JPH07111174B2 - Suction muffler - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air compressor, and particularly to a suction silencer suitable for use in a low noise region.

(Prior Art) Conventionally, as a device for compressing air used for various purposes, there is an air compressor 1 (hereinafter, referred to as compressor 1) as shown in FIG. The compressor 1 is usually covered with a resin-made storage case, and can be supported with the lower side in the figure facing upward when carrying it. FIG. 3 is a cross-sectional plan view of the compressor 1 installed in an operable state, with the cover removed.

The compressor 1 includes an air compression cylinder 2 that constitutes a compressor body and a piston 3 that slides in the air compression cylinder 2.
And an electric motor 5 for operating the piston 3 and having a cooling fan 4, and an air storage tank (not shown). Further, in order to reduce noise during operation of the compressor 1, an intake muffler 8 (hereinafter referred to as muffler 8), which is a premise of the present invention, is attached to an air suction port 7 provided in the cylinder head 6. Has been.

The muffler 8 will be described with reference to FIG. Silencer 8
Is roughly composed of a casing 9, which is a silencer body, a silencer plate 10, a filter 11, and a cover 12. The casing 9 has a box shape attached to the air suction port 7, and an air insertion hole 13 is provided in the bottom wall portion 9a (the right side wall of the casing 9 in FIG. 4) substantially at the center. A locking portion 14 is formed inside the opening of the casing 9, and a cover locking portion 15 facing outward is formed at the outer peripheral edge of the opening of the casing 9. There is.
The sound deadening plate 10 and the filter 11 are attached to the locking portion 14 inside the casing 9. As a result, the expansion chamber 16 is formed in the casing 9 to suddenly expand a part of the intake passage.

The sound deadening plate 10 divides the passage of the intake air into a plurality of elongated passages and throttles the sucked air to reduce intake noise. One side surface thereof extends in the lateral direction as shown in FIG. A plurality of ribs 17 are formed, and ribs 17 and ribs 17 are formed.
Four communication holes 18 for passing suction air are formed in the central portion between and. When attaching the sound deadening plate 10 to the casing 9, the surface on which the rib 17 is formed is placed on the casing 9
Install with the opening side of.

The filter 11 is for filtering suction air so as to prevent dust and the like in the atmosphere from entering the cylinder 2, and is made of felt or the like. Also, the cover 12 is a sound deadening plate.
The filter 10, the filter 11, etc. are fixed to the casing 9, and one side thereof, that is, the surface facing the casing 9 side, has a filter.
A plurality of partition walls 19 for pressing and fixing the sound absorbing plate 11 on the sound deadening plate 10 are formed. Moreover, the casing 9 is provided on the inner peripheral edge thereof.
The claw portion 20 related to the cover locking portion 15 is provided. The cover 12 is attached to the casing 9 so that air is sucked into the compressor 1 when the compressor is operated.
A gap is formed in the upper and lower engaging portions of the claw portion 12 of 12 and the engaging portion 15 for the cover of the casing 9. In the figure, 21 is an intake port, 22 is an intake valve, 23 is a cylinder chamber, 24 is an exhaust port, and 25 is an exhaust valve.

When the compressor 1 having the silencer 8 configured as described above is operated, that is, when the piston 3 is operated downward in FIG. 4, air is introduced from the suction port 7 to the cylinder head 6. Although it is inhaled, since the muffler 8 is integrally attached to the air intake port 7, the air is absorbed by the muffler 8.
It is sucked into the cylinder head 6 via the.
That is, as shown by the arrow A in FIG. 4, the intake air is sucked through the upper and lower gaps between the casing 9 and the cover 12, filtered by the filter 11, and then passed through the communication hole 18 of the sound deadening plate 10 to reach the expansion chamber 16 to go into. Further, air flows into the cylinder head 6 from the expansion chamber 16 through the air insertion hole 13 and the air suction port 7, and opens the intake valve 22 from the intake port 21 and flows into the cylinder chamber 23. Then, when the piston 3 is operated upward in FIG. 4, air flows out from the cylinder chamber 23 by opening the exhaust valve 25 from the exhaust port 24 and is stored in an air storage tank (not shown).

The intake sound generated at the time of intake is attenuated by the passages elongated by the ribs 17 of the muffling plate 10 and is throttled and reduced by the air communication hole 18 formed in the muffling plate 10. Moreover, the pressure of the intake air also decreases due to the expansion chamber 16,
The intake noise will be further reduced.

(Problem to be Solved by the Invention) However, in the above-described conventional silencer having such a configuration, since the intake sound of the compressor is reduced by the expansion throttle type device including the expansion chamber and the communication hole, Further, in order to reduce the intake noise, it is necessary to make the expansion chamber large, and there is a problem that there is a limit to downsizing. Further, even if a resonance type device having a resonance chamber or the like provided in the middle of a pipe is used to reduce intake noise, it is necessary to form a large resonance chamber similarly, which is also unsuitable for downsizing. There was a point.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a small silencer capable of minimizing the volume of the space occupied by the silencer.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention is box-shaped, and an air insertion hole is formed at an eccentric position of the bottom wall portion, and the air insertion hole is formed in the air compressor. A casing adapted to be attached to the air suction port, and a filter receiver formed in a bottom wall portion of the casing so as to restrict the intake air passage and extend in one direction so as to expand and project at a plurality of positions at intervals. A filter having one side surface abutting against the filter receiver for filtering suction air and having elasticity, and a plurality of filters extending on one side surface at intervals in a direction substantially orthogonal to the extending direction of the filter receiver. Ribs are formed, and a plurality of communication holes that communicate a plurality of spaces formed between the plurality of ribs with the other side surface are formed, and the sound deadening plate is in contact with the other side surface of the filter via the rib. And the case A cover attached to the casing so as to form a space between the casing and the other side surface of the sound deadening plate, and a cover that is inserted into the space inside the casing and has one end protruding outside the casing and an outer periphery formed by the cover and the casing. A cylindrical member that is sandwiched and extends to a position sufficiently distant from the air insertion hole provided at the eccentric position of the bottom wall of the casing, and an outer periphery of a portion of the cylindrical member located in the space inside the casing. It is provided with a protrusion that is provided and abuts on each of the cover and the sound deadening plate and presses them to position the sound deadening plate.

(Operation) With the above configuration, when the compressor 1 is operated, the suction air flows into the muffler 26 from the upper portion of the cylindrical member 29. The intake sound generated at this time is reduced by the communication hole 30 of the cylindrical member 29 and the sound deadening plate 31. That is,
The suction sound is reduced by the cylindrical member 29, and is further throttled and reduced by the communication hole 30. Therefore, it is not necessary to take a large space portion, and it is possible to provide a small silencer 26. At this time, the end of the cylindrical member is sufficiently separated from the air insertion hole, the passage of the intake air is made sufficiently long through the mutually divided spaces formed by the ribs of the sound deadening plate, and the intake air is cut by the communication hole of the sound deadening plate. The sound is effectively silenced by expanding in the space formed by the diaphragm and the ribs and further by expanding and expanding in the intake air passage formed by the filter receiver. Further, one end side of the cylindrical member is sandwiched between the cover and the casing, and a protrusion provided on the outer periphery of the portion located inside the casing contacts the cover and the sound deadening plate.
By pressing and holding these by the elasticity of the filter, the cover, the sound deadening plate, and the cylindrical member are positioned without play and noise is reduced.

(Embodiment) Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The members corresponding to those in FIGS. 3 and 4 are designated by the same reference numerals, and detailed description thereof will be omitted.
A feature of the muffler 26 according to the present invention is that a part of a cylindrical member 29 is inserted into a space formed by a casing 27 and a cover 28, and the inserted cylindrical member 29 and the compressor 1 The sound deadening plate 31 having a plurality of communication holes 30 is interposed between the sound absorbing plate 31 and the casing 27 attached to the air suction port 7. That is, the muffler 26 is configured such that the filter 32, the muffling plate 31, and the cylindrical member 29 are inserted into the casing 27 that is integrated with the air suction port 7 of the compressor 1, and the cover 28 is attached to the casing 27 and fixed. It was done.

Each of these members will be described with reference to FIG. 2. The casing 27 is a box-shaped member attached to the air suction port 7 of the cylinder head 6, and the notch insertion portion 33 for assembling the cylindrical member 29 is mounted on the upper portion thereof. Are formed. Further, an air insertion hole 34 through which air is inserted is provided at an eccentric position of the bottom wall portion 27a of the casing 27 (the wall on the right side of the casing 27 in FIG. 1), and at the inner side of the bottom wall portion 27a, A filter receiver 35 is provided which is narrowed in the intake air passage and extends in one direction (vertical direction in the drawing) so as to be expanded and which is formed at a plurality of positions at intervals with protrusions. The filter 32 attached to the filter receiver 35 filters intake air and is made of an elastic member such as felt. The muffling plate 31 is for reducing intake noise by restricting the intake air, and the muffling plate 31 is provided on one side surface of the muffling plate 31.
When assembled on the 27, a plurality of ribs 36 are provided in the lateral direction (direction substantially orthogonal to the extending direction of the filter receiver 35) for maintaining the distance from the filter 32 and improving the flowability of the intake air. ing. Further, six communication holes 30 for drawing are formed in the central portion between the ribs 36.

The cylindrical member 29 has two cylinders 37 arranged in the vertical direction, and
Are connected by two connecting members 38 in the horizontal direction in the upper and lower directions to form a double girder shape. And this lateral connecting member
The upper part of 38 is attached so as to surround the vertical cylinder 37, and a groove 39 is formed around it. The notch insertion portion 33 of the casing 27 and the insertion portion 41 of the cover 28, which will be described later, can be inserted into the groove portion 39 with good sealing properties. Further, a protrusion 40 is formed in the front-back direction of the lower portion of the connecting member 38, that is, in the portion facing the bottom wall portion 27a of the casing 27 and the portion facing the cover 28 side, and the lower portion of the cylindrical member 29. Can be easily positioned.

Furthermore, when the cover 28 described later is attached to the casing 27, the protrusion 40 of the cylindrical member 29 is sandwiched by the sound deadening plate 31 and the cover 28, and these are pressed and fixed by positioning the sound deadening plate 31. As a result, the cylindrical member 29 is also fixed, which has the effect of reliably reducing noise.

The cover 28 inserts a cylindrical member 29 or the like to cover and fix the casing 27, and connects the cylinder 37 of the cylindrical member 29 to the upper part of one surface thereof, and is inserted into the groove 39 on the upper side of the connecting member 38. The part 41 is formed. The insertion portion 41 improves the sealing property inside the silencer 26. Further, four protrusions 42 are formed at the four corners of the surface of the cover 28 on the insertion portion 41 side. By providing such a protrusion 42 on the cover 28, when the cover 28 is assembled to the casing 27, there is an effect that the sound deadening plate 31 and the filter 32 can be reliably fixed.

Similarly, when the cover 28 is assembled to the casing 27, the casing 27 is protected so that suction noise does not leak from the outer periphery.
The packing 43 is inserted between the cover 28 and the cover 28. The packing 43 is attached, and the groove 39 of the cylindrical member 29 is attached.
By inserting the notch insertion portion 33 of the casing 27, further, by inserting the insertion portion 41 of the cover 28 in the groove 39 of the cylindrical member 29, it is possible to prevent the leakage of suction sound from the inside of the casing 27, There is an effect that noise due to the Eustachian tube effect can be surely reduced.

When assembling the filter 32, the muffling plate 31, and the cylindrical member 29 to the casing 27 of the silencer 26, first, the filter 32 made of felt or the like is inserted in contact with the filter receiver 35 of the casing 27, and the filter 32 is inserted from the rear surface. Mute plate by pressing
Is inserted into the casing 27. The sound deadening plate 31 is attached so that the side where the ribs 36 are formed faces the filter 32 inside the casing 27. Then, the filter 32 and the sound deadening plate 31 are pressed by the protrusions 40 provided on the cylindrical member 29,
Is moved to insert the notch insertion portion 33 of the casing into the groove portion 39 of the cylindrical member 29. And further, this cylindrical member 29
The insertion portion 41 formed in the cover 28 is inserted into the groove portion 39 on the cover 28 side. As a result, the cover 28 is attached to the casing 27 to form the silencer 26.

When the compressor 1 having the silencer 26 configured as described above is operated, that is, when the piston 3 is slid toward the compression side, air is silenced from the upper end of the cylinder 37 of the cylindrical member 29.
It flows into the inside of 26, that is, into the space formed by the casing 27 and the cover 28. Then, after passing through the communication hole 31 of the sound deadening plate 31 and being filtered by the filter 32, the air insertion hole
34, flows into the cylinder head 6 from the air suction port 7 (see the arrow in FIG. 1). Further, air flows into the air storage tank (not shown) from the intake port 21 through the cylinder chamber 23 and from the cylinder chamber 23 through the exhaust port 24.

The intake sound generated when the compressor 1 is operated is reduced by the cylindrical member 29, and at the same time, the communication hole 30 formed in the sound deadening plate 31.
Squeezed and reduced by. Since the noise is reduced in this way, it is possible to suppress the noise without taking up a large space portion, and it is possible to obtain a small silencer 26.

(Effects of the Invention) Since the present invention is configured as described above, the intake sound is formed by the cylindrical member inserted into the space formed by the cousing and the cover, the communication hole of the sound deadening plate, and the filter receiver. And the intake air passage. Therefore, it is not necessary to form a large space portion such as the expansion chamber, and it is possible to reduce the size of the silencer. Furthermore, by changing the number and length of the cylindrical members, it is possible to match the frequency range where the sound is reduced, and there is also an effect that the application range is widened. Further, the elasticity of the filter can be used to position the cover, the sound deadening plate, and the cylindrical member without play, so that noise can be reduced.

[Brief description of drawings]

1 is a sectional view showing an embodiment of the present invention, FIG. 2 is an exploded perspective view of a silencer, FIG. 3 is a sectional side view of a compressor with a silencer attached, and FIG. 4 is a cylinder of the compressor. FIG. 5 is a cross-sectional view of a muffler attached to the vicinity of the head and the air inlet of the cylinder head, and FIG. 5 is a front view of the muffling plate. 1 …… Air compressor 7 …… Air suction port 26 …… Suction silencer 27 …… Casing 28 …… Cover 29 …… Cylindrical member 30 …… Communication hole 31 …… Silence plate

Claims (1)

[Claims] 1. A casing, which is box-shaped, has an air insertion hole formed at an eccentric position in a bottom wall portion, and the air insertion hole is attached to an air intake port of an air compressor; and a bottom wall of the casing. A filter receiver is formed on the inner surface of the part, which expands in one direction so as to narrow and expand the intake air passage, and which is formed to project at a plurality of places at intervals, and one side of which is provided in contact with the filter receiver to suck air. And a filter having elasticity and a plurality of ribs formed on one side surface and extending at intervals in a direction substantially orthogonal to the extending direction of the filter receiver, and formed between the plurality of ribs. A plurality of communication holes that communicate the plurality of spaces with the other side surface, and between the sound deadening plate that abuts the other side surface of the filter via the rib, and between the other side surface of the sound deadening plate in the casing. Before forming a space The cover attached to the casing, inserted into the space inside the casing, one end protruding outside the casing, the outer periphery is sandwiched by the cover and the casing, the other end is provided at a position eccentric between the casing and the bottom wall portion. A cylindrical member extending to a position far away from the air insertion hole, and an outer periphery of a portion of the cylindrical member located in the space inside the casing, abutting against and pressing each of the cover and the sound deadening plate. And a projection for positioning the sound deadening plate.