period of time. The fixed time in the “stable state” is, eg, about 1 to 2 seconds. Both the pressure value in the "transition" and the pressure value in the "stable state" are digitally displayed on the digital display unit 25. By displaying the "stable state", it is possible to confirm that the adjustment of the discharge pressure Pn is completed.

If “Pt≧threshold value P1” (S18) and “Did you sense pressure sensor 11?” (S20) are Y and “Pt≧threshold value P2” (S22) is N, the digital display unit 25 displays “tank”. The detected values of the pressure Pt and the discharge pressure Pn” (S23) are sequentially and repeatedly displayed. That is, the discharge pressure Pn can be adjusted, but the discharge pressure Ph cannot be adjusted yet.

When “Pt≧threshold value P1” (S18), “Did you sense the pressure sensor 11?” (S20) and “Pt≧threshold value P2” (S22) are Y, “Discharge pressure Ph” (S24) is displayed on the digital display unit 25. ) Display the detected value. This is because the high pressure sensor 11 has a pressure change and the discharge pressure Ph is in an adjustable state. While confirming the discharge pressure Ph displayed on the digital display 25, the high pressure reducing valve 10 is operated to adjust the discharge pressure Ph to a desired value. On the digital display unit 25, the “transition” and the “stable state” are continuously displayed as in the case of S21.

The display method of the digital display unit 25, the display method of the information display unit 26 of FIG. 4 and the like are the same as those in the above <when the air compressor is started up>.

<When using pneumatic tools>
In FIG. 5, the case where “pressure change per unit time≦threshold value P3” (S17) is N indicates that the pneumatic tool 33 or 34 is being used. S13, S15 or S16 represents a display target of the digital display unit 25 when the pneumatic tool 33 or 34 is used. When using the air tools 33 and 34, S12 to S16 are the same as those described in the above <At the time of starting the air compressor>, and only different portions will be described. Specifically, the display method of the discharge pressures Pn and Ph in S15 and S16 is different. Here, the discharge pressure Pn will be described, but the discharge pressure Ph is also the same.

In FIG. 7, the broken line (a) shows the change in the discharge pressure Pn when the pneumatic tool 33 is driven. When the discharge pressure Pn before using the air tool 33 is the set value Pn3, the discharge pressure Pn is pulsed up to (Pn3-P4) each time the air tool 33 is driven (for example, nails or screws are driven). To descend. The pressure P4 is a pressure drop of the discharge pressure Pn due to the driving of the air tool 33, and is about 0.1 MPa, for example. The pressure P4 has a value substantially equal to the above-mentioned threshold P3. The time per pulse is 0.5 sec. When the discharge pressure Pn having the characteristic of the broken line (a) is displayed on the digital display unit 25, “flicker” occurs in the display, and the visibility of the numerical value deteriorates. Therefore, in the present embodiment, even if the pressure P4 drops in the discharge pressure Pn, the set value Pn3 is displayed on the digital display unit 25 if the pressure change per unit time is equal to or less than the threshold value P5. Continue to display. In this way, display flicker can be prevented. Here, the threshold value P5 is a value slightly higher than the pressure 4 and the threshold value P3, and is, for example, about 0.2 MPa.

<Effects of this embodiment>
In the air compressor 1 of the present embodiment, the pressures of three parts (tank pressure Pt, discharge pressure Pn, and discharge pressure Ph) are sequentially and digitally displayed on one digital display unit 25 provided on the operation panel 20. be able to.

Since the pressure values of the tank pressure Pt, the discharge pressure Pn, and the discharge pressure Ph are digitally displayed, the visibility of the tank pressure Pt, the discharge pressures Pn, and Ph is improved as compared with the analog pressure gauge.

Further, since the pressures of three parts are displayed on one digital display unit 25, the digital display unit can be displayed without enlarging the size of the operation panel 20 as compared with a study example in which three digital display units are independently provided on the operation panel. 25 sizes can be expanded. Therefore, the visibility of the digital display unit 25 is improved. Further, it is possible to avoid the size increase of the air compressor 1 due to the size increase of the operation panel 20.

Character information representing three target parts of the information display unit 26 and three LEDs corresponding to the three target parts identify which target part the pressure displayed on the digital display unit 25 corresponds to. be able to. In addition, the target portion can be specified by displaying the pressure value of the digital display unit 25 in different colors. In that case, the LEDs 27, 28 and 29 of the information display unit 26 can be omitted, the size of the digital display unit 25 can be enlarged, and the visibility of the pressure value can be further improved. Further, the character information of the information display unit 26 can be omitted, and the size of the digital display unit 25 can be further expanded.

The pressure values of the tank pressure Pt, the discharge pressure Pn, and the discharge pressure Ph are detected by the tank pressure sensor 6, the normal pressure pressure sensor 8, and the high pressure pressure sensor 11. Therefore, compared with the analog pressure gauge, Miniaturization and cost reduction can be realized.

When the tank pressure Pt rises, the discharge pressure corresponding to the usable outlet is displayed, and the discharge pressure corresponding to the outlet under preparation is not displayed, so that the pneumatic tools 33 and 34 can be used appropriately.

When the pneumatic tools 33 and 34 are used, if the change in the discharge pressure Pn or Ph per unit time is equal to or less than the predetermined threshold value P5, the set value of the discharge pressure Pn or Ph is displayed on the digital display unit 25. It is possible to prevent the display of the digital display unit 25 from flickering.

In the adjustment of the discharge pressure Pn or Ph, the manner in which the discharge pressure Pn changes from the initial value Pn1 to the set value Pn2 is digitally displayed, so that highly accurate adjustment is possible. Further, since the pressure values in the “transition” and “stable state” of the discharge pressure Pn or Ph are continuously displayed, it is possible to confirm that the adjustment of the discharge pressure Pn or Ph is completed.

Although the present embodiment has been described by using the example in which the tank pressure Pt, the discharge pressure Pn, and the discharge pressure Ph are sequentially and repeatedly displayed, the “tank pressure Pt and the discharge pressure Pn” or the “tank pressure Pt and the discharge pressure Ph” are described. It is also applicable when repeatedly displaying "." Further, the display order is not limited to the order of the tank pressure Pt, the discharge pressure Pn, and the discharge pressure Ph.

DESCRIPTION OF SYMBOLS 1... Air compressor, 2... Motor (electric motor), 3... Compressed air generation part, 4, 4a, 4b... Tank, 5... Control part, 6... Tank pressure sensor (pressure sensor), 7... Normal pressure reducing valve (Pressure reducing valve), 8... Pressure sensor for normal pressure (pressure sensor), 9... Coupler for normal pressure (take-out port), 10... Pressure reducing valve for high pressure (pressure reducing valve), 11... Pressure sensor for high pressure (pressure sensor), 12... High-voltage coupler (take-out port), 20... Operation panel, 21... Power switch, 22, 24, 27 to 29... LED, 23... Operation mode switch, 25... Digital display section (first display section, display section), 26 ... information display section (second display section), 30... cover (housing), 31... AC power supply, 32... power cord, 33, 34... pneumatic tool

Claims (13)

A compressed air generator that generates compressed air;
A tank for storing compressed air at a first pressure,
A first pressure reducing valve that reduces the compressed air of the first pressure to generate compressed air of a second pressure;
A first outlet for discharging the compressed air of the second pressure;
A second pressure reducing valve for reducing the compressed air having the first pressure to generate compressed air having a third pressure;
A second outlet for discharging the compressed air of the third pressure;
A first display unit capable of sequentially and digitally displaying pressure values at three locations including the tank, the first outlet, and the second outlet,
Having an air compressor. The air compressor according to claim 1,
An air compressor that displays the pressure values of the three parts in different colors. The air compressor according to claim 1,
further,
An air compressor having a second display section for specifying which of the three parts the pressure value displayed on the first display section corresponds to. The air compressor according to claim 3,
The second display section,
Character information representing each of the three parts,
Three LEDs corresponding to each of the three parts,
Have
An air compressor that specifies one of the three target parts by lighting the LED. The air compressor according to claim 1,
The said 1st display part is an air compressor which continues displaying the said 1st pressure, the said 2nd pressure, and the said 3rd pressure for a fixed time, respectively. The air compressor according to claim 1,
further,
A first pressure sensor for detecting the first pressure;
A second pressure sensor for detecting the second pressure;
A third pressure sensor for detecting the third pressure,
An air compressor having. The air compressor according to claim 1,
An air compressor in which the second pressure is lower than the third pressure. The air compressor according to claim 7,
An air compressor that displays only the first pressure on the first display unit when the first pressure is lower than a first threshold value. The air compressor according to claim 8,
When the first pressure is higher than the first threshold and lower than a second threshold that is higher than the first threshold, the first pressure and the second pressure are sequentially repeated on the first display unit. Show, air compressor. The air compressor according to claim 9,
An air compressor that sequentially and repeatedly displays the first pressure, the second pressure, and the third pressure on the first display unit when the first pressure is higher than a second threshold. The air compressor according to claim 1,
An air compressor for displaying the second pressure before the pressure drop on the first display unit if the pressure drop due to the driving of the air tool connected to the first outlet is equal to or less than a third threshold value. A compressed air generator that generates compressed air;
A tank for storing compressed air at a first pressure,
A pressure reducing valve that reduces the compressed air of the first pressure to generate compressed air of the second pressure;
An outlet for discharging compressed air at a second pressure;
A pressure sensor for detecting the pressure of the compressed air discharged from the outlet,
A display unit for digitally displaying the value detected by the pressure sensor,
Have
When the pressure reducing valve is adjusted to change the pressure of the compressed air discharged from the outlet from the second pressure to the third pressure, the display unit reaches the third pressure from the second pressure. An air compressor that displays a pressure value in a transition and a pressure value in a stable state after reaching the third pressure. The air compressor according to claim 12,
The display of the pressure value in the transition and the pressure value in the stable state is performed when the first pressure is higher than the third pressure.

Images