JPH09250457A - Air compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To try to reduce noises of an air compressor. SOLUTION: A dynamic damper 21 is fixed to the inner wall of an air tank 3 of an air compressor 1. The dynamic damper 21 is constituted by a weight attached to a guide shaft and a compression coil spring acting to both faces of the weight, and a resonance frequency f0 of the weight is set so as to be equal to the vibration frequency of a compressor unit 2. The air tank 3 and the weight of the dynamic damper 21 is resonated in reverse phase by vibration generated during actuation of the compressor unit 2. And, the inertial force of the weight acts to the air tank 3 via the compression coil spring, and the vibration of the air compressor 1 is restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air compressor, and more particularly to an air compressor which has reduced vibration and noise.

[0002]

In a portable air compressor, a compressor unit and an air tank are integrally connected, and high pressure air discharged from a compressor unit driven by a motor or an engine is stored in the air tank.

An air compressor used for a pneumatic tool or the like is generally equipped with a reciprocating compressor unit. Particularly, a compressor unit having a larger discharge amount has a larger vibration and noise, and a lower noise is demanded. . Therefore, a technical problem to be solved in order to provide an air compressor with low noise occurs, and an object of the present invention is to solve the above problem.

[0004]

DISCLOSURE OF THE INVENTION The present invention is proposed in order to achieve the above object, and is an air compressor in which an air tank and a compressor unit for compressing and filling air into the air tank are combined, A weight is attached to a rail or a guide so that the weight can travel freely, and an elastic means such as a combination of springs or magnets is provided on both front and rear sides of the weight in the traveling direction to move the weight to an intermediate position in the traveling range of the rail or the guide. A stabilized dynamic vibration reducer is installed in the air tank, and a resonance frequency of the dynamic vibration reducer is set to be substantially equal to a fundamental frequency of vibration generated by the compressor unit. is there.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows an air compressor 1 in which an air tank 3 is connected to an electric compressor unit 2. The compressor unit 2 has a motor 4
Is a reciprocating compressor in which an eccentric shaft 6 attached to a rotary shaft 5 of a cylinder 7 and a piston 8 inserted in a cylinder 7 are connected by a connecting rod 9, and an air is discharged through a discharge valve 10 provided at the top of the cylinder 7. Compressed air is discharged into the tank 3. A balance weight 11 for balancing the mass of the rotating system is attached to the eccentric shaft 6 of the motor 4. Reference numeral 12 is a power cord, and 13 is a power plug.

The air tank 3 includes an air pressure regulator 1
There are provided two systems of air outlets, namely, a coupler 15 for taking out the pressured air through 4 and a coupler 16 for directly taking out the uncontrolled pressured air. A dynamic vibration absorber 21 is installed in the air tank 3.
Are stored and fixed to the inner wall of the air tank 3.

FIG. 2 shows a dynamic vibration absorber 21 in which a weight 23 is slidably mounted on a guide shaft 22, and compression coil springs 26 and 27 are provided on both surfaces of the weight 23 and both end plates 24 and 25 of the guide shaft 22, respectively. It is installed. Weight 2
3 is pressed by the compression coil springs 26 and 27 from both sides, and is stable at an intermediate position of the guide shaft 22 where the elastic forces of the compression coil springs 26 and 27 on both sides are balanced.

The mass m _{0 of the} weight 23 and the compression coil spring 26,
Dynamic vibration absorber 21 determined by the spring constant k _{0 of} 27
The resonance frequency f _{0 of} is expressed by the following equation. 1 / 2π√ (k ₀ / m ₀ ) = f ₀ (Hz) Here, if the rotation speed of the motor 4 of the compressor unit 2 is, for example, 1440 rpm = 24 Hz, the mass m _{0 of the} weight 23 is 1 kg, Spring constant k ₀ = 2.3
The resonance frequency f ₀ is set equal to the fundamental vibration frequency of the compressor unit 2, with f ₀ ≈24 Hz as kgf.

As is generally known, the dynamic vibration absorber 21
Is the weight 2 when the acceleration in the guide shaft direction is zero.
3 is stationary at the central position of the guide shaft 22, and the weight 23 starts to move relatively along the guide shaft 22 when acceleration is applied. Then, the weight 23 vibrates together with the air tank 3 due to the vibration generated during the operation of the compressor unit 2, and the vibration phase of the air tank 3 and the weight 23 deviates by 180 degrees when the resonance frequency f ₀ ≈24 Hz,
The amplitude of the weight 23 also becomes maximum. At this time, the inertial force of the weight 23 acts on the air tank 3 via the compression coil springs 26 and 27 and the guide shaft 22 to reduce the inertia of the entire air compressor 1 and suppress the amplitude. Furthermore, the vibration of the fundamental vibration frequency of the compressor unit 2 = 24 Hz is attenuated, so that high-order harmonic vibration (48 Hz, 72 H) is generated.
z, ...) also decays.

As the dynamic vibration reducer, various types other than the one using a metal spring can be applied, and as shown in FIG.
A movable magnet 32 is slidably attached to the guide shaft 31, and fixed magnets 33, 34 are attached to both ends of the guide shaft 31.
And the N pole of the movable magnet 32 and the N pole of the fixed magnet 33 face each other, and the S pole of the movable magnet 32 and the N pole of the fixed magnet 34 face each other so that the movable magnet 32 is guided by the repulsive force of the magnetic force lines. The magnet type dynamic vibration reducer 35 stabilized at the intermediate position of 31 may be used.

The installation direction of the dynamic vibration absorber is generally effective if the vibration direction of the weight is matched with the reciprocating direction of the piston 8 which is the vibration source, but the invention is not limited to this. The amplitude should be analyzed to determine the most effective installation location and orientation. Further, when a plurality of dynamic vibration absorbers are installed in an orthogonal posture, the vibration damping effect against vibrations in multiple directions is further improved.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the technical scope of the present invention, and it goes without saying that the present invention extends to those modifications. is there.

[0013]

As described above, in the air compressor of the present invention, the vibration generated by the compressor unit is damped by using the dynamic vibration reducer, so that the vibration and noise are remarkably reduced and the working environment is improved. Exert. Further, since the dynamic vibration reducer is housed in the air tank, it does not hinder transportation and handling, and damage to the dynamic vibration reducer can be prevented.
In addition, dust and foreign matter do not adhere to the dynamic vibration reducer, and in particular, when a magnet type dynamic vibration reducer is used, it is possible to prevent malfunctions due to adsorption of sand iron or iron powder by the magnet, which can prevent long operation. You can expect stable operation for a certain period.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of an air compressor according to an embodiment of the present invention.

FIG. 2 is a front view of a coil spring type dynamic vibration reducer.

FIG. 3 is a front view of a magnet type dynamic vibration reducer.

[Explanation of symbols]

 1 Air Compressor 2 Compressor Unit 3 Air Tank 21 Dynamic Vibration Absorber 22 Guide Shaft 23 Weight 24, 25 End Plate 26, 27 Compression Coil Spring 31 Guide Shaft 32 Movable Magnet 33, 34 Fixed Magnet 35 Magnet Dynamic Vibration Absorber

Claims (1)

[Claims] 1. An air compressor comprising an air tank and a compressor unit for compressing and filling air into the air tank, wherein a weight is movably mounted on a rail or a guide, and the weight is mounted on both front and rear sides of the weight in the traveling direction. A dynamic vibration absorber that stabilizes the weight at an intermediate position of the travel range of the rail or guide by interposing an elastic means such as a combination of springs or magnets is installed in the air tank to resonate the dynamic vibration absorber. An air compressor having a frequency set to be substantially equal to a fundamental frequency of vibration generated by the compressor unit.