Air compressor

Abstract

To provide an air compressor including a filter cleaning mechanism capable of efficiently removing dust accumulated on the outer face of a filter.SOLUTION: An air compressor 1 has a filter 32 covering an intake port 31b. The air compressor 1 has a cover 33 covering a filter 32 from the outside. The air compressor 1 has a cleaning pipe 16 extending from a tank storing compressed air. The air compressor 1 has a cleaning intake port 34c connected to the cleaning pipe 16 for introducing compressed air between the filter 32 and the cover 33. The air compressor 1 has a cleaning discharge port 33b for discharging the compressed air from between the filter 32 and the cover 33.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to an air compressor that supplies compressed air to air tools such as compressed air-driven nailers and air dusters. [Background technology]

[0002] Conventionally available air compressors have, for example, a reciprocating compression mechanism that generates compressed air. The compression mechanism converts the rotational output of a motor into the reciprocating motion of a piston in a cylinder using a crank mechanism. Compressed air is generated by compressing outside air with the piston. The compressed air generated by the compression mechanism is stored in a tank. The compressed air stored in the tank is supplied to pneumatic tools such as compressed air-driven nailers and air dusters.

[0003] When generating compressed air, outside air is introduced into the crankcase that houses the crank mechanism. The intake section that introduces outside air into the crankcase is provided with an intake port that connects the inside and outside of the crankcase and a filter that covers the intake port. The filter prevents dust and other particles contained in the introduced outside air from entering the crankcase through the intake port. The filter also suppresses the operating noise of the crank mechanism from leaking outside the crankcase. For this reason, for example, wool felt or the like having a predetermined thickness is used for the filter.

[0004] When an air compressor is used repeatedly, dust accumulates on the outer surface of the filter. When the accumulated dust clogs the filter, its breathability is impaired. If the air compressor is used with the filter's breathability impaired, for example, outside air and dust may enter the crankcase through the gap between the outer edge of the filter and the crankcase. Filter cleaning mechanisms to prevent filter clogging have been proposed. The filter cleaning mechanism described in Patent Document 1 blows compressed air stored in a tank onto the filter in conjunction with the operation of shutting down the air compressor. The operation of shutting down the air compressor is, for example, by turning off the main power switch. Therefore, the filter cleaning mechanism cannot be activated unless the compressor is connected to a power source, making it impossible to clean the filter, for example, away from the work site. The filter cleaning mechanism can also be activated if the main power switch is accidentally turned on.

[0005] The filter cleaning mechanism described in Patent Document 2 reverse-jet compressed air stored in a tank into the crankcase. This causes a reverse jet of air to flow from the inner surface of the filter to the outer surface through the crankcase's air intake, blowing away dust that has accumulated on the outer surface. However, the filter is made of thick wool felt to prevent sound leakage. Therefore, in order to blow away dust that has accumulated on the outer surface of the filter from the inner surface, it is necessary to increase the air pressure and flow rate of the reverse jet. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7005765 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-127506 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, there is a need for an air compressor equipped with a filter cleaning mechanism that can efficiently remove dust accumulated on the outer surface of the filter. [Means for solving the problem]

[0008] According to one aspect of the present disclosure, an air compressor has a filter covering an air inlet. The air compressor has a cover covering the filter from the outside. The air compressor has a cleaning pipe extending from a tank that stores compressed air. The air compressor has a cleaning inlet connected to the cleaning pipe for introducing compressed air between the filter and the cover. The air compressor has a cleaning outlet for discharging compressed air from between the filter and the cover.

[0009] Therefore, compressed air is introduced from the tank through the cleaning pipe and cleaning air intake into the area between the filter and cover. This allows the compressed air to flow over the outer surface of the filter, blowing away accumulated dust. The blown-away dust can be quickly removed from around the filter through the cleaning outlet. Furthermore, even if the air compressor is not connected to a power source, compressed air can be introduced from the tank to the cleaning air intake by mechanical or manual operation, for example, by connecting a valve or cock to the cleaning pipe. This allows for efficient removal of dust accumulated on the outer surface of the filter. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view of an air compressor according to a first embodiment of the present disclosure, as viewed from the right front. FIG. [Figure 2] This is an oblique view of the air compressor with the main body cover removed, viewed from the left rear. [Figure 3] This is a left side view of the air compressor with the main body cover and cooling fan removed. [Figure 4] FIG. 4 is a cross-sectional view of the air compressor taken along line IV-IV in FIG. 3. [Figure 5] 5 is a cross-sectional view taken along line VV in FIG. 4. [Figure 6]FIG. 2 is an exploded perspective view of the intake section as seen from the left rear. [Figure 7] FIG. 2 is an exploded perspective view of the intake section as seen from the front right. [Figure 8] 8 is a cross-sectional view of the intake section taken along line VIII-VIII in FIG. 3. [Figure 9] 9 is a cross-sectional view taken along line IX-IX in FIG. 8. [Figure 10] 9 is a cross-sectional view taken along the line XX in FIG. 8. [Figure 11] FIG. 10 is a left side view of the air compressor according to the second embodiment with the body cover and cooling fan removed. [Figure 12] FIG. 2 is an exploded perspective view of the intake section as seen from the front right. [Figure 13] 13 is a cross-sectional view of the intake section taken along line XIII-XIII in FIG. 11. [Figure 14] 14 is a cross-sectional view taken along the line XIV-XIV in FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0011] According to another feature of the present disclosure, the cleaning outlet also serves as an inlet for introducing outside air into the filter. Therefore, the inlet through which outside air is introduced when generating compressed air can be used as the cleaning outlet when cleaning the filter. This allows dust to be quickly removed from around the filter without significantly changing the shape of the cover compared to conventional covers.

[0012] According to another feature of the present disclosure, the cover has a connecting pipe portion that connects the cleaning pipe so that the opening is between the filter and the cover. Therefore, by providing the connecting pipe portion, the cleaning pipe can be guided close to the outer surface of the filter, which makes it easier to blow away dust accumulated on the outer surface of the filter.

[0013] According to another feature of the present disclosure, a pressure accumulation passage communicating with the connecting pipe is provided between the filter and the cover. Therefore, the pressure accumulation passage can guide compressed air to a position suitable for blowing away dust accumulated on the outer surface of the filter. This allows dust accumulated on the outer surface of the filter to be blown away more efficiently.

[0014] According to another feature of the present disclosure, the pressure accumulation passage is provided with a plurality of cleaning intake ports along the flow path, so that compressed air can be introduced to the outer surface of the filter from the plurality of cleaning intake ports provided at different positions, thereby evenly blowing away dust accumulated on the outer surface of the filter.

[0015] According to another feature of the present disclosure, the filter and cover are arranged upright. A cleaning intake port is provided at the top of the cover. A cleaning outlet port is provided below the cleaning intake port. Therefore, dust accumulated on the outer surface of the filter is blown away by compressed air blown out from the cleaning intake port and falls downward. Furthermore, the dust can be quickly removed from the cleaning outlet port provided below.

[0016] According to another feature of the present disclosure, the pressure accumulation passage is provided in a central region of the inner surface of the cover. A cleaning intake port opens from the pressure accumulation passage toward the outer periphery of the cover. A cleaning discharge port is provided on the outer periphery of the cover. Therefore, dust accumulated on the outer surface of the filter can be blown from the cleaning intake port located radially inward of the cover to the cleaning discharge port located radially outward. Therefore, uneven removal of dust accumulated on the outer surface of the filter in the circumferential direction can be suppressed.

[0017] According to another feature of the present disclosure, the cleaning intake ports are arranged at equal intervals around the circumference of the cover, allowing compressed air blown out from the cleaning intake ports to flow radially and around the entire circumference of the filter at equal intervals around the circumference, thereby more reliably removing dust accumulated on the filter's outer surface.

[0018] According to another feature of the present disclosure, the cleaning outlet is located on an extension of the opening of the cleaning inlet, so that dust blown by the compressed air can be removed from the cleaning outlet along an extension of the opening of the cleaning inlet, thereby enabling dust to be removed quickly over a short path.

[0019] According to another feature of the present disclosure, the cleaning intake and exhaust ports are opened along the outer surface of the filter. This allows the compressed air to flow approximately parallel to the outer surface of the filter. This allows the compressed air to flow evenly over the outer surface of the filter. This more reliably blows away dust accumulated on the outer surface of the filter. Furthermore, compared to, for example, blowing compressed air from the outer surface of the filter toward the inner surface, this prevents dust from entering the interior of the filter from the outer surface.

[0020] Next, a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 10. As shown in FIGS. 1 and 2, an air compressor 1 has two cylindrical tanks 2 that are long from front to back. The two tanks store the generated compressed air. A total of four legs 2a are provided at the front and back of the two tanks 2. Each leg 2a is made of a rubber material with high vibration damping properties. Side protectors 2b are provided on the top of each leg 2a. The tops of the two tanks 2 are connected to each other by a base 3. A main body 10 that generates compressed air is mounted on the top surface of the base 3. The main body 10 is covered by a main body cover 4 that is attached above the two tanks 2. Carrying handles 3a are provided at the front and rear of the base 3, spanning the tops of the two tanks 2.

[0021] As shown in FIG. 1, the front of the main body cover 4 is provided with two low-pressure outlets 5 and two high-pressure outlets 6. Compressed air of, for example, 0.85 MPa is supplied from the low-pressure outlet 5. Compressed air of, for example, 2.5 MPa is supplied from the high-pressure outlet 6. Adjustment dials 5a and 6a for setting the discharge pressure are provided above the outlets 5 and 6, respectively. An operation panel 4b equipped with various display units and operation units mainly for startup operations, such as a power switch, is provided on the front upper surface of the main body cover 4. A plurality of air vents 4a are provided in a mesh pattern on the front, rear, left, and right sides of the main body cover 4. The air vents 4a on the rear and left surfaces of the main body cover 4 are not visible in FIG. 1.

[0022] As shown in Figure 1, a drain discharge device 7 is provided between the front parts of the two tanks 2 to discharge drain water accumulated in the tanks 2. The drain discharge device 7 has a drain cock 7a and a drain discharge pipe 7b. The drain cock 7a is closed when the air compressor 1 is in use. When the drain cock 7a is opened after using the air compressor 1, the drain water in the tanks 2 is discharged from the tip of the drain discharge pipe 7b.

[0023] As shown in Figures 2 to 4, the main body 10 has a cylindrical crankcase 20 in the center in the front-to-rear direction. The main body 10 has a first compression section 11 extending forward from the crankcase 20. The main body 10 has a second compression section 12 extending rearward from the crankcase 20. The crankcase 20 is fixed onto the base 3. A motor 21 is provided on the right side of the crankcase 20, between the first compression section 11 and the second compression section 12 in the front-to-rear direction.

[0024] As shown in Figures 2, 4, and 5, the motor 21 is a brushless motor capable of generating a relatively large starting torque. The motor 21 has an annular rotor 21a and a stator 21b, in which multiple coils are arranged in an annular shape on the inner periphery of the rotor 21a. The stator 21b is fixed to the right side of the crankcase 20. An output shaft 21c is coupled to the radial center of the rotor 21a. A cooling fan 22 is attached to the right end of the output shaft 21c. The cooling fan 22 rotates integrally with the output shaft 21c, thereby dissipating heat and cooling the motor 21. The output shaft 21c is rotatably supported by a right bearing 21d and a left bearing 21e, straddling the left and right sides of the crankcase 20. The left end of the output shaft 21c protrudes leftward via an intake section 30, which will be described later. A cooling fan 23 is attached to the left end of the output shaft 21c. Cooling fan 23 rotates integrally with output shaft 21c, so that outside air is blown into intake section 30, thereby cooling main body section 10.

[0025] As shown in FIGS. 2 to 4, a first cylinder 11a of the first compression section 11 is connected to the front of the crankcase 20 and extends in the front-rear direction. A second cylinder 12a of the second compression section 12 is connected to the rear of the crankcase 20 and extends in the front-rear direction. Outside air is taken into the crankcase 20 via an intake section 30. The first cylinder 11a takes in air from within the crankcase 20 via a communication passage not visible in the figure. A first piston 11b is housed within the first cylinder 11a and is capable of reciprocating back and forth. The first piston 11b is connected to a first crank 24 connected to an output shaft 21c via a first rod 11c extending in the front-rear direction. A second piston 12b is housed within the second cylinder 12a and is capable of reciprocating back and forth. The second piston 12b is connected to a second crank 25 connected to the output shaft 21c via a second rod 12c extending in the front-rear direction.

[0026] As shown in Figure 4, the first crank 24 and the second crank 25 are eccentric in the same direction around the output axis J. Therefore, when the first piston 11b moves forward in the first compression section 11 to perform the compression stroke, the second piston 12b moves forward in the second compression section 12 to perform the intake stroke. When the first piston 11b moves rearward in the first compression section 11 to perform the intake stroke, the second piston 12b moves rearward in the second compression section 12 to perform the compression stroke.

[0027] 2 and 4, a communicating pipe 13 is connected to the front of the first compression chamber 11d of the first cylinder 11a. The communicating pipe 13 communicates the first compression chamber 11d with the second compression chamber 12d of the second cylinder 12a. A check valve 11e is provided between the first compression chamber 11d and the communicating pipe 13 to prevent compressed air from flowing back from the communicating pipe 13 to the first compression chamber 11d. Compressed air that flows from the first compression chamber 11d through the check valve 11e and into the communicating pipe 13 is supplied to the second compression chamber 12d.

[0028] As shown in Figures 2 and 4, a supply pipe 14 is connected to the rear of the second compression chamber 12d of the second cylinder 12a. The supply pipe 14 branches into two branch pipes 14a, which are connected to the two tanks 2, respectively. A check valve 12e is provided between the second compression chamber 12d and the supply pipe 14 to prevent backflow of compressed air from the supply pipe 14 to the second compression chamber 12d. Compressed air flowing from the second compression chamber 12d through the check valve 12e into the supply pipe 14 is supplied to each tank 2. Thus, by starting the motor 21, compressed air is generated in two stages: the first compression section 11 and the second compression section 12. The compressed air compressed in the first compression section 11 is further compressed to a higher pressure, for example, 4.5 MPa, in the second compression section 12 and then sent to the tank 2.

[0029] As shown in Figures 2 to 4, a valve 15 is connected above the left tank 2. The valve 15 is connected to the interior of the left tank 2 and to a cleaning pipe 16 extending upward. The valve 15 has an inlet valve through which compressed air is sent from the tank 2 and an outlet valve through which compressed air is sent to the cleaning pipe 16. A space is provided between the inlet and outlet valves of the valve 15 in order to temporarily store a predetermined amount of compressed air. The inlet valve of the valve 15 opens when the pressure inside the tank 2 is, for example, 2 MPa or higher and closes when the pressure is lower than that. The inlet valve of the valve 15 closes when the pressure inside the tank 2 is, for example, 1.5 MPa or higher and opens when the pressure is lower than that.

[0030] Before using the air compressor 1, when the pressure inside the tank 2 is the same as atmospheric pressure, the outlet valve of the valve 15 is open but the inlet valve is closed. Therefore, compressed air is not discharged from the cleaning pipe 16. When the air compressor is started and the pressure inside the tank 2 increases, the outlet valve closes first. Therefore, compressed air is not discharged from the cleaning pipe 16. As the pressure inside the tank 2 increases further, the inlet valve opens. This allows some of the compressed air inside the tank 2 to accumulate in the space inside the valve 15. After using the air compressor 1, when the pressure inside the tank 2 drops, for example, when draining, the inlet valve of the valve 15 closes first. This stops the supply of compressed air from the tank 2 to the valve 15. As the pressure inside the tank 2 drops further, the outlet valve of the valve 15 opens. This allows the compressed air accumulated inside the valve 15 to flow into the cleaning pipe 16. In this way, compressed air can be mechanically and automatically discharged from the cleaning pipe 16 when the air compressor 1 is not in use.

[0031] As shown in Figures 2 to 5, an intake section 30 is provided on the left side of the crankcase 20. Outside air is introduced into the crankcase 20 through the intake section 30. The intake section 30 has a filter case (crankcase cover) 31 that covers a circular opening 20a provided at the left end of the crankcase 20. The intake section 30 has a filter 32 housed in the filter case 31. The intake section 30 has a cover 33 that is connected to the left side of the filter case 31 and covers the filter 32 from the left side. The filter case 31, filter 32, and cover 33 are assembled in an upright position.

[0032] 2, 6, and 7, the filter case 31 is disk-shaped. The filter case 31 is screwed to the left side of the crankcase 20 at its periphery. This allows the filter case 31 to close the opening 20a (see FIG. 4) of the crankcase 20. A filter housing section 31a capable of housing a filter 32 is recessed in the left side of the filter case 31. The filter case 31 is provided with a plurality of air intake ports 31b that open in a circular shape and penetrate in the left-right direction. The plurality of air intake ports 31b are provided on the bottom surface (right surface) of the filter housing section 31a. Outside air flows into the crankcase 20 through the air intake ports 31b.

[0033] As shown in FIGS. 5 to 7 , a cylindrical protrusion 31c that protrudes to the left is provided at the center of the filter case 31. A circular insertion hole 31d is provided at the center of the protrusion 31c, through which the output shaft 21c is inserted, penetrating the filter case 31 in the left-right direction. A bearing 21e is held in a recess on the right side corresponding to the protrusion 31c on the left side. A restricting plate 21f is screwed to the right side of the filter case 31 with four fixing screws 36 so as to cover the bearing 21e from the right. The restricting plate 21f restricts misalignment of the bearing 21e relative to the filter case 31 in the direction of the output axis J. A total of four protrusions 31e that protrude radially outward are provided at four equal circumferential positions of the protrusion 31c. Each protrusion 31e is provided with a screw hole 31f that extends in the left-right direction. Fixing screws 36 that screw-connect the restricting plate 21f to the filter case 31 are screwed into the screw holes 31f.

[0034] 5 and 6, a plurality of cylindrical bosses 31g protruding to the left are provided on the bottom surface of the filter case 31. In this embodiment, a total of four bosses 31g are provided at quarter-spaced positions around the circumference of the filter case 31. The bosses 31g and the protruding portions 31e are alternately provided at approximately 45° intervals around the circumference of the filter case 31. Each boss 31g is provided with a female thread 31h extending from the left end to the right. The cover 33 is screwed to the filter case 31 by fastening a fixing screw 35 into each female thread 31h.

[0035] 5, 6, and 9, the inner peripheral surface of filter accommodating portion 31a has approximately the same diameter as outer peripheral edge 32c of filter 32 so as to be in close contact with outer peripheral edge 32c. The depth of filter accommodating portion 31a is approximately the same as the thickness of filter 32. Therefore, the left end face of filter case 31 and outer surface 32a of filter 32 are approximately flush with each other.

[0036] As shown in Figures 6 and 7, the filter 32 is made of, for example, felt and has a generally disk-like shape. The filter 32 has a left outer surface 32a and a right inner surface 32b. The outer surface 32a and the inner surface 32b are planar and generally parallel to each other. A circular insertion hole 32d is provided in the center of the filter 32, through which the protrusion 31c of the filter case 31 is inserted. Semicircular arc-shaped recesses 32f are provided at four equal circumferential positions of the insertion hole 32d, extending radially outward and through which the protrusions 31e of the filter case 31 are inserted. Four circular insertion holes 32e are provided around the insertion hole 32d, through which the bosses 31g of the filter case 31 are inserted.

[0037] As shown in FIGS. 5 to 9 , a cover 33 is provided on the outer side (left side) of the outer surface 32a of the filter 32. The cover 33 is disk-shaped and has a diameter slightly larger than that of the filter 32. The cover 33 covers the entire outer surface 32a of the filter 32 from the left. A circular insertion hole 33c is provided in the center of the cover 33, penetrating in the left-right direction and through which the output shaft 21c is inserted. An annular center rib 33f is provided on the inner surface 33e on the right side of the cover 33, protruding to the right and surrounding the insertion hole 33c radially outward. Protruding portions 33g are provided at four equal circumferential positions of the center rib 33f, protruding radially outward in a semicircular arc shape from the center rib 33f. The center rib 33f and protruding portions 33g accommodate the convex portions 31c and protruding portions 31e of the filter case 31 on their inner peripheral sides, respectively.

[0038] As shown in Figures 6, 7, and 9, the cover 33 is provided with a plurality of inlets 33a that open in a circular shape and penetrate in the left-right direction. Outside air is introduced into the inside (right side) of the cover 33 from the plurality of inlets 33a. A plurality of cleaning outlets 33b that open radially outward and generally downward and are lined up in the circumferential direction are provided in the lower part of the cover 33. The cleaning outlets 33b open in a rectangular shape that is long in the circumferential direction of the cover 33. The plurality of cleaning outlets 33b also serve as inlets that introduce outside air into the inside of the cover 33.

[0039] As shown in Figure 7, four cylindrical annular ribs 33i that protrude to the right are provided at four equal circumferential positions on the inner surface 33e of the cover 33. The annular ribs 33i and the protruding portions 33g are alternately provided at approximately 45° intervals around the circumferential direction of the cover 33. The boss portions 31g of the filter case 31 are inserted into the annular ribs 33i. The centers of the annular ribs 33i are provided with insertion holes 33j through which fixing screws 35 are inserted. The four fixing screws 35 are inserted through the insertion holes 33j of the cover 33 and the insertion holes 32e of the filter 32 and fastened to the female threads 31h of the filter case 31. As a result, the filter 32 is sandwiched between the cover 33 and the filter case 31 and is held against left-right movement or circumferential rotation.

[0040] 8 and 9, the cover 33 is provided with a retaining rib 33h that protrudes to the right. The retaining rib 33h is provided on the right portion of the outer peripheral wall 33d of the cover 33, the right portion of the center rib 33f, the right portion of the annular rib 33i, and the right portion of the inner peripheral wall 34b (described later), etc. The retaining rib 33h abuts against the outer surface 32a of the filter 32 to hold the filter 32. This restricts movement of the filter 32 relative to the cover 33.

[0041] As shown in FIGS. 7 and 10 , a pressure accumulation passage 34, through which compressed air flows from the cleaning pipe 16, is provided on the inner surface 33e side (right side) of the cover 33. The pressure accumulation passage 34 is formed between the inner surface 33e of the cover 33 and the outer surface 32a of the filter 32. The pressure accumulation passage 34 is provided in an approximately semi-circumferential region at the upper part along the outer peripheral edge of the cover 33. The pressure accumulation passage 34 has a connecting pipe portion 34a that introduces the cleaning pipe 16 between the cover 33 and the filter 32. The connecting pipe portion 34a is cylindrical and extends radially in front of the outer peripheral wall 33d of the cover 33. The cleaning pipe 16 is inserted radially inward from the connecting pipe portion 34a into the cover 33. The opening 16a of the cleaning pipe 16 is located at the front end of the pressure accumulation passage 34 formed between the cover 33 and the filter 32.

[0042] As shown in Figures 7, 9, and 10, an inner peripheral wall 34b is provided on the inner surface 33e of the cover 33, protruding to the right and extending circumferentially of the cover 33. The inner peripheral wall 34b is provided radially inward of the outer peripheral wall 33d of the cover 33 at a substantially constant distance from the outer peripheral wall 33d. The inner peripheral wall 34b is provided in a substantially semi-circular region at the top of the cover 33. The front and rear ends of the inner peripheral wall 34b are radially connected to the outer peripheral wall 33d. The opening 16a of the cleaning pipe 16 inserted through the connecting pipe portion 34a faces the front end of the inner peripheral wall 34b. Thus, a pressure accumulation passage 34 is formed that is connected to the connecting pipe portion 34a and the opening 16a of the cleaning pipe 16 and extends in an arc shape along the outer peripheral edge of the cover 33 in a substantially semi-circular region at the top. The inner peripheral wall 34b is in close contact with the outer surface 32a of the filter 32. Therefore, the compressed air cannot bypass the right end of the inner circumferential wall 34b and pass over the inner circumferential wall 34b, and instead flows along the pressure accumulation passage 34.

[0043] As shown in FIGS. 7 and 10 , a plurality of slit-shaped cleaning air intakes 34c are provided in the inner circumferential wall 34b. The cleaning air intakes 34c open radially inward and generally downward. The cleaning air intakes 34c are provided at approximately regular intervals in the circumferential direction of the inner circumferential wall 34b along the flow path of the pressure accumulating passage 34. The cleaning air intakes 34c are connected to the openings 16a of the cleaning pipes 16 via the pressure accumulating passage 34, and compressed air is supplied to the cleaning air intakes 34c. Below each cleaning air intake 34c, a space is provided between the inner surface 33e of the cover 33 and the outer surface 32a of the filter 32, with the outer surface 32a exposed to the space. Below an extension line of the opening of each cleaning air intake 34c, a cleaning outlet 33b opens downward.

[0044] With reference to Figure 9, the intake flow path W1 through which outside air is introduced from the intake section 30 will be described. First, the motor 21 is driven to create a negative pressure inside the crankcase 20 (see Figure 5). Outside air is introduced into the space between the inner surface 33e of the cover 33 and the outer surface 32a of the filter 32 from the inlet 33a or the cleaning outlet 33b of the cover 33. The outside air flows from the outer surface 32a of the filter 32 to the inner surface 32b while being filtered through the interior. The filtered outside air flows into the crankcase 20 from the intake port 31b of the filter case 31.

[0045] Referring to FIG. 10, the cleaning flow path W2 that blows away dust accumulated on the outer surface 32a of the filter 32 (see FIG. 9) will be described. First, the pressure inside the tank 2 drops to a predetermined level, and compressed air is discharged from the valve 15 into the cleaning pipe 16 (see FIG. 3). The compressed air discharged from the opening 16a of the cleaning pipe 16 flows through the pressure accumulation passage 34 along the outer peripheral edge of the cover 33. The compressed air flows from the cleaning intake port 34c, which opens downward in the pressure accumulation passage 34, into the space between the inner surface 33e of the cover 33 and the outer surface 32a of the filter 32. The compressed air flowing from the cleaning intake port 34c flows generally downward and substantially parallel to the outer surface 32a of the filter 32. As a result, dust accumulated on the outer surface 32a of the filter 32 is blown downward by the compressed air. The blown-away dust is quickly removed from the lower cleaning outlet 33b to the outside of the cover 33 by the flow of compressed air and gravity.

[0046] As described above, the air compressor 1 has a filter 32 that covers the air intake port 31b as shown in Figures 6 and 7. The air compressor 1 has a cover 33 that covers the filter 32 from the outside. The air compressor 1 has a cleaning pipe 16 that extends from a tank 2 (see Figure 2) that stores compressed air. The air compressor 1 has a cleaning intake port 34c that is connected to the cleaning pipe 16 and introduces compressed air between the filter 32 and the cover 33. The air compressor 1 has a cleaning outlet 33b that discharges compressed air from between the filter 32 and the cover 33.

[0047] Therefore, compressed air is introduced from the tank 2 into the area between the filter 32 and the cover 33 via the cleaning pipe 16 and the cleaning intake port 34c. This allows the compressed air to flow over the outer surface 32a of the filter 32, blowing away accumulated dust. The blown-away dust can be quickly removed from around the filter 32 through the cleaning outlet 33b. Moreover, even if the air compressor 1 is not connected to a power source, compressed air can be introduced from the tank 2 into the cleaning intake port 34c mechanically or manually by connecting a valve, cock, or the like to the cleaning pipe 16. In this way, dust accumulated on the outer surface 32a of the filter 32 can be efficiently removed.

[0048] 9, cleaning outlet 33b also serves as an inlet for introducing outside air into filter 32. Therefore, inlet 33b, through which outside air is introduced when compressed air is generated, can be used as cleaning outlet 33b when cleaning filter 32. Therefore, dust can be quickly removed from around filter 32 without significantly changing the shape of cover 33 from the conventional cover.

[0049] 7 and 8, the cover 33 has a connecting pipe portion 34a that connects the cleaning pipe 16 so that it opens between the filter 32 and the cover 33. Therefore, by providing the connecting pipe portion 34a, the cleaning pipe 16 can be guided to the vicinity of the outer surface 32a of the filter 32. This makes it easier to blow away dust that has accumulated on the outer surface 32a of the filter 32.

[0050] 7 and 8, a pressure accumulation passage 34 communicating with the connecting pipe portion 34a is provided between the filter 32 and the cover 33. Therefore, the compressed air can be guided to a position suitable for blowing away dust accumulated on the outer surface 32a of the filter 32 by the pressure accumulation passage 34. This makes it possible to more efficiently blow away dust accumulated on the outer surface 32a of the filter 32.

[0051] 7 and 10, a plurality of cleaning intake ports 34c are provided along the flow path in the pressure accumulation passage 34. Therefore, compressed air can be introduced to the outer surface 32a of the filter 32 from the plurality of cleaning intake ports 34c provided at different positions. As a result, dust accumulated on the outer surface 32a of the filter 32 can be blown away evenly.

[0052] 7 and 9, the filter 32 and cover 33 are arranged upright. A cleaning intake port 34c is provided at the top of the cover 33. A cleaning outlet 33b is provided below the cleaning intake port 34c. Therefore, dust accumulated on the outer surface 32a of the filter 32 is blown away by compressed air blown out from the cleaning intake port 34c and falls downward. Furthermore, the dust can be quickly removed from the cleaning outlet 33b provided below.

[0053] As shown in Figure 10, cleaning outlet 33b is located on an extension of cleaning intake port 34c. Therefore, dust blown away by compressed air can be removed from cleaning outlet 33b along an extension of cleaning intake port 34c. This allows dust to be removed quickly over a short path.

[0054] As shown in FIG. 7, the cleaning intake port 34c and the cleaning exhaust port 33b are opened to follow the outer surface 32a of the filter 32. This allows the compressed air to flow substantially parallel to the outer surface 32a of the filter 32. This allows the compressed air to flow evenly over the outer surface 32a of the filter 32. This makes it possible to more reliably blow away dust accumulated on the outer surface 32a of the filter 32. Furthermore, compared to, for example, a case in which compressed air is blown from the outer surface 32a side of the filter 32 toward the inner surface 32b side, this makes it possible to prevent dust from entering the interior of the filter 32 from the outer surface 32a.

[0055] Next, a second embodiment of the present disclosure will be described with reference to Figures 11 to 14. Air compressor 40 of the second embodiment has intake section 41 instead of intake section 30 shown in Figure 2. Intake section 41 is the same as intake section 30 in that it has filter case 31 and filter 32, but has cover 42 instead of cover 33. In the following explanation, only the parts that differ from the first embodiment will be described in detail.

[0056] 12 and 13, the cover 42 is provided in a disk shape with a diameter slightly larger than that of the filter 32. The cover 42 covers the entire outer surface 32a of the filter 32 from the left. A circular insertion hole 42c is provided in the center of the cover 42, penetrating in the left-right direction and through which the output shaft 21c (see FIG. 11) is inserted. A center rib 42f, a protruding portion 42g, an annular rib 42i, and an insertion hole 42j are provided on an inner surface 42e on the right side of the cover 42, and have the same shapes as the center rib 33f, the protruding portion 33g, the annular rib 33i, and the insertion hole 33j shown in FIG.

[0057] As shown in Figures 11 and 12, the cover 42 is provided with a plurality of inlets 42a that open in a circular shape and penetrate in the left-right direction. Outside air is introduced into the inside (right side) of the cover 42 through the plurality of inlets 42a. The outer periphery of the cover 42 is provided with a plurality of cleaning outlets 42b that open radially outward and are aligned in the circumferential direction. The cleaning outlets 42b open in a rectangular shape that is long in the circumferential direction of the cover 42. The plurality of cleaning outlets 42b also serve as inlets that introduce outside air into the inside of the cover 42.

[0058] 13, the cover 42 is provided with a retaining rib 42h that protrudes to the right. The retaining rib 42h is provided on the right portion of the outer peripheral wall 42d of the cover 42, the right portion of the center rib 42f, the right portion of the annular rib 42i, the right portion of the annular wall 43b (described later), and the like. The retaining rib 42h abuts against the outer surface 32a of the filter 32 to hold the filter 32. This restricts movement of the filter 32 relative to the cover 42.

[0059] As shown in FIGS. 12 and 14 , a pressure accumulation passage 43, through which compressed air flows from the cleaning pipe 16, is provided in a central region on the inner surface 42e side (right side) of the cover 42. The pressure accumulation passage 43 is formed between the inner surface 42e of the cover 42 and the outer surface 32a of the filter 32. The pressure accumulation passage 43 has a connecting pipe portion 43a that introduces the cleaning pipe 16 between the cover 42 and the filter 32. The connecting pipe portion 43a is provided in a cylindrical shape extending in the left-right direction at the front part of the inner surface 42e side of the cover 42. The cleaning pipe 16 is inserted through the connecting pipe portion 43a. The opening 16a of the cleaning pipe 16 is located at the front end of the pressure accumulation passage 43 formed between the cover 42 and the filter 32.

[0060] As shown in Figures 12 and 14, an annular wall 43b that protrudes to the right and surrounds the center in a rectangular shape is provided on the inner surface 42e of the cover 42. The annular wall 43b is provided so as to radially surround the center rib 42f and the protruding portion 42g. A connecting pipe portion 43a is connected to the front end of the annular wall 43b. Thus, a pressure accumulation passage 43 is formed in the central region of the inner surface 42e of the cover 42, communicating with the connecting pipe portion 43a and the opening 16a of the cleaning pipe 16. The annular wall 43b is in close contact with the outer surface 32a of the filter 32. Therefore, the compressed air cannot bypass the right end of the annular wall 43b or pass over the annular wall 43b, but instead flows along the pressure accumulation passage 43.

[0061] As shown in FIGS. 12 and 14 , a plurality of slit-shaped cleaning intake ports 43c are provided in the annular wall 43b. The cleaning intake ports 43c open radially outward from four corners of the annular wall 43b. The cleaning intake ports 43c are provided at approximately regular intervals around the circumference of the annular wall 43b along the flow path of the pressure accumulation passage 43. The cleaning intake ports 43c are connected to the openings 16a of the cleaning pipes 16 via the pressure accumulation passage 43, and compressed air is supplied through the cleaning intake ports 43c. A space is disposed radially outward from each cleaning intake port 43c between the inner surface 42e of the cover 42 and the outer surface 32a of the filter 32, with the outer surface 32a exposed to the space. A cleaning exhaust port 42b opens radially outward on an extension of the radially outward opening of each cleaning intake port 43c.

[0062] With reference to Figure 13, the intake flow path W1 through which outside air is introduced from the intake section 30 will be described. First, the motor 21 is driven to create a negative pressure inside the crankcase 20 (see Figure 5). Outside air is introduced from the cleaning outlet 42b of the cover 42 into a space between the inner surface 42e of the cover 42 and the outer surface 32a of the filter 32. Although not visible in the figure, outside air is also introduced from the inlet 42a of the cover 42. The outside air flows from the outer surface 32a of the filter 32 to the inner surface 32b while being filtered through the interior. The filtered outside air flows into the crankcase 20 from the intake port 31b of the filter case 31.

[0063] Referring to Figure 14, the cleaning flow path W2 that blows away dust accumulated on the outer surface 32a of the filter 32 (see Figure 13) will be described. First, the pressure inside the tank 2 drops to a predetermined level or lower, and compressed air is discharged from the valve 15 to the cleaning pipe 16 (see Figure 3). The compressed air discharged from the opening 16a of the cleaning pipe 16 flows over the pressure accumulating passage 43 surrounded by the annular wall 43b. The compressed air flows from a cleaning intake port 43c that opens radially outward in the pressure accumulating passage 43 into the space between the inner surface 42e of the cover 42 and the outer surface 32a of the filter 32. The compressed air flowing from the cleaning intake port 43c flows approximately parallel to the outer surface 32a of the filter 32. As a result, dust accumulated on the outer surface 32a of the filter 32 is blown radially outward by the compressed air. The blown-off dust is quickly removed to the outside of the cover 42 through the cleaning exhaust port 42b, which is disposed on the extension line of the opening of the cleaning intake port 43c.

[0064] As described above, the pressure accumulation passage 43 is provided in the central region of the inner surface 42e of the cover 42, as shown in Figures 12 and 14. The cleaning intake port 43c opens from the pressure accumulation passage 43 toward the outer peripheral wall 42d of the cover 42. The cleaning discharge port 42b is provided in the outer peripheral wall 42d of the cover 42. Therefore, dust accumulated on the outer surface 32a of the filter 32 can be blown from the cleaning intake port 43c on the radially inner side of the cover 42 to the cleaning discharge port 42b on the radially outer side. Therefore, it is possible to prevent the removal of dust accumulated on the outer surface 32a of the filter 32 from being unevenly distributed in the circumferential direction.

[0065] 14, the cleaning intake ports 43c are arranged at equal intervals around the circumferential direction of the cover 42. Therefore, the compressed air blown out from the cleaning intake ports 43c can flow radially and at equal intervals around the entire circumferential direction of the outer surface 32a of the filter 32. Therefore, dust accumulated on the outer surface 32a of the filter 32 can be removed more reliably.

[0066] 14, cleaning outlet 42b is located on an extension of cleaning intake port 43c. Therefore, dust blown away by compressed air can be removed from cleaning outlet 42b along an extension of cleaning intake port 43c. This allows dust to be removed quickly over a short path.

[0067] Various modifications can be made to the above-described embodiment of the present disclosure. For example, in this embodiment, the intake units 30, 41 are provided on the left side of the main body 10, and the filter 32 is held in a position extending in the vertical direction. Alternatively, the intake units 30, 41 may be provided on the lower part of the main body 10, and the filter 32 may be held in a position extending in the substantially horizontal direction.

[0068] In the illustrated example, the valve 15 sends compressed air stored in the valve 15 to the intakes 30, 41 via the cleaning pipe 16 when, for example, the air compressor 1, 40 is stopped and the pressure in the tank 2 falls below a predetermined value. Alternatively, for example, compressed air may not be stored in the valve 15, and compressed air may be sent from the tank 2 to the intakes 30, 41 via the valve 15 and the cleaning pipe 16 when the pressure in the tank 2 meets a predetermined condition. The pressure at which the valve 15 operates is not limited to the illustrated value and may be changed as appropriate. Furthermore, instead of the valve 15, the compressed air in the tank 2 may be sent to the intakes 30, 41 using, for example, a manually openable cock. In this case, the filter 32 can also be cleaned even when the power to the air compressor 1, 40 is turned off.

[0069] The arrangement, number, shape, etc. of the cleaning intake ports 34c, 43c and the cleaning exhaust ports 33b, 42b may be changed as appropriate depending on the structure, etc. of the intake units 30, 41. To prevent the outer surface 32a of the filter 32 from coming into close contact with the inner surfaces 33e, 42e of the covers 33, 42, a separate member such as a spacer may be further interposed between the two members. This more reliably ensures a flow path for compressed air to flow between the outer surface 32a of the filter 32 and the inner surfaces 33e, 42e of the covers 33, 42. [Explanation of symbols]

[0070] 1...Air compressor 2...Tank, 2a...Leg, 2b...Side protector 3...base part, 3a...handle 4...Main body cover, 4a...Ventilation hole, 4b...Operation panel 5...Discharge port (for low pressure), 5a...Adjustment dial 6...Discharge port (for high pressure), 6a...Adjustment dial 7...Drain discharge device, 7a...Drain cock, 7b...Drain discharge pipe 10...Main body 11...first compression section, 11a...first cylinder, 11b...first piston, 11c...first rod 11d...first compression chamber, 11e...check valve 12... second compression section, 12a... second cylinder, 12b... second piston, 12c... second rod 12d...second compression chamber, 12e...check valve 13...Communication pipe 14...supply pipe, 14a...branch pipe 15...Valve 16...Cleaning pipe, 16a...Opening 20... crankcase, 20a... opening 21...motor, 21a...rotor, 21b...stator, 21c...output shaft 21d, 21e... bearing, 21f... restricting plate 22, 23...Cooling fan 24...1st crank 25...Second crank 30...Intake section 31...Filter case (crankcase cover) 31a...filter housing portion, 31b...air intake port, 31c...projection portion, 31d...insertion hole 31e...protrusion, 31f...screw hole, 31g...boss, 31h...female thread 32...filter, 32a...outer surface, 32b...inner surface, 32c...outer rim 32d, 32e...through holes, 32f...recess 33...Cover, 33a...Inlet, 33b...Cleaning outlet (inlet) 33c...through hole, 33d...outer wall, 33e...inner surface, 33f...center side rib 33g...protruding portion, 33h...holding rib, 33i...annular rib, 33j...insertion hole 34... pressure accumulation passage, 34a... connecting pipe portion, 34b... inner peripheral wall, 34c... cleaning intake port 35,36...Fixing screws 40...Air compressor 41...Intake section 42...cover, 42a...inlet, 42b...cleaning outlet (inlet) 42c...through hole, 42d...outer wall, 42e...inner surface, 42f...center side rib 42g...protrusion, 42h...retaining rib, 42i...annular rib, 42j...insertion hole 43... pressure accumulation passage, 43a... connecting pipe portion, 43b... annular wall, 43c... cleaning intake port J…Output axis line W1: Inlet flow path, W2: Cleaning flow path

Claims

1. An air compressor, A filter covering the air intake; a cover that covers the filter from the outside; a cleaning pipe extending from a tank storing compressed air; a cleaning air intake connected to the cleaning pipe for introducing compressed air between the filter and the cover; an air compressor having a cleaning outlet for discharging compressed air from between the filter and the cover;

2. 2. The air compressor of claim 1, The cleaning outlet is an air compressor that also serves as an inlet for introducing outside air into the filter.

3. 3. The air compressor according to claim 1 or 2, The cover has a connecting pipe portion that connects the cleaning pipe so that it opens between the filter and the cover.

4. 4. The air compressor according to claim 3, The air compressor further comprises a pressure accumulation passage provided between the filter and the cover, the pressure accumulation passage communicating with the connecting pipe portion.

5. 5. The air compressor according to claim 4, an air compressor, wherein a plurality of the cleaning intake ports are provided in the pressure accumulation passage along a flow path;

6. 6. The air compressor according to claim 5, The filter and the cover are arranged in an upright position, The cleaning intake port is provided on the top of the cover, The air compressor has the cleaning outlet located below the cleaning intake.

7. 6. The air compressor according to claim 5, The pressure accumulation passage is provided in a central region of an inner surface of the cover, the cleaning intake port opens from the pressure accumulation passage toward the outer periphery of the cover, The cleaning outlet is provided on the outer periphery of the cover.

8. 8. The air compressor according to claim 7, The plurality of cleaning air intakes are arranged at equal intervals around the circumference of the cover.

9. An air compressor according to any one of claims 1 to 8, The cleaning outlet is an air compressor located on an extension line of the opening of the cleaning intake.

10. An air compressor according to any one of claims 1 to 9, The cleaning intake port and the cleaning exhaust port of the air compressor are opened along the outer surface of the filter.

Images