JP2022022618A - Work machine - Google Patents

Abstract

To improve cooling performance of a cylinder in a work machine.SOLUTION: An air compressor 10 includes a rotating shaft rotated by driving force of a driving source, and a piston operated by rotation of the rotating shaft, a motion conversion mechanism which converts the rotation of the rotating shaft into a reciprocating motion of the piston, a second cylinder 45 which accommodates the piston in a state of allowing reciprocation in a center axis direction, and a cooling fan 28 for generating wind. The second cylinder 45 has fins 45a which are erected in a radial direction of the second cylinder 45 from the outer peripheral surface of the second cylinder 45, and the plurality of fins 45a are provided spaced apart in a rotation axis direction of the cooling fan 28. The plurality of fins 45a include a plurality of fins 45a which are erected so as to increase in height as they recede from the cooling fan 28 in the rotation axis direction of the cooling fan 28.SELECTED DRAWING: Figure 3

Description

The present invention relates to a working machine such as an air compressor.

As an example of a working machine, an air compressor that discharges compressed air to the outside is known. Such an air compressor includes a drive source, a piston that reciprocates by the drive force of the drive source to compress air, a cylinder that accommodates the piston in a reciprocating state, and a cooling air in the cylinder. Patent Document 1 describes an air compressor having a fan for supplying a cylinder and having fins formed in the cylinder to increase the cooling efficiency of the cylinder.

Japanese Unexamined Patent Publication No. 2020-70762

In the air compressor described in Patent Document 1, a plurality of fins are formed in the cylinder, and the cylinder is cooled by the cooling air supplied from the fan hitting the plurality of fins.

However, since the heights of the plurality of fins are formed to be equal, it is difficult for the cooling wind to hit the fins on the side far from the fan, and the cooling efficiency of the cylinder is not high. That is, further improvement in the cooling property of the cylinder has been desired.

An object of the present invention is to provide a working machine in which the cooling property of a cylinder is improved.

The working machine of one embodiment includes a drive source, a rotating shaft rotated by the driving force of the drive source, a tubular cylinder, a piston reciprocally housed in the cylinder, and the rotating shaft. A motion conversion mechanism that converts rotation into reciprocating motion of the piston and a fan that rotates by the driving force of the drive source to generate wind are provided, and the cylinder is provided in the radial direction of the cylinder from the outer peripheral surface of the cylinder. The plurality of fins are provided apart from each other in the rotation axis direction of the fan, and the height of the plurality of fins increases as the distance from the fan increases in the rotation axis direction of the fan. Includes multiple fins erected to be high.

According to the present invention, it is possible to improve the cooling property of the cylinder in the working machine.

It is a perspective view which shows the air compressor which is an example of the working machine of embodiment of this invention. It is a front view of the air compressor shown in FIG. It is a perspective view which shows the internal structure of the air compressor shown in FIG. It is a front view of the structure shown in FIG. It is sectional drawing which cut along the AA line shown in FIG. It is sectional drawing which shows the positional relationship of a fan, a cylinder, and a pedestal part mounted on the air compressor shown in FIG. 1. It is a perspective view which shows the structure of the pedestal part shown in FIG. 7 is a view showing the structure of the pedestal portion shown in FIG. 7, where FIG. 7A is a front view, FIG. 7B is a side view, and FIG. 7C is a rear view. It is sectional drawing which shows the positional relationship of a fan, a cylinder, and a pedestal part of a modification. It is a perspective view which shows the structure of the pedestal part shown in FIG. 10A and 10B are views showing the structure of the pedestal portion, where FIG. 10A is a front view, FIG. 10B is a side view, and FIG. 10C is a rear view.

The working machine of the present embodiment will be described with reference to the drawings.

In the present embodiment, the air compressor 10 will be described as an example of the working machine. An example of the air compressor 10 is shown in FIGS. 1, 2, 3, 4, and 5. The same elements or equivalent elements shown in each figure are designated by the same reference numerals. The air compressor 10 includes a metal frame 11, a cover 12, an electric motor 13, a first compression unit 14, a second compression unit 15, a control unit 16, and air tanks 17, 18. The air tanks 17 and 18 are made of metal, and the air tanks 17 and 18 are connected by a connecting arm 70. Both the air tanks 17 and 18 have a tubular shape and store compressed air. The center line A1 of the air tank 17 and the center line A2 of the air tank 18 are arranged substantially in parallel. A plurality of legs 19 are attached to the air tanks 17 and 18, respectively. The plurality of legs 19 come into contact with the installation location 20 of the air compressor 10.

The frame 11 is made of metal, and the frame 11 is attached from the air tank 17 to the air tank 18. The frame 11 supports the electric motor 13, the first compression unit 14, and the second compression unit 15. A plurality of brackets 71 are provided in the air tanks 17 and 18, respectively. The plurality of brackets 71 are provided at intervals in the directions along the center lines A1 and A2.

The cover 12 is made of synthetic resin as an example. The cover 12 is attached to the upper part of the air tanks 17 and 18 in the vertical direction, which is the direction of action of gravity. Specifically, the cover 12 is fixed to the plurality of brackets 71 by a fixing element, for example, a screw member 93.

The grips 22 and 23 are provided so as to be exposed to the outside. The grips 22 and 23 are provided at intervals in the directions along the center lines A1 and A2, and the grips 22 and 23 are fixed to the connection arm 70, respectively. The air compressor 10 is portable, and the operator can lift and carry the air compressor 10 by grasping the grips 22 and 23 with both hands.

The electric motor 13, the first compression unit 14, and the second compression unit 15 are provided inside. That is, the electric motor 13, the first compression unit 14, and the second compression unit 15 are covered with the cover 12. The crankcase 24 is provided inside and is fixed to the frame 11. As shown in FIG. 5, the crankcase 24 is provided between the first compression unit 14 and the second compression unit 15 in the direction along the center lines A1 and A2.

The crankcase 24 is made of metal, and the rotary shaft 25 is arranged from the inside to the outside of the crankcase 24. The center line B1 is a virtual line representing the rotation center of the rotation axis 25. When the air compressor 10 is viewed in a plan view, the center line B1 intersects the center lines A1 and A2 at a predetermined angle, for example, at an angle of approximately 90 degrees.

The electric motor 13 as a drive source has a stator 26 and a rotor 27. The stator 26 is provided so as not to rotate with respect to the crankcase 24. The rotor 27 is attached to the rotating shaft 25. The electric motor 13 is, for example, a three-phase AC type electric brushless motor. When electric power is supplied to the electric motor 13, the rotor 27 rotates, whereby the rotating shaft 25 rotates.

The cooling fan 28 is attached to the rotating shaft 25. The cooling fan 28 is provided inside the cover 12. The cooling fan 28 is, for example, an axial fan. As shown in FIG. 4, the cooling fan 28 has a plurality of blades 28a and a ventilation path 28b. The plurality of blades 28a are provided at intervals in the rotation direction of the cooling fan 28 with the center line B1 as the center. The plurality of blades 28a extend from the inside to the outside in the radial direction about the center line B1. The ventilation path 28b is a hole in the direction along the center line B1. The cooling fan 28 is rotated by the driving force of the electric motor 13 to generate wind. That is, when the cooling fan 28 is rotated, an air flow is generated.

As shown in FIG. 5, the cooling fan 28, the electric motor 13, the crankcase 24, and the control unit 16 are arranged at different positions in the direction along the center line B1.

When the air compressor 10 is placed at the installation location 20, that is, when the surface of the installation location 20 is substantially horizontal in a state where the plurality of legs 19 are in contact with the installation location 20 as shown in FIG. 2, the center line A1 and B1 are substantially horizontal. Further, the cooling fan 28, the electric motor 13, the crankcase 24, the first compression unit 14, and the second compression unit 15 are located above the air tanks 17 and 18 in the direction of gravity action, that is, in the vertical direction.

As shown in FIG. 5, in the direction along the center lines A1 and A2, between the grip 22 and the grip 23, a cover 12, a cooling fan 28, an electric motor 13, a crankcase 24, a first compression unit 14, and a first 2 The compression unit 15 is arranged.

The first compression unit 14 has a first cylinder 36, a first cylinder head 37, a first connecting rod 39, a first piston 40, a first compression chamber 41, and a first exhaust chamber 42. The first piston 40 reciprocates by the rotation of the rotating shaft 25 rotated by the driving force of the electric motor 13, and the tubular first cylinder 36 reciprocates the first piston 40 in the central axis C1 direction. Contain. The first cylinder 36 and the first cylinder head 37 are fixed to the crankcase 24. One end of the first connecting rod 39 is connected to the rotating shaft 25. The first piston 40 is provided at the other end of the first connecting rod 39. The first piston 40 is operable in the first cylinder 36.

The second compression unit 15 has a second cylinder 45, a second cylinder head 46, a second connecting rod 48, a second piston 49, a second compression chamber 50, and a second exhaust chamber 51. The second piston 49 reciprocates by the rotation of the rotating shaft 25 rotated by the driving force of the electric motor 13, and the tubular second cylinder 45 reciprocates the second piston 49 in the central axis C1 direction. Contain. The second cylinder 45 and the second cylinder head 46 are fixed to the crankcase 24. The second piston 49 is operably provided in the second cylinder 45. One end of the second connecting rod 48 is rotatably connected to the rotating shaft 25. The other end of the second connecting rod 48 is connected to the second piston 49.

That is, in the first compression unit 14, in order to convert the rotational motion of the rotary shaft 25 of the electric motor 13 into the reciprocating motion of the first piston 40, the first piston 40 has one end of the first connecting rod 39. The portions are coupled and the other end of the first connecting rod 39 is rotatably coupled to an eccentric cam (not shown) provided on the rotating shaft 25. In other words, the first connecting rod 39 straddles the crankcase 24 and the first cylinder 36, and connects the rotary shaft 25 and the first piston 40.

Further, in the second compression unit 15, in order to convert the rotational motion of the rotary shaft 25 of the electric motor 13 into the reciprocating motion of the second piston 49, the second piston 49 has one end of the second connecting rod 48. The portions are coupled and the other end of the second connecting rod 48 is rotatably coupled to an eccentric cam (not shown) provided on the rotating shaft 25. In other words, the second connecting rod 48 straddles the crankcase 24 and the second cylinder 45, and connects the rotary shaft 25 and the second piston 49.

As described above, the rotational motion of the rotary shaft 25 of the electric motor 13 is carried out by the motion conversion mechanism 39a including the eccentric cam and the first connecting rod 39, and the motion conversion mechanism 48a including the eccentric cam and the second connecting rod 48. It is converted into a reciprocating motion and transmitted to the first piston 40 and the second piston 49. In other words, the rotational driving force output from the electric motor 13 is converted into a reciprocating driving force by the motion conversion mechanism 39a and the motion conversion mechanism 48a, and is input to the first piston 40 and the second piston 49. As a result, the first piston 40 and the second piston 49 reciprocate in the direction along the central axis C1 (see FIG. 4) that intersects the direction of the rotation axis 25 (the direction of the center line B1 shown in FIG. 5).

Further, one end of the connecting pipe 60 is connected to the first exhaust chamber 42, and the other end of the connecting pipe 60 is connected to the second compression chamber 50. The connecting pipe 60 is made of metal as an example. As shown in FIGS. 3 and 4, the connecting pipe 60 is curved, and the connecting pipe 60 is arranged so as to bypass above the electric motor 13 and the cooling fan 28.

As shown in FIG. 5, the second exhaust chamber 51 is connected to the air tanks 17 and 18. As shown in FIGS. 3 and 5, connecting pipes 73 and 87 for connecting the air tank 17 and the air tank 18 are provided. The air pressures in the two air tanks 17 and 18 are the same.

Further, a pressure sensor 74 that detects the pressure in the air tanks 17 and 18 and outputs a signal is provided. As shown in FIG. 4, the pressure sensor 74 projects upward from the upper end of the air tank 17. The air tank 17 is connected to the supply pipe 76 via the pressure reducing valve 75. The pressure reducing valve 75 projects upward from the upper end of the air tank 17. The operation knob 75a is attached to the pressure reducing valve 75, and the operator can operate the operation knob 75a. The pressure reducing valve 75 adjusts the pressure of the air sent from the air tank 17 to the supply pipe 76, specifically, reduces the pressure.

Further, a pressure gauge 77 for displaying the air pressure in the supply pipe 76 is provided. The coupler 78 is attached to the supply pipe 76. The coupler 78 can be attached to and detached from the air hose. The coupler 78 is connected to another working machine via an air hose.

The air tank 18 is connected to the supply pipe 80 via the pressure reducing valve 79. The operation knob 79a is attached to the pressure reducing valve 79, and the operator can operate the operation knob 79a. The pressure reducing valve 79 adjusts the pressure of the air sent from the air tank 18 to the supply pipe 80, specifically, reduces the pressure. Further, a pressure gauge 81 for displaying the air pressure in the supply pipe 80 is provided as shown in FIGS. 1 and 3. The operation knobs 75a and 79a and the pressure gauges 77 and 81 are arranged so as to be exposed to the outside of the cover 12. The coupler 82 is attached to the supply pipe 80. The coupler 82 can be attached to and detached from the air hose. The coupler 82 is connected to another working machine via an air hose.

As shown in FIG. 4, the relief valve 90 is attached to the air tank 17. The relief valve 90 projects upward from the upper end of the air tank 17. The relief valve 90 suppresses the air pressure in the air tanks 17 and 18 from becoming equal to or higher than a predetermined pressure. The relief valve 90 is closed when the air pressure in the air tanks 17 and 18 is less than a predetermined pressure. The relief valve 90 opens when the air pressure in the air tanks 17 and 18 is equal to or higher than a predetermined pressure, and discharges the compressed air in the air tanks 17 and 18.

As shown in FIG. 1, an operation unit 83 is provided on the top plate 86 of the cover 12, and the operation unit 83 has a power switch, a display panel, and the like. As shown in FIG. 5, the control unit 16 is a mechanism for controlling the operation and stop of the first compression unit 14 and the second compression unit 15. The control unit 16 is a microcomputer having an input interface, an output interface, a central arithmetic processing unit, and a storage unit.

An inverter circuit is provided inside the cover 12. The control unit 16 controls the inverter circuit. Inside the cover 12, a sensor for detecting the phase in the rotation direction of the electric motor 13 and a sensor for detecting the rotation speed of the electric motor 13 are provided. Signals from the pressure sensor 74, the power switch, and various sensors are input to the control unit 16. The control unit 16 may be configured to include an inverter circuit.

Next, an example in which the operator uses the air compressor 10 will be described. When the operator turns on the power switch of the operation unit 83, the control unit 16 controls the inverter circuit, and the rotor 27 of the electric motor 13 rotates. When the rotor 27 and the rotating shaft 25 rotate integrally, the first piston 40 and the second piston 49 are reciprocated by the torque of the rotating shaft 25, respectively.

When the first piston 40 is operated, the air outside the cover 12 is sucked into the first compression chamber 41 of the first compression unit 14, and the air is compressed in the first compression chamber 41. The air compressed in the first compression chamber 41 is discharged to the first exhaust chamber 42. When the second piston 49 is operated, the air in the first exhaust chamber 42 is sucked into the second compression chamber 50 of the second compression unit 15 through the connecting pipe 60. The second compression chamber 50 further compresses the air, and the air compressed in the second compression chamber 50 is sent to the air tanks 17 and 18 via the second exhaust chamber 51. The air pressure in the second compression chamber 50 is higher than the air pressure in the first compression chamber 41.

In this way, the air compressor 10 compresses the air in two stages. The operator may perform at least one of decompression of the air in the air tanks 17 and 18 to the supply pipe 76 by the decompression valve 75 and decompression by the decompression valve 79 to the supply pipe 80. It is possible.

The control unit 16 processes the signal of the pressure sensor 74 to detect the air pressure in the air tanks 17 and 18. The control unit 16 controls the rotation, stop, rotation speed, and torque of the electric motor 13 based on the data stored in the storage unit. When the power switch is turned on, the control unit 16 controls the rotation speed and torque of the electric motor 13 so that the air pressure in the air tanks 17 and 18 rises to the target pressure. The control unit 16 stops the electric motor 13 when the air pressure in the air tanks 17 and 18 reaches the target pressure.

Further, the cooling fan 28 is rotated clockwise together with the rotation shaft 25 as shown in FIG. Then, the air outside the cover 12 is sucked into the inside through the plurality of air passages 34 shown in FIGS. 1 and 2. A part of the air passes outside the cooling fan 28 in the radial direction of the cooling fan 28. Further, a part of the air passes through the air passage 28b shown in FIG. As shown in FIG. 5, the air flows internally along the flow direction D1 so as to hit the second cylinder 45 of the second compression unit 15. The heat of the electric motor 13, the first compression unit 14, the second compression unit 15, the crankcase 24, and the control unit 16 is supplied from the cooling fan 28 and transferred to the air flowing inside. The air flowing inside is discharged to the outside from the ventilation passage provided on the opposite side of the ventilation passage 34.

Therefore, the heat of each of the electric motor 13, the first compression unit 14, the second compression unit 15, the crankcase 24, and the control unit 16 is transferred to the air, and the temperature rise of these elements is suppressed, that is, cooled. As air flows inside, heat transfer by forced convection occurs between each element and the air.

Next, the cooling means of the second cylinder (cylinder) 45 of the second compression unit 15 on the high pressure side in the air compressor 10 of the present embodiment will be described. In the air compressor 10 of the present embodiment, as shown in FIG. 6, the second cylinder 45 is used as a cooling means thereof from the outer peripheral surface of the second cylinder 45 to the central axis C1 of the second cylinder 45 (see FIG. 4). It has fins 45a erected along the radial direction 45c that intersects the direction. A plurality of fins 45a are provided apart from each other along the rotation axis 25 direction of the cooling fan 28. The plurality of fins 45a include a plurality of fins 45a erected so that the height increases as the distance from the cooling fan 28 increases in the direction of the rotation axis 25 of the cooling fan 28. That is, a plurality of fins 45a are erected on the outer peripheral surface of the second cylinder 45, and the height of the plurality of fins 45a gradually increases as the distance from the cooling fan 28 increases. A plurality of fins 45a erected in the above are included. Specifically, among the plurality of fins 45a erected on the semi-cylindrical portion side of the outer peripheral surface of the second cylinder 45 shown in FIG. 6, four erected along the direction orthogonal to the rotation axis 25. Comparing the heights of the adjacent upstream fins 45a and downstream fins 45a with respect to the wind flow direction D1 of the cooling fan 28 in the fins 45a, the fins 45a on the downstream side of the upstream fins 45a are compared. The height is higher. That is, in these four fins 45a, the wind sent from the cooling fan 28 hits the fins 45a on the upstream side and the fins 45a on the downstream side substantially equally.

Here, the height of each of the plurality of fins 45a is the length in the radial direction 45c of the second cylinder 45 in each of the fins 45a, and when the height of the fins 45a is high, the second in the fins 45a. It means that the length of the cylinder 45 in the radial direction 45c is long.

In the second cylinder 45 shown in FIG. 6, a plurality of fins 45a erected so as to gradually increase in height as the distance from the cooling fan 28 increases are provided with respect to the rotation shaft 25 of the cooling fan 28. It is similarly provided on the upper side and the lower side of the outer peripheral surface of the second cylinder 45.

Further, as shown in FIG. 3, each of the plurality of fins 45a provided on the outer peripheral surface of the second cylinder 45 has a flat surface portion 45d extending along the central axis C1 (see FIG. 4) of the second cylinder 45. It is formed in the shape of a plate. This means that when the second cylinder 45 is formed by drawing, the flat surface portions 45d of the plurality of plate-shaped fins 45a extend along the central axis C1 (see FIG. 4) of the second cylinder 45. It is possible to form a plurality of fins 45a by drawing so as to be integrated with the second cylinder 45.

This makes it possible to efficiently process the plurality of fins 45a. Further, since the plurality of fins 45a are integrally formed with the second cylinder 45, the heat of the second cylinder 45 can be efficiently transferred to the plurality of fins 45a, and the cooling efficiency of the second cylinder 45 can be improved. .. However, the plurality of fins 45a may be formed separately from the second cylinder 45, or may be retrofitted to the outer peripheral surface of the second cylinder 45.

Next, the pedestal portion 52 attached to the end portion of the second cylinder 45 shown in FIG. 3 will be described. The pedestal portion 52 has a valve seat function for entering and discharging air into and from the second compression chamber 50 of the second compression portion 15 shown in FIG. Specifically, as shown in FIG. 4, the pedestal portion 52 is attached to the end portion of the second cylinder 45 on the second compression chamber 50 side as a plate-shaped valve seat larger than the outer shape of the second cylinder 45. ing. Specifically, a plate-shaped pedestal portion 52 larger than the outer peripheral portion in the radial direction 45c of the second cylinder 45 is attached to the end portion of the second cylinder 45 on the second compression chamber 50 side. In the second compression portion 15, the pedestal portion 52 is attached to the end portion of the second cylinder 45 so as to abut on the plurality of fins 45a provided near the end portion of the outer peripheral surface of the second cylinder 45. ..

As shown in FIG. 6, the wind sent from the cooling fan 28 flows and hits the pedestal portion 52 along the wind flow direction D1. As shown in FIGS. 7 and 8, the pedestal portion 52 has a discharge hole 55 for discharging air from the second cylinder 45 and an intake hole 57 for allowing air to enter the second cylinder 45. .. Further, the pedestal portion 52 is attached with a metal thin plate-shaped valve member 54 that swings when air enters from the intake hole 57 to form a gap between the pedestal portion 52 and the intake hole 57, and the air enters. Occasionally, the valve is opened and closed by swinging from the swing fulcrum 54a provided at the end.

Further, the pedestal portion 52 has a screw hole 58 for attaching a plate-shaped member covering the discharge hole 55, a screw hole 52a for fixing the second cylinder head 46 of the second cylinder 45, a cylinder, and a valve seat. , A plurality of through holes 56 through which bolts for fixing the cylinder head to the crankcase 24 pass are formed. Further, as shown in FIG. 8A, the pedestal portion 52 is provided with an O-ring 59 that closely seals with the second cylinder head 46.

As shown in FIG. 6, the outer peripheral portion of the pedestal portion 52 is located outside the radial direction 45c of the second cylinder 45 with respect to the tip of the fin 45a having the highest height among the plurality of fins 45a. .. That is, the outer peripheral portion of the pedestal portion 52 is located outside the tip of the fin 45a having the highest height. In other words, the size of the plane of the pedestal portion 52 is larger than the size of the cut surface of the second cylinder 45 including all the fins 45a in the radial direction 45c.

Then, on the back surface side (second cylinder 45 arrangement side) of the pedestal portion 52, a second cylinder 45 is formed on a part of the upper portion of the outer peripheral portion of the pedestal portion 52 along the central axis C1 direction of the second cylinder 45. It has a wind guide rib 53 that projects toward the side. The wind guide rib 53 is a wall that guides the wind so that the wind sent from the cooling fan 28 moves along the plurality of fins 45a and also guides the wind to the lower side of the second cylinder 45. be. Since the wind sent from the cooling fan 28 also hits the wind guide rib 53, the pedestal portion 52 itself can be cooled.

The pedestal portion 52 shown in FIG. 6 has a wind guide rib (first rib) 53a arranged so as to sandwich the second cylinder 45 with the cooling fan 28 in a part of the upper half of the outer peripheral portion thereof. The air guide rib (second rib) 53b extending along the rotation axis 25 direction of the cooling fan 28 is outside the radial direction 45c (extending direction of the plurality of fins 45a) of the second cylinder 45 of the plurality of fins 45a. It is connected and provided. That is, the pedestal portion 52 is provided with the wind guide rib 53a and the wind guide rib 53b connected to each other in a part of the upper half of the outer peripheral portion thereof. In other words, the wind guide ribs 53a and the wind guide ribs 53b are connected and provided along the plurality of fins 45a provided on the upper half of the outer peripheral surface of the second cylinder 45.

As a result, the wind sent from the cooling fan 28 can be guided to move along the plurality of fins 45a provided in the upper half of the outer peripheral portion of the pedestal portion 52, and is directed to the lower side of the second cylinder 45. Can also let the wind wrap around.

According to the air compressor 10 of the present embodiment, the height of the plurality of fins 45a provided on the outer peripheral surface of the second cylinder 45 gradually increases as the distance from the cooling fan 28 increases. Since the plurality of fins 45a erected in the above are included, the wind sent from the cooling fan 28 hits the plurality of fins 45a erected so as to gradually increase in height. Therefore, the cooling performance of the second cylinder 45 on the high pressure side in the air compressor 10 can be improved, and the durability of the air compressor 10 can be improved. Specifically, it is possible to prevent the durability of the second cylinder 45 from being lowered due to the wear of the sealing member that seals between the second piston 49 and the second cylinder 45, which is caused by the temperature rise of the second cylinder 45. can. As a result, the performance of the air compressor 10 can be maintained for a long time.

Further, since the second cylinder 45 has a plurality of fins 45a erected so that the height gradually increases as the distance from the cooling fan 28 increases, the heat dissipation area by the plurality of fins 45a Can be increased. As a result, the cooling effect of the second cylinder 45 can be enhanced, and the durability of the air compressor 10 can be improved as described above. Further, since the cooling effect of the second cylinder 45 can be enhanced, the discharge performance of the second cylinder 45 can be improved.

Further, the pedestal portion 52 joined to the end portion of the second cylinder 45 is provided with a wind guide rib 53a arranged so as to sandwich the second cylinder 45 with the cooling fan 28, so that the second cylinder is provided. The wind sent from the cooling fan 28 can be circulated around the lower side of the 45. Further, the air guide ribs 53a are provided so as to be connected to the air guide ribs 53b extending along the rotation axis 25 direction of the cooling fan 28 outside the extending direction of the plurality of fins 45a (the radial direction 45c of the second cylinder 45). As a result, the wind sent from the cooling fan 28 can be guided to flow along the plurality of fins 45a, and the wind can also wrap around to the lower side of the second cylinder 45.

As a result, the air from the cooling fan 28 can be applied over substantially the entire circumference of the air guide rib 53, and the cooling effect of the second cylinder 45 can be further enhanced.

Further, the wind guide rib 53 provided on the pedestal portion 52 also has a function of a fin of the pedestal portion 52 itself. That is, since the air sent from the cooling fan 28 also hits the wind guide rib 53, the pedestal portion 52 itself can be cooled. Therefore, the heat dissipation of the second cylinder 45 joined to the pedestal portion 52 can be further improved.

Further, since the pedestal portion 52 itself joined to the end portion of the second cylinder 45 has the function of the heat radiation fin of the second cylinder 45, it is necessary to separately provide a heat sink for enhancing the heat dissipation of the second cylinder 45. There is no. Therefore, as compared with the case where a separate heat sink is attached, the air compressor 10 of the present embodiment does not require a separate heat sink, so that the number of parts can be reduced and the separate heat sink can be reduced. The work man-hours for installing the heat sink can also be reduced.

Next, the modified examples shown in FIGS. 9 to 11 will be described.

In the fin structure of the modified example provided in the second cylinder 45 shown in FIG. 9, a plurality of fins 45a erected so as to gradually increase in height as the distance from the cooling fan 28 increases are adjacent to each other. The gap 45b between the fins 45a is provided so as to open toward the cooling fan 28. In other words, a plurality of fins 45a erected so as to gradually increase in height as the distance from the cooling fan 28 increases, and a gap 45b between adjacent fins 45a is sent from the cooling fan 28. It is provided so as to open toward the upstream side of the.

As a result, air can be reliably sent between the fins 45a of the fins 45a erected so as to gradually increase in height, and the cooling effect of the second cylinder 45 by the fins 45a can be further enhanced.

Further, in the pedestal portion 52 shown in FIG. 9, the wind guide rib 53a and the wind guide rib 53b are provided in a state where the wind guide rib 53a and the wind guide rib 53b are connected to a part of the upper half of the outer peripheral portion thereof, and are shown in FIGS. 10 and 11. As described above, the wind guide rib 53c is also provided in a part of the lower half of the outer peripheral portion of the pedestal portion 52. That is, the air guide rib 53c is located outside the extending direction of the plurality of fins 45a (the radial direction 45c of the second cylinder 45) in the lower half of the outer peripheral portion of the pedestal portion 52 in the direction of the rotation shaft 25 of the cooling fan 28. It is provided so as to extend along the.

As a result, the air sent from the cooling fan 28 can flow along the plurality of fins 45a even on the lower side of the second cylinder 45. As a result, the cooling property of the second cylinder 45 can be further improved.

Further, in the structure shown in FIG. 9, the plurality of fins 45a erected so as to gradually increase in height are shown in FIGS. 10 and 11 so as to straddle the adjacent fins 45a. A horizontally long slit 56a is provided. That is, the slit 56a is provided in the pedestal portion 52 so that the horizontally long slits 56a are located straddling each of the adjacent fins 45a in the plurality of fins 45a erected so as to gradually increase in height. ing.

As a result, the wind sent between the fins 45a of the plurality of fins 45a erected so as to gradually increase in height can be pulled out to the front side of the pedestal portion 52, and the air permeability between these fins 45a can be taken out. Can be improved. As a result, the cooling property of the second cylinder 45 can be further improved.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist thereof. For example, in the above embodiment, the case where the working machine is an air compressor has been described, but the working machine is provided with a cylinder and a cooling fan so that the height gradually increases as the distance from the cooling fan increases. A working machine other than an air compressor may be used as long as it has a cylinder provided with a plurality of fins.

Further, in the above embodiment, the case where the air guide rib is provided on the outer peripheral portion of the pedestal portion of the air compressor has been described, but the air guide rib may not necessarily be provided.

10 ... air compressor (working machine), 11 ... frame, 12 ... cover, 13 ... electric motor (drive source), 14 ... first compression unit, 15 ... second compression unit, 16 ... control unit, 17, 18 ... Air tank, 19 ... legs, 20 ... installation location, 22, 23 ... grip, 24 ... crank case, 25 ... rotating shaft, 26 ... stator, 27 ... rotor, 28 ... cooling fan (fan), 28a ... blades , 28b ... Ventilation path, 34 ... Ventilation path, 36 ... 1st cylinder, 37 ... 1st cylinder head, 39 ... 1st connecting rod, 39a ... Motion conversion mechanism, 40 ... 1st piston, 41 ... 1st compression chamber, 42 ... 1st exhaust chamber, 45 ... 2nd cylinder (cylinder), 45a ... fins, 45b ... gap, 45c ... radial, 45d ... flat surface, 46 ... 2nd cylinder head, 48 ... 2nd connecting rod, 48a ... Motion conversion mechanism, 49 ... second piston (piston), 50 ... second compression chamber, 51 ... second exhaust chamber, 52 ... pedestal, 52a ... screw hole, 53 ... wind guide rib, 53a ... wind guide rib (first) 1 rib), 53b ... air guide rib (second rib), 53c ... air guide rib, 54 ... valve member, 54a ... swing fulcrum, 55 ... discharge hole, 56 ... through hole, 56a ... slit, 57 ... intake hole , 58 ... screw hole, 59 ... O-ring, 60 ... connection pipe, 70 ... connection arm, 71 ... bracket, 73 ... connection pipe, 74 ... pressure sensor, 75 ... pressure reducing valve, 75a ... operation knob, 76 ... supply pipe, 77 ... pressure gauge, 78 ... coupler, 79 ... pressure reducing valve, 79a ... operation knob, 80 ... supply pipe, 81 ... pressure gauge, 82 ... coupler, 83 ... operation unit, 86 ... top plate, 87 ... connection pipe, 90 ... Relief valve, 93 ... Screw member

Claims (7)

With the drive source
A rotating shaft that is rotated by the driving force of the driving source,
Cylindrical cylinder and
A piston housed in the cylinder so as to be reciprocating,
A motion conversion mechanism that converts the rotation of the rotation axis into the reciprocating motion of the piston,
A fan that is rotated by the driving force of the driving source to generate wind,
Equipped with
The cylinder has a plurality of fins erected in the radial direction of the cylinder from the outer peripheral surface of the cylinder.
The plurality of fins are provided apart from each other in the rotation axis direction of the fan, and the plurality of fins are erected so as to increase in height as the distance from the fan increases in the rotation axis direction of the fan. Including, working machine. The working machine according to claim 1, wherein a plate-shaped pedestal portion larger than the radial outer peripheral portion of the cylinder is attached to an end portion of the cylinder on the compression chamber side. The working machine according to claim 2, wherein the outer peripheral portion of the pedestal portion is located outside the radial direction of the cylinder with respect to the tip of the fin having the highest height among the plurality of fins. 2. The work machine described. The pedestal portion has a second rib that projects toward the cylinder side along the central axis direction of the cylinder and extends along the rotation axis direction of the fan outside the extending direction of the plurality of fins. , The working machine according to claim 4. The invention according to any one of claims 1 to 5, wherein each of the plurality of fins is formed in a plate shape having a flat surface portion, and the flat surface portion is arranged along the central axis direction of the cylinder. Working machine. The working machine according to any one of claims 1 to 6, wherein a part of the plurality of fins is provided so that a gap between adjacent fins opens toward the fan.

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