Air pump and air compressor with same

Abstract

Provided are an air pump for reducing high frequency components of noise caused by seating of an inlet-side check valve on a valve seat, and an air compressor provided with the same. The present invention is provided with: a first air supply unit comprising a first piston rod that reciprocates in a first cylinder and changes the volume of a first air chamber formed between the first cylinder and the first piston rod, and a metal inlet-side check valve by which a first intake hole for introducing air into the first air chamber is opened during intake and closed during exhaust; a second air supply unit comprising a second piston rod that reciprocates in a second cylinder and changes the volume of a second air chamber formed between the second cylinder and the second piston rod, and a metal inlet-side check valve by which a second intake hole for introducing air into the second air chamber is opened during intake and closed during exhaust. The first intake hole formed in the first air supply unit and the second intake hole formed in the second air supply unit are in communication via an inlet-side communication conduit comprising an air intake hole for taking in outside air.

Description

Air pump and air compressor equipped with same

[0001] The present invention relates to an air pump and an air compressor including the same, and more particularly to an air pump having two piston rods and an air compressor including the same.

[0002] Conventionally, a small air pump has been known that has a first piston rod that reciprocates within a first cylinder to change the volume of a first air chamber formed between the first cylinder and the second piston rod, and a second piston rod that reciprocates within a second cylinder to change the volume of a second air chamber formed between the first cylinder and the second cylinder (for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2004-211708

[0004] The cylinders (first and second cylinders) of the air pump described above are provided with a metal flapper valve that functions as a check valve at least on the inlet side (intake side), and as the piston rods (first and second piston rods) reciprocate, the flapper valve repeatedly seats on and disengages from a valve seat formed on the cylinder. The inventors have discovered that in such air pumps, the repeated seating of the flapper valve while the air pump is operating generates an unpleasant opening and closing sound containing high-frequency components.

[0005] Therefore, the present invention is intended to solve the problems of the prior art as described above, and an object of the present invention is to provide an air pump and an air compressor equipped with the same that reduce the high frequency components of noise caused by the inlet check valve sitting on the valve seat.

[0006] The invention of claim 1 is an air pump comprising: a first piston rod that reciprocates within a first cylinder to change the volume of a first air chamber formed between the first piston rod and the first cylinder; a first air supply unit having a metal inlet check valve that opens a first intake port that introduces air into the first air chamber during intake and closes it during exhaust; a second piston rod that reciprocates within a second cylinder to change the volume of a second air chamber formed between the second piston rod and the second cylinder; and a second air supply unit having a metal inlet check valve that opens a second intake port that introduces air into the second air chamber during intake and closes it during exhaust; and the first intake port formed in the first air supply unit and the second intake port formed in the second air supply unit are connected by an inlet communicating conduit that has an air intake port that takes in air from the outside, thereby solving the above-mentioned problem.

[0007] The invention according to claim 2 solves the above-mentioned problem by, in addition to the configuration of the air pump described in claim 1, driving it at a volume of 45 dB or more and 55 dB or less.

[0008] The invention according to claim 3 further solves the above-mentioned problem by providing the inlet-side connecting pipe with flexibility in addition to the configuration of the air pump described in claim 1 or claim 2.

[0009] The invention of claim 4 solves the above-mentioned problem by providing an air compressor that supplies compressed air to an external device, comprising: an air pump as defined in claim 1 or claim 2; an air tank that communicates with the outlet of the air pump to store the air supplied from the air pump and that communicates with the external device to supply the compressed air to the external device; a controller that controls a drive motor that reciprocates a first piston rod and a second piston rod of the air pump; and an external communication port that is connected to a signal line extending from the controller and is freely connectable to a signal line extending from an external control device that controls the controller.

[0010] The invention of claim 5 solves the above-mentioned problem by including, in addition to the configuration of the air compressor described in claim 4, a pressure gauge that measures the internal pressure of the air tank, and the controller connected to the pressure gauge outputs the internal pressure value of the air tank to the external control device.

[0011] According to the air pump of the invention of claim 1, the first intake port formed in the first air supply section and the second intake port formed in the second air supply section are connected by an inlet side communicating pipe having an air intake hole that takes in air from the outside. Therefore, when the first intake port is opened and closed by the inlet side check valve in conjunction with the reciprocating movement of the first piston rod, or when the second intake port is opened and closed by the inlet side check valve in conjunction with the reciprocating movement of the second piston rod, the harsh high frequency components of the impact sound caused by the inlet side check valve sitting on the valve seat are attenuated by the air present in the inlet side communicating pipe, and therefore the high frequency components of the noise caused by the inlet side check valve sitting on the valve seat when the air pump is operated can be reduced.

[0012] According to the air pump of the invention of claim 2, in addition to the effects achieved by the air pump of the invention of claim 1, by operating at a volume of 45 dB or more and 55 dB or less, the noise level of the air pump's operation is at a level that would be heard on an everyday basis, so that the health of the worker can be maintained even if the air pump is placed near a worker who uses equipment that operates using air supplied by the air pump.

[0013] According to the air pump of the invention of claim 3, in addition to the effects achieved by the air pump of the invention of claim 1 or claim 2, the inlet side connecting pipe is flexible, so when the air pump is placed inside the housing, the inlet side connecting pipe deforms depending on the degree of interference with the housing, making it easier to make the housing smaller.

[0014] According to the air compressor of the invention of claim 4, in addition to the effects achieved by the air pump of the invention of claim 1 or claim 2, it is equipped with an external communication port that is connected to a signal line extending from the controller and can be freely connected to a signal line extending from an external control device that controls the controller, so that the external control device that controls the controller can be connected to the air compressor, and the operation of the air compressor can be controlled by the external control device.

[0015] According to the air compressor of the invention of claim 5, in addition to the effects of the air compressor of the invention of claim 4, the controller connected to the pressure gauge outputs the internal pressure value of the air tank to an external control device, which enables the external control device to control the drive of the air compressor according to the internal pressure value of the air tank, and therefore the drive motor of the air pump can be driven according to the usage environment of the air compressor, minimizing the time during which noise is generated by the air compressor.

[0016] 1A is a perspective view showing the front, right side, and top of an air compressor 10 according to an embodiment of the present invention; 2 is a perspective view showing the back, left side, and bottom of an air compressor 10 according to an embodiment of the present invention; 3A is a piping system diagram of the air compressor 10 shown in FIG. 1A; 4A is a front view of the air pump 100 shown in FIG. 2; 5A is a left side view of the air pump 100 shown in FIG. 2; 6A is a partial cross-sectional view taken along IIIA-IIIA of FIG. 3A; 7A is a cross-sectional view taken along IIIB-IIIB of FIG. 3B; 8A is a cross-sectional view taken along VI-VI of FIG. 5; 9A is a cross-sectional view taken along VII-VII of FIG. 3B.

[0017] The air pump of the present invention is an air pump comprising: a first piston rod that reciprocates within a first cylinder to change the volume of a first air chamber formed between the first piston rod and the first cylinder; a first air supply unit having a metal inlet check valve that opens a first intake port that introduces air into the first air chamber during intake and closes it during exhaust; a second piston rod that reciprocates within a second cylinder to change the volume of a second air chamber formed between the second piston rod and the second cylinder; and a second air supply unit having a metal inlet check valve that opens a second intake port that introduces air into the second air chamber during intake and closes it during exhaust; the first intake port formed in the first air supply unit and the second intake port formed in the second air supply unit are connected by an inlet communicating conduit that has an air intake port that takes in air from the outside, and any specific embodiment is possible as long as the pump reduces the high-frequency components of noise caused by the inlet check valve seating on the valve seat.

[0018] For example, an air compressor equipped with the air pump of the present invention is preferably built into a collaborative robot such as a robot arm, a transport robot such as an AMR (autonomous mobile transport robot) or an AGV (automated guided vehicle), or an external device that uses compressed air, such as an analytical device, but is not limited to this.

[0019] 1 to 7, an air compressor 10, which is an example of an apparatus according to an embodiment of the present invention, and an air pump 100 incorporated into this air compressor 10. The air compressor 10 is incorporated into a transport robot such as an AMR (autonomous transport robot) or an AGV (automated guided vehicle), or an external device that uses compressed air, such as an analytical device, and supplies compressed air to a pneumatic device in the external device that requires air pressure.

[0020] 1A and 1B, the external appearance of the air compressor 10 will be described. Fig. 1A is a perspective view showing the front, right side, and top of the air compressor 10 according to one embodiment of the present invention, and Fig. 1B is a perspective view showing the back, left side, and bottom of the air compressor 10 according to one embodiment of the present invention.

[0021] As shown in FIGS. 1A and 1B, the air compressor 10 has a height of 10 cm and a base area of ​​310 cm. ２ This is a small air compressor consisting of a rectangular parallelepiped housing 11 of about 1 / 4.

[0022] A power switch 12 for turning on / off the operation of the air compressor 10 is provided on the front surface of the housing 11. Power is supplied to the air compressor 10 via a power cord (not shown) connected to the back surface of the housing 11.

[0023] 1A, a heat dissipation hole 11a for dissipating heat inside the housing to the outside is formed on the left side surface of the housing 11. The number and shape of the heat dissipation hole 11a may be any as long as it can dissipate heat inside the housing to the outside, and are not limited to the number and shape shown in FIG.

[0024] 1B, an intake hole 11b is formed on the left side surface of the housing 11 to take in air into the housing 11. The number and shape of the intake holes 11b may be any as long as they can take in air into the air compressor 10, and are not limited to the number and shape shown in FIG.

[0025] An external communication port 13 is provided at the top of the rear surface of the housing 11, which can be connected to a signal line extending from an external control device that is not part of the air compressor 10. Of the external communication ports 13, the first external communication port 13a is a port for performing serial communication with a computer or the like, such as RS-485, and the second external communication port 13b is an I / O port (input / output port) for connecting to a PLC (Programmable Logic Controller) or the like. Therefore, in the air compressor 10 of this embodiment, an external control device can be connected to the air compressor 10, and the operation of the air compressor 10 can be controlled by the external control device. In other words, the air compressor 10 of this embodiment has not only an internal control mode in which it is operated independently of an external control device, but also an external control mode in which its operation is controlled by an external control device.

[0026] An outlet 14 is formed at the bottom of the rear surface of the housing 11 and can be freely connected to an air pipe extending from an air pressure device of an external device.

[0027] 2. Flow Channel Configuration of Air Compressor 10 Next, the flow channel configuration of the air compressor 10 will be described with reference to FIG. 2, which is a piping diagram of the air compressor 10 shown in FIG. 1A.

[0028] As shown in FIG. 2, the air compressor 10 includes an air pump 100, an air tank 200 that communicates with the outlet of the air pump 100 and stores the air supplied from the air pump 100, a pressure gauge 300 that is connected to the air tank 200 and measures the internal pressure of the air tank 200, a check valve 400 that is disposed between the air pump 100 and the air tank 200 and prevents air from flowing back from the air tank 200 to the air pump 100, and a relief valve 500 that is connected to the outlet of the air tank 200 and reduces the pressure inside the air tank 200 to a predetermined pressure value or below.

[0029] As shown in FIG. 1A, the pressure gauge 300 has a display / operation unit 310 on the surface of the housing 11 that displays the internal pressure value of the air tank 200 and operates the pressure gauge 300.

[0030] The air compressor 10 also includes a controller 600 electrically connected to the electrically operated components of the air pump 100 and the pressure gauge 300. The controller 600 has a signal line 610 connected at one end to the external communication port 13. Therefore, when the signal line EC1 extending from the external control device EC is connected to the external communication port 13, the controller 600 connected to the pressure gauge 300 outputs the internal pressure value of the air tank 200 to the external control device EC, allowing the external control device EC to control the operation of the air compressor 10 in accordance with the internal pressure value of the air tank 200. Therefore, in the air compressor 10 of this embodiment, when the external control device EC operates the air compressor 10 in accordance with the internal pressure value of the air tank 200, the air pump 100 is operated in accordance with the operating environment of the air compressor 10, thereby minimizing the amount of time the air compressor 10 generates noise.

[0031] 3. Air Pump Structure Next, air pump 100 will be described in detail with reference to Figures 2 to 7. Figure 3A is a front view of air pump 100 shown in Figure 2, Figure 3B is a left side view of air pump 100 shown in Figure 2, Figure 4 is a partial cross-sectional view taken along line IIIA-IIIA in Figure 3A, Figure 5 is a cross-sectional view taken along line IIIB-IIIB in Figure 3B, Figure 6 is a cross-sectional view taken along line VI-VI in Figure 5, and Figure 7 is a cross-sectional view taken along line VII-VII in Figure 3B.

[0032] As shown in Figures 3A and 3B, the air pump 100 is composed of a rectangular parallelepiped drive unit 110, a first air supply unit 120 connected to the left side of the drive unit 110, a second air supply unit 130 connected to the right side of the drive unit 110, a flow path forming member 140 attached to the front of the drive unit 110, and an inlet side connecting pipe 150 that connects the first air supply unit 120 and the second air supply unit 130.

[0033] The noise level of air pump 100 according to JIS B 8346 is approximately 45 dB to 55 dB. Therefore, since the driving noise of air pump 100 is at a noise level comparable to that of everyday noise, the health of the worker can be maintained even when air pump 100 is placed near a worker who uses equipment that operates using the air supplied by air pump 100.

[0034] 5 and 6 , the drive unit 110 has a housing 111, a drive motor 112 mounted on the housing 111, a base 113 that rotates integrally with the drive motor 112, and an upper crank 114 and a lower crank 115 that are connected to the base 113.

[0035] The drive motor 112 is connected to the controller 600 and is controlled by the controller 600. Therefore, in the external control mode, the drive motor 112 is controlled by the external control device EC via the controller 600, and in the internal control mode, the drive motor 112 is controlled by the controller 600 alone.

[0036] 6, the base 113 has a cylindrical portion 113a into which the motor shaft 112a hanging down from the drive motor 112 is inserted, and a hollow disk-shaped portion 113b connected to the lower end of the cylindrical portion 113a, and is fixed to the motor shaft 112a by a fixing screw (not shown). Therefore, the base 113 rotates integrally with the motor shaft 112a.

[0037] 6 and other figures, an upper key 113c and a lower key 113d below the upper key 113c are attached to the cylindrical portion 113a of the base 113. The upper key 113c and the lower key 113d are provided in opposing positions (positions offset by 180 degrees) around the motor shaft 112a as the center, as shown in FIG.

[0038] As shown in Figures 5 and 6, the upper crank 114 is composed of a hollow, disk-shaped crank base 114a that engages with an upper key 113c attached to the base 113 and rotates integrally with the base 113, a crank body 114b consisting of an annular portion and a square portion protruding from the annular portion, and a radial bearing 114c that is arranged between the crank base 114a and the crank body 114b.

[0039] As shown in Fig. 5, the center of the crank base 114a is eccentric to the axis of the motor shaft 112a. As shown in Fig. 5, the center of the crank body 114b coincides with the center of the crank base 114a, the center of the radial bearing 114c, and the center of the annular portion of the crank body 114b. Therefore, when the motor shaft 112a rotates, the crank body 114b reciprocates left and right.

[0040] As shown in Figure 6, the lower crank 115 is composed of a hollow, disk-shaped crank base 115a that engages with a lower key 113d attached to the base 113 and rotates integrally with the base 113, a crank body 115b consisting of an annular portion and a square portion protruding from the annular portion, and a radial bearing 115c that is arranged between the crank base 115a and the crank body 115b.

[0041] The center of the crank base 115a is eccentric to the axis of the motor shaft 112a, similar to the center of the crank base 114a of the upper crank 114. The center of the crank body 115b is also aligned with the center of the crank base 115a, the center of the radial bearing 115c, and the center of the annular portion of the crank body 115b, similar to the upper crank 114. Therefore, when the motor shaft 112a rotates, the crank body 115b also reciprocates left and right.

[0042] 5 and 6 , the first air supply unit 120 includes a cylindrical first cylinder 121 inserted into the left side surface of the housing 111 of the drive unit 110, a first piston rod 122 connected to the crank body 114b of the drive unit 110 to close one end of the first cylinder 121 and reciprocating within the first cylinder 121, a cover member 123 that closes the other end of the first cylinder 121, a flow path member 124 attached to the cover member 123, a heat sink 125 attached to the flow path member 124, and an inlet joint 126 and an outlet joint 127 connected to the flow path member 124. Therefore, in the first air supply unit 120, the first cylinder 121, the first piston rod 122, and the cover member 123 form a first air chamber AC1 as shown in FIG. The first piston rod 122 reciprocates within the first air chamber AC1, thereby changing the volume of the first air chamber AC1.

[0043] 5 and 6, the first piston rod 122 is made up of a disk-shaped piston body 122a, a seal member 122b that covers the outer periphery of the piston body 122a and seals the gap with the first cylinder 121, and a connecting bolt 122c that connects the piston body 122a to the crank body 114b of the drive unit 110. Therefore, the first piston rod 122 reciprocates within the first air chamber AC1 by the drive motor 112 of the drive unit 110.

[0044] The cover member 123 is a rectangular plate-shaped member, and as shown in Figure 5, has an inlet hole (first intake hole) 123a that introduces air into the first air chamber AC1, and an exhaust hole 123b that exhausts air from the first air chamber AC1.

[0045] 5 and 6, a metallic flap-shaped inlet check valve 123c is provided at the outlet end of the inlet hole 123a to prevent air from flowing into the inlet hole 123a from the first air chamber AC1. That is, the inlet check valve 123c opens the inlet hole 123a during intake and abuts against the valve seat 123d to close the inlet hole 123a during exhaust.

[0046] 4 and 5, an outlet-side check valve 123e is provided at the outlet end of the exhaust hole 123b to prevent air from flowing into the first air chamber AC1 through the exhaust hole 123b. In addition, a stopper 123f is provided at the outlet end of the exhaust hole 123b to limit the opening degree of the outlet-side check valve 123e.

[0047] The flow path member 124 is a rectangular plate-shaped member, and as shown in Figures 4 and 5, has an inlet flow path 124a that extends forward from the rear surface of the flow path member 124 and communicates with the inlet hole 123a of the cover member 123, and an outlet flow path 124b that communicates with the exhaust hole 123b of the cover member 123 and extends toward the front surface of the flow path member 124.

[0048] As shown in FIGS. 3B and 4 , the inlet side joint 126 is an L-shaped joint connected to the rear end side of the flow path member 124 , and its downstream end communicates with the inlet flow path 124 a of the flow path member 124 .

[0049] As shown in FIGS. 3B and 4 , the outlet side joint 127 is a linear joint connected to the front end side of the flow path member 124 , and its upstream end communicates with the outlet flow path 124 b of the flow path member 124 .

[0050] 5 and 6 , the second air supply unit 130 includes a cylindrical second cylinder 131 inserted into the right side surface of the housing 111 of the drive unit 110, a second piston rod 132 connected to the crank body 114b of the drive unit 110 to close one end of the second cylinder 131 and reciprocating within the second cylinder 131, a cover member 133 that closes the other end of the second cylinder 131, a flow path member 134 attached to the cover member 133, a heat sink 135 attached to the flow path member 134, and an inlet joint 136 and an outlet joint 137 connected to the flow path member 134. Therefore, in the second air supply unit 130, the second cylinder 131, the second piston rod 132, and the cover member 133 form a second air chamber AC2 as shown in FIG. The second piston rod 132 reciprocates within the second air chamber AC2, thereby changing the volume of the second air chamber AC2.

[0051] 6, the second piston rod 132 is made up of a disk-shaped piston body 132a, a seal member 132b that covers the outer periphery of the piston body 132a and seals the gap with the second cylinder 131, and a connecting bolt 132c that connects the piston body 132a to the crank body 115b of the drive unit 110. Therefore, the second piston rod 132 reciprocates within the second air chamber AC2 by the drive motor 112 of the drive unit 110.

[0052] The cover member 133 is a rectangular plate-shaped member, and as shown in Figures 5 and 6, has an inlet hole (second intake hole) 133a that introduces air into the second air chamber AC2, and an exhaust hole 133b that exhausts air from the second air chamber AC2.

[0053] 5, a metallic flap-shaped inlet check valve 133c is provided at the outlet end of the inlet hole 133a to prevent air from flowing into the inlet hole 133a from the second air chamber AC2. That is, the inlet check valve 133c opens the inlet hole 133a during intake and abuts against the valve seat 133d to close it during exhaust.

[0054] As shown in Fig. 6, an outlet check valve 133e is provided at the outlet end of the exhaust hole 133b to prevent air from flowing into the second air chamber AC2 from the exhaust hole 133b. Also, as shown in Fig. 6, a stopper 133f is provided at the outlet end of the exhaust hole 133b to limit the opening degree of the outlet check valve 133e.

[0055] The flow path member 134 is a rectangular plate-shaped member, and as shown in Figure 5, etc., has an inlet flow path 134a that extends forward from the rear surface of the flow path member 134 and communicates with the introduction hole 133a of the cover member 133, and an outlet flow path 134b that communicates with the exhaust hole 133b of the cover member 133 and extends toward the front surface of the flow path member 134.

[0056] As shown in FIG. 5 and other figures, the inlet side joint 136 is an L-shaped joint connected to the rear end side of the flow path member 134 , and its downstream end communicates with the inlet flow path 134 a of the flow path member 134 .

[0057] As shown in FIG. 5 and other figures, the outlet side joint 137 is a linear joint connected to the front end side of the flow path member 134 , and its upstream end communicates with the outlet flow path 134 b of the flow path member 134 .

[0058] 3.4. Flow path forming member> As shown in Fig. 3B , the flow path forming member 140 is disposed in front of the drive unit 110. This flow path forming member 140 has a plate material 141, a hollow connecting member 142 that connects this plate material 141 to the outlet side joint 127 of the first air supply unit 120 and the outlet side joint 137 of the second air supply unit 130 as shown in Fig. 4 , and an upper joint 143 provided on the upper surface of the plate material 141.

[0059] The plate material 141 is a rectangular plate-shaped member as shown in FIG. 3, and has a horizontal flow path 141a extending in the left-right direction as shown in FIG. 7, and an upper flow path 141b extending upward from near the center of the horizontal flow path 141a.

[0060] 7, the horizontal flow path 141a is a through-hole that passes through the plate material 141 in the left-right direction. Flow path sealing plugs 144 that seal both ends of the horizontal flow path 141a are inserted into both ends of the horizontal flow path 141a.

[0061] The outlet end of the upper joint 143 is connected to an air supply line Ta which communicates with a check valve 400 as shown in FIG. 3A.

[0062] 3.5. Inlet-Side Communication Pipeline As shown in FIG. 3A , the inlet-side communication pipeline 150 is made up of a first intake member 151 connected to the first air supply unit 120, a second intake member 152 connected to the second air supply unit 130, and a communication pipe (communication pipe) 153 that connects the first intake member 151 and the second intake member 152.

[0063] 3B , the first intake member 151 has a three-way joint 151a and a filter 151b with an air intake hole connected to the front connection port of the three-way joint 151a. One end of a communication conduit 153 is connected to the upper connection port of the three-way joint 151a. One end of a connection pipe 151c, which connects to the inlet side of the inlet-side joint 126 of the first air supply unit 120, is connected to the lower connection port of the three-way joint 151a. Therefore, the first intake member 151 connects the communication conduit 153 to the introduction port 123a of the first air supply unit 120.

[0064] 3A, the second intake member 152 has a three-way joint 152a and a filter 152b with an air intake hole connected to the front connection port of the three-way joint 152a. The other end of the communication conduit 153 is connected to the upper connection port of the three-way joint 152a. One end of a connection pipe 152c, which connects to the inlet side of the inlet-side joint 136 of the second air supply unit 130, is connected to the lower connection port of the three-way joint 152a. Therefore, the second intake member 152 connects the communication conduit 153 to the introduction port 133a of the second air supply unit 130.

[0065] The communication pipe 153 that connects the inlet hole 123a of the first air supply unit 120 and the inlet hole 133a of the second air supply unit 130 is an arch-shaped pipe made of resin and has flexibility.

[0066] 4. Air Flow in Air Compressor Next, the air flow in the air compressor 10 will be described with reference to FIGS. 1B, 2, 4, 5, and 7.

[0067] When the drive motor 112 rotates, the first piston rod 122 moves away from the cover member 123, and the second piston rod 132 moves away from the cover member 133, the first air chamber AC1 and the second air chamber AC2 tend to become negative pressure, and the air pump 100 takes in air from the outside. Therefore, the air compressor 10 takes in air A through the intake hole 11b, as shown in Figure 1B.

[0068] The air A taken into the air compressor 10 is taken into the air pump 100 through the air intake holes (filters 151b, 152b) of the air pump 100, as shown in FIGS.

[0069] 4, air A taken in through filter 151b of air pump 100 fills communicating conduit 153 and flows into first air supply unit 120 via connecting pipe 151c. Although not shown, air A taken in through filter 152b of air pump 100 fills communicating conduit 153 and flows into second air supply unit 130 via connecting pipe 152c. Since the flow of air A in second air supply unit 130 is similar to the flow of air A in first air supply unit 120, a description thereof will be omitted.

[0070] As shown in FIG. 5, air A flowing into the first air supply unit 120 flows through the inlet flow path 124a of the flow path member 124 and the introduction hole 123a of the cover member 123 into the first air chamber AC1.

[0071] Then, when the drive motor 112 rotates further and the first piston rod 122 approaches the cover member 123, the air in the first air chamber AC1 flows into the flow path forming member 140 via the exhaust hole 123b of the cover member 123, the outlet flow path 124b of the flow path member 124, and the outlet side joint 127.

[0072] The air A that has flowed into the flow path forming member 140 flows out from the horizontal flow path 141a, the upper flow path 141b, and the outlet 143a of the upper joint 143, as shown in FIG.

[0073] As shown in FIG. 2, air A flowing out from the outlet 143a of the air pump 100 passes through the air supply pipe Ta and the check valve 400 and is stored in the air tank 200.

[0074] The air A stored in the air tank 200 is compressed and discharged from the discharge port 14 to an external device.

[0075] <5. Effects> According to air pump 100, which is one embodiment of the present invention, as described above, introduction hole 123a, which is a first intake hole formed in first air supply unit 120, and introduction hole 133a, which is a second intake hole formed in second air supply unit 130, are connected by inlet-side communication conduit 150, which has an air intake hole that takes in air from the outside. Therefore, when introduction hole 123a is opened or closed by inlet-side check valve 123c in accordance with the reciprocating motion of first piston rod 122, or When the inlet side check valve 133c opens and closes the introduction hole 133a due to the reciprocating movement of the second piston rod 132, the harsh high frequency components of the impact noise caused by the inlet side check valves 123c, 133c sitting on the valve seats 123d, 133d are attenuated by the air present in the inlet side communicating conduit 150, so that the high frequency components of the noise caused by the inlet side check valves 123c, 133c sitting on the valve seats 123d, 133d when the air pump 100 is operated can be reduced.

[0076] Furthermore, since the communication line 153 of the inlet side communication line 150 is flexible, when the air pump 100 is placed inside the housing 11, the communication line 153 deforms depending on the degree of interference with the housing 11, making it easier to make the housing 11 smaller.

[0077] 6. Supplementary Items The above description allows the reader to grasp the following technology. [Supplementary Item 1] An air compressor comprising: an air pump that takes in air from the outside; and an air tank that communicates with an outlet of the air pump to store the air supplied from the air pump and that communicates with an external device to supply compressed air to the external device, wherein the air pump has an air supply section that has a piston rod that reciprocates within a cylinder to change the volume of an air chamber formed between the air pump and the cylinder, and an inlet-side check valve that opens an intake port through which air is introduced into the air chamber during intake and closes it during exhaust; the air compressor also comprises: a controller that controls a drive motor that reciprocates the piston rod of the air pump; and a housing that has an external communication port that is connected to a signal line extending from the controller, wherein the external communication port on the housing is connectable to a signal line extending from an external control device that is provided outside the housing and that controls the controller. With this air compressor configuration, an external control device that is provided outside the housing and controls the controller can be connected to the housing, allowing the external control device provided outside the housing to control the controller and drive the air pump.

[0078] [Appendix 2] An air compressor comprising an air pump that takes in air from the outside, and an air tank that communicates with the outlet of the air pump to store the air supplied from the air pump and that communicates with an external device to supply compressed air to the external device, wherein the air pump operates at a volume of 45 dB to 55 dB in the vicinity of a worker using an appliance powered by the air supplied by the air pump, and further comprising a controller that controls the drive motor of the air pump, and a housing that has an external communication port that is connected to a signal line extending from the controller, the external communication port on the housing being freely connectable to a signal line extending from an external control device that is provided outside the housing and controls the controller. With this configuration of the air compressor, an external control device that is provided outside the housing and controls the controller can be connected to the housing, and the air compressor can be driven by controlling the controller from the external control device provided outside the housing. Furthermore, by operating the air pump at a volume of 45 dB or more and 55 dB or less, the noise level of the air pump's operation is at a level that would be heard on an everyday basis, so the health of the worker can be maintained even if the air pump is placed near a worker who uses equipment that operates using the air supplied by the air pump.

[0079] [Supplementary Item 3] The air compressor according to Supplementary Items 1 and 2, further comprising a pressure gauge that measures the internal pressure of the air tank, the controller connected to the pressure gauge outputs the internal pressure value of the air tank to the external control device, and the air compressor is controlled by the external control device in accordance with the internal pressure of the air tank. With this air compressor configuration, the external control device can drive the drive motor of the air pump in accordance with the usage environment of the air compressor, thereby minimizing the amount of time the air compressor generates noise.

[0080] [Appendix 4] A device comprising an air pump that takes in air from the outside, a controller that controls a drive motor that reciprocates a piston rod of the air pump, and a housing having an external communication port that is connected to a signal line extending from the controller, wherein the external communication port provided on the housing is freely connectable to a signal line extending from an external control device provided outside the housing that controls the controller. Such a device is sometimes called an air compressor or a vacuum pump. With this device configuration, an external control device provided outside the housing that controls the controller can be connected to the housing, so that the external control device provided outside the housing can control the controller and drive the air pump.

[0081] <Modifications> The air pump 100 according to one embodiment of the present invention and the air compressor 10 equipped with the same have been described above, but the air pump and air compressor of the present invention are not limited to the air pump 100 and air compressor 10 of the above-described embodiment.

[0082] For example, in this embodiment, the inlet-side connecting pipe 150 has two air intake holes, but the number of air intake holes in the inlet-side connecting pipe may be at least 1. Also, in this embodiment, the inlet-side connecting pipe 150 is composed of the first air intake member 151, the second air intake member 152, and the connecting pipe 153, but any pipe may be used as long as it can connect the inlet side of the first air supply unit 120 and the inlet side of the second air supply unit 130 and has an air intake hole.

[0083] DESCRIPTION OF SYMBOLS 10: Air compressor (device) 11: Housing 11a: Heat exhaust port 11b: Intake port 12: Power switch 13: External communication port 13a: First external communication port 13b: Second external communication port 14: Discharge port 100: Air pump 110: Drive unit 111: Housing 112: Drive motor 112a: Motor shaft 113: Base 113a: Cylindrical portion 113b: Disc portion 113c: Upper key 113d: Lower key 114: Upper crank 114a: Crank base 114b: Crank body 114c: Radial bearing 115: Lower crank 115a: Crank base DESCRIPTION OF SYMBOLS 115b Crank body 115c Radial bearing 120 First air supply section 121 First cylinder 122 First piston rod 122a Piston body 122b Seal member 122c Connecting bolt 123 Cover member 123a Inlet hole (first intake hole) 123b Exhaust hole 123c Inlet check valve 123d Valve seat 123e Outlet check valve 123f Stopper 124 Flow path member 124a Inlet flow path 124b Outlet flow path 125 Heat sink 126 Inlet joint 127 Outlet joint 130 Second air supply section 131 21st cylinder 132: Second piston rod 132a: Piston body 132b: Seal member 132c: Connecting bolt 133: Cover member 133a: Inlet hole (second intake hole) 133b: Exhaust hole 133c: Inlet check valve 133d: Valve seat 133e: Outlet check valve 133f: Stopper 134: Flow path member 134a: Inlet flow path 134b: Outlet flow path 135: Heat sinkDESCRIPTION OF SYMBOLS 136 Inlet side joint 137 Outlet side joint 140 Flow path forming member 141 Plate material 141a Horizontal flow path 141b Upper flow path 142 Connecting member 143 Upper joint 143a Outlet 144 Flow path sealing plug 150 Inlet side communicating conduit 151 First intake member 151a Three-way joint 151b Filter 151c Connecting pipe 152 Second intake member 152a Three-way joint 152b Filter 152c Connecting pipe 153 Communicating conduit (communicating pipe) 200 Air tank 300 Pressure gauge 310 Display operation unit 400 Check valve 500: Relief valve 600: Controller 610: Signal line EC: External control device EC1: Signal line AC1: First air chamber AC2: Second air chamber Ta: Air supply line A: Air

Claims

1. An air pump comprising: a first piston rod that reciprocates within a first cylinder to change the volume of a first air chamber formed between the first cylinder and the first piston rod; a first air supply unit having a metal inlet check valve that opens a first intake port that introduces air into the first air chamber during intake and closes it during exhaust; a second piston rod that reciprocates within a second cylinder to change the volume of a second air chamber formed between the second piston rod and the second cylinder; and a second air supply unit having a metal inlet check valve that opens a second intake port that introduces air into the second air chamber during intake and closes it during exhaust; wherein the first intake port formed in the first air supply unit and the second intake port formed in the second air supply unit are connected by an inlet connecting conduit that has an air intake port that takes in air from the outside.

2. The air pump according to claim 1, characterized in that it is driven at a volume of 45 dB or more and 55 dB or less.

3. An air pump according to claim 1 or 2, characterized in that the inlet-side communication pipe is flexible.

4. An air compressor that supplies compressed air to an external device, comprising: an air pump as defined in claim 1 or claim 2; an air tank that communicates with the outlet of the air pump to store the air supplied from the air pump and that communicates with the external device to supply the compressed air to the external device; a controller that controls a drive motor that reciprocates a first piston rod and a second piston rod of the air pump; and an external communication port that is connected to a signal line extending from the controller and is freely connectable to a signal line extending from an external control device that controls the controller.

5. The air compressor according to claim 4, further comprising a pressure gauge for measuring the internal pressure of the air tank, and the controller connected to the pressure gauge outputs the internal pressure value of the air tank to the external control device.

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