JP2011027063A - Air compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the misalignment of the grounding location of an air compressor body caused by vibration generated by the reciprocation of a piston when an air compressor generates compressed air. <P>SOLUTION: This air compressor includes: a motor; a compressed air generation section driven by a drive force of the motor; a tank storing the compressed air generated in the compressed air generation section; and a plurality of mounts supporting the tank with respect to a floor. In the air compressor, a means is provided to make pressure in a space formed by the mounts and floor negative. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an air compressor that generates compressed air necessary for driving a pneumatic tool such as a nail driver.

  In general, an air compressor that drives a pneumatic tool converts a rotary motion of a rotary output shaft in a drive unit such as a motor into a reciprocating motion of a piston in a cylinder via a crankshaft in a compressed air generating unit, thereby reciprocating the piston. Thus, the air sucked from the intake valve of the cylinder is compressed, and the compressed air compressed in the cylinder is discharged from the exhaust valve of the cylinder through the pipe to the air tank and stored in this tank. A pneumatic tool such as a nail driver operates using compressed air stored in the tank. Such an air compressor is disclosed in Patent Document 1 below, for example.

  In the conventional air compressor, a vibration that shakes the entire air compressor is generated by reciprocating motion of the piston in order to generate compressed air. In order to provide vibration-proof support for the air compressor main body that generates such vibration, a structure in which vibration-proof rubber is provided at the lower part of the tank is known.

JP 2006-125237 A

  The support method using the vibration-proof rubber feet generally used in the above conventional air compressor is a structure that is inexpensive and easy to install, but it does not fully exhibit the vibration-proof function depending on the environment and the state of the floor. “Position shift” phenomenon occurs in which the ground contact position moves little by little.

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide an air compressor provided with a displacement prevention mechanism without impairing the vibration isolation mechanism.

  The object is to support a motor, a compressed air generation unit driven by the driving force of the motor, a tank unit for storing compressed air generated by the compressed air generation unit, and the tank unit with respect to the floor surface. In an air compressor provided with a plurality of mounts, this is achieved by providing means for making a negative pressure in the space formed by the mount and the floor surface.

  According to the present invention, by providing a means for negative pressure in the space formed by the mount and the floor surface, the space formed by the lower portion of the leg portion and the floor surface becomes negative pressure, enabling a strong adsorption state. , "Position shift" phenomenon can be avoided.

Overall view of the air compressor of the present invention Partial sectional view of the product of the present invention (compressed section sectional view) Schematic diagram of air flow in the compressor (compressed air generator) Sectional drawing of one Embodiment of the air compressor leg part of this invention Sectional drawing of one Embodiment of the air compressor leg part of this invention

  A structure of an air compressor according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view for explaining an air compressor 1 according to an embodiment of the present invention.

  An air compressor 1 according to the present invention includes a tank unit 3 that stores compressed air, and a compressed air generation unit 4 that generates compressed air and supplies the compressed air to the tank unit 3 (hereinafter simply referred to as a “compression unit”). And a drive unit 5 having a motor for driving the compressed air generation unit 4, a main power switch 6, and a control circuit for controlling start / stop (on / off) of the motor constituting the drive unit 5 Part 7. A leg portion 8 is provided below the tank portion 3 so that the air compressor 1 can be easily placed on the floor. A transport handle 9 is provided on the side of the tank unit 3 to facilitate the movement of the air compressor 1.

  The main power switch 6 is provided to turn on or off the commercial AC power supplied to the air compressor 1, and electricity is supplied to the control circuit unit 7 and the drive unit 5 through the main power switch 6. .

  The motor constituting the drive unit 5 detects, for example, the rotational position of the rotor of the motor by detection means (not shown) such as a Hall element and controls the supply of electricity to the stator coil of the motor by this detection signal. The DC brushless motor that controls the supply of electricity is controlled by inverter control in the control circuit section.

  The control circuit unit 7 includes power supply circuit parts (not shown), semiconductor switching elements for inverter control of motor operation, and other circuit element parts. Heat generation parts such as semiconductor switching elements are made of heat such as aluminum. It is arranged in a housing made of a material with good conductivity.

  One end of the motor rotation shaft of the drive unit 5 passes through the crankcase 10 of the compression unit 4, and a cooling fan 11 is attached to the tip.

  The tank unit 3 stores compressed air, and includes a pair of cylindrical tanks 3a and 3b arranged in parallel. Compressed air is generated by the compressed air generation unit (compression unit) 4 and is supplied to the tank unit 3 through the discharge pipe 12b (air flow passage) from the discharge port. The discharge pipe 12b and the tank 3b are connected to a screw seat provided in the tank 3b via a joint. The supplied compressed air has a pressure of, for example, 3.0 to 4.2 MPa in the tank unit 3.

  Both tanks 3a and 3b are provided with couplers 14 serving as compressed air outlets, to which pneumatic tools (not shown) such as nailers are connected via hoses (not shown). Is done. In this embodiment, two couplers are provided at the top and bottom, but the number of couplers and the place to be arranged may be arbitrarily set.

  Next to the coupler 14, a pressure reducing valve 15 is provided, and the pressure reducing valve 15 has the highest compressed air pressure on the outlet side (coupler side) regardless of the magnitude of the compressed air pressure on the inlet side (tank side). Has a function to keep the pressure constant. For example, when the pressure reducing valve 15 having a maximum pressure of 2.0 MPa is used, even if the pressure of the compressed air in the tanks 3a and 3b is 2.0 MPa or higher, the compressed air of 2.0 MPa or lower from the pressure reducing valve 15 is used. Is only output. Therefore, compressed air having a pressure equal to or lower than the maximum pressure is obtained from the outlet side of the pressure reducing valve 15 regardless of the pressure in the tanks 3a and 3b. A pressure gauge 16 is attached in the vicinity of the coupler 14 so that the pressure on the outlet side of the pressure reducing valve 15 can be monitored.

  FIG. 2 is a cross-sectional view of the drive unit 5 and the compression unit 4. The compression unit 4 includes a compressor 17, a compressor 18, a crankcase 10, and a crankshaft 19. The compressor 17 includes a low pressure side cylinder 20a, a low pressure side piston portion 21a, and a low pressure side connecting rod 22a. The compressor 18 includes a high-pressure side cylinder 20b, a high-pressure side piston portion 21b, and a high-pressure side connecting rod 22b. The cylinder 20a of the first-stage compressor 17 and the cylinder 20b of the second-stage compressor 18 are horizontally disposed so as to face each other via the crankcase 10.

  The rotational movement of the motor of the drive unit 5 is transmitted to the crankshaft 19 defined by the crankcase 10, and the rotational movement of the crankshaft 19 is performed by the high-pressure side connecting rod 22b and the low-pressure side connecting rod 22a. It is converted into a reciprocating motion of the high pressure side piston 21b and the low pressure side piston 21a that are in contact with each other. The first-stage compressor 17 compresses the external air (atmospheric pressure) sucked through the crankcase 10 and sends the compressed air to the second-stage compressor 18 through the first discharge pipe 12a. . The second-stage compressor 18 compresses the compressed air supplied from the first-stage compressor 17 to an allowable maximum pressure of, for example, 3.0 to 4.2 MPa, and the tank 3b via the second discharge pipe 12b. Supply in.

  Piston rings (not shown) are provided on the pistons 21a and 21b. The piston ring seals the compression chambers 24a and 24b so as to prevent the air being compressed in the high-pressure side compression chamber 24b and the low-pressure side compression chamber 22a from being released into the crankcase 10 or to the outside air. The piston ring also has a function of preventing the pistons 21a and 21b and the cylinders 20a and 20b from being in direct contact with each other and being damaged.

  The process in which compressed air is generated by the reciprocating motion of the piston 21a is shown in FIG. FIG. 3 is a conceptual diagram of the air flow 23 in the compression unit (compressed air generation unit) 4 during operation of the air compressor. First, when the piston 21a moves downward from the top dead center in the cylinder 20a to the bottom dead center (right direction in the figure), the air inside the crankcase 10 enters the compression chamber 24a through the suction port 25 formed in the cylinder 20a. Inhaled. The suction port 25 is provided with a suction valve 26 that allows a flow only from the inside of the crankcase 10 to the compression chamber 24a side. Therefore, since the air inside the crankcase 10 is taken into the cylinder 20a by the movement of the piston 21a, the inside of the crankcase 10 becomes a negative pressure during the operation of the air compressor 1. When the inside of the crankcase 10 is in a negative pressure state, external air flows through the air filter 27. The air filter 27 is made of a nonwoven fabric or the like, and has a role of filtering dust contained in the external air sucked into the crankcase 10.

  In the compression process in which the piston 21a moves upward from the bottom dead center to the top dead center in the cylinder 20a, the piston 21a compresses the intake air in the compression chamber 24a to generate compressed air. Since the suction valve 26 is provided in the suction port 25 of the cylinder 20a, air does not flow back into the crankcase 10. The compressed air generated in the discharge process in which the piston 21a reaches the top dead center of the compression chamber 24a passes through the discharge port 28 provided in the cylinder 20a and is sent to the discharge pipe 12a that circulates in the compression chamber 24b. A discharge valve 29 is provided at the discharge port 28 and allows air to flow only from the compression chamber 24a toward the discharge pipe 12a.

  By repeating the above suction process, compression process, and discharge process by the reciprocating motion of the pistons 21a, 21b, compressed air having an allowable maximum pressure can be supplied from the compressed air generation unit 4 to the tank unit 3.

  The detail of the leg part 8 of the air compressor 1 of this invention is demonstrated using FIG. The leg portion 8 includes a holder 30 and a mount 31a. The material of the holder is steel or hardened plastic, and has a role of covering the tank portion 3. At the lower part of the tank part 3, four attachment parts 32 to be described later are formed. The attachment portion 32 is a metal member having a substantially L-shaped cross-section attached to the outer peripheral portion of a cylindrical air tank, for example, by welding. The mount 31 a is screwed to the attachment portion 32 via the holder 30. The mount 31a is made of a flexible elastic body such as rubber.

A pipe 34 passes through the side surface of the holder 30, and this pipe 34 communicates a space inside the crankcase 10 with a space portion 37 formed between a mount 31 a and a floor surface 33 described later.
Example 1
FIG. 4 shows a first embodiment of the leg 8 of the air compressor 1 according to the present invention. The mount 31 a and the holder 30 are screwed into the mounting portion 32. The lower portion of the mount 31a is integrally formed with a double cylindrical projection comprising an outer cylindrical portion 35 and an inner cylindrical portion 36. Since the inner cylindrical portion 36 is configured to be longer in the vertical direction than the outer cylindrical portion 35, the outer cylindrical portion 35 does not contact the floor surface when the air compressor 1 is placed on the floor surface 33. A space 37 is formed by the inner cylindrical portion 36 and the floor surface 33. Further, the tube 34 is configured to face the space 37. One end of the tube 34 faces the space 37, and the other end faces the inside of the crankcase 10 as shown in FIG. A filter 38 made of a nonwoven fabric or the like is provided at a connection portion between the tube 34 and the crankcase 10. Thereby, it is possible to prevent dust or the like in the space 37 from entering the crankcase 10.

  Since the inside of the crankcase 10 is in a negative pressure state during the operation of the air compressor 1, the air in the space 37 flows into the crankcase 10 through the pipe 34. Thereby, the space part 37 becomes a negative pressure, maintains a stronger adsorption state, and prevents a displacement due to vibration during operation.

The leg portion 8 is provided with switching means 40. The switching means 40 is provided to be slidable with respect to the mount 31a. The switching means 40 is made of a material having a sufficient strength to support the weight of the air compressor 1 such as a steel material and has a plate shape. A hole is formed in the switching means 40. Therefore, by moving the switching means 40, the position of the hole is moved, and when the hole is aligned with the opening of the tube 34, the interior of the crankcase 10 and the space 37 are brought into communication. Thereby, the switching means 40 can selectively bring the inside of the crankcase 10 and the space portion 37 into communication.
(Example 2)
FIG. 5 shows a second embodiment of the leg 8 of the air compressor 1 according to the present invention. Similar to the mount 31a, the lower portion of the mount 31b is integrally formed with a double cylindrical projection comprising an outer cylindrical portion 35 and an inner cylindrical portion 36, and the inner cylindrical portion 36 is longer than the outer cylindrical portion 35 in the vertical direction. Is done.

  A slope 39 is provided below the inner cylindrical portion 36 of the mount 31b. Due to the inclination 39, the inner diameter of the inner cylindrical portion 36 gradually increases downward and is maximum at the lower end. Therefore, the lower part of the inner cylindrical portion 36 of the mount 31b has a suction cup shape. By configuring the lower portion of the mount 31b like a suction cup, the lower end of the inner cylindrical portion 36 comes into contact with the floor surface, and the contact area of the elastic body, which is a soft material, with the floor surface increases. It is difficult to form a gap in the contact portion with the surface, and a stronger adsorption state is possible.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the said embodiment, A various change is possible within the range which does not deviate from the summary.

1: Air compressor 2: Cover 3: Tank portions 3a, 3b: Tank 4: Compressed air generating portion 5: Drive portion 6: Main power switch 7: Control circuit portion 8: Leg portion 9: Transport handle 10: Crank case 11 : Fan 12a, 12b: Discharge pipe 13: Screw seat 14: Coupler 15: Pressure reducing valve 16: Pressure gauge 17, 18: Compressor 19: Crankshaft 20a, 20b: Cylinder 21a, 21b: Piston 22a, 22b: Connecting rod 23: Air flow 24a, 24b: compression chamber 25: suction port 26: suction valve 27: air filter 28: discharge port 29: discharge valve 30: holder 31a, 31b: mount 32: mounting portion 33: floor surface 34: pipe 35: Outer cylindrical part 36: Inner cylindrical part 37: Space part 38: Filter 39: Inclination 40: Switching means

Claims (4)

A motor,
A compressed air generator driven by the driving force of the motor;
A tank unit for storing the compressed air generated by the compressed air generation unit;
In an air compressor comprising a plurality of mounts for supporting the tank portion with respect to the floor surface,
An air compressor comprising means for making a negative pressure in a space formed by the mount and the floor surface. A motor,
A compressed air generator driven by the driving force of the motor;
A crankcase constituting the compressed air generating unit;
A cylinder provided opposite to the crankcase, which constitutes the compressed air generation unit;
A piston capable of reciprocating in the cylinder;
A suction port provided in the cylinder, for sucking air taken into the crankcase that is in a negative pressure state due to reciprocation of the piston, into the cylinder;
A suction valve provided at the suction port to prevent an air flow from the cylinder to the crankcase;
A tank unit for storing the compressed air generated by the compressed air generation unit;
In an air compressor comprising a plurality of mounts for supporting the tank portion and fixing the tank portion to the floor surface,
An air compressor characterized in that a communication member that communicates the space formed by the mount and the floor surface and the space inside the crankcase is provided, and the space formed by the mount and the floor surface has a negative pressure. . The air compressor according to claim 2, wherein a filter is provided in a mounting portion between the communication member and the crankcase. The air compressor according to claim 2 or 3, further comprising switching means capable of selecting communication between a space formed by the mount and the floor surface and a space inside the crankcase.

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