JP2012112283A - Air compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air compressor for supplying compressed air to an air tool such as a nailing machine, and to increase durability of flow channel auxiliary devices such as a pressure gauge or a pressure switch against a pressure fluctuation in a discharge flow channel when the air compressor is not provided with a storage tank for achieving miniaturization and lightweight, wherein because a large pressure fluctuation is generated in the discharge flow channel caused by air consumption upon the usage of the air tool, the durability may decrease due to the damage of the pressure gauge or the pressure switch connected to the discharge flow channel.SOLUTION: Flow channel auxiliary devices such as a pressure gauge 42 and a pressure switch 43 are connected to a discharge flow channel 31 via a fluctuation regulation hole 41e of a base block 41. The large pressure fluctuation generated in the discharge flow channel 31 acts on the pressure gauge 42 or the like in such a state relaxed by a small-diameter fluctuation regulation hole 42e. Accordingly, the damage is prevented and the durability increases.

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air compressor for supplying compressed air to an air tool such as a compressed air driven nail driver or an air tacker, and mainly relates to a simple air compressor that is relatively small and excellent in portability. .

Although this simple air compressor has a smaller discharge capacity than a large stationary air compressor, it is relatively small and easy to carry, so it offers great convenience for simple light work using an air tool. . Techniques relating to this simple air compressor are disclosed in the following patent documents.
This simple air compressor has a resin case with an electric motor and a compression part, and a rechargeable battery pack is used as a power source. The compression unit is configured to convert the rotational output of the electric motor and reciprocate the piston in the cylinder to discharge the compressed air, and supply and store the discharged compressed air directly to the air tool. By omitting the tank, the size and weight are reduced.
According to the simple type air compressor disclosed in the above, it can be used while being carried on an operator's shoulder or on his / her shoulder, so that it is used in a construction work site where a power outlet is not prepared. Compressed air can be supplied to an air tool such as a nail driver without being restricted by the above-described restrictions, and thus light work such as repair work can be efficiently performed.

U.S. Pat. No. 7,140,845 Japanese Patent Laid-Open No. 2-108878

However, various improvements have been required for the conventional air compressor. For example, as described above, this type of simple air compressor often does not include a tank for storing compressed air in order to reduce the size and weight, and the compressed air discharged from the compression unit is The air tool is supplied as it is. For this reason, if a large pressure fluctuation occurs in the discharge flow path due to air consumption due to the use of an air tool, this may directly act on flow path auxiliary equipment such as a pressure gauge or pressure switch, and these may be damaged. As a result, there is a problem that the durability is lowered.
An object of this invention is to improve the durability with respect to the pressure fluctuation of the flow-path auxiliary apparatus connected to the discharge flow path.

The above problems are solved by the following invention.
In the first invention, an electric motor is connected to a main body case through an air hose and an electric motor, a compression portion that converts the rotational output of the electric motor into a reciprocating motion of a piston in the cylinder and discharges compressed air. An air compressor equipped with a discharge joint for discharge and a discharge flow path for allowing compressed air to flow from the compression section to the discharge joint, and includes a flow passage auxiliary device including at least a pressure gauge operated by the air pressure of the discharge flow path This is an air compressor in which this flow path auxiliary device is connected to the discharge flow path through a fluctuation adjusting hole having a smaller diameter than the discharge flow path.
According to the first aspect of the invention, the flow passage auxiliary device such as a pressure gauge is connected to the discharge flow passage through the small-diameter fluctuation adjusting hole. For this reason, since large pressure fluctuations in the discharge flow path due to the use of the air tool act on the flow path auxiliary equipment in a state where the fluctuation adjustment hole has eased, the damage to the flow path auxiliary equipment can be prevented and its durability can be prevented. Can be increased.
According to a second invention, in the first invention, the flow path auxiliary device is connected to the discharge flow path via a base block having at least three connection ports, and the upstream first of the three connection ports. A discharge channel is connected to the connection port, a discharge joint is connected to the second connection port on the downstream side, and a third connection port is connected between the first connection port and the second connection port via a fluctuation adjusting hole, It is an air compressor in which the pressure gauge is connected to the third connection port.
According to the second aspect of the present invention, the pressure gauge is connected to the discharge flow path through the fluctuation adjusting hole of the base block, the damage or the like is prevented, and the durability is enhanced.
In a third aspect based on the second aspect, the base block is provided with a fourth connection port between the first connection port and the second connection port via the fluctuation adjusting hole, and a discharge channel is provided in the fourth connection port. This is an air compressor to which a pressure switch for detecting the air pressure is connected.
According to the third invention, the pressure of the discharge flow path is detected, and based on this, damage and the like due to pressure fluctuations of the pressure switch for starting and stopping the electric motor are prevented in advance, and its durability is improved. Can be increased.
A fourth invention is the air compressor according to any one of the first to third inventions, wherein the flow passage area of the fluctuation adjusting hole is 10% or less of the flow passage area of the discharge flow passage.
According to the fourth aspect of the invention, the large pressure fluctuation in the discharge flow path due to the use of the air tool is sufficiently mitigated by the fluctuation adjusting hole and acts on the flow path auxiliary device, thereby preventing the flow path auxiliary device from being damaged. The durability can be reliably increased. The fluctuation adjusting hole can be a small diameter hole of about 1.5 mm, for example.

It is a whole perspective view of the air compressor of this embodiment. This figure has shown the state seen from the back diagonally right. It is a whole perspective view of the air compressor of this embodiment. This figure has shown the state seen from the diagonally left front. It is a whole top view of the air compressor of this embodiment. It is a disassembled perspective view of the air compressor of this embodiment. This figure has shown the state seen from the diagonally left front. It is a longitudinal cross-sectional view of the air compressor of this embodiment. This figure is a left side view of the internal structure with the left half case removed. FIG. 6 is a sectional view taken along line (VI)-(VI) in FIG. 5, and is a longitudinal sectional view of a compression unit. FIG. 6 is a cross-sectional view taken along line (VII)-(VII) of FIG.

Next, an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 to 3, the air compressor 1 according to the present embodiment has a structure that is relatively small and excellent in portability that can be easily carried. In the upper center of the main body case 10 of the air compressor 1, a handle portion 2 is provided for gripping when the user carries it. Belt handle portions 3 and 4 for hooking a shoulder belt (not shown) when carrying the air compressor 1 on the shoulder are provided in front and rear of the handle portion 2. Further, a discharge joint 30 for connecting an air tool via an air hose is provided on the rear surface of the main body case 10, and a battery pack 6 is mounted as a power source below the discharge joint 30. The battery pack 6 can be removed by sliding backward, and can be repeatedly used by being removed and charged by a separately prepared charger.
Further, on the upper surface of the main body case 10 and behind the handle portion 2, an operation panel 5 having push buttons 5a and 5b for start / stop operation and a pressure adjustment dial 5c and a pressure gauge 42 to be described later are provided. Yes. In addition, elastic rubber legs 7 are attached to the four corners of the bottom of the main body case 10.
As shown in FIG. 4, the main body case 10 of the air compressor 1 has a half-case structure that is divided into right and left. Each of the left half case 10L and the right half case 10R manufactured by resin molding abuts each other and is screwed at a plurality of locations, so that the main body case 10 includes a compression unit 20 described later. As shown in FIGS. 1-3, the code | symbol D is attached | subjected to the mutual abutting part (separation line) of the left and right half cases 10L and 10R. The left and right half cases 10L and 10R are separated into left and right by the separation line D. As shown in FIG. 4, the left and right half cases 10L and 10R are coupled to each other by a plurality of case fixing screws 11-11.

FIG. 5 shows details of the internal structure housed in the main body case 10. The compression unit 20 is accommodated in the front side of the main body case 10. The compression unit 20 is a drive unit for the air compressor 1, and includes an electric motor 21, a speed reduction unit 22, a compression unit 23, and a unit case 24 that houses and assembles them. The unit case 24 includes a motor case portion 24c that accommodates the electric motor 21, a gear case portion 24d that accommodates the gear train of the speed reduction portion 22, and a crankcase portion 24e that mainly accommodates the crank disc 23a of the compression portion 23. Yes.
The electric motor 21 is a drive source of the air compressor 1 and starts up using power supplied from the battery pack 6 as a power source. In the figure, the wiring (power supply circuit) and the power supply circuit for this purpose are not shown. A cooling fan 21 b and a drive gear 21 c are attached to the output shaft 21 a of the electric motor 21. The drive gear 21c is meshed with a larger-diameter driven gear 22a. Engagement of the drive gear 21c and the driven gear 22a constitutes the speed reduction unit 22. The rotational output of the electric motor 21 is decelerated by the meshing of the gear train of the speed reducing unit 22.
The reduced rotational output of the electric motor 21 is output to the compression unit 23 via the output shaft 25 to which the driven gear 22a is fixed. A crank disk 23 a of the compression unit 23 is attached to the output shaft 25. A base end portion of a crank rod 23c is supported on the crank disc 23a via a crank shaft 23b so as to be relatively rotatable. The crankshaft 23 b is eccentric with respect to the output shaft 25 of the speed reduction unit 22. A piston 23d is attached to the tip of the crank rod 23c. The piston 23d is held so as to be capable of reciprocating in the cylinder 23e. The cylinder 23e is airtightly attached to the upper part of the crankcase portion 24e. The upper chamber of the cylinder 23e and the piston upper chamber communicates with the exhaust port 26 through the exhaust hole 23f.

When the electric motor 21 is activated, the rotational output is decelerated by the speed reduction unit 22 and output to the output shaft 25, whereby the crank disk 23a rotates. When the crank disk 23a rotates, the crankshaft 23b revolves around the output shaft 25, so that the crank rod 23c moves up and down, thereby causing the piston 23d to reciprocate up and down in the cylinder 23e. As the piston 23d reciprocates in the cylinder 23e, outside air is supplied to the upper chamber of the piston, and compressed air is supplied from the exhaust hole 23f to the exhaust port 26.
A discharge hose 28 is connected to the exhaust port 26 via an L-shaped joint 27. The discharge hose 28 is routed from the front side of the compression part 23 to the rear side of the main body case 10 through the side. The discharge hose 28 is connected to a discharge joint 30 attached to the rear portion of the main body case 10 through a straight joint 29 and a pressure display unit 40 described later. The air flow path including the discharge hose 28 and extending from the compression portion 23 to the discharge joint 30 functions as a discharge flow path 31 for flowing compressed air.
Support boss portions 24 a to 24 a for supporting the unit case 24 with respect to the main body case 10 are integrally provided on the outer surface of the unit case 24. In the present embodiment, support boss portions 24a to 24a are provided at a total of four locations including a lower portion of the motor case portion 24c, an upper portion of the gear case portion 24d, a lower portion of the crankcase portion 24e, and the front surface. A rubber cap 24b as an elastic body is put on the support boss portions 24a to 24a. Each support boss part 24a-24a is hold | maintained in the state fitted by the holding rib 10a provided in the main body case 10 (10L, 10R) via the rubber cap 24b. The holding rib 10a is provided in a state of facing both the left and right half cases 10L and 10R. For this reason, as shown in FIG. 7, each support boss portion 24a is sandwiched and held with the rubber cap 24b interposed between the holding ribs 10a, 10a of the left and right half cases 10L, 10R.
In the present embodiment, the four support boss portions 24 a to 24 a are all arranged along the separation line D of the main body case 10. For this reason, as described above, when the main body case 10 is assembled by abutting the left and right half cases 10L and 10R, all the four support boss portions 24a to 24a are respectively left and right half cases 10L and 10R via the rubber caps 24b. It is configured to be sandwiched between them.

Thus, the compression unit 20 as the main vibration source is floating supported (elastically supported) on the main body case 10 via the rubber caps 24b to 24b as elastic bodies. For this reason, the vibration generated in the electric motor 21 and the compression portion 23 is absorbed by the rubber cap 24b of each support boss portion 24a, and the vibration of the main body case 10 and thus the air compressor 1 is reduced.
As shown in FIG. 5, the battery pack 6 is mounted on the bottom rear end side of the main body case 10. Further, the electric motor 21 is disposed in the vicinity of the bottom portion of the main body case 10 in the substantially front-rear direction center. Furthermore, the speed reduction part 22 is arrange | positioned in the front side of the electric motor 21, and the compression part 23 is arrange | positioned in the front side.
For this reason, the compression part 23 is arrange | positioned in the bottom part near the front end of the main body case 10. Thus, among the components constituting the air compressor 1, the relatively heavy battery pack 6, the electric motor 21, and the compression portion 23 are arranged side by side in the front-rear direction (motor axial direction) near the bottom. Therefore, the center of gravity G of the air compressor 1 is set to be approximately in the middle in the front-rear direction near the bottom. Moreover, as shown in FIGS. 3 and 4, the battery pack 6 and the compression unit 20 are arranged along the separation line D between the left and right half cases 10L and 10R in the center in the left-right width direction of the main body case 10. As a result, the center of gravity G of the air compressor 1 is located at the center in the left-right direction.
As described above, the center of gravity G of the air compressor 1 is set at a middle position in the front-rear direction and the left-right width direction at a low position near the bottom of the main body case 10, so that the air compressor 1 is less likely to fall. In addition, the center of gravity G is positioned below the handle portion 2 disposed substantially in the center in the front-rear direction of the main body case 10, so that stability during carrying is enhanced.

Next, the compressed air discharged from the compression unit 20 is supplied to the discharge joint 30 through the discharge flow path 31 including the discharge hose 28. The discharge joint 30 is disposed above the battery pack 6 and in the middle of the rear surface of the main body case 20 in the height direction. By connecting an air tool such as a nail driver to the discharge joint 30 via an air hose (not shown), the air tool can be operated. The air compressor 1 of the present embodiment does not include a tank for accumulating compressed air discharged from the compression unit 20. For this reason, the compressed air discharged from the compression unit 20 is directly supplied to the air tool as it is. As a result, air pressure fluctuation (pressure fluctuation) in the discharge hose 28 becomes relatively large due to air consumption by the air tool. This large pressure fluctuation causes damage to the pressure gauge and pressure switch that indicate the air pressure of the compressed air to be discharged, thereby reducing its durability.
In this regard, the air compressor 1 of the present embodiment is devised in the pressure display unit 40. As shown in FIGS. 4 and 5, the pressure display unit 40 of this embodiment is interposed in the middle of the discharge flow path 31. The pressure display unit 40 includes a base block 41, a pressure gauge 42 as a flow path auxiliary device, and a pressure switch 43. The base block 41 is held in a state of being sandwiched between holding ribs 10b and 10b provided to face the left and right half cases 10L and 10R. The pressure of compressed air discharged from the compression unit 20 (air pressure in a discharge passage 31 to be described later) is displayed on the pressure gauge 42, and when this air pressure reaches a set pressure, this is detected by the pressure switch 43. . When the pressure switch 43 detects the set pressure, this is output to the motor control circuit, the electric motor 21 is stopped, and therefore the compression unit 20 is stopped. When the supplied air pressure falls below the set pressure, this is detected by the pressure switch 43 and the electric motor 21 is restarted, so that the compressed air starts to be supplied again from the compression unit 20.
The base block 41 is provided with four connection ports 41a to 41d. A discharge hose 28 is connected to the first connection port 41 a on the upstream side of the discharge flow path 31 via a joint 29. The discharge joint 30 is connected to the second connection port 41b on the downstream side of the discharge flow path 31. Between the first connection port 41a and the second connection port 41b, the third connection port 41c and the fourth connection port 41d are communicated with the discharge flow path 31 through a small-diameter variation adjustment hole 41e. In the present embodiment, the fluctuation adjusting hole 41e is set to a hole diameter of about 1.5 mm at the maximum, and the flow path area is a discharge flow path between the first connection port 41a and the second connection port 41b. It is set to approximately 10% or less of the flow path area of 31.
The third connection port 41 c is opened on the upper surface of the base block 41. A pressure gauge 42 is attached to the third connection port 41c as a flow path auxiliary device. The fourth connection port 41d communicates with the third connection port 41c in a state where it intersects. The fourth connection port 41 d is opened on the front side surface of the base block 41. A pressure switch 43 is attached to the fourth connection port 41d as another flow path auxiliary device. Thus, the third connection port 41c to which the pressure gauge 42 is connected and the fourth connection port 41d to which the pressure switch 43 is attached communicate with the discharge flow path 31 via the small-diameter variation adjustment hole 41e. For this reason, the pressure fluctuation in the discharge flow path 31 is not directly transmitted to the third and fourth connection ports 41c and 41d, but is transmitted in a relaxed state by the fluctuation adjusting hole 41e. It is possible to prevent damage and the like and improve its durability.

According to the air compressor 1 of the present embodiment configured as described above, the pressure gauge 42 and the pressure switch 43 attached to the base block 41 as flow path auxiliary devices are connected to the discharge flow path 31 via the small-diameter fluctuation adjusting hole 41e. Has been. For this reason, when a large pressure fluctuation occurs in the discharge flow path 31 due to air consumption due to the use of the air tool, the pressure fluctuation is relaxed by the fluctuation adjusting hole 41e and the third connection port 41c and the fourth connection port 41d. Therefore, the pressure gauge 42 and the pressure switch 43 can be prevented from being damaged and the durability thereof can be improved.
Further, since the pressure gauge 42 and the pressure switch 43 are connected to the single base block 41 and connected to the discharge flow path 31, the structure can be simplified and the assemblability can be improved. Can do.

Various modifications can be made to the embodiment described above. For example, although the pressure gauge 42 and the pressure switch 43 are illustrated as the flow path auxiliary device, when the pressure switch 43 is omitted and only the pressure gauge 42 is attached, or conversely, in addition to the pressure gauge 42 and the pressure switch 43, other The same can be applied to the case where a flow path auxiliary device having a function is attached.
Moreover, although the structure which attached and assembled the pressure gauge 42 and pressure switch 43 as a flow path auxiliary apparatus to the one base block 41 was illustrated, the structure connected to the discharge flow path 31 individually via a fluctuation | variation adjustment hole It is good.
Furthermore, although the configuration in which the pressure display unit 40 is supported in the main body case 10 by being sandwiched between the holding ribs 10b and 10b provided in the left and right half cases 10L and 10R is exemplified, the configuration may be fixed by screwing or the like.
Moreover, although the main body case 10 of the half structure comprised by abutting and joining the right and left half cases 10L and 10R was illustrated, for example, the pressure display part 40 illustrated also about the main body case divided into up and down is applied. can do.
Furthermore, although the air compressor 1 of the form which is not provided with the tank for storing the compressed air discharged from the compression part unit 20 was illustrated, applying the pressure display part 40 illustrated also about the air compressor provided with a storage tank is applicable. it can.
Further, the present invention can also be applied to a stationary or large-sized air compressor that does not include the handle portion 2 or the belt hanging portions 3 and 4 for the shoulder.
Moreover, although the direct power supply type air compressor 1 which uses a rechargeable battery pack as a power source has been illustrated, it can also be applied to an AC power supply type or engine type air compressor.

DESCRIPTION OF SYMBOLS 1 ... Air compressor G ... Center of gravity 2 ... Handle part 3, 4 ... Belt hook part 5 ... Operation panel, 5a, 5b ... Push button, 5c ... Pressure adjustment dial 6 ... Battery pack 7 ... Leg part 10 ... Main body case, 10a, 10b ... Holding rib D ... Separation line 10L ... Left half case 10R ... Right half case 11 ... Case fixing screw 20 ... Compression unit 21 ... Electric motor 22 ... Deceleration part 23 ... Compression part 23a ... Crank disc, 23b ... Crankshaft, 23c ... Crank rod 23d ... Piston, 23e ... Cylinder, 23f ... Exhaust hole 24 ... Unit case 24a ... Support boss part, 24b ... Rubber cap (elastic body)
24c ... motor case portion, 24d ... gear case portion, 24e ... crankcase portion 25 ... output shaft 26 ... exhaust port 27 ... joint 28 ... discharge hose 29 ... joint 30 ... discharge joint 31 ... discharge flow path 40 ... pressure display portion 41 ... Base block 41a ... 1st connection port, 41b ... 2nd connection port, 41c ... 3rd connection port, 41d ... 4th connection port 41e ... Fluctuation adjustment hole 42 ... Pressure gauge (flow path auxiliary equipment)
43 ... Pressure switch (channel auxiliary device)

Claims (4)

An electric motor, a compression part that discharges compressed air by converting the rotational output of the electric motor into a reciprocating motion of a piston in the cylinder, a discharge joint for connecting an air tool via an air hose, An air compressor having a discharge flow path for flowing compressed air from the compression section to the discharge joint,
An air compressor comprising a flow path auxiliary device including at least a pressure gauge that is operated by the air pressure of the discharge flow path, and connecting the flow path auxiliary device to the discharge flow path through a fluctuation adjusting hole having a smaller diameter than the discharge flow path. . 2. The air compressor according to claim 1, wherein the flow path auxiliary device is connected to the discharge flow path via a base block having at least three connection ports, and is located upstream of the three connection ports. The discharge flow path is connected to the first connection port, the discharge joint is connected to the second connection port on the downstream side, and the first adjustment port is connected to the second connection port via the fluctuation adjusting hole. An air compressor in which three connection ports are connected and the pressure gauge is connected to the third connection port. 3. The air compressor according to claim 2, wherein a fourth connection port is provided in the base block between the first connection port and the second connection port through the fluctuation adjusting hole, and the fourth connection port is provided with the fourth connection port. The air compressor which connected the pressure switch for detecting the air pressure of the said discharge flow path. The air compressor according to any one of claims 1 to 3, wherein a flow passage area of the fluctuation adjusting hole is 10% or less of a flow passage area of the discharge flow passage.

Images