JP7458561B1 - Silencer manufacturing method - Google Patents

Abstract

The interior member of the silencer is held inside a dummy shell that is separate from the shell of the silencer, and the sound absorbing material is filled into the compartment that will become the sound absorbing chamber from a filling port provided on the end and/or side of the dummy shell, and then the interior member and the sound absorbing material are transferred from the dummy shell to the shell. This provides a roving method that can be applied to a shell having an irregular cross section and/or a silencer equipped with multiple sound absorbing chambers.

Description

The present invention relates to a method for manufacturing a silencer.

The inside of mufflers used in motors such as internal combustion engines is often filled with sound-absorbing material, which is a laminate of heat-resistant fibers such as glass wool. Recently, in order to shorten and simplify the filling process, the so-called "roving method" has been widely used, in which a tape-shaped sound-absorbing material made of continuous long fibers is defibrated in a nozzle and blown into the inside of the muffler's outer tube (shell) with high-pressure air, filling the entire internal space of the shell or a specified section inside the shell.

In the above-mentioned blowing, in order to reliably fill the sound-absorbing material, a method (direct filling method) in which the sound-absorbing material is blown into the shell while forcibly discharging (suctioning) the air inside the shell is generally adopted. From the viewpoint of ensuring and maintaining sound deadening performance, it is desirable that a predetermined region inside the shell be uniformly filled with sound absorbing material at a predetermined density. However, depending on the internal structure of the silencer (for example, the layout of the compartments and/or the arrangement of holes in a pipe with multiple through holes punched on the side (punching pipe), etc.), the flow of suction air during filling may be biased. may occur, making it difficult to make the packing density of the sound absorbing material uniform.

Furthermore, when filling a sound absorbing material into a silencer such as a sub-muffler, which has a structure in which a punching pipe is inserted inside the shell, the filling is performed with metal fibers such as stainless wool wrapped around the punching pipe and fixed. Start. In this case, the sound absorbing material that has flowed into the space between the punching pipe and the shell may be caught by the metal fibers, which may prevent uniform filling of the sound absorbing material.

Therefore, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2007-16764) proposes a silencer in which a cover pipe is arranged outside the metal fiber complex to block the suction route through the holes of the punching pipe and to draw suction from the bottom of the shell. A method of filling a sound absorbing material is disclosed. According to this method, the flow of suction air in the space between the punching pipe and the shell becomes uniform, and the sound absorbing material can be deposited and filled uniformly (particularly as shown in FIGS. 6 and 7 of Patent Document 1). (see the second example).

However, in recent years, there has been a growing trend for the cross section of mufflers to be flattened and/or narrowed, making it difficult to insert a nozzle for injecting sound-absorbing material into the space between the punching pipe and the shell. The above-mentioned filling method cannot be applied to mufflers with such cross sections.

On the other hand, a preform, which is a mass of fibers constituting the sound-absorbing material, is formed in advance to match the shape of the compartment (hereinafter sometimes referred to as a "sound-absorbing chamber") in which the sound-absorbing material is to be filled. A method of filling a sound absorbing material by the so-called "preform method" in which a preform is inserted into a sound absorption chamber is disclosed in Patent Document 2 (Japanese Utility Model Application Publication No. 2010-513774) and Patent Document 3 (Japanese Patent Application Publication No. 2010-513774). ing.

However, in the above method, it is necessary to form a preform in advance by bonding the fibers that make up the sound absorbing material by curing a binder such as resin or water, so a special process (work) is required for this purpose. ) and/or equipment is required. Furthermore, when the preform is placed in a predetermined position that will become a sound-absorbing chamber and the half-shells are closed and fixed, the fibers of the sound-absorbing material are likely to be caught between the joint surfaces of the half-shells. Furthermore, unless the binder is removed from the preform, it cannot perform its original function as a sound absorbing material, and even if the binder is removed from the preform, it is possible for the laminate of fibers that make up the sound absorbing material to recover to the desired density. Due to the low performance, it is difficult to achieve and/or maintain the desired silencing performance.

In addition to the above, in a silencer that has a structure with multiple compartments (multi-chamber structure) like a main muffler, instead of a structure with only one compartment (single-chamber structure) like a sub-muffler, There is a need to fill only my sound-absorbing room with sound-absorbing material. However, in recent years, there has been a demand for a plurality of sound-absorbing chambers and for the cross-section of the shell to be irregularly shaped (particularly flattened and oval), making it even more difficult to apply the roving method.

However, when the roving method is not used, the fibers that make up the sound-absorbing material are packed into the sound-absorbing chamber by hand, or the cloth packs filled with the fibers that make up the sound-absorbing material are manually inserted into the sound-absorbing chamber. There is a need to use the roving method as much as possible because it requires time-consuming and difficult manual work. That is, in this technical field, a roving construction method that can be applied to a silencer having a shell having an irregular cross section and/or a plurality of sound absorption chambers has been awaited.

JP 2007-16764 A Utility Model Publication No. 2-50008 Special Publication No. 2010-513774 Japanese Patent Application Publication No. 2022-30975 Patent No. 7001893

As mentioned above, the technical field has been waiting for a roving construction method that can be applied to a silencer having a shell having an irregular cross section and/or a plurality of sound absorption chambers.

Therefore, as a result of intensive research, the inventor of the present invention has developed a method of holding the interior components of a silencer inside a dummy shell that is separate from the shell of the silencer, and absorbing sound from the filling port provided at the end and/or side of the dummy shell. It has been found that the above problem can be solved by filling the compartment that will become the room with the sound absorbing material and then moving the interior members and the sound absorbing material from the dummy shell to the shell.

Specifically, the method for manufacturing a silencer according to the present invention (hereinafter sometimes referred to as the "method of the present invention") includes at least one section filled with a sound absorbing material inside a cylindrical shell. A method of manufacturing a silencer comprising: The method of the present invention includes a holding step, a filling step, a communicating step, a relocation step, and a closing step listed below.

The holding process involves preparing a cylindrical dummy shell that is different from the shell and holding the interior components of the silencer inside the dummy shell.

In the filling process, a nozzle is inserted into the compartment to be filled with the sound absorbing material through the filling port, which is an opening at the end and/or side surface of the dummy shell, and the nozzle is inserted into the compartment where the sound absorbing material is to be filled. Alternatively, while discharging the air inside the compartment through the exhaust port, which is an opening different from the filling port on the side, the continuous long fibers constituting the sound-absorbing material are filled into the compartment from the nozzle, and the sound-absorbing material is This is the process of forming lumps.

In the communication process, one end of the insertion jig, which is a cylindrical jig having an inner circumferential surface that continuously connects the inner circumferential surface of the dummy shell and the inner circumferential surface of the shell, is inserted after filling with the sound absorbing material. Connect to the end of the dummy shell, connect the other end of the insertion jig to the end of the shell, and communicate the internal space of the dummy shell with the internal space of the shell via the internal space of the insertion jig. It is a process.

The relocation process is a process of relocating the interior member and the mass of sound absorbing material inside the dummy shell into the interior of the shell through the internal space of the insertion jig.

The closing step is a step of removing the dummy shell and the insertion jig from the shell to which the interior member has been relocated, and closing the end of the shell.

According to the present invention, the roving method can also be applied to a silencer having a shell having an irregular cross section and/or a plurality of sound absorbing chambers, so that the sound absorbing material can be efficiently filled into the sound absorbing chambers.

Other objects, other features, and attendant advantages of the present invention will be readily understood from the following description of embodiments of the present invention with reference to the drawings.

It is a flowchart which shows an example of the flow of each process included in the manufacturing method (first method) of the silencer concerning a 1st embodiment of the present invention. It is a schematic diagram which shows an example of the component of the silencer to which the 1st method is applied, and the equipment and jig for carrying out the 1st method. FIG. 4 shows a process of manufacturing a silencer by a first method having a structure in which the internal space of a shell is partitioned into a plurality of compartments by an interior member constituted by a plurality of mutually fixed pipes and a plurality of partition walls. It is a typical perspective view showing one example. FIG. 3 shows a process of manufacturing a silencer by a first method, having a structure in which the internal space of a shell is partitioned into a plurality of compartments by an interior member constituted by a plurality of mutually fixed pipes and a plurality of partition walls. It is a typical perspective view showing one example. 1 is a schematic diagram illustrating an example of the arrangement of components of a silencer and equipment and jigs for carrying out the first method according to Specific Example 1 when performing a filling process included in the first method according to Specific Example 1. FIG. . By the first method, a silencer having a structure in which the internal space of the shell is partitioned into a plurality of sections by an interior member constituted by a plurality of mutually fixed pipes and a plurality of partition walls and a flat oval cross section is produced by the first method. It is a typical perspective view showing another example of a manufacturing process. 2 is a schematic diagram illustrating an example of the arrangement of constituent members of a silencer and equipment and jigs for carrying out the first method according to Specific Example 2 when performing a filling process included in the first method according to Specific Example 2. FIG. . A schematic diagram showing an example of a state in which a dummy shell and a shell are connected with an insertion jig in between in the communication step included in the method for manufacturing a silencer (second method) according to the second embodiment of the present invention. FIG. Referring to FIG. 10, there is shown a silencer in which an interior member is made of a punched pipe with a plurality of through holes formed on its side surface and a metal fiber wound around at least the area where the through holes are formed on the outer peripheral surface of the punched pipe. It is a typical sectional view showing one example of the manufacturing process by the manufacturing method (the 4th method) of the silencer concerning a 4th embodiment of the present invention. Referring to FIG. 9, there is shown a silencer in which the interior member is made of a punched pipe with a plurality of through-holes formed on its side surface and a metal fiber wound around at least the area where the through-holes are formed on the outer peripheral surface of the punched pipe. It is a typical sectional view showing one example of a manufacturing process by a 4th method. FIG. 2 is a schematic diagram showing an example of the configuration of a muffler according to a first embodiment, which has a standard configuration in which an inlet and an outlet for exhaust gas are provided at both ends in the axial direction of the muffler. 10 is a schematic diagram showing an example of the configuration of a silencer according to a second embodiment, in which an inlet pipe is connected to the outer surface of a shell and an exhaust outlet is provided at one end of the silencer in the axial direction. FIG. FIG. 11 is a schematic diagram showing an example of the configuration of a silencer according to a third embodiment, in which an inlet pipe equipped with a stay is connected to the outer surface of a shell and an exhaust outlet is provided at one end in the axial direction of the silencer. An example of the configuration of a silencer according to a fourth embodiment, in which an inlet pipe is connected to a stay provided on the outer surface of the shell and inside the shell, and an exhaust outlet is provided at one end in the axial direction of the silencer. It is a schematic diagram.

《First embodiment》
Hereinafter, a method for manufacturing a silencer according to a first embodiment of the present invention (hereinafter, sometimes referred to as a "first method") will be described with reference to the drawings.

<composition>
The first method is a method for manufacturing a silencer having at least one compartment filled with a sound-absorbing material inside a cylindrical shell. The configuration of the silencer to which the first method is applied is not particularly limited as long as it has at least one compartment filled with a sound-absorbing material. The sound-absorbing chamber, which is a compartment filled with a sound-absorbing material, may be a compartment in which a resonance chamber through which exhaust gas does not flow is filled with a sound-absorbing material, or a compartment in which a resonance chamber through which exhaust gas flows and which further has an expansion function is filled with a sound-absorbing material. Specific examples of the silencer to which the first method is applied include a silencer (e.g., a main muffler for a four-wheeled vehicle, etc.) having a structure in which the internal space of the shell is divided into a plurality of compartments by an interior member composed of a plurality of pipes and a plurality of partition walls fixed to each other, and a silencer (e.g., a sub-muffler for a four-wheeled vehicle and a silencer for a two-wheeled vehicle, etc.) having a structure in which a punching pipe is inserted inside the shell.

FIG. 1 is a flowchart showing an example of the flow of each step included in the first method. FIG. 2 is a schematic diagram showing an example of components of a silencer to which the first method is applied, as well as equipment and jigs for carrying out the first method. Figure 2 (a) shows the silencer observed from the axial direction of the silencer, and Figure 2 (b) shows the silencer observed from the direction perpendicular to the axial direction of the silencer. . Although FIG. 2 shows a state in which the shell, insertion jig, and dummy shell are connected, please refer to the following description for the arrangement of each member, equipment, and jig in each step.

As illustrated in FIG. 1, the first method includes a holding process, a filling process, a connecting process, a transferring process and a blocking process, as listed below.

In the holding step executed in step S10 of the flowchart illustrated in FIG. This is a holding process.

As a specific example of the interior member 120 of the silencer, in the case of a silencer having a structure in which the interior space of the shell is partitioned into a plurality of sections by the interior member, a plurality of mutually fixed pipes (for example, an inlet pipe , an outlet pipe and/or an inner pipe, etc.) and a plurality of partition walls (for example, separators, etc.). On the other hand, in the case of a silencer having a structure in which a punching pipe is inserted inside a shell, a punching pipe with a plurality of through holes punched on the side surface and at least a through hole punched in the outer peripheral surface of the punching pipe are used. An example may be an interior member made of metal fibers wound around a region.

In the filling step performed in step S20, the nozzle 220 is inserted into the compartment to be filled with the sound absorbing material through the filling port 211, which is an opening at the end and/or side of the dummy shell 210, and the dummy shell 210 is filled with the sound absorbing material. The sound absorbing material is configured while exhausting the air inside the compartment through an exhaust port (not shown) which is an opening different from the filling port 211 at the end and/or side opposite to the port 211. This is a step of filling the interior of the section with continuous long fibers from the nozzle 220 to form a mass of sound absorbing material.

The continuous long fibers that make up the sound-absorbing material are made of a material that has both high heat resistance and high sound-absorbing properties to withstand the environment in which it is used as a silencer. An example of such a fiber is glass wool roving.

In the example shown in FIG. 2, the interior member 120 is composed of three pipes and four partitions fixed to each other, and these four partitions divide the internal space of the muffler into five compartments, two of which are filled with sound-absorbing material to form sound-absorbing chambers. Therefore, filling ports 211 are provided on the side of the dummy shell 210 at positions corresponding to these two sound-absorbing chambers, and two nozzles 220 can be inserted from the two filling ports 211 into the two compartments to be filled with sound-absorbing material, so that the continuous long fibers constituting the sound-absorbing material can be filled into the interior of the compartments from the nozzles 220. In addition, exhaust ports (not shown) are provided on the side opposite the two filling ports 211. In addition, suction devices 230 are connected to the exhaust ports, and the suction devices 230 can be used to exhaust air from the corresponding compartments (see the white arrows), so that the compartments can be evenly filled with sound-absorbing material.

As described above, the filling port 211 is provided on the side of the dummy shell 210, so that even in compartments where it is impossible to fill with sound-absorbing material when the interior member 120 is held inside the shell 110, the nozzle 220 can be inserted into the filling port 211 to easily fill the continuous long fibers that make up the sound-absorbing material.

Note that, for example, a transparent portion may be provided in a part of the dummy shell 210 for the purpose of visually confirming the filling status of the sound absorbing material in the filling process. Alternatively, the entire dummy shell 210 may be made of a transparent material. Specific examples of materials constituting such a transparent portion or transparent dummy shell 210 include resin materials such as polycarbonate.

The communication step executed in step S30 is performed on one side of the insertion jig 240, which is a cylindrical jig having an inner circumferential surface that continuously connects the inner circumferential surface of the dummy shell 210 and the inner circumferential surface of the shell 110. The end is connected to the end of the dummy shell 210 filled with sound absorbing material, the other end of the insertion jig 240 is connected to the end of the shell 110, and the dummy is inserted through the internal space of the insertion jig 240. This is a step of communicating the internal space of the shell 210 and the internal space of the shell 110.

As described above, FIG. 2 illustrates a state in which the shell 110, the insertion jig 240, and the dummy shell 210 are connected. Although not shown, the inner circumferential surface of the insertion jig 240 has a shape that continuously connects the inner circumferential surface of the dummy shell 210 and the inner circumferential surface of the shell 110, and in this state in which the shell 110, the insertion jig 240, and the dummy shell 210 are connected, the inner space of the dummy shell 210 and the inner space of the shell 110 are connected through the inner space of the insertion jig 240.

The relocation step executed in step S40 is a step of relocating the interior member 120 and the mass of sound absorbing material inside the dummy shell 210 into the inside of the shell 110 through the internal space of the insertion jig 240. In FIG. 2B, the interior member 120 is held inside the dummy shell 210 on the left side as viewed from the drawing. This interior member 120 is moved into the inside of the shell 110 on the right side in the drawing together with the sound absorbing material filled in the filling process performed in step S20 described above.

The closing step executed in step S50 is a step of removing the dummy shell 210 and the insertion jig 240 from the shell 110 to which the interior member 120 has been relocated, and closing the end of the shell 110. Specific examples of methods for closing the end of the shell 110 include attaching a closed end plate to the end of the shell 110 and forming a tapered part by spinning the end of the shell 110. can be mentioned.

Note that the order of the steps included in the first method is not limited to the above as long as it does not impede the implementation of the present invention and does not impair the effects achieved by the present invention. For example, a communication process of communicating the internal space of the dummy shell and the internal space of the shell via the internal space of the insertion jig may be performed before the filling process or before the holding process.

<Specific example 1>
Here, the details of the first method will be explained using one specific example. 3(a) and (b) and FIG. 4(c), (d), and (e), the shell is constructed by an interior member composed of a plurality of mutually fixed pipes and a plurality of partition walls. FIG. 2 is a schematic perspective view illustrating one example of a process of manufacturing a silencer having a structure in which an internal space is partitioned into a plurality of sections and a flat elliptical cross section by a first method.

In addition, in (a) and (b) of Figure 3 and (c) of Figure 4, for the purpose of facilitating understanding of the present invention, the interior members 120 that are held inside the dummy shell 210 or the shell 110 and should not be visible from the outside are drawn by solid lines. On the other hand, in (d) and (e) of Figure 4, the interior members 120 that are held inside the shell 110 and should not be visible from the outside are drawn by dashed lines.

In addition, in FIGS. 3A and 3B and FIG. 4C, the insertion jig 240 connected in the above-mentioned communication process is also drawn with a solid line. Further, in FIGS. 3A and 3B, the shell 110 is drawn by a broken line, and in FIG. 4, the shell 110 is drawn by a solid line. However, as described above, the insertion jig 240 and the shell 110 do not necessarily need to be connected to the dummy shell 210 in the state depicted in FIG. The arrangement of the jigs is as explained above.

In FIG. 3A, an interior member 120 made up of three mutually fixed pipes and four partition walls is held inside the dummy shell 210. Two filling ports 211 are provided on the side surfaces of the dummy shell 210 so as to communicate with each of the two compartments that are to become sound absorption chambers out of the five compartments partitioned by four partition walls. That is, in the state illustrated in FIG. 3(a), the above-described holding step has already been completed, and the nozzle 220 is inserted into each filling port 211 to fill the continuous long fibers constituting the sound absorbing material in each section. It is in a state where the filling process to fill the inside is about to start.

Next, in the state illustrated in FIG. 3(a), a step of filling a section to become a sound-absorbing chamber with a sound-absorbing material is performed. Specifically, the inside of the compartment is pumped by the suction device 230 through the exhaust port 212 (shown in FIG. 3(b)) on the side opposite to the filling port 211 provided on the side of the dummy shell 210. While exhausting air, continuous long fibers constituting the sound absorbing material are filled into the compartment from the nozzle 220.

FIG. 5 shows an example of the arrangement of components of a silencer and equipment and jigs for carrying out the first method according to Specific Example 1 when performing the filling process included in the first method according to Specific Example 1. It is a schematic diagram. FIG. 5(a) shows the state of the oval cross section of the shell 110 constituting the silencer observed from the minor axis direction, and FIG. 5(b) includes the straight line AA shown in FIG. 5(a). A cross section taken along a plane parallel to the short axis of the elliptical cross section of the shell 110 is shown as viewed from the long axis direction of the elliptical cross section of the shell 110. Although FIG. 5 also shows a state in which the shell 110, the insertion jig 240, and the dummy shell 210 are connected, the arrangement of each member, equipment, and jig in each process is as described above.

As is clear from FIG. 5, since the filling port 211 is provided on the side surface of the dummy shell 210, it is impossible to fill the sound absorbing material while the interior member 120 is held inside the shell 110. The continuous fibers constituting the sound absorbing material can be easily filled into the compartments by inserting the nozzle 220 into the filling port 211.

When the sound-absorbing material is filled into the interior of a predetermined section as described above, a communication process is carried out to connect the interior space of the dummy shell 210 to the interior space of the shell 110 via the internal space of the insertion jig 240. Then, as shown in (b) of Fig. 3, a transfer process is carried out to transfer the interior member 120 and the mass of sound-absorbing material 140 inside the dummy shell 210 to the interior of the shell 110 through the internal space of the insertion jig 240, resulting in the state shown in (c) of Fig. 4. In Fig. 4, the shell 110 depicted by the dashed line in Fig. 3 is depicted by a solid line.

Next, as illustrated in FIG. 4(d), the dummy shell 210 and the insertion jig 240 are removed from the shell 110 to which the interior member 120 has been relocated, and as illustrated in FIG. 4(e), the shell 110 is removed. The open end of 110 on the side connected to insertion jig 240 is closed. Specifically, the end plate 130 is attached to the end of the shell 110 by, for example, welding or the like. That is, the above-described closing step is executed. As a result, the silencer 100 is manufactured by the first method according to the first specific example.

<Specific example 2>
In the first method according to Specific Example 1 described above, sound absorbing material was simultaneously filled in both of the two compartments that were to become sound absorbing chambers out of the five compartments partitioned by the four partition walls constituting the interior member 120. However, the sound-absorbing material may be sequentially filled into a plurality of sections that are to become sound-absorbing chambers.

FIG. 6 shows a silencer having a structure in which the internal space of the shell is partitioned into a plurality of sections by an interior member composed of a plurality of mutually fixed pipes and a plurality of partition walls, and a flat oval cross section. FIG. 3 is a schematic perspective view showing another example of the manufacturing process using the first method. Also in FIG. 6, the interior member 120, which is held inside the dummy shell 210 or the shell 110 and is not supposed to be visible from the outside, is drawn with solid lines for the purpose of facilitating understanding of the present invention.

Similar to the above-mentioned Example 1, the silencer manufactured by the first method according to Example 2 has an inner space of the shell by an interior member constituted by a plurality of mutually fixed pipes and a plurality of partition walls. This is a silencer having a structure partitioned into a plurality of compartments and a flat oval cross section, and includes two compartments that are to serve as sound absorption chambers.

However, the dummy shell 210 used in the first method according to the specific example 2 has only one set of the filling port 211 and the exhaust port 212, as illustrated in FIG. 6. Therefore, in the first method according to the specific example 2, since the sound absorbing material can be filled in only one compartment at a time, the sound absorbing material is filled sequentially into the two compartments to be the sound absorbing chambers. Specifically, as illustrated in FIG. 6(a), the interior member 120 of the silencer is held inside the dummy shell 210 at a position where the internal space of one of the two compartments to be the sound absorbing chambers is connected to the filling port 211 and the exhaust port 212 provided in the dummy shell 210. Then, in this state, the air inside the compartment is discharged by the suction device 230 through the exhaust port 212 on the side opposite to the filling port 211 provided on the side of the dummy shell 210, and the continuous long fibers constituting the sound absorbing material 140 are filled into the interior of the compartment from the nozzle 220 inserted into the filling port 211.

When the interior of one compartment is filled with the sound absorbing material 140 as described above, the interior space of the other of the two compartments that should become a sound absorbing chamber is filled with the dummy shell 210, as illustrated in FIG. 6(b). The interior member 120 of the silencer is moved inside the dummy shell 210 to a position where it communicates with the provided filling port 211 and exhaust port 212. Although not shown, in this state, continuous long fibers constituting the sound absorbing material are filled into the compartment in the same manner as described above.

FIG. 7 shows an example of the arrangement of components of a silencer and equipment and jigs for carrying out the first method according to Specific Example 2 when performing the filling process included in the first method according to Specific Example 2. It is a schematic diagram. FIG. 7(a) shows the state of the oval cross section of the shell 110 constituting the silencer observed from the minor axis direction, and FIG. 7(b) includes the straight line AA shown in FIG. 7(a). A cross section taken along a plane parallel to the short axis of the elliptical cross section of the shell 110 is shown as viewed from the long axis direction of the elliptical cross section of the shell 110. Although FIG. 7 also shows a state in which the shell 110, the insertion jig 240, and the dummy shell 210 are connected, the arrangement of each member, equipment, and jig in each process is as described above.

As is clear from FIG. 7, since the filling port 211 is provided on the side surface of the dummy shell 210, it is impossible to fill the sound absorbing material while the interior member 120 is held inside the shell 110. By inserting the nozzle 220 into the filling port 211, continuous long fibers constituting the sound-absorbing material can be easily filled even in a large section. Furthermore, even when the dummy shell 210 has only one set of the filling port 211 and the exhaust port 212, as illustrated in FIG. By moving 120, it is possible to sequentially fill a plurality of sections to become sound-absorbing chambers with sound-absorbing material. In this way, when sequentially filling a plurality of sections that are to become sound-absorbing chambers with sound-absorbing materials, the filling process and the partial relocation process are performed alternately.

When the sound absorbing material is filled into the two compartments as described above, a communication process is carried out to connect the internal space of the dummy shell 210 to the internal space of the shell 110 via the internal space of the insertion jig 240. Then, a transfer process is carried out to transfer the interior member 120 and the mass of sound absorbing material through the internal space of the insertion jig 240 into the inside of the shell 110, resulting in the state illustrated in (c) of Figure 6. Thereafter, as in the above-mentioned specific example 1, a closing process is carried out and the manufacture of the silencer 100 is completed.

In the above explanation regarding the first method, a structure in which the internal space of the shell is partitioned into a plurality of sections by an interior member constituted by a plurality of mutually fixed pipes and a plurality of partition walls, and a flat elliptical cross section are described. The case of manufacturing a silencer having the following is described in detail. However, as described above and as will be described later in the description of other embodiments, a punching pipe in which a plurality of through holes are bored in the side surface and at least the through holes in the outer circumferential surface of the punching pipe are bored. The manufacturing method of a silencer according to the present invention including the first method also applies to a silencer having a structure in which an interior member made of metal fibers wound around a region is inserted inside a shell (method of the present invention) can be applied.

<effect>
As described above, in the first method, the nozzle is inserted into the compartment that will become the sound absorption chamber from the filling port on the end and/or side of the dummy shell, and And/or while the air inside the compartment is exhausted through the exhaust port on the side, the continuous long fibers constituting the sound absorbing material can be filled into the compartment from the nozzle. Therefore, continuous long fibers constituting the sound absorbing material can be easily filled even in sections where it is impossible to fill the sound absorbing material while the interior member is held inside the shell. That is, according to the first method, the roving method can also be applied to a silencer having a shell having an irregular cross section and/or a plurality of sound absorbing chambers, so that the sound absorbing material can be efficiently filled into the sound absorbing chambers.

《Second embodiment》
Hereinafter, a method for manufacturing a silencer according to a second embodiment of the present invention (hereinafter sometimes referred to as a "second method") will be described with reference to the drawings.

As described above, in the first method, in the filling step, the sound-absorbing material is filled into the section that will become the sound-absorbing chamber through the filling port of the dummy shell. Therefore, according to the first method, the roving method can also be applied to a silencer having a shell having an irregular cross section and/or a plurality of sound absorbing chambers, so that the sound absorbing material can be efficiently filled into the sound absorbing chambers.

From the viewpoint of making filling the sound absorbing material easier and more reliable in the filling process, the cross section of the inner circumferential surface of the dummy shell is larger than the cross section of the inner circumferential surface of the shell, and the filling path of the sound absorbing material inside the dummy shell is It is desirable that there be fewer narrow areas that impede the flow of the continuous fibers that make up the sound absorbing material.

In addition, as described above, the interior member and the mass of sound absorbing material that have undergone the filling process are shaped into a cylindrical shape having an inner circumferential surface that continuously connects the inner circumferential surface of the dummy shell and the inner circumferential surface of the shell in the relocation process. The interior member and the mass of sound-absorbing material are transferred from the inside of the dummy shell to the inside of the shell through the internal space of the insertion jig, which is a jig. Therefore, if the cross section of the inner circumferential surface of the dummy shell is larger than the cross section of the inner circumferential surface of the shell as described above, the cross section of the inner circumferential surface of the dummy shell becomes smaller continuously from the cross section of the inner circumferential surface of the shell. It is desirable that the insertion jig is configured to have a tapered inner peripheral surface.

<composition>
Therefore, the second method is the first method described above, in which the cross section of the inner circumferential surface of the dummy shell is larger than the cross section of the inner circumferential surface of the shell, and the cross section of the inner circumferential surface of the dummy shell is In this method of manufacturing a silencer, the insertion jig has a tapered inner circumferential surface that continuously becomes smaller in cross section. Furthermore, in the second method, in the communication step, the end of the insertion jig on the side where the cross section of the inner peripheral surface is larger is connected to the end of the dummy shell, and the end of the side of the insertion jig with the smaller cross section of the inner peripheral surface is connected to the end of the dummy shell. Connect the ends to the ends of the shell.

FIG. 8 is a schematic cross-sectional view showing an example of a state in which the dummy shell 210 and the shell 110 are connected with the insertion jig 240 interposed therebetween in the communication step included in the second method. As illustrated in FIG. 8, the cross section of the inner circumferential surface of the dummy shell 210 is larger than the cross section of the inner circumferential surface of the shell 110. Preferably, the cross section of the inner circumferential surface of the shell 110 is included in the cross section of the inner circumferential surface of the dummy shell 210 in a vertical projection onto a plane perpendicular to the axial direction of the shell 110.

In addition, the insertion jig 240 has a tapered inner circumferential surface that becomes smaller continuously from the cross section of the inner circumferential surface of the dummy shell 210 to the cross section of the inner circumferential surface of the shell 110. In the example shown in FIG. 8, the tapered inner circumferential surface of the insertion jig 240 decreases linearly from the cross section of the inner circumferential surface of the dummy shell 210 to the cross section of the inner circumferential surface of the shell 110. However, the inner circumferential surface of the insertion jig 240 only needs to become smaller continuously from the cross section of the inner circumferential surface of the dummy shell 210 to the cross section of the inner circumferential surface of the shell 110. That is, the tapered inner circumferential surface of the insertion jig 240 only needs to be a smoothly continuous surface, and is not limited to a shape that decreases linearly (at a constant rate of change). For example, the tapered inner peripheral surface of the insertion jig 240 may be convex or concave toward the central axis of the insertion jig 240.

Furthermore, the end of the insertion jig 240 on the side where the cross section of the inner peripheral surface is large is connected to the end of the dummy shell 210, and the end of the side of the inner peripheral surface of the insertion jig 240 with the small cross section is connected to the end of the shell 110. connected to the section.

<effect>
As described above, in the second method, the cross section of the inner circumferential surface of the dummy shell is larger than the cross section of the inner circumferential surface of the shell. Therefore, it is possible to reduce the number of narrow spots that impede the flow of the continuous fibers constituting the sound absorbing material in the filling path of the sound absorbing material inside the dummy shell, making it easier and more reliable to fill the sound absorbing material in the filling process. It can be done. In addition, since the insertion jig has a tapered inner circumferential surface that becomes smaller continuously from the cross section of the inner circumferential surface of the dummy shell to the cross section of the inner circumferential surface of the shell, the dummy can be inserted through the internal space of the insertion jig during the relocation process. The interior member and the mass of sound absorbing material can be easily moved from the inside of the shell to the inside of the shell. Furthermore, as the mass of sound-absorbing material is compressed radially inward as it is transferred from the dummy shell to the shell, the bulk density of the sound-absorbing material in the section that will become the sound-absorbing chamber can be increased, so the compression ratio can be adjusted appropriately. It can also be adjusted to adjust the sound absorption performance.

《Third embodiment》
Hereinafter, a method for manufacturing a silencer according to a third embodiment of the present invention (hereinafter may be referred to as a "third method") will be described with reference to the drawings.

As mentioned above, the structure of the silencer to which the method of manufacturing a silencer according to the present invention including the first method (method of the present invention) is provided with at least one section filled with a sound absorbing material. Not particularly limited. As a specific example of a silencer to which the method of the present invention is applied, for example, the interior space of a shell is partitioned into a plurality of compartments by an interior member composed of a plurality of mutually fixed pipes and a plurality of partition walls. Examples include a silencer having a structure and a silencer having a structure in which a punching pipe is inserted inside a shell.

<composition>
Therefore, the third method is the above-mentioned first or second method, in which the interior member is constituted by a plurality of pipes and a plurality of partition walls fixed to each other, and the interior space of the shell is divided into a plurality of compartments by the interior member.
A method for manufacturing a silencer.

The structure of the above-mentioned silencer to which the third method is applied has already been explained with reference to FIGS. 2 to 7 in the explanation of the first method and the second method, so the explanation will be omitted here.

<effect>
As mentioned above, in the silencer to which the third method is applied, the interior space of the shell is partitioned into a plurality of compartments by an interior member composed of a plurality of mutually fixed pipes and a plurality of partition walls. There is. In a silencer having a plurality of compartments as described above, it is possible to provide compartments having various functions such as not only a sound absorption chamber but also a resonance chamber and an expansion chamber. As a result, it is possible to exhibit silencing performance in more frequency bands or to exhibit higher silencing performance.

Fourth Embodiment
A method for manufacturing a silencer according to a fourth embodiment of the present invention (hereinafter, may be referred to as a "fourth method") will be described below with reference to the drawings.

As mentioned above, the structure of the silencer to which the method of the present invention is applied is not particularly limited as long as it includes at least one section filled with sound absorbing material. As a specific example of a silencer to which the method of the present invention is applied, for example, the interior space of a shell is partitioned into a plurality of compartments by an interior member composed of a plurality of mutually fixed pipes and a plurality of partition walls. Examples include a silencer having a structure and a silencer having a structure in which a punching pipe is inserted inside a shell.

<composition>
Therefore, the fourth method is a method for manufacturing a silencer which is the above-mentioned first or second method, in which the interior member is constituted by a punching pipe having a plurality of through holes drilled in its side surface and metal fibers wound around at least the area of the outer surface of the punching pipe where the through holes are drilled.

The metal fibers wrapped around the outer circumferential surface of the punching pipe prevent the sound absorbing material from leaking out of the silencer for a long period of time through the through holes drilled in the punching pipe when the silencer is in operation. Functionality is required. Therefore, as the metal fibers wound around the outer circumferential surface of the punching pipe, fibers made of metal are used that have both high heat resistance and sufficient mechanical strength and durability to withstand the environment in which they are used as a silencer. . Specific examples of such metal fibers include stainless wool and the like.

Furthermore, the third method further includes a cover mounting step and a cover removal step, which are listed below.
The cover fitting step is a step performed before the filling step in which a cover pipe, which is a cylindrical member having a smooth outer circumferential surface, is fitted onto an interior member.
The cover removal step is a step of removing the cover pipe after the filling step and before the closing step.

In addition, in the third method, in the filling process, a nozzle is inserted into the filling compartment from one axial end of the filling compartment, which is the space between the dummy shell and the cover pipe, and continuous long fibers that constitute the sound-absorbing material are filled into the filling compartment from the nozzle while the air inside the filling compartment is discharged from the other end of the filling compartment.

(a), (b), (c), (d) and (e) of FIG. 9 and (f) and (g) of FIG. A schematic cross-sectional view showing one example of the process of manufacturing, by the fourth method, a silencer in which the interior member is made of metal fibers wound around at least a region of the outer circumferential surface of a punched pipe in which a through hole is formed. It is.

FIG. 9(a) shows a punching pipe 121 having a plurality of through holes (not shown) formed on its side surface and a metal wound around at least an area of the outer peripheral surface of the punching pipe 121 in which the through holes are formed. A state in which an interior member 120 made of fibers 122 is held by a receiving jig 250 is illustrated. An exhaust port (not shown) is provided in a region outside the interior member 120 in the radial direction of the receiving jig 250, and air is exhausted through the exhaust port from the section filled with the sound absorbing material in the filling process. Note that an exhaust port is not provided in a region of the receiving jig 250 that faces the interior member 120, and the configuration is such that the air inside the punching pipe 121 is not exhausted.

As described above, when the interior member is composed of a punching pipe with multiple through holes drilled on the side and metal fibers wound around at least the area of the outer surface of the punching pipe where the through holes are drilled, the sound absorbing material that flows into the space between the dummy shell and the interior member during the filling process may get caught on the metal fibers, hindering uniform filling of the sound absorbing material. Therefore, in the fourth method, as shown in (b) of FIG. 9, a cover attachment process is performed before the filling process, in which a cover pipe 260, which is a cylindrical member with a smooth outer surface, is attached to the interior member 120.

Next, as illustrated in FIG. 9C, the dummy shell 210 is fixed to the receiving jig 250 so as to surround the outer surface of the interior member 120. That is, FIG. 9(c) illustrates a state in which the holding step has been completed. Next, as illustrated in FIG. 9(d), the filling compartment is opened from the end opposite to the receiving jig 250 in the axial direction of the filling compartment, which is the space between the dummy shell 210 and the cover pipe 260. A nozzle (not shown) is inserted inside. Then, while exhausting the air inside the filling compartment from the end of the filling compartment on the receiving jig 250 side through the exhaust port provided in the receiving jig 250 (see the white arrow), the sound absorbing material 140 is constructed. The continuous long fibers are filled into the filling compartment from the nozzle (see black arrow). That is, FIG. 9(d) illustrates a state in which the filling process is being performed.

Next, as illustrated in FIG. 9(e), a cover removal step, which is a step of removing the cover pipe 260, is performed. Note that in the example shown in FIG. 9(e), the receiving jig 250 is also removed. Next, FIG. 10(f) illustrates a state in which the dummy shell 210 and the shell 110 are connected with the insertion jig 240 interposed therebetween in the communication process. Next, as illustrated in FIG. 10(g), a relocation process is performed in which the interior member 120 and the sound absorbing material 140 inside the dummy shell 210 are moved into the inside of the shell 110 through the internal space of the insertion jig 240. (see solid arrow).

After the relocation step is executed, although not shown, a closing step is performed in which the dummy shell 210 and the insertion jig 240 are removed from the shell 110 to which the interior member 120 and the sound absorbing material 140 have been relocated, and the ends of the shell 110 are closed. be done. In the example shown in FIGS. 9 and 10, a tapered portion is formed at the lower end of the shell 110 from the beginning, and only the upper end, which serves as the filling port for the sound absorbing material, is open. Therefore, in the closing step, a tapered portion is formed by spinning the upper end of the shell 110.

<effect>
As described above, in the silencer to which the fourth method is applied, the interior member is formed by a punched pipe having a plurality of through holes drilled on its side surface and metal fibers wound around at least the area of the outer circumferential surface of the punched pipe where the through holes are drilled. In the fourth method, the cover mounting step of fitting the cover pipe to the interior member is performed before the filling step, so that the sound absorbing material that has flowed into the space between the dummy shell and the interior member in the filling step is less likely to get caught by the metal fibers and hinder uniform filling of the sound absorbing material. In other words, according to the fourth method, even in a silencer in which the interior member is formed by a punched pipe having a plurality of through holes drilled on its side surface and metal fibers wound around at least the area of the outer circumferential surface of the punched pipe where the through holes are drilled, the sound absorbing material can be efficiently filled into the sound absorbing chamber by applying the roving method.

Here, some variations of the structure of a silencer to which the method for manufacturing a silencer according to the present invention (method of the present invention) can be applied will be illustrated below with reference to the drawings.

11 is a schematic diagram showing an example of the configuration of a muffler according to Example 1 having a standard (so-called "vertical") configuration in which an exhaust inlet and an exhaust outlet are provided at both ends of the muffler in the axial direction. In FIG. 11, in order to facilitate understanding of the present invention, an interior member 120 that is held inside the shell 110 and should not be visible from the outside is drawn by solid or dashed lines.

FIG. 11A shows a state in which the silencer 101 whose end portion is not yet closed by the end plate 130 is observed from the axial direction of the shell 110. (b) shows the completed silencer 101 whose ends are closed by the end plates 130, as viewed from the short axis direction of the oval cross section of the shell 110. (c) shows a perspective view of the silencer 101 whose end is not yet closed by the end plate 130. (d) shows a perspective view of the completed silencer 101 whose end portion is closed by the end plate 130.

Also in the silencer 101 illustrated in FIG. 11, the interior member 120 is composed of three mutually fixed pipes and four partition walls, and these four partition walls divide the internal space of the shell 110 into five sections. It is divided into Of these five sections, the two sections whose pipes are shaded are filled with sound absorbing material 140 and serve as sound absorbing chambers.

According to the method of the present invention, even in the silencer 101 according to the first embodiment having the above-described complicated structure, the sound-absorbing material can be efficiently filled into the sound-absorbing chamber by applying the roving method.

The silencer 101 according to the first embodiment described with reference to FIG. 11 has a standard vertical configuration in which the exhaust inlet and outlet are provided at both ends in the axial direction of the silencer. Nowadays, silencers with a configuration in which the inlet pipe is connected to the outer surface of the shell and the exhaust outlet is provided at one end in the axial direction of the silencer (so-called ``side-fitting type'') have come into widespread use. There is.

FIG. 12 is a schematic diagram illustrating an example of the configuration of a silencer according to the second embodiment having the horizontal insertion type configuration as described above. In FIG. 12 as well, the interior member 120, which is held inside the shell 110 and is not supposed to be visible from the outside, is drawn with solid or broken lines for the purpose of facilitating understanding of the present invention.

FIG. 12(a) shows the silencer 102 in which the inlet pipe 150 is press-fitted into the outer surface of the shell 110 whose end is not yet closed by the end plate 130, as viewed from the axial direction of the shell 110. . However, for the purpose of clearly showing the arrangement of the inlet pipe 150, the entire inlet pipe 150, including the portion that is not supposed to be visible from the outside, is drawn with solid lines. (b) shows the silencer 102 in which the inlet pipe 150 is press-fitted into the outer surface of the shell 110 whose end is closed by the end plate 130, as viewed from the minor axis direction of the oval cross section of the shell 110. There is. (c) shows a perspective view of the silencer 102 before the inlet pipe 150 is press-fitted into the outer surface of the shell 110 whose end is closed by the end plate 130. (d) shows a perspective view of the silencer 102 in which the inlet pipe 150 is press-fitted into the outer surface of the shell 110 whose end is closed by the end plate 130, and the fitting portion is welded around the entire circumference.

Also in the silencer 102 illustrated in FIG. 12, the interior member 120 is composed of three mutually fixed pipes and four partition walls, and these four partition walls divide the internal space of the shell 110 into five sections. It is divided into Of these five sections, two sections whose pipes are shaded are filled with sound absorbing material 140 to form sound absorbing chambers.

According to the method of the present invention, even in the silencer 102 according to the second embodiment having the above-described complicated structure, the sound absorbing material can be efficiently filled into the sound absorbing chamber by applying the roving method.

FIG. 13 is a schematic diagram showing an example of the configuration of the silencer according to the third embodiment, which has a horizontal insertion type configuration like the silencer according to the second embodiment described above. Also in FIG. 13, the interior member 120, which is held inside the shell 110 and is not supposed to be visible from the outside, is drawn with solid or broken lines for the purpose of facilitating understanding of the present invention.

FIG. 13A shows a silencer 103 in which an inlet pipe 150 including a stay 151 is fitted into a notch 111 formed on the outer surface of the shell 110 whose end is not yet closed by the end plate 130. The figure shows a state observed from the axial direction of the shell 110. However, for the purpose of clearly showing the arrangement of the inlet pipe 150 and stay 151, the entire inlet pipe 150 and stay 151, including portions that are not supposed to be visible from the outside, are drawn with solid lines. (b) shows a silencer 103 in which an inlet pipe 150 including a stay 151 is fitted into a notch 111 formed on the outer surface of the shell 110 whose end is closed by an end plate 130. It shows the state observed from the short axis direction of the cross section of the shape. (c) is a perspective view of the silencer 103 before the inlet pipe 150 including the stay 151 is fitted into the notch 111 formed on the outer surface of the shell 110 whose end is closed by the end plate 130. It shows. In (d), an inlet pipe 150 equipped with a stay 151 is fitted into a notch 111 formed on the outer surface of the shell 110 whose end is closed by an end plate 130, and the fitting part is welded around the entire circumference. 2 shows a perspective view of the silencer 103.

In the silencer 103 according to the third embodiment, since the inlet pipe 150 includes the stay 151 as described above, the fixing strength of the connection portion between the inlet pipe 150 and the shell 110 is high. Therefore, the muffler 103 is able to maintain its stay even when stress is applied to the connection between the inlet pipe 150 and the muffler 103 due to, for example, vibrations caused by the operation of the internal combustion engine to which the muffler 103 is installed. Higher durability can be achieved compared to a silencer with an inlet pipe without one.

In the silencer 103 illustrated in FIG. 13 as well, the interior member 120 is composed of three mutually fixed pipes and four partition walls, and these four partition walls reduce the internal space of the shell 110 to five. It is divided into two sections. Of these five sections, the two sections whose pipes are shaded are filled with sound absorbing material 140 and serve as sound absorbing chambers.

According to the method of the present invention, the sound absorbing material can be efficiently filled into the sound absorbing chamber by applying the roving method to the silencer 103 according to the third embodiment having the above-described complicated structure.

FIG. 14 is a schematic diagram showing an example of the configuration of a silencer according to Example 4, which has a side-loading type configuration like the silencers according to Examples 2 and 3 described above. Also in FIG. 14, the interior member 120, which is held inside the shell 110 and is not supposed to be visible from the outside, is drawn with solid lines or broken lines for the purpose of facilitating understanding of the present invention.

FIG. 14A shows a silencer 104 with an inlet pipe 150 press-fitted into the outer surface of the shell 110 whose end is not yet closed by the end plate 130 and a stay 152 provided inside the shell 110. The state observed from the axial direction is shown. However, for the purpose of clearly showing the arrangement of the inlet pipe 150 and stay 152, the entire inlet pipe 150 and stay 152, including portions that are not supposed to be visible from the outside, are drawn with solid lines. (b) shows a muffler 104 in which an inlet pipe 150 is press-fitted into the outer surface of the shell 110 whose end is closed by an end plate 130 and a stay 152 provided inside the shell 110, in an oval cross section of the shell 110. The state observed from the short axis direction is shown. (c) shows a perspective view of the silencer 104 before the inlet pipe 150 is press-fitted into the outer surface of the shell 110 whose end is closed by the end plate 130 and the stay 152 provided inside the shell 110. There is. (d) shows that the inlet pipe 150 is press-fitted into the outer surface of the shell 110 whose end is closed by the end plate 130 and the stay 152 provided inside the shell 110, and the outer surface of the shell 110 and the inlet pipe 150 are fitted together. 2 shows a perspective view of a silencer 104 in which parts are welded around the entire circumference.

In the silencer 104 according to the fourth embodiment, as described above, the inlet pipe 150 is press-fitted not only on the outer surface of the shell 110 but also on the stay 152 provided inside the shell 110, so that the outer surface of the shell 110 and the inlet pipe Since the fitting portion with the inlet pipe 150 is welded over the entire circumference, the fixing strength of the connection portion between the inlet pipe 150 and the shell 110 is high. Therefore, the muffler 104 is able to maintain its shell even when stress is applied to the connecting portion between the inlet pipe 150 and the muffler 104 due to, for example, vibrations accompanying the operation of the internal combustion engine to which the muffler 104 is installed. Higher durability can be achieved compared to a silencer without an internal stay.

In the silencer 104 illustrated in FIG. 14 as well, the interior member 120 is composed of three mutually fixed pipes and four partition walls, and these four partition walls reduce the internal space of the shell 110 to five. It is divided into two sections. Of these five sections, the two sections whose pipes are shaded are filled with sound absorbing material 140 and serve as sound absorbing chambers.

According to the method of the present invention, even in the silencer 104 according to the fourth embodiment having the above-described complicated structure, the sound absorbing material can be efficiently filled into the sound absorbing chamber by applying the roving method.

For the purpose of explaining the present invention, several embodiments and examples having specific configurations have been described above, sometimes with reference to the attached drawings. However, the scope of the present invention should not be construed as being limited to these exemplary embodiments and examples, and it goes without saying that appropriate modifications can be made within the scope of the claims and the matters described in the specification. In addition, mufflers to which the manufacturing method for a muffler according to the present invention is applicable include not only mufflers installed on conventional internal combustion engines that use gasoline or diesel as fuel, but also mufflers installed on all internal combustion engines, including internal combustion engines that use hydrogen or alternative fuels. Furthermore, the manufacturing method for a muffler according to the present invention can also be applied to mufflers installed on devices and/or equipment other than internal combustion engines, such as mufflers installed in building piping.

100, 101, 102, 103, 104... Silencer 110... Shell 111... Notch portion 120... Interior member 121... Punching pipe 122... Metal fiber 130... End plate 140... Sound absorbing material 150... Inlet pipe 151, 152... Stay 210 ...Dummy shell 211...Filling port 212...Exhaust port 220...Nozzle 230...Suction device 240...Insertion jig 250...Receiving jig 260...Cover pipe

Claims (4)

A method for manufacturing a silencer comprising at least one section filled with a sound absorbing material inside a cylindrical shell, the method comprising:
a holding step which is a step of preparing a cylindrical dummy shell different from the shell and holding an interior member of the silencer inside the dummy shell;
A nozzle is inserted into the compartment through the filling port, which is an opening on the end and/or side of the dummy shell, and While discharging the air inside the compartment through an exhaust port, which is an opening different from the filling port, continuous long fibers constituting the sound-absorbing material are filled into the compartment from the nozzle, and the sound-absorbing material is a filling process, which is a process of forming a lump;
One end of an insertion jig, which is a cylindrical jig having an inner circumferential surface that continuously connects the inner circumferential surface of the dummy shell and the inner circumferential surface of the shell, is filled with the sound absorbing material. The other end of the insertion jig is connected to the end of the shell, and the insertion jig is connected to the inner space of the dummy shell and the inside of the shell through the inner space of the insertion jig. A communication process is a process of communicating with the space,
a relocation step, which is a step of relocating the interior member and the mass of sound absorbing material inside the dummy shell into the inside of the shell through the internal space of the insertion jig;
a closing step, which is a step of removing the dummy shell and the insertion jig from the shell to which the interior member has been relocated, and closing an end of the shell;
A method of manufacturing a silencer, including: A method for manufacturing the silencer according to claim 1,
a cross section of the inner circumferential surface of the dummy shell is larger than a cross section of the inner circumferential surface of the shell;
the insertion jig has a tapered inner circumferential surface that is continuously smaller from the cross section of the inner circumferential surface of the dummy shell to the cross section of the inner circumferential surface of the shell,
In the communication step, an end portion of the inner circumferential surface of the insertion jig having a larger cross section is connected to an end portion of the dummy shell, and an end portion of the inner circumferential surface of the insertion jig having a smaller cross section is connected to an end portion of the shell.
A method for manufacturing a silencer. A method for manufacturing a silencer according to claim 1 or 2,
The interior member is composed of a plurality of pipes and a plurality of partition walls fixed to each other,
The interior space of the shell is divided into a plurality of compartments by the interior member.
A method for manufacturing a silencer. A method for manufacturing a silencer according to claim 1 or 2,
the interior member is formed by a punching pipe having a plurality of through holes drilled in a side surface thereof and metal fibers wound around at least an area of an outer circumferential surface of the punching pipe where the through holes are drilled,
a cover fitting step, which is a step of fitting a cover pipe, which is a cylindrical member having a smooth outer circumferential surface, to the interior member before the filling step;
a cover removing step, which is a step of removing the cover pipe after the filling step and before the closing step;
Further comprising:
In the filling step, the nozzle is inserted into the filling section, which is the space between the dummy shell and the cover pipe, from one end in the axial direction of the filling section, and continuous long fibers constituting the sound absorbing material are filled into the filling section from the nozzle while discharging air from the filling section from the other end of the filling section.
A method for manufacturing a silencer.

Images