Air Compressor

Abstract

To provide an air compressor which can inhibit transmission of vibration generated by a compressor to a tank.SOLUTION: An air compressor 1 includes: an electric motor 12 serving as a driving source; and a compressor 20 which reciprocates pistons 23, 27 in cylinders 22, 26 by the electric motor 12 to compress air. The air compressor 1 is provided with: a tank 3 for storing compressed air discharged from the compressor 20; and a flexible hose 30 which connects an outlet 28 of the compressor 20 with an inlet 31 of the tank 3. The outlet 28 of the compressor 20 and the inlet 31 of the tank 3 are disposed on a plane P1 which is orthogonal to a reciprocating direction of the pistons 23, 27.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an air compressor that compresses introduced air to generate compressed air. [Background technology]

[0002] An air compressor generates compressed air using, for example, a compressor equipped with a piston mechanism. Compressed air is generated by introducing outside air into a cylinder and compressing it with a piston. The generated compressed air is sent to a tank and stored. The compressed air stored in the tank is supplied to a tool, for example, an air-driven nailer or air tacker, to drive the tool.

[0003] When compressed air is generated, the piston reciprocates and slides against the cylinder. Therefore, in the compressor, vibrations occur in the reciprocating direction (sliding direction) of the piston when compressed air is generated. In order to prevent the vibrations of the compressor from being transmitted to the tank in which the high-pressure compressed air is stored, a configuration in which a vibration absorbing member is provided at the connection part between the compressor and the tank, for example, is generally used. As the vibration absorbing member, for example, a highly elastic material or a highly flexible material is used.

[0004] The compressor and the tank are connected by a hose that sends compressed air generated by the compressor to the tank. The tank is supported by a plurality of legs so that movement relative to the installation surface is suppressed. The invention described in Patent Document 1 describes a configuration in which a pipe that connects the compressor and the tank extends along the longitudinal direction of the cylinder of the compressor. Conventionally, this pipe is made of metal, such as copper. Also, a configuration in which the compressor and the tank are connected by a highly flexible hose instead of this pipe has been conventionally known. The flexibility of the flexible hose can be used to absorb vibrations of the compressor and suppress the transmission of vibrations to the tank installed on the installation surface.

[0005] In order to increase the absorption rate of compressor vibrations in a flexible hose, for example, the flexible hose is arranged so that the amount of bending of the flexible hose due to vibrations is large. In the invention described in Patent Document 1, the pipe is arranged along the reciprocating direction of the piston, i.e., the vibration direction of the compressor. Therefore, if the pipe is replaced with a flexible hose, it is considered that the amount of bending of the flexible hose in the vibration direction will be small. Therefore, it is difficult to increase the amount of bending. Also, in order to reduce the manufacturing cost of the air compressor, for example, an expensive flexible hose is provided in a short length. However, a flexible hose that is too short loses flexibility. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-190334 A Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, there is room for improvement in air compressors that use flexible hoses to suppress the transmission of vibrations. Therefore, there is a demand for an air compressor that can suppress the transmission of vibrations generated by the compressor to the tank. [Means for solving the problem]

[0008] According to one aspect of the present disclosure, an air compressor includes a drive source and a compressor that compresses air by reciprocating a piston in a cylinder using the drive source. The air compressor includes a tank that stores compressed air discharged from the compressor and a flexible hose that connects an outlet of the compressor to an inlet of the tank. The outlet of the compressor and the inlet of the tank are both disposed on a plane perpendicular to the reciprocating direction of the piston.

[0009] Therefore, the flexible hose connected to the outlet of the compressor and the inlet of the tank can be arranged approximately perpendicular to the reciprocating direction of the piston. Therefore, the flexible hose bends significantly in the reciprocating direction of the piston. This allows the amount of bending of the flexible hose in response to the vibration of the compressor to be increased. This increases the vibration absorption rate of the flexible hose. Thus, the vibration generated by the compressor can be efficiently absorbed by the flexible hose, and the transmission of the vibration to the tank can be suppressed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a front perspective view of the air compressor according to the embodiment. [Diagram 2] FIG. 2 is a rear perspective view of the air compressor with the mechanism cover removed. [Diagram 3] FIG. 2 is a cross-sectional view of the air compressor seen from above. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 3. [Diagram 5] 4 is a cross-sectional view taken along line VV in FIG. 3. [Figure 6] FIG. 2 is a rear view of the air compressor with the mechanism cover removed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] According to another feature of the present disclosure, the flexible hose is disposed only on a flat surface. Therefore, compared with a flexible hose of the same length, the amount of bending of the flexible hose can be maximized with respect to vibrations whose vibration direction is the reciprocating direction of the piston. Therefore, the vibration absorption rate of the flexible hose can be further increased.

[0012] According to another feature of the present disclosure, the compressor has both ends in the reciprocating direction of the piston. The outlet of the compressor and the inlet of the tank are located between both ends of the compressor in the reciprocating direction. Therefore, it is possible to prevent the flexible hose from protruding outward in the front-rear direction from both ends of the compressor in the reciprocating direction of the piston. Therefore, it is possible to form a compact air compressor.

[0013] According to another feature of the present disclosure, the entire flexible hose is located between both ends of the compressor in the reciprocating direction, so that the flexible hose can be arranged compactly relative to the compressor, and a space can be secured for the flexible hose to bend in the reciprocating direction of the piston so that the flexible hose does not interfere with the mechanism cover that covers the compressor.

[0014] According to another feature of the present disclosure, the compressor is a two-stage compression mechanism including a first compressor that introduces air and compresses it to a first pressure, and a second compressor that compresses the air supplied from the first compressor to a second pressure higher than the first pressure. Therefore, the vibrations in the reciprocating direction of the pistons generated in the first compressor and the second compressor can be absorbed by using flexible hoses. In addition, the tank stores compressed air at a higher pressure than that of an air compressor equipped with a one-stage compression mechanism, for example. Therefore, the transmission of vibrations to the tank storing the high-pressure compressed air can be suppressed with a configuration with a small number of parts.

[0015] According to another feature of the present disclosure, a piston is located between the compressor outlet and the tank inlet, so that a flexible hose connected to the compressor outlet and the tank inlet can be provided at a length that maintains sufficient flexibility to absorb vibrations.

[0016] According to another feature of the present disclosure, an air compressor has an outlet connection part for connecting a flexible hose to an outlet of the compressor, and an inlet connection part for connecting a flexible hose to an inlet of a tank. A first axial direction in which the outlet connection part extends and a second axial direction in which the inlet connection part extends intersect with each other. Therefore, the flexible hose has a naturally bent region between one end connected to the outlet connection part and the other end connected to the inlet connection part. Therefore, it is easier to bend the flexible hose than when the flexible hose is arranged in a straight line, for example. This allows the flexible hose to efficiently absorb vibrations of the compressor.

[0017] According to another feature of the present disclosure, the air compressor has a second tank connected to the tank. This allows a larger amount of compressed air to be stored. This allows the compressor to run for a longer period of time until the tank and the second tank are filled. A flexible hose can be used to absorb vibrations from the compressor running for a long period of time.

[0018] Next, an embodiment according to the present disclosure will be described with reference to Figs. 1 to 6. As shown in Fig. 1, the air compressor 1 has two tanks 3 that are substantially cylindrical and extend in the front-rear direction. The two tanks 3 are arranged side by side on the left and right, and are connected at two points, front and rear, by a base 2. A compressor body 10 is provided above the two tanks 3. The compressor body 10 is covered with a substantially box-shaped mechanism cover 4 that is open at the bottom. Support legs 5 are provided at the bottom of both front and rear ends of the two tanks 3. A total of four support legs 5 support the two tanks 3 and the compressor body 10, so that the air compressor 1 can be installed on an installation surface F (see Fig. 4) such as the ground or a floor. In the following description, the up-down direction refers to the installation surface F side being the bottom, the front-rear direction refers to the side where a drain cock 41, which will be described later, is provided being the front, and the left-right direction is defined based on the air compressor 1 viewed from the front.

[0019] As shown in FIG. 1, a plurality of ventilation holes 4a arranged in a mesh pattern are formed on the front, rear, left and right sides of the mechanism cover 4. Outside air can be supplied to the compressor body 10 through the ventilation holes 4a. An operation panel 4b for operating the air compressor 1 is provided on the top of the mechanism cover 4. The operation panel 4b is electrically connected to the electrical components of the compressor body 10. For example, the air compressor 1 can be started or stopped by pressing a button provided on the operation panel 4b. Loop-shaped handle sections 8 that stand upward are provided on the front and rear of the mechanism cover 4. The two handle sections 8 are connected to the mechanism cover 4 and the base 2, respectively. The air compressor 1 can be carried by holding the two handle sections 8.

[0020] As shown in Fig. 1, tank guards 5a are provided at both front and rear ends of the two tanks 3 and above the support legs 5. The tank guards 5a stand upright and have an outer periphery that is curved in an arc shape in a plan view. The tank guards 5a protect the corners at the front and rear ends of the tanks 3 and the support legs 5 by covering them from the outside.

[0021] As shown in FIGS. 2 and 3, the compressor body 10 has a compressor 20 that generates compressed air and an electric motor 12 as a drive source for the compressor 20. The compressor 20 is accommodated in a mechanism case 11. The electric motor 12 is a so-called outer rotor type brushless motor. The electric motor 12 has an output shaft 12a that extends substantially horizontally in the left-right direction. The output shaft 12a penetrates the mechanism case 11 and is rotatably supported by bearings 13 and 14 in the mechanism case 11. A cylindrical rotor 12c that is integrally connected to the output shaft 12a is provided on the right side of the mechanism case 11. A plurality of stators 12b around which coils are wound are arranged on the radial inner periphery side of the rotor 12c. The plurality of stators 12b are arranged at substantially equal intervals in the circumferential direction of the output shaft 12a. When power is supplied to the electric motor 12, the output shaft 12a and the rotor 12c rotate around the axis of the output shaft 12a.

[0022] As shown in Figs. 2 and 3, a fan 15 is attached to the right end of the output shaft 12a. The fan 15 rotates together with the output shaft 12a, generating motor cooling airflow from the electric motor 12 on the left side toward the radially outward direction of the fan 15. A fan 16 is attached to the left end of the output shaft 12a. A plurality of holes are formed to the right of the fan 16 and on the left side of the mechanism case 11, and the holes are covered by a filter 11a. The fan 16 rotates together with the output shaft 12a, causing airflow from the left of the fan 16 to the filter 11a on the right side. Air is introduced into the mechanism case 11 through the filter 11a.

[0023] 3, the compressor 20 is a two-stage compression mechanism including a first compressor 21 and a second compressor 25. The first compressor 21 has a first cylinder 22 located forward of the output shaft 12a and extending forward and backward, and a first piston 23 that reciprocates within the first cylinder 22. The second compressor 25 has a second cylinder 26 located rearward of the output shaft 12a and extending forward and backward, and a second piston 27 that reciprocates within the second cylinder 26.

[0024] As shown in FIG. 3, a first crank disk 17a and a second crank disk 18a are connected to the output shaft 12a with their centers shifted from the center of the output shaft 12a. A first crank rod 17 extends linearly from the first crank disk 17a radially outward. A first piston 23 is connected to the tip of the first crank rod 17. The rotational motion of the first crank disk 17a around the axis of the output shaft 12a is converted into a reciprocating motion of the first piston 23 by the first crank rod 17. The first piston 23 reciprocates in the front-rear direction in which the first cylinder 22 extends. A second crank rod 18 extends linearly from the second crank disk 18a radially outward. A second piston 27 is connected to the tip of the second crank rod 18. The rotational motion of the second crank disk 18a around the axis of the output shaft 12a is converted into a reciprocating motion of the second piston 27 by the second crank rod 18. The second piston 27 reciprocates in the front-rear direction in which the second cylinder 26 extends.

[0025] As shown in FIG. 3, the first cylinder 22 and the first piston 23 cooperate to form a first piston chamber 22a. The first piston chamber 22a has a communication passage through which air can pass between the first piston chamber 22a and the center of the mechanism case 11 where the filter 11a is provided. Therefore, air at atmospheric pressure is supplied to the first piston chamber 22a through the filter 11a. A first intermediate chamber 22b formed airtight is provided in front of the first piston chamber 22a. A first check valve 22c is provided between the first piston chamber 22a and the first intermediate chamber 22b to prevent backflow of air from the first intermediate chamber 22b to the first piston chamber 22a. The first compressor 21 pressurizes the air introduced at atmospheric pressure to a first pressure of, for example, 0.7 to 1 MPa.

[0026] As shown in FIG. 3, the second cylinder 26 and the second piston 27 cooperate to form the second piston chamber 26a. The second piston chamber 26a is airtight with respect to the center of the mechanism case 11 where the filter 11a is provided, and is connected to the first intermediate chamber 22b via the vent pipe 24. Therefore, the compressed air generated by the first compressor 21 is supplied to the second piston chamber 26a. The second intermediate chamber 26b formed airtight is provided behind the second piston chamber 26a. A second check valve 26c is provided between the second piston chamber 26a and the second intermediate chamber 26b to prevent the backflow of air from the second intermediate chamber 26b to the second piston chamber 26a. In the second compressor 25, the air compressed by the first compressor 21 is increased to a second pressure of, for example, 3 to 4.5 MPa higher than the first pressure.

[0027] As shown in Figures 2 and 3, the air compressor 1 is provided with a first tank 3a and a second tank 3b. The second intermediate chamber 26b is connected to an outlet 28 that discharges compressed air. The first tank 3a is connected to an inlet 31 that takes in compressed air. By connecting the outlet 28 and the inlet 31 with a flexible hose 30, compressed air can be sent from the second compressor 25 to the first tank 3a. The flexible hose 30 will be described in detail later. The first tank 3a and the second tank 3b are connected by a tank connecting pipe 3c. The pressure of the compressed air sent from the first tank 3a to the second tank 3b is detected by a pressure sensor attached to the tank connecting pipe 3c.

[0028] As shown in FIGS. 1 and 2, a plurality of joints 33 for supplying compressed air to a tool are provided at the front of the compressor body 10. The joints 33 communicate with the tank 3 so that the compressed air stored in the tank 3 can be discharged. The joints 33 protrude outward from the mechanism cover 4 so that an air hose can be connected. A pressure reducing valve adjustment knob 34 connected to the joints 33 is provided at the front upper portion of the compressor body 10. The pressure reducing valve adjustment knob 34 protrudes from the upper surface of the mechanism cover 4 so that it can be operated from outside the mechanism cover 4. By rotating the pressure reducing valve adjustment knob 34, the compressed air discharged from the joints 33 can be adjusted to the operating pressure of the tool. The pressure of the compressed air adjusted by the pressure reducing valve adjustment knob 34 is detected by a pressure sensor 34a.

[0029] As shown in Figs. 2 and 4, a main body support member 7 is provided on the upper surfaces of the two tanks 3 to connect the two tanks 3 in the left-right direction. Two main body support members 7 are provided, one in the front and one in the back. Rubber vibration absorbing members 10b are attached to the upper surfaces of the main body support members 7. A total of four vibration absorbing members 10b are provided on each of the left and right sides of the two main body support members 7. Four main body legs 10a formed integrally with the mechanism case 11 are respectively connected to the upper surfaces of the four vibration absorbing members 10b. This supports the compressor main body 10 above the two tanks. Therefore, vibrations of the compressor main body 10 generated by the operation of the compressor 20 are absorbed by the vibration absorbing members 10b, and transmission to the tanks 3 is suppressed.

[0030] As shown in Fig. 4, below the compressor body 10, a controller 32 housed in a shallow rectangular box-shaped case is provided. The controller 32 is supported by the lower parts of the front and rear body support members 7 in an attitude in which the longitudinal direction is the front-rear direction and the thickness direction is the left-right direction. The controller 32 controls the power supply, the drive of the electric motor 12, etc., based on a control signal received from the operation panel 4b, a detection signal from a pressure sensor 3d (see Fig. 3), etc. An underguard 6 that covers the lower part of the controller 32 is provided below the controller 32 and between the two tanks 3 in the left-right direction.

[0031] As shown in Fig. 4, a cylindrical cover 43 is formed integrally with the front part of the rectangular, flat underguard 6. The cylindrical cover 43 is a bottomed cylinder that extends upward from the underguard 6, has a bottom that is the ceiling surface and is open at the bottom. The underguard 6 is screwed to the base 2 at the front and rear parts so as to straddle the two tanks 3 in the left-right direction.

[0032] As shown in FIGS. 2 and 4, the air compressor 1 has a drain discharge section 40 for discharging the compressed air and drain water remaining inside the two tanks 3. The drain discharge section 40 has a drain discharge pipe 42 that extends from the tank 3 and discharges the compressed air and drain water to the outside, and a drain cock 41 that is provided in the middle of the drain discharge pipe 42 and opens and closes the drain discharge pipe 42. The drain cock 41 is provided on the front surface of the front base 2. When the drain cock 41 is closed, the compressed air and drain water in the tank 3 are not discharged from the drain discharge pipe 42. When the drain cock 41 is opened, the compressed air and drain water in the tank 3 are discharged from the outlet of the drain discharge pipe 42 according to the opening amount. The drain discharge pipe 42 that extends to the lower end of the base 2 passes under the front base 2 and the underguard 6, extends rearward, and extends approximately vertically upward from a position below the cylindrical cover 43. The drain outlet at the tip of the drain pipe 42 opens upward.

[0033] As shown in Fig. 4, the drain discharge section 40 has a sound-absorbing chamber 44 into which the tip of the drain discharge pipe 42 is inserted. A cylindrical cover 43 and a lower cover 45 connected to the lower part of the cylindrical cover 43 cooperate to form the cylindrical sound-absorbing chamber 44. A sound-absorbing member 47 made of metal wool in the form of fine fibrous members intertwined with each other is housed in the sound-absorbing chamber 44. The sound-absorbing member 47 covers at least the periphery of the discharge port of the drain discharge pipe 42.

[0034] The flexible hose 30 shown in Fig. 2 has a skin formed by weaving metal fibers and an inner tube made of a highly flexible resin material such as PTFE. Therefore, the flexible hose 30 has high flexibility and high strength against shear and bending. An outlet end 30a of the flexible hose 30 is connected to an outlet connection part 28a provided at the outlet 28 of the second compressor 25. An inlet end 30b of the flexible hose 30 opposite the outlet end 30a is connected to an inlet connection part 31a provided at the inlet 31 of the tank 3. The outlet connection part 28a and the inlet connection part 31a are each cylindrical and extend linearly in the longitudinal direction.

[0035] As shown in Figures 2 and 3, the outlet 28 is disposed to the right of the second cylinder 26 on the right side of the second compressor 25. The inlet 31 is disposed to the left of the second compressor 25. Therefore, the second piston 27 of the second compressor 25 is disposed between the outlet 28 and the inlet 31 in the left-right direction. The outlet connecting portion 28a and the inlet connecting portion 31a are disposed so as to extend on a plane P1 passing through the center of the outlet 28 and the center of the inlet 31. This plane P1 is perpendicular to the front-rear direction which is the reciprocating direction of the first piston 23 and the second piston 27. The outlet end 30a, the inlet end 30b and the intermediate portion 30c therebetween of the flexible hose 30 are all disposed on the plane P1.

[0036] 3 to 5, the outlet 28, the outlet connecting portion 28a, the entire flexible hose 30, the inlet 31, and the inlet connecting portion 31a are all disposed forward of a plane P2 that passes through the rear end portion 26d of the second cylinder 26 and is parallel to the plane P1. The flexible hose 30 passes below the second cylinder 26 to connect the outlet 28 and the inlet 31. In addition, the outlet 28, the outlet connecting portion 28a, the entire flexible hose 30, the inlet 31, and the inlet connecting portion 31a are all disposed rearward of a plane P3 that passes through the front end portion 22d of the first cylinder 22 and is parallel to the plane P1.

[0037] As shown in FIG. 6, the outlet connecting portion 28a extends in the direction of a first axis J1 that is inclined with respect to the horizontal direction when viewed from the rear. The first axis J1 is inclined downward from the right to the left. The inclination angle of the first axis J1 is, for example, within a range of 30° to 60° with respect to the horizontal direction. The inlet connecting portion 31a is provided along a second axis J2 that extends in a substantially horizontal direction when viewed from the rear. Therefore, the first axis J1 and the second axis J2 intersect at an obtuse angle of, for example, 120° to 150°. As a result, the middle portion 30c of the flexible hose 30 has a bending region that is bent up and down on the plane P1 (see FIG. 3).

[0038] As described above, the air compressor 1 has an electric motor 12 as a drive source, and a compressor 20 that compresses air by causing pistons 23, 27 to reciprocate in cylinders 22, 26 by the electric motor 12, as shown in Fig. 3. The air compressor 1 is provided with a tank 3 that stores compressed air discharged from the compressor 20, and a flexible hose 30 that connects an outlet 28 of the compressor 20 to an inlet 31 of the tank 3. The outlet 28 of the compressor 20 and the inlet 31 of the tank 3 are both disposed on a plane P1 that is perpendicular to the reciprocating direction of the pistons 23, 27.

[0039] Therefore, the flexible hose 30 connected to the outlet 28 of the compressor 20 and the inlet 31 of the tank 3 can be disposed approximately perpendicular to the reciprocating direction of the pistons 23, 27. The flexible hose 30 is most flexible in the direction perpendicular to the extending direction of the flexible hose 30. On the other hand, the vibration of the compressor 20 has the largest amplitude in the reciprocating direction of the pistons 23, 27. Therefore, the flexibility of the flexible hose 30 can be utilized to absorb the vibration of the compressor 20 with a high absorption rate. This can suppress the vibration generated in the compressor 20 from being transmitted to the tank 3 via the flexible hose 30.

[0040] 3 to 5, the flexible hose 30 is disposed only on the plane P1. Therefore, when comparing flexible hoses 30 of the same length, the amount of bending of the flexible hose 30 can be maximized with respect to the vibration in the reciprocating direction of the pistons 23, 27. Therefore, the vibration absorption rate of the flexible hose 30 can be further increased.

[0041] As shown in Fig. 3, the compressor 20 has a front end 22d and a rear end 26d in the reciprocating direction of the pistons 23, 27. An outlet 28 of the compressor 20 and an inlet 31 of the tank 3 are located between the front end 22d and the rear end 26d in the reciprocating direction. This makes it possible to prevent the flexible hose 30 from protruding outward in the front-to-rear direction from the front end 22d or the rear end 26d of the compressor 20 in the vibration direction of the compressor 20. This makes it possible to make the air compressor 1 compact in the vibration direction of the compressor 20.

[0042] 3, the entire flexible hose 30 is located between the front end 22d and the rear end 26d of the compressor 20 in the reciprocating direction. Therefore, the flexible hose 30 can be arranged compactly with respect to the compressor 20. Also, a space can be secured for the flexible hose 30 to bend in the reciprocating direction of the pistons 23, 27 so that the flexible hose 30 does not interfere with the mechanism cover 4 that covers the compressor 20, etc.

[0043] As shown in FIG. 3, the compressor 20 is a two-stage compression mechanism including a first compressor 21 that introduces air and compresses it to a first pressure, and a second compressor 25 that compresses the air supplied from the first compressor 21 to a second pressure higher than the first pressure. Therefore, the vibration in the reciprocating direction of the pistons 23, 27 generated in both the first compressor 21 and the second compressor 25 can be absorbed by using a flexible hose 30. In addition, the tank 3 stores compressed air at a higher pressure than that of the air compressor 1 having a one-stage compression mechanism, for example. Therefore, a large amount of energy can be stored in the tank 3 by storing the high-pressure compressed air. The flexible hose 30 can be used to suppress the vibration of the compressor 20 from being transmitted to the tank 3 that stores a large amount of energy.

[0044] 3 and 6, the pistons 23, 27 are located between the outlet 28 of the compressor 20 and the inlet 31 of the tank 3. Therefore, the flexible hose 30 connected to the outlet 28 of the compressor 20 and the inlet 31 of the tank 3 can be arranged with a length that has sufficient flexibility to absorb vibrations.

[0045] As shown in FIG. 6, the air compressor 1 has an outlet connection part 28a for connecting the flexible hose 30 to the outlet 28 of the compressor 20, and an inlet connection part 31a for connecting the flexible hose 30 to the inlet 31 of the tank 3. The direction of the first axis J1 from which the outlet connection part extends and the direction of the second axis J2 from which the inlet connection part 31a extends intersect with each other. Therefore, the flexible hose 30 has a naturally bent region in the intermediate part 30c between the outlet end 30a connected to the outlet connection part 28a and the inlet end 30b connected to the inlet connection part 31a. Therefore, the flexible hose 30 is easier to bend than when the flexible hose 30 is arranged in a straight line. This allows the flexible hose 30 to efficiently absorb vibrations of the compressor 20.

[0046] As shown in Figures 2 and 3, the air compressor 1 has a second tank 3b connected to the first tank 3a. This allows a large amount of compressed air to be stored. This increases the operating time of the compressor 20 until the first tank 3a and the second tank 3b are filled. The flexible hose 30 can be used to absorb vibrations of the compressor 20 that operates for a long time.

[0047] Various modifications can be made to the air compressor 1 of the present embodiment described above. The configuration in which the flexible hose 30 is disposed only on the plane P1 has been exemplified. Instead of this, for example, the outlet connecting portion 28a or the inlet connecting portion 31a may be inclined so as to intersect with the plane P1 in the front-rear direction. This allows a part of the flexible hose 30 to be disposed at a position shifted in the front-rear direction from the plane P1.

[0048] The extending directions of the first axis J1 and the second axis J2 are not limited to those illustrated, and for example, the second axis J2 may be inclined with respect to the horizontal direction when viewed from the rear. The flexible hose 30 is illustrated as passing below the second cylinder 26. Alternatively, the flexible hose 30 may be arranged so as to straddle above the second cylinder 26.

[0049] The air compressor 1 has been exemplified in which two tanks 3 are arranged side by side in the horizontal direction. Alternatively, one tank 3 or three or more tanks 3 may be provided. The multiple tanks 3 may be arranged vertically in a vertical line or may be arranged in a mountain-shaped stack. Although the compressor 20 has been exemplified in which a two-stage compression mechanism is used, a one-stage compression mechanism or a three or more stage compression mechanism may also be used. Instead of the electric motor 12, for example, an internal combustion engine may be used as the power source. [Explanation of symbols]

[0050] 1. Air compressor 2. Base 3...tank, 3a...first tank, 3b...second tank, 3c...tank connecting pipe 3d…Pressure sensor 4...Mechanism cover, 4a...Ventilation hole, 4b...Operation panel 5...Support leg, 5a...Tank guard 6…Underguard 7...Main body support member 8…Handle section 10... Compressor body, 10a... Body leg, 10b... Vibration absorbing member 11...Mechanism case, 11a...Filter 12...electric motor, 12a...output shaft, 12b...stator, 12c...rotor 13, 14...Bearings 15,16…Fan 17...first crank rod, 17a...first crank disc 18... second crank rod, 18a... second crank disc 20…Compressor 21…First compressor 22...first cylinder, 22a...first piston chamber, 22b...first intermediate chamber 22c...first check valve, 22d...front end 23…First piston 24…Ventilation pipe 25…Second compressor 26... second cylinder, 26a... second piston chamber, 26b... second intermediate chamber 26c...second check valve, 26d...rear end 27…Second piston 28...Exit, 28a...Outlet connection part 30... flexible hose, 30a... outlet end, 30b... inlet end, 30c... middle section 31...Entrance, 31a...Entrance connection part 32…Controller 33…Joint part 34...Reducing valve adjustment knob, 34a...Pressure sensor 40…Drain discharge section 41…Drain cock 42…Drain discharge pipe 43…Cylindrical cover 44…Sound reduction room 45…Lower cover 47...Sound deadening material F…Installation surface P1,P2,P3…Plane J1…1st axis line, J2…2nd axis line

Claims

1. An air compressor, A driving source; a compressor that compresses air by causing a piston to reciprocate in a cylinder using the drive source; A tank for storing compressed air discharged from the compressor; A flexible hose is provided to connect the outlet of the compressor and the inlet of the tank, The outlet of the compressor and the inlet of the tank are both disposed on a plane perpendicular to the reciprocating direction of the piston, the piston is located between the outlet of the compressor and the inlet of the tank; an outlet connecting portion for connecting the flexible hose to the outlet of the compressor, and an inlet connecting portion for connecting the flexible hose to the inlet of the tank, wherein a first axis in a direction in which the outlet connecting portion extends and a second axis in a direction in which the inlet connecting portion extends intersect at an obtuse angle when viewed from a reciprocating direction of the piston, An air compressor in which an entire circumferential circumference of at least a portion of the flexible hose is located between the piston and the intersection of the first axis and the second axis, when viewed in the reciprocating direction of the piston.

2. 2. The air compressor of claim 1, The flexible hose is disposed only on the flat surface of the air compressor.

3. 3. An air compressor according to claim 1 or 2, The compressor has both ends in a reciprocating direction of the piston, An air compressor, wherein the outlet of the compressor and the inlet of the tank are located between the two ends of the compressor in the reciprocating direction.

4. 4. The air compressor according to claim 3, An air compressor, wherein the entire flexible hose is located between the two ends of the compressor in the reciprocating direction.

5. An air compressor according to any one of claims 1 to 4, The compressor is an air compressor which is a two-stage compression mechanism including a first compressor which introduces air and compresses it to a first pressure, and a second compressor which compresses the air supplied from the first compressor to a second pressure which is higher than the first pressure.

6. An air compressor according to any one of claims 1 to 5, An air compressor having a second tank connected to the tank.

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