Method of manufacturing resin silencer

Abstract

To prevent flashes from being generated, and to prevent a space for disposing a silencer from becoming large.SOLUTION: A method of manufacturing a resin silencer comprises: a matching step for disposing a first member 1, a second member 2, and a third member 3 so that an opening of the other end portion of a first drum portion 1t and an opening of the other end portion of a second drum portion 2t face each other, and the third member (a small diameter portion) 3 is disposed on an inner side of the first drum portion 1t and on an inner side of the second drum portion 2t; and a bonding step of laser bonding the first drum portion 1t and the third member 3 inside the first drum portion, and laser bonding the second drum portion 2t and the third member 3 inside the second drum portion by applying a laser beam onto overlapped portions formed by disposing the third member 3 on the inner sides of the first drum portion 1t and the second drum portion 2t, from outer sides of the first drum portion 1t and the second drum portion 2t.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a resin silencer that is connected to piping for an air conditioner in an automobile. [Background technology]

[0002] Silencers are often attached to the piping of automobile air conditioners. Silencers are roughly cylindrical components that are thicker than the piping of air conditioners. A space is formed inside the silencer, and this space reduces the noise of the refrigerant. Silencers are generally made of metal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-205701 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, in order to reduce the weight of automobiles, the use of resin silencers has been considered. Resin silencers are produced, for example, by the following method.

[0005] As shown in FIG. 7, two cylindrical members (501, 502) with one closed end are prepared. The two members (501, 502) are made of resin and are molded, for example, by injection molding. The two members (501, 502) are butted together with their open ends facing each other, and are welded together by vibration welding, spin welding, or the like. This integrates the two members (501, 502). However, this method has the following problems.

[0006] As shown in the lower diagram of Figure 7, burrs B are generated around the welded parts (501s, 502s) and the end faces. Burrs B generated inside the silencer cause pressure loss of the refrigerant flowing through the silencer. Furthermore, if burrs B inside the silencer peel off, they are emitted from the silencer together with the refrigerant, becoming foreign matter and adversely affecting the air conditioning system.

[0007] Furthermore, in order to ensure a welding surface, it is necessary to provide welding portions (501s, 502s). The welding portions (501s, 502s) protrude outward from the surrounding portion 500I that surrounds the space 500i inside the silencer. The welding portions (501s, 502s) make it necessary to ensure a space inside the vehicle that is larger than the surrounding portion 500I that surrounds the space 500i necessary for noise reduction.

[0008] An object of the present invention is to provide a method for manufacturing a resin silencer that does not produce burrs and that prevents the space required for arranging the silencer from becoming too large. [Means for solving the problem]

[0009] The method for manufacturing a resin silencer disclosed in the present specification is a method for manufacturing a resin silencer having an internal space, the silencer comprising: a first member and a second member made of resin that are transparent to laser light; and a third member made of resin that is absorptive to laser light, the first member having a cylindrical first body portion and a first side portion formed to close one end of the first body portion, the second member having a cylindrical second body portion and a second side portion formed to close one end of the second body portion, and the third member being a cylindrical member having a small diameter portion that is smaller in diameter than the first body portion and the second body portion. and includes an alignment step of arranging the first member, the second member, and the third member so that an opening at the other end of the first body and an opening at the other end of the second body face each other and so that the small diameter portions are located inside the first body and the second body; and a joining step of irradiating laser light from outside the first body and the second body to overlapping portions of the first body and the second body, where the small diameter portions are located inside, to laser-join the first body and the small diameter portions located inside the first body. [Effects of the Invention]

[0010] According to the above method, it is possible to manufacture a resin silencer that does not produce burrs and that does not require a large space for arranging the silencer. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of a resin silencer according to a first embodiment. [Figure 2] 1 is an exploded cross-sectional view of a resin silencer according to a first embodiment. FIG. [Figure 3] 3A to 3C are cross-sectional views showing a method for manufacturing the resin silencer according to the first embodiment. [Figure 4] FIG. 6 is a cross-sectional view of a resin silencer according to a second embodiment. [Figure 5] FIG. 10 is an exploded cross-sectional view of a resin silencer according to a second embodiment. [Figure 6] 10(a) and 10(b) are cross-sectional views of a resin silencer according to a modified example. [Figure 7] 10A and 10B are cross-sectional views showing an example of a manufacturing method for a resin silencer under study. DETAILED DESCRIPTION OF THE INVENTION

[0012] [First embodiment] 1 shows a cross-sectional view and a partially enlarged cross-sectional view of a silencer 100 according to a first embodiment. The silencer 100 is connected to, for example, an air conditioning pipe for an automobile. The silencer 100 is made of resin.

[0013] As shown in Fig. 1, silencer 100 has a space 100S inside. Space 100S is surrounded by an enclosure 100A. Silencer 100 has enclosure 100A, a first pipe section 100a, and a second pipe section 100b. Pipes (not shown) are connected to first pipe section 100a and second pipe section 100b.

[0014] The inner diameter of the surrounding portion 100A, centered on the axis C1, is larger than the inner diameters of the first pipe portion 100a and the second pipe portion 100b. The surrounding portion 100A is larger than the piping connected to the first pipe portion 100a and the piping connected to the second pipe portion 100b. Noise from the refrigerant flowing into the space 100S from the piping (not shown) is reduced in the space 100S.

[0015] The first pipe portion 100a is formed at one end of the silencer 100 in the direction of the axis C1. The axis C1 is also the axis of the surrounding portion 100A. The second pipe portion 100b is formed between the one end and the other end in the direction of the axis C1.

[0016] The surrounding portion 100A has a parallel portion 100p whose outer surface is parallel to the direction of the axis C1. The parallel portion 100p is formed over the entire circumferential direction centered on the axis C1. The parallel portion 100p is located in the portion of the surrounding portion 100A where the outer diameter centered on the axis C1 is the largest. The parallel portion 100p is located between the first pipe portion 100a and the second pipe portion 100b in the direction of the axis C1.

[0017] In a cross section of the silencer 100 passing through the direction of the axis C1, the inner surface of the enclosure portion 100A is elliptical. An elliptical shape is one in which both longitudinal ends are curved outwardly convexly (for example, semicircular or arc-shaped), and both curved ends are connected by a straight line. In this specification, the "elliptical" shape may be either symmetrical or asymmetrical in the curved shape at both ends. The axis C1 shown in FIG. 1 is also the major axis of the elliptical inner surface of the enclosure portion 100A.

[0018] The inner surface of the surrounding portion 100A is not limited to the above-mentioned shape. In a cross section of the silencer 100 passing through the direction of the axis C1, the inner surface of the silencer 100 may be a circle, a flattened circle, an oval, an ellipse, a polygon, or the like. A flattened circle is a shape that resembles a circle that has been crushed toward the center. An oval is a shape in which both ends in the longitudinal direction are curved and convex outward (for example, a circle or an arc), and the both ends are asymmetrical with respect to the minor axis. The polygon here may also have rounded corners.

[0019] The silencer 100 is composed of a first member 1, a second member 2, and a third member 3 shown in Fig. 2. The first member 1, the second member 2, and the third member 3 are integrated together to obtain the silencer 100 shown in Fig. 1.

[0020] 2, the first member 1 has a cylindrical first body portion 1t and a first side portion 1s. The first side portion 1s is formed so as to close one end of the first body portion 1t.

[0021] In this specification, "cylindrical" refers to a cylindrical shape that penetrates in the axial direction and has openings at both ends that are not surrounded by straight lines only, such as circles, ellipses, or ovals. In the "cylindrical" specification, the opening at one end and the opening at the other end may have the same shape or different shapes. In the "cylindrical" specification, the outer diameter and inner diameter of the cylindrical shape may be constant in the axial direction or may change along the way.

[0022] The first body portion 1t of the first member 1 shown in FIG. 2 has a first parallel portion 1tp. The outer surface of the first parallel portion 1tp is parallel to the axis over the entire circumferential direction. The thickness of the first parallel portion 1tp is constant in the axial direction. The thickness of the first parallel portion 1tp is thinner than the other portions of the first member 1 (excluding the first pipe portion 100a). The inner surface of the first member 1, the inner surface of the first parallel portion 1tp, is recessed.

[0023] The inner surface of the first side portion 1s is hemispherical or arc-shaped. A first pipe portion 100a is formed near the center of the first side portion 1s. The first pipe portion 100a extends in the axial direction of the first body portion 1t.

[0024] The second member 2 shown in Fig. 2 has a cylindrical second body portion 2t and a second side portion 2s. The second side portion 2s is formed so as to close one end of the second body portion 2t.

[0025] The second body portion 2t has a second parallel portion 2tp. The outer surface of the second parallel portion 2tp is parallel to the axis over the entire circumferential direction. The thickness of the second parallel portion 2tp is constant in the axial direction. The thickness of the second parallel portion 2tp is thinner than the thickness of other portions of the second member 2 (excluding the second pipe portion 100b). The inner surface of the second member 2, the inner surface of the second parallel portion 2tp, is recessed.

[0026] The inner surface of the second side portion 2s is hemispherical or arc-shaped.

[0027] The second pipe portion 100b is formed between one end and the other end of the second member 2 in the axial direction of the second member 2. The second pipe portion 100b extends in a direction perpendicular to the axis.

[0028] The third member 3 is cylindrical. The third member 3 is disposed inside the first body portion 1t and the second body portion 2t. In this embodiment, the third member 3 is disposed inside the first parallel portion 1tp and the second parallel portion 2tp. The outer diameter of the third member 3 is smaller than the outer diameter of the first body portion 1t and the outer diameter of the second body portion 2t. In this specification, the portion having an outer diameter smaller than the outer diameter of the first body portion 1t and the outer diameter of the second body portion 2t is referred to as the "small diameter portion." The third member 3 comprises a small diameter portion. The outer diameter of the third member 3 is equal to or slightly larger than the inner diameter of the first parallel portion 1tp and the inner diameter of the second parallel portion 2tp.

[0029] As shown in the enlarged view of Figure 1, a recess f1 is formed by the inner surfaces of the first body portion 1t and the second body portion 2t. A third member 3 is fitted into the recess f1. The first parallel portion 1tp and the second parallel portion 2tp are arranged on the outside of the third member 3. The first parallel portion 1tp and the second parallel portion 2tp and the third member 3 inside them form a parallel portion 100p. The first parallel portion 1tp and the third member 3 inside it are laser joined. The second parallel portion 2tp and the third member 3 inside it are laser joined. In this specification, "laser joining" means joining by irradiating laser light.

[0030] In the parallel portion 100p, the radial thickness of the first parallel portion 1tp and the radial thickness of the second parallel portion 2tp are the same. In the parallel portion 100p, the radial thickness of the first parallel portion 1tp and the radial thickness of the second parallel portion 2tp are constant in the direction of the axis C1. In the parallel portion 100p, the outer surfaces of the first parallel portion 1tp and the second parallel portion 2tp are parallel to the direction of the axis C1 and are linear or nearly linear.

[0031] As shown in the overall view of the silencer 100 in FIG. 1 , the end face of the first member 1 and the end face of the second member 2 are in contact. On the outer surfaces of the silencer 100, the outer surfaces of the first member 1 and the second member 2 are continuous. There are almost no steps or corners between the outer surfaces of the adjacent first member 1 and second member 2. The third member 3 does not appear on the outer surface of the silencer 100. The third member 3 is arranged inside the first member 1 and the second member 2. Specifically, a portion of the third member 3 is arranged inside the first member 1, and the remaining portion of the third member 3 is arranged inside the second member 2.

[0032] On the inner surface of the silencer 100, the inner surface of the first member 1, the inner surface of the third member 3, and the inner surface of the second member 2 are aligned in order in a direction parallel to the direction of the axis C1 and are continuous. There are almost no steps or corners between the inner surfaces of the adjacent first member 1 and the third member 3. There are almost no steps or corners between the inner surfaces of the adjacent third member 3 and the second member 2.

[0033] The first member 1 and the second member 2 are made of a resin that is transparent to laser light. Examples of resins that are transparent to laser light include PA66, PA612, and PA9T. The third member 3 is made of a resin that is absorptive of laser light. Examples of resins that are absorptive of laser light include PA66, PA612, and PA9T. The first member 1, the second member 2, and the third member 3 are formed by, for example, injection molding.

[0034] Next, a method for manufacturing the silencer 100 will be described with reference to FIGS.

[0035] The first member 1, the second member 2, and the third member 3 are arranged so that the opening at the end of the first body portion 1t and the opening at the end of the second body portion 2t shown in FIG. 2 face each other, and so that the third member (small diameter portion) 3 is arranged inside the first body portion 1t and the second body portion 2t (alignment process). The left diagram in FIG. 3 shows an example of an intermediate stage of the alignment process. In the left diagram in FIG. 3, a portion of the third member (small diameter portion) 3 is arranged inside the first body portion 1t and the second body portion 2t. From the state shown in the left diagram in FIG. 3, the first member 1 and the second member 2 are brought closer together, and the other end of the first body portion 1t and the other end of the second body portion 2t are brought into contact, as shown in the right diagram in FIG. 3. As a result, the entire third member (small diameter portion) 3 is arranged inside the first body portion 1t and the second body portion 2t. The alignment process is not limited to proceeding from the left to the right in Fig. 3. For example, a portion of the third member (small diameter portion) 3 may be placed inside the first body portion 1t, and then the remaining portion of the third member (small diameter portion) 3 may be placed inside the second body portion 2t. In the fitting step, the third member 3 is fitted into the recess f1 formed by the inner surface of the first body portion 1t and the inner surface of the second body portion 2t. As shown in the right diagram of Figure 3, the completion of the joining process can be determined by confirming from the outside of each component that the other end of the first body portion 1t and the other end of the second body portion 2t are abutting.

[0036] Next, the overlapping portion of the first body 1t and the second body 2t, where the third member 3 is located inside, is irradiated with laser light from the outside of the first body 1t and the second body 2t. For example, as shown in the right diagram of FIG. 3, the first member 1, the second member 2, and the third member 3 are rotated around the axis C1, while the laser light is irradiated from the laser light emitting portion M toward the first body 1t. This allows the laser light to be irradiated over the entire circumferential direction of the first body 1t in a range parallel to the axis C1 direction. If necessary, to irradiate portions that have not been irradiated with laser light, the emitting portion M is moved in a direction parallel to the axis C1 direction, and the first member 1, the second member 2, and the third member 3 are rotated around the axis C1, while the laser light is irradiated from the emitting portion M toward the first body 1t. This process is repeated. The same process is performed when irradiating the second body 2t with laser light.

[0037] The laser light passes through the first body portion 1t and is irradiated onto the third member 3. The laser light passes through the second body portion 2t and is irradiated onto the third member 3. At the overlapping portions, the first body portion 1t and the third member 3 are laser-joined, and the second body portion 2t and the third member 3 are laser-joined (joining process). The first member 1, the second member 2, and the third member 3 are integrated, and the silencer 100 shown in FIG. 1 is obtained.

[0038] Regarding the overlapping portion, for example, if the first member 1 and the second member 2 are made of milky white, translucent, or transparent resin, it is easy to identify the portion where the third member 3 is located inside (the overlapping portion), and the laser light is easily transmitted through the first member 1 and the second member 2. In addition, if the third member 3 is made of a resin that is a different color from the first member 1 and the second member 2, for example, a black resin, it is even easier to identify the overlapping portion, and the third member 3 is more likely to absorb the laser light. In this embodiment, the overlapping portion and the parallel portion 100p coincide with each other. In this case, the overlapping portion can be identified by identifying the parallel portion 100p from the outer surface of the first body portion it and the outer surface of the second body portion 2t.

[0039] The above method provides the following effects. 3, by irradiating the overlapping portion (in this embodiment, the "parallel portion 100p") of the first body portion 1t and the second body portion 2t, where the third member 3 is located inside, with laser light, the first body portion 1t and the third member 3 are joined, and the second body portion 2t and the third member 3 are joined. With this method, no burrs are generated at the joint between the two members. Furthermore, the joint does not protrude outward from the surrounding portion 100A that surrounds the internal space 100S of the silencer 100 shown in FIG. As a result, it is possible to manufacture a resin silencer 100 that does not produce burrs and that does not require an increased space for arranging the silencer 100.

[0040] Furthermore, as shown in FIG. 3, by placing a third member 3 inside the first body portion 1t and the second body portion 2t and irradiating laser light from the outside of the first body portion 1t and the second body portion 2t, the three members, the first member 1, the second member 2, and the third member 3, can be easily integrated.

[0041] As shown in the enlarged view of FIG. 1 , in the overlapping portion (the “parallel portion 100p” in this embodiment) where the third member 3 is disposed inside the first body portion 1t and the second body portion 2t, the radial thickness of the first parallel portion 1tp and the radial thickness of the second parallel portion 2tp are constant, and the radial thickness of the first parallel portion 1tp and the radial thickness of the second parallel portion 2tp are the same. In addition, in the overlapping portion (the “parallel portion 100p” in this embodiment), the outer surfaces of the first parallel portion 1tp and the second parallel portion 2tp are parallel to the axis C1 direction and are linear or nearly linear. In this case, the operation of the emission portion M is not complicated because it is not necessary to move the emission portion M toward or away from the first body portion 1t and the second body portion 2t in a direction perpendicular to the axis C1 direction. The three members, the first member 1, the second member 2, and the third member 3, can be easily integrated.

[0042] 1, a large internal pressure is likely to be applied to both end portions in the direction of the axis C1. In the case where the inner surfaces of both end portions in the direction of the axis C1 are circular or arc-shaped in a cross section of the silencer 100 passing through the direction of the axis C1 as in this embodiment, both end portions are configured to be able to withstand a large internal pressure. As a result, it is possible to provide a silencer 100 that is pressure resistant even though it is made of resin.

[0043] 1, when the third member 3 is fitted into the recess f1, the inner surfaces of the first member 1, the third member 3, and the second member 2, which are arranged in this order, are continuous with each other. This reduces the pressure loss of the fluid flowing through the silencer 100.

[0044] Second Embodiment Next, a method for manufacturing the silencer 200 according to the second embodiment will be described below with reference to Figures 4 and 5. The second embodiment differs from the first embodiment mainly in the configurations of the first member, the second member, and the third member. Note that the description of the same configurations and steps as those of the first embodiment will be omitted as appropriate.

[0045] 4 shows a cross-sectional view and a partially enlarged cross-sectional view of a silencer 200 according to the second embodiment. The silencer 200 has a space 200S therein. The space 200S is surrounded by an surrounding portion 200A. The silencer 200 has the surrounding portion 200A, a first pipe portion 200a, and a second pipe portion 200b. Except for the portions described below, the surrounding portion 200A, the first pipe portion 200a, and the second pipe portion 200b of the silencer 200 are similar to the surrounding portion 100A, the first pipe portion 100a, and the second pipe portion 100b of the silencer 100 according to the first embodiment, respectively.

[0046] The surrounding portion 200A has a parallel portion 200p whose outer surface is parallel to the direction of the axis C2. The parallel portion 200p is formed over the entire circumferential direction centered on the axis C2. The parallel portion 200p is located in the portion of the surrounding portion 200A where the outer diameter centered on the axis C2 is the largest. The parallel portion 200p is located between the first pipe portion 200a and the second pipe portion 200b in the direction of the axis C2.

[0047] In a cross section of the silencer 200 taken along the axis C2, the inner surface of the surrounding portion 200A has an elliptical shape. The axis C2 shown in Fig. 4 is also the major axis of the elliptical inner surface of the surrounding portion 200A. The inner surface of the surrounding portion 200A is not limited to the above shape, and may have a shape such as that exemplified in the description of the surrounding portion 100A of the first embodiment.

[0048] The silencer 200 is composed of a first member 201, a second member 202, and a third member 203 shown in Fig. 5. The first member 201, the second member 202, and the third member 203 are integrated together to obtain the silencer 200 shown in Fig. 4.

[0049] 5, the first member 201 has a cylindrical first body portion 201t and a first side portion 201s. The first side portion 201s is formed so as to close one end of the first body portion 201t. The first side portion 201s has a configuration similar to that of the first side portion 201s of the first embodiment.

[0050] The first body portion 201t has a first parallel portion 201tp. The outer surface of the first parallel portion 201tp is parallel to the axis over the entire circumferential direction. The first parallel portion 201tp is shorter in the axial direction than the first parallel portion 1tp of the first embodiment shown in FIG. 2. The radial thickness of the first parallel portion 201tp is constant in the axial direction. The thickness of the first parallel portion 201tp is thinner than the other portions of the first member 201 (excluding the first pipe portion 200a). The inner surface of the first parallel portion 201tp is recessed within the inner surface of the first member 201.

[0051] The inner surface of the first side portion 201s is semispherical or arc-shaped. A first pipe portion 200a is formed near the center of the first side portion 201s.

[0052] The second member 202 has a cylindrical second body portion 202t and a second side portion 202s. The second side portion 202s is formed so as to close one end of the second body portion 202t. The second side portion 202s has a configuration similar to that of the second side portion 202s of the first embodiment.

[0053] The second body portion 202t has a second parallel portion 202tp. The outer surface of the second parallel portion 202tp is parallel to the axis over the entire circumferential direction. The second parallel portion 202tp is shorter in the axial direction than the second parallel portion 202tp of the first embodiment shown in FIG. 2. The radial thickness of the second parallel portion 202tp is constant in the axial direction. The thickness of the second parallel portion 202tp is thinner than the thickness of other portions of the second member 202 (excluding the second pipe portion 200b). The inner surface of the second parallel portion 202tp is recessed within the inner surface of the second member 202.

[0054] The inner surface of the second side portion 202s is hemispherical or arc-shaped.

[0055] The second pipe portion 200b is formed between one end and the other end of the second member 202 in the axial direction of the second member 202.

[0056] The third member 203 has a cylindrical shape and includes a large diameter portion 203D and a first small diameter portion (small diameter portion) 203d1 and a second small diameter portion (small diameter portion) 203d2 formed on both sides of the large diameter portion 203D.

[0057] The outer diameter of the large diameter portion 203D is the same as or approximately the same as the outer diameter of the first body portion 201t and the outer diameter of the second body portion 202t. The outer surface of the large diameter portion 203D is parallel to the axial direction.

[0058] The outer diameter of the first small diameter portion 203d1 and the outer diameter of the second small diameter portion 203d2 are smaller than the outer diameter of the large diameter portion 203D. The outer diameter of the first small diameter portion 203d1 and the outer diameter of the second small diameter portion 203d2 are both smaller than the outer diameter of the first body portion 201t and the outer diameter of the second body portion 202t. The outer diameter of the first small diameter portion 203d1 is equal to or slightly larger than the inner diameter of the first parallel portion 201tp. The second small diameter portion 203d2 is equal to or slightly larger than the inner diameter of the second parallel portion 202tp. The outer diameter of the first small diameter portion 203d1 and the second small diameter portion 203d2 are the same or almost the same.

[0059] 4, the first small diameter portion 203d1 is disposed inside the first parallel portion 201tp of the first body portion 201t. The second small diameter portion 203d2 is disposed inside the second parallel portion 202tp of the second body portion 202t. The large diameter portion 203D is located between the first body portion 201t and the second body portion 202t in the direction parallel to the axis C2.

[0060] As shown in the enlarged view of Figure 4, the first small diameter portion 203d1 is fitted into the recess f21 on the inner surface of the first body portion 201t. The first parallel portion 201tp is disposed outside the first small diameter portion 203d1. The second small diameter portion 203d2 is fitted into the recess f22 on the inner surface of the second body portion 202t. The second parallel portion 202tp is disposed outside the second small diameter portion 203d2.

[0061] The first parallel portion 201tp and the first small diameter portion 203d1 located inside thereof are laser-bonded. The second parallel portion 202tp and the second small diameter portion 203d2 located inside thereof are laser-bonded. The first parallel portion 201tp, the first small diameter portion 203d1 located inside thereof, the large diameter portion 203D, the second parallel portion 202tp, and the second small diameter portion 203d2 located inside thereof form the parallel portion 200p.

[0062] In the parallel portion 200p, the thickness of the first parallel portion 201tp and the thickness of the second parallel portion 202tp are the same. In the parallel portion 200p, the thickness of the first parallel portion 201tp and the thickness of the second parallel portion 202tp are constant in the direction of the axis C2. In the parallel portion 200p, the outer surfaces of the first parallel portion 201tp and the second parallel portion 202tp are parallel to the direction of the axis C2 and are linear or nearly linear.

[0063] As shown in the enlarged view of the silencer 200 in FIG. 4, the end face of the first member 201 contacts the large diameter portion 203D, and the end face of the second member 203 contacts the large diameter portion 203D. On the outer surface of the silencer 200, the outer surface of the first member 201, the outer surface of the large diameter portion 203D, and the outer surface of the second member 202 are continuous. There are almost no steps or corners between the outer surfaces of the adjacent first member 201 and large diameter portion 203D. There are almost no steps or corners between the outer surfaces of the adjacent large diameter portion 203D and second member 202. The large diameter portion 203D of the third member 203 appears on the outer surface of the silencer 200. The first small diameter portion 203d1 and the second small diameter portion 203d2 of the third member 203 do not appear on the outer surface of the silencer 200. The first small diameter portion 203d1 is disposed inside the first member 201, and the second small diameter portion 203d2 is disposed inside the second member 202.

[0064] On the inner surface of silencer 200, the inner surface of first member 201, the inner surface of third member 203, and the inner surface of second member 202 are aligned in order in a direction parallel to the direction of axis C2 and are continuous. There are almost no steps or corners between the inner surfaces of adjacent first member 201 and third member 203. There are almost no steps or corners between the inner surfaces of adjacent third member 203 and second member 202.

[0065] The first member 201 and the second member 202 are made of a resin that is transparent to laser light. Examples of the resin for the first member 201 and the second member 202 include the resins exemplified for the first member 1 and the second member 2 in the first embodiment. The third member 203 is made of a resin that is absorptive of laser light. Examples of the resin for the third member 203 include the resins exemplified for the third member 3 of the first embodiment. The first member 201, the second member 202, and the third member 203 are formed by, for example, injection molding.

[0066] Next, a method for manufacturing the silencer 200 will be described.

[0067] The first member 201, the second member 202, and the third member 203 are arranged so that the opening at the end of the first body portion 201t and the opening at the end of the second body portion 202t shown in Fig. 5 face each other, so that the first small diameter portion 203d1 is arranged inside the first body portion 201t, and so that the second small diameter portion 203d2 is arranged inside the second body portion 202t (alignment step). The specific method of the alignment step is not limited. For example, the first small diameter portion 203d1 may be arranged inside the first body portion 201t, and then the second small diameter portion 203d2 may be arranged inside the second body portion 202t, or these steps may be performed simultaneously.

[0068] In the mating step, the first small diameter portion 203d1 fits into the recess f21 formed on the inner surface of the first body portion 201t, and the second small diameter portion 203d2 fits into the recess f22 formed on the inner surface of the second body portion 202t. As shown in the enlarged view of Figure 4, it can be determined that the joining process is complete by confirming from the outside of each member that the other end of the first body portion 201t is in contact with the large diameter portion 203D of the third member 203 and the other end of the second body portion 202t is in contact with the large diameter portion 203D of the third member 203.

[0069] Next, a laser beam is applied to the portion of the first barrel 201t overlapping with the first small diameter portion 203d1. A laser beam is applied to the portion of the second barrel 202t overlapping with the second small diameter portion 203d2. For example, while the first member 201, the second member 202, and the third member 203 shown in FIG. 4 are rotated about the axis C2, a laser beam is applied from a laser beam emitting portion (not shown) toward the first barrel 201t. This allows the laser beam to be applied to the entire circumferential direction of the first barrel 201t in a range parallel to the axis C2. If necessary, to irradiate portions that have not been irradiated with the laser beam, the emitting portion is moved in a direction parallel to the axis C2, and then the first member 201, the second member 202, and the third member 203 are rotated about the axis C2, and the laser beam is repeatedly applied from the emitting portion toward the first barrel 201t. The same applies when irradiating the second body portion 202t with laser light.

[0070] The laser light passes through the first body portion 201t and is irradiated onto the third member 203. The laser light passes through the second body portion 202t and is irradiated onto the third member 203. At the overlapping portions, the first body portion 201t and the third member 203 are laser-joined, and the second body portion 202t and the third member 203 are laser-joined (joining process). The first member 201, the second member 202, and the third member 203 are integrated, and the silencer 200 shown in FIG. 4 is obtained.

[0071] Regarding the overlapping portion, for example, if the first member 201 and the second member 202 are made of milky white, semi-transparent, or transparent resin, it is easy to identify the portion where the third member 203 is disposed inside (the overlapping portion). In addition, if the first small diameter portion 203d1 and the second small diameter portion 203d2 of the third member 203 are made of a resin of a different color from the first member 201 and the second member 202, for example, a black resin, it is even easier to identify the overlapping portion. In this embodiment, the overlapping portion is a part of the parallel portion 200p. In this case, the overlapping portion can be identified by identifying the parallel portion 200p from the outer surface of the first body portion 201t and the outer surface of the second body portion 202t.

[0072] The above method provides the following effects. 4, by irradiating laser light onto the overlapping portions (in this embodiment, the "first parallel portion 201tp" and the "second parallel portion 202tp") of the first body portion 201t and the second body portion 202t, where the third member 203 is located inside, the first body portion 201t and the first small diameter portion 203d1 are joined, and the second body portion 202t and the second small diameter portion 203d2 are joined. With this method, no burrs are generated at the joint between the two members. Furthermore, the joint does not protrude outward from the surrounding portion 200A that surrounds the internal space 200S of the silencer 200 shown in FIG. As a result, it is possible to manufacture a resin silencer 200 that does not produce burrs and that does not require an increased space for arranging the silencer 200.

[0073] Furthermore, as shown in FIG. 4, by arranging the first small diameter portion 203d1 inside the first body portion 201t and the second small diameter portion 203d2 inside the second body portion 202t, and irradiating laser light from the outside of the first body portion 201t and the second body portion 202t, the three members, the first member 201, the second member 202, and the third member 203, can be easily integrated.

[0074] 4, in the overlapping portion (the "first parallel portion 201tp" and the "second parallel portion 202tp" in this embodiment) where the third member 203 is disposed inside the first body portion 201t and the second body portion 202t, the radial thickness of the first parallel portion 201tp and the radial thickness of the second parallel portion 202tp are constant and the radial thickness of the first parallel portion 201tp and the radial thickness of the second parallel portion 202tp are the same. In the overlapping portion (the "first parallel portion 201tp" and the "second parallel portion 202tp" in this embodiment), the outer surface of the first parallel portion 201tp and the outer surface of the second parallel portion 202tp are parallel to the direction of the axis C2 and are linear or substantially linear. In this case, it is not necessary to move the laser light emission part closer to or farther away from the first body 201t and the second body 202t in a direction perpendicular to the direction of the axis C2, and therefore operation of the emission part M is not complicated. The three members, the first member 201, the second member 202, and the third member 203, can be easily integrated.

[0075] 4, a large internal pressure is likely to be applied to both end portions in the direction of the axis C2. In the case where the inner surfaces of both end portions in the direction of the axis C2 are circular or arc-shaped in a cross section of the silencer 200 passing through the direction of the axis C2 as in this embodiment, the both end portions are configured to be able to withstand a large internal pressure. As a result, it is possible to provide a silencer 200 that is pressure resistant even though it is made of resin.

[0076] 4, when the first small diameter portion 203d1 is fitted into the recess f21 on the inner surface of the first body portion 201t and the second small diameter portion 203d2 is fitted into the recess f22 on the inner surface of the second body portion 202t, the inner surfaces of the first member 201, the third member 203, and the second member 202, which are arranged in this order, are continuous with each other. This reduces the pressure loss of the fluid flowing through the silencer 100.

[0077] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present invention is defined not by the above description but by the claims, and includes all modifications within the meaning and scope of the claims.

[0078] For example, in the first embodiment, as shown in Fig. 1, the surrounding portion 100A of the silencer 100 has a parallel portion 100p whose outer surface is parallel to the direction of the axis C1. However, the parallel portion 100p does not have to be formed in the silencer 100. In this case, the first parallel portion 1tp is not formed in the first body portion 1t of the first member 1 shown in Fig. 2. The second parallel portion 2tp is not formed in the second body portion 2t of the second member 2. In the second embodiment, similarly to the first embodiment, the silencer 200 does not necessarily have to have the parallel portion 200p formed therein.

[0079] 1, the thickness of the first body portion 1t and the thickness of the second body portion 2t do not have to be constant on the outside of the third member 3. On the outside of the third member 3, the thickness of the first body portion 1t and the thickness of the second body portion 2t may be different. In the second embodiment, as in the first embodiment, the thickness of the first body portion 201t and the thickness of the second body portion 202t may be different on the outside of the first small diameter portion 203d1 and the outside of the second small diameter portion 203d2 of the third member 203.

[0080] Furthermore, in the first embodiment, the configuration and shape of the silencer 100 are not limited to those described above and can be modified. For example, in a cross section passing through the axis C1 of the silencer 100, the inner and outer surfaces of the silencer 100 can have the same type of shape or different types of shapes. For example, in a cross section passing through the axis C1 of the silencer 100, the inner surface of the silencer 100 can be oval and the outer surface of the silencer 100 can be polygonal. The positions and directions of the first pipe section 100a and the second pipe section 100b shown in FIG. 1 can be modified.

[0081] 6(a), the inner surface of the silencer 300 may be oval in a cross section passing through the axis C3 of the silencer 300. Also, the first pipe section 300a and the second pipe section 300b may be formed at both ends of the silencer 300 in the direction of the axis C2.

[0082] 6(b), the inner surface of the silencer 400 may have an elliptical shape that is long in the direction of the axis C4 in a cross section passing through the axis C4 of the silencer 400. Also, the first pipe section 400a and the second pipe section 400b may be formed at both ends of the silencer 400 in the direction of the axis C4.

[0083] In the second embodiment, as in the first embodiment, the configuration and shape of the silencer 200 are not limited to those described above and may be modified. For example, the configuration of the second embodiment may be modified as shown in Figures 6(a) and 6(b).

[0084] In the first embodiment, the third member 3 fits into the recess f1 as shown in the enlarged view of Fig. 1. However, the inner surfaces of the first body portion 1t and the second body portion 2t may not have recesses, and the third member 3 may simply overlap the inner surfaces of the first body portion 1t and the second body portion 2t. In the second embodiment, as in the first embodiment, there may be no recesses on the inner surfaces of the first body portion 201t and the second body portion 202t shown in the enlarged view of Figure 4, and the third member 203 may simply overlap the inner surfaces of the first body portion 201t and the second body portion 202t.

[0085] 1, the inner surface of the first member 1, the inner surface of the third member 3, and the inner surface of the second member 2 are continuous with each other. However, the inner surfaces of adjacent members do not have to be continuous with each other. In the second embodiment, similarly to the first embodiment, the inner surfaces of the first member 201, the third member 203, and the second member 202 shown in FIG. 4 do not have to be continuous. [Explanation of symbols]

[0086] 1, 201 First member 1t, 201t First fuselage 1tp, 201tp 1st parallel part 2, 202 second member 2t, 202t Second fuselage 2tp, 202tp 2nd parallel part 3, 203 Third member C1, C2, C3, C4 axis center f1, f21, f22 recesses 100, 200, 300, 400 silencer 100a, 200a, 300a, 400a First pipe section 100b, 200b, 300b, 400b Second pipe section 100p, 200p parallel part 100A, 200A, 500I Enclosure 100S, 200S, 500i space 203D large diameter section 203d1 1st small diameter section (small diameter section) 203d2 2nd small diameter section (small diameter section)

Claims

1. A method for manufacturing a resin silencer having an internal space, comprising: the silencer includes a first member and a second member made of a resin that is transparent to laser light, and a third member made of a resin that is absorptive of laser light; the first member has a cylindrical first body portion and a first side portion formed to close one end of the first body portion, the second member has a cylindrical second body portion and a second side portion formed to close one end of the second body portion, the third member is a cylindrical member having a small diameter portion having a diameter smaller than that of the first body portion and the second body portion, an alignment process of arranging the first member, the second member, and the third member so that an opening at the other end of the first body portion faces an opening at the other end of the second body portion and so that the small diameter portions are arranged inside the first body portion and inside the second body portion; a joining step of laser-joining the first body portion and the small diameter portion located inside thereof and the second body portion and laser-joining the second body portion and the small diameter portion located inside thereof by irradiating a laser beam from outside the first body portion and the second body portion to an overlapping portion where the small diameter portion is located inside thereof; A method for manufacturing a resin silencer, comprising:

2. the first body portion has a first parallel portion whose outer surface is parallel to the axis of the first body portion, the second body portion has a second parallel portion whose outer surface is parallel to the axis of the second body portion, The thickness of the first parallel portion in the radial direction is constant, The second parallel portion has a constant radial thickness, 2. The method for manufacturing a resin silencer according to claim 1, wherein in the alignment process, the first member, the second member, and the third member are arranged so that the small diameter portion is positioned inside the first parallel portion and inside the second parallel portion.

3. 3. The method for manufacturing a resin silencer according to claim 1, wherein the inner surface of the silencer is circular, oval, elliptical or oval in a cross section passing through the axis of the silencer.

4. In the fitting step, the small diameter portion is fitted into a recess formed on the inner surface of the first body portion and a recess formed on the inner surface of the second body portion, 3. The method for manufacturing a resin silencer according to claim 1, wherein when the small diameter portion is fitted into the recess formed on the inner surface of the first body portion and the recess formed on the inner surface of the second body portion, the inner surfaces of the first member, the third member, and the second member are aligned in order and continuous.

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