JPH03488Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silencer for an air cylinder that reduces noise generated by exhaust air from the air cylinder.

Traditionally, as a noise reduction device to reduce the noise generated by the exhaust air from air cylinders used to drive equipment, a noise reduction box made of a perforated plate with breathable sound-absorbing material pasted on the inside has been attached to the exhaust outlet. Some devices are designed to muffle the sound by letting the air pass through the muffling box and exhaust the air, but in order to reduce the ventilation resistance of the muffling box, the total area of the openings must be increased, so the shape of the muffling box must be changed. The disadvantage is that it becomes large. In addition, reducing the ventilation resistance of the sound deadening material itself will reduce the sound deadening effect, and the sound absorbing material facing the opening will be severely damaged and deteriorated.Furthermore, this type of sound deadening device does not have a very good sound deadening effect; The difference in noise level between when it is used and when it is not used is such that the noise is reduced by less than 10 phona (A).

Except for the above-mentioned drawbacks, the present invention was completed with the aim of creating a silencer for air cylinders that is small in size, has low ventilation resistance, is free from damage and deterioration, and has a high silencing effect.The present invention is illustrated below. Examples will be described in detail.

Reference numeral 1 denotes a primary silencing chamber, in which a cylindrical outer cylinder 5 having an inner diameter three times the inner diameter and six times the length of the exhaust introduction pipe 4 is closed at both ends with end plates 2 and 3. A porous sound absorbing material 6 is attached to the outer cylinder 5, and the internal space of this outer cylinder 5 is formed as a primary sound deadening chamber 1. 4 is an exhaust introduction pipe, and the exhaust introduction pipe 4 is connected to one end plate 2.
is inserted into the center of the outer cylinder 5 so that its tip opening is located near the center of the outer cylinder 5, and the base end of the exhaust introduction pipe 4 is connected to the exhaust pipe of the air cylinder outside the outer cylinder 5. . Reference numeral 7 denotes a circular exhaust pipe connection port provided in the cylinder wall on the end plate 2 side of the outer cylinder 5;
is located more proximally than the tip opening of the exhaust introduction pipe 4, and the opening area of the exhaust pipe connection port 7 is about three times as large as the internal cross-sectional area of the exhaust introduction pipe 4. Reference numeral 8 denotes an exhaust pipe portion connected to the exhaust pipe connection port 7 and placed along the cylinder wall of the outer cylinder 5 so as to form an exhaust flow path parallel to the exhaust flow path of the exhaust introduction pipe 4; The opening at the tip of the part 8 is located at least at the center of the outer cylinder 5, that is, beyond the position of the opening at the tip of the exhaust introduction pipe 4, and a porous sound absorbing material 9 is attached to the inner surface of the exhaust tube 8 to prevent the exhaust from flowing. Cylinder part 8
A secondary silencing chamber 10 is formed inside. The inner diameter of the outer cylinder 5 is preferably at least three times the inner diameter of the exhaust introduction pipe 4, and the length is preferably 6 to 20 times the inner diameter of the exhaust introduction pipe 4. Also, the opening position of the tip of the exhaust introduction pipe 4 is It is preferable that the length is equal to the diameter of the exhaust introduction pipe 4 before and after the central position that bisects the length of the outer cylinder 5, and furthermore, the shape of the exhaust pipe connection port 7 is as described above. It may be rectangular instead of circular as in the embodiment, and its opening area is preferably 1 to 5 times the cross-sectional area of the exhaust introduction pipe 4 and approximately equal to the opening area of the cross-sectional area of the exhaust cylinder portion 8.

With this structure, when exhaust gas is introduced through the exhaust introduction pipe 4 which is inserted into the center of one end plate 2 and whose tip opening is located near the center of the outer cylinder 5, the exhaust gas is Since a considerable gap is formed between the opening at the tip of the introduction pipe 4 and the other end plate 3, the exhaust flow path is suddenly expanded when exiting the opening at the tip of the exhaust introduction pipe 4, and the exhaust gas is The noise is attenuated by the expansion and depressurization, and when it reaches the end plate 3 and changes its course in the direction shown by the arrow in the figure, it is further attenuated by bending, and exits the exhaust introduction pipe 4 to the end plate 2 of the outer cylinder 5. A sound-absorbing material 6 is applied to the inner surface of the outer cylinder 5 while passing through a bent flow path that reaches the exhaust pipe connection port 7 provided on the side cylinder wall.
Together with the sound absorption effect of the sound absorbing material 6, the sound is considerably reduced in the primary silencing chamber 1 formed by attaching the Since the exhaust pipe forms an exhaust flow path parallel to the exhaust flow path of the exhaust introduction pipe 4, it is attenuated by bending when the course is changed by 180 degrees, and the exhaust pipe is Together with the silencing effect of the sound absorbing material 9 in the secondary sound damping chamber 10 in which the sound absorbing material 9 is attached to the inner surface of the section 8, the sound is reduced secondary. By cleverly combining the sound absorption properties of sound-absorbing materials, excellent sound-absorbing effects can be achieved. Moreover, by providing the exhaust pipe connection port 7 on one end plate 2 side, the overall length can be shortened and an exhaust flow path sufficient for noise reduction can be formed with a bend, resulting in miniaturization. By locating the opening at the tip near the center of the outer cylinder 5, a sufficient distance can be created between the end plate 3 and the other end plate 3, so that there is little exhaust resistance and there is no risk of interfering with the operation of the air cylinder. In addition, when looking at the noise reduction effect of the present invention with respect to the above embodiment, it was 106.5 phon (A) without a muffler and 99.8 phon (A) with a conventional muffler, compared to the sound reduction effect of this embodiment. When the instrument was attached, it became 89.7 hon(A).

As is clear from the above explanation, the present invention has low ventilation resistance, smooth operation of the air cylinder, and no parts of the silencer that can be damaged or deteriorated, and moreover, has a greater noise reduction effect than conventional silencers. It can satisfy the maximum performance of a silencer, and has the advantages of simple structure, miniaturization, and low manufacturing cost, and has extremely great practical value.

[Brief explanation of the drawing]

The drawing is a partially cutaway front view showing an embodiment of the present invention. 1: Primary silencing chamber, 2, 3: End plate, 4: Exhaust introduction pipe, 5: Outer cylinder, 6: Sound absorbing material, 7: Exhaust pipe connection port,
8: Exhaust tube part, 9: Sound absorbing material, 10: Secondary silencing chamber.

Claims (1)

[Scope of utility model registration request] A sound absorbing material 6 is attached to the inner surface of an outer cylinder 5 whose both ends are closed by end plates 2 and 3 to form a primary silencing chamber 1 inside the outer cylinder 5, and an exhaust gas introduction pipe 4 is installed in the center of one end plate 2. is inserted so that its tip opening is located near the center of the outer cylinder 5, and an exhaust pipe connection port 7 is provided in the cylinder wall of the outer cylinder 5 on the side of the end plate 2 to connect the exhaust pipe connection port. An exhaust tube section 8 having an exhaust flow path parallel to the exhaust flow path of the exhaust introduction pipe 4 is connected to 7, and a sound absorbing material 9 is attached to the inner surface of the exhaust tube section 8 to make the inside of the exhaust tube section 8 double. A muffler for an air cylinder, characterized in that it is formed in a muffler chamber 10.