Method for manufacturing resin silencer

Abstract

To provide a highly versatile manufacturing method applicable even if a joining part of respective divided bodies has various shapes when manufacturing a silencer by joining two divided bodies made of resin.SOLUTION: A 6A and a 8A of divided bodies are resin-molded in such a shape that a muffler 1 in which small-diameter pipe parts 4 are connected to both axial ends of a cylindrical barrel part 2 through expanded pipe parts 3 is divided into two parts across the axial direction or along the axial direction. Ultrasonic waves are applied or slide vibration is applied to at least one of the opposed faces 7, 9 in a state that the opposed faces 7, 9 of the side 6A and the side 8A of the respective divided bodies are press-bonded to each other, so that the opposed faces 7, 9 are welded to each other to join and integrate the side 6A and the side 8A of the divided bodies.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Silencers are attached to the piping of automotive air conditioners to suppress noise caused by the flow of circulating refrigerant. In recent years, with the trend toward lighter automobiles, various studies have been conducted on replacing metal piping with plastic piping to reduce weight.

[0003] In order to manufacture a resin silencer that is lightweight yet has sufficient resistance to internal pressure, a method has been proposed in which a cylindrical insertion part (insertion part) and a cylindrical receiving part (receiving part) are integrated into a cylindrical part by spin welding (see Patent Document 1). In this proposed method, the specifications of the insertion part and the receiving part are devised to enable a stable and strong joining of the two.

[0004] However, in this method of manufacturing a silencer by joining two resin parts by spin welding, the joining portions of the resin parts are limited to a cylindrical shape, so another method is needed to make the joining portion of the two resin parts applicable to various shapes other than cylindrical. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-155659 Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide a highly versatile manufacturing method for manufacturing a resin silencer connected to the piping of an automotive air conditioner by joining two resin segments, which can be applied even when the joining portions of the segments are not limited to being cylindrical but have various shapes. [Means for solving the problem]

[0007] In order to achieve the above object, the method for manufacturing a resin silencer of the present invention is a method for manufacturing a resin silencer to be connected to the piping of an automotive air conditioner, the silencer having a cylindrical body and pipe sections connected to both axial ends of the body via expanded sections and having a smaller diameter than the body, characterized in that the silencer is formed by molding a split body into two parts across the axial direction or along the axial direction using resin molding, and while the opposing surfaces of each of the split bodies are pressed together, ultrasonic or sliding vibrations are applied to at least one of the opposing surfaces to weld the opposing surfaces together and join the split bodies together into a single unit. [Effects of the Invention]

[0008] According to the present invention, ultrasonic waves or sliding vibrations are applied to at least one of the opposing surfaces in a pressure-bonded state to weld the opposing surfaces together, so that the joining portions of the segments are not limited to being cylindrical, and segments having other shapes can be joined together and integrated. A segment in which the silencer is divided into two across the axial direction can be used, or a segment in which the silencer is divided into two along the axial direction can be used. Therefore, this manufacturing method is highly versatile, as it can produce lightweight resin silencers of various shapes that have sufficient internal pressure resistance. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an explanatory diagram illustrating a silencer manufactured according to the present invention as viewed from the front. [Figure 2] 2 is an explanatory diagram illustrating the silencer of FIG. 1 in a vertical cross-sectional view. FIG. [Figure 3] 3 is an explanatory view illustrating one divided body and the other divided body of FIG. 2 in a separated state. FIG. [Figure 4] 4 is an explanatory view illustrating the structure of one of the divided bodies in a cross section taken along the line AA in FIG. 3. FIG. [Figure 5] 4 is an explanatory view illustrating a step of applying ultrasonic waves to the opposing surfaces of one divided body and the other divided body in FIG. 3 in a state where they are pressure-bonded together. FIG. [Figure 6] 4A to 4C are explanatory views showing modified examples of the opposing surfaces of FIG. 3. [Figure 7] 7 is an explanatory view illustrating a step of applying ultrasonic waves to the opposing surfaces of one divided body and the other divided body in FIG. 6 in a state where they are pressure-bonded together. FIG. [Figure 8] 10 is an explanatory diagram showing a modified example of a reinforcing rib in a front view of the silencer. FIG. [Figure 9] 10 is an explanatory diagram showing another modified example of the reinforcing rib in a front view of the silencer. FIG. [Figure 10] 10 is an explanatory diagram illustrating another embodiment of the silencer as viewed from the front. FIG. [Figure 11] 11 is an explanatory view illustrating one divided body and the other divided body of FIG. 10 in a separated state in a vertical cross section. FIG. [Figure 12] 12 is an explanatory view illustrating a step of applying ultrasonic waves to the opposing surfaces of one divided body and the other divided body in FIG. 11 in a state where they are pressure-bonded together. FIG. [Figure 13] 12A to 12C are explanatory views showing modified examples of the opposing surfaces of FIG. 11. [Figure 14] 14 is an explanatory view illustrating a step of applying ultrasonic waves to the opposing surfaces of one divided body and the other divided body in FIG. 13 in a state where they are pressure-bonded together. FIG. [Figure 15] 10 is an explanatory diagram illustrating another embodiment of the silencer as viewed from the front. FIG. [Figure 16] 16 is an explanatory diagram illustrating the silencer of FIG. 15 in a vertical cross-sectional view. FIG. [Figure 17] 16 is an explanatory diagram illustrating the silencer of FIG. 15 in cross section. FIG. [Figure 18]17 is an explanatory diagram illustrating one divided body and the other divided body of FIG. 16 in a separated state. FIG. [Figure 19] 18 is an explanatory diagram illustrating one divided body and the other divided body of FIG. 17 in a separated state. FIG. [Figure 20] 20 is an explanatory view illustrating a step of applying ultrasonic waves to the opposing surfaces of one divided body and the other divided body in FIG. 19 in a state where they are pressure-bonded together. FIG. [Figure 21] 20A and 20B are explanatory views showing modified examples of the opposing surfaces of FIG. 19. [Figure 22] 22 is an explanatory view illustrating a step of applying ultrasonic waves to the opposing surfaces of one divided body and the other divided body in FIG. 21 in a state where they are pressure-bonded together. FIG. [Figure 23] 10 is an explanatory diagram illustrating, in vertical cross section, a process of applying sliding vibration to one divided body and the other divided body with their opposing surfaces pressed together. FIG. [Figure 24] 10 is an explanatory view illustrating, in vertical cross section, a process of applying sliding vibration to one divided body and the other divided body of another silencer in a state where the opposing surfaces of the divided bodies are pressed against each other. FIG. [Figure 25] This is an explanatory diagram showing, in cross section, a process in which the opposing surfaces of one divided body and the other divided body constituting yet another form of silencer are pressed together and subjected to sliding vibration in a direction perpendicular to the axial direction. [Figure 26] 26 is an explanatory front view illustrating a step of applying axial sliding vibration to the opposing surfaces of one divided body and the other divided body in FIG. 25 in a state of being pressed against each other. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a method for manufacturing a resin silencer according to the present invention will be described based on an embodiment shown in the drawings.

[0011] According to the present invention, a resin silencer 1 as shown in FIGS. 1 and 2 is manufactured. This silencer 1 has a cylindrical body 2, and pipe sections 4 each having a smaller diameter than the body 2 are connected to both axial ends of the body 2 via expanded sections 3. Each pipe section 4 is connected to the piping of an automotive air conditioner. A refrigerant C used in the air conditioner circulates inside the hollow silencer 1. The refrigerant C flows in from one pipe section 4 and out from the other pipe section 4. The dashed-dotted line CL in the figures indicates the axis of the silencer 1, which passes through the center of the cross section of the body 2, expanded section 3, and pipe section 4. The direction in which the axis center CL extends is the axial direction.

[0012] The silencer 1 is manufactured by joining together two resin divided bodies 6A and 8A, as shown in FIG. 3. While FIG. 4 shows one divided body 6A as an example, the other divided body 8A has a similar shape. Each divided body 6A and 8A is basically made of the same resin. Various known moldable resins are used as this resin. For example, nylon resin (such as 66 nylon), polypropylene, ABS resin, etc. are used.

[0013] For reinforcement, short fibers (such as glass fibers or carbon fibers) can be mixed into the resin at a predetermined ratio (for example, 30% to 40% by mass per 100 parts by mass of the resin). The size of the short fibers is, for example, an outer diameter of about 0.001 mm to 1.0 mm and a length of about 0.01 mm to 10 mm.

[0014] Each divided body 6A, 8A has a shape in which the silencer 1 is divided into two parts transverse to the axial direction, and is manufactured by resin molding. In this embodiment, each divided body 6A, 8A has a shape in which the silencer 1 is divided into two parts along a direction perpendicular to the axial direction (at an angle of 90°). Each divided body 6A, 8A has a body portion 2, an expanded tube portion 3, and a pipe portion 4, which are divided into two parts in the axial direction, and they have substantially the same shape.

[0015] The peripheral walls of the opposing surfaces 7, 9 are butted together in a non-overlapping manner in the wall thickness direction (left-right direction in Figures 2 and 3) along the entire circumferential length. However, in this embodiment, one opposing surface 7 has a convex, annular engaging portion 7a, and the other opposing surface 9 has a concave, annular engaging portion 9a, with the engaging portion 7a shaped to fit into the engaging portion 9a. Only these engaging portions 7a, 9a overlap in the wall thickness direction. Since the engaging portions 7a, 9a only need to engage with each other to prevent misalignment between the opposing surfaces 7, 9, they are not limited to being annular, and any desired shape of engaging convex and concave portions can be used. For example, the engaging portions 7a can be formed by circumferentially spaced convex portions on the opposing surface 7, and the engaging portions 9a can be formed by circumferentially spaced concave portions on the opposing surface 9. The engaging portions 7a, 9a are not essential and can be provided optionally.

[0016] The inner diameter of the body portion 2 is, for example, about 30 mm to 60 mm. The inner diameter of the pipe portion 4 is, for example, about 10 mm to 20 mm. The thickness of the peripheral walls of the body portion 2, the expanded tube portion 3, and the pipe portion 4 are approximately the same, for example, about 2 mm to 5 mm.

[0017] The opposing surfaces 7, 9 are welded together, and the boundary between the opposing surfaces 7, 9 is unclear in the manufactured silencer 1. In the drawings, the boundary between the opposing surfaces 7, 9 is shown by a dashed line for convenience. In this embodiment, the inner diameter of each opposing surface 7, 9 is the same as the inner diameter of the surrounding body portion 2 (the inner diameter of the portion where the circumferential rib 5b described later does not exist), but the outer diameter is larger than the outer diameter of the surrounding body portion 2 (the outer diameter of the portion where the circumferential rib 5a described later does not exist), and protrudes outward. Therefore, the joint portion between the segments 6A, 8A (the portion corresponding to the opposing surfaces 7, 9) functions as a circumferential rib. The inner and outer diameters of each opposing surface 7, 9 can also be made the same as those of the surrounding body portion 2 (the portion where the circumferential rib 5a, 5b does not exist).

[0018] The expanded tube section 3 is a tubular body (a cylindrical body in this embodiment) whose diameter expands from the cylindrical pipe section 4 toward the body section 2. The body section 2 is not limited to a cylindrical shape, and can have, for example, an elliptical cylindrical shape or a polygonal cylindrical shape, and therefore the expanded tube section 3 becomes a tubular body that changes from the small-diameter pipe section 4 to the shape of the large-diameter body section 2.

[0019] The inclination angle of the peripheral wall of the expanded tube section 3 relative to the axis CL is, for example, approximately 30° to 60°. The boundary between the expanded tube section 3 and the body section 2 is a convex arc, and the arc radius (R1 dimension) of the outer surface of this boundary is, for example, approximately 10 mm to 20 mm. The arc radius (R2 dimension) of the inner surface of this boundary is set so that the thickness (thickness between the outer and inner surfaces) is constant. The boundary between the expanded tube section 3 and the pipe section 4 is a concave arc, and the arc radius (R3 dimension) of the outer surface of this boundary is, for example, approximately 10 mm to 20 mm. The arc radius (R4 dimension) of the inner surface of this boundary is set so that the thickness (thickness between the outer and inner surfaces) is constant. Therefore, the cylindrical body section 2 and the cylindrical pipe section 4 are smoothly connected by the expanded tube section 3, whose inner and outer diameters gradually change.

[0020] Circumferential ribs 5a are provided on the outer peripheral surface of the body 2 so as to reinforce the body 2 and extend continuously in the circumferential direction. In this embodiment, the multiple circumferential ribs 5a are arranged at intervals in the axial direction. The circumferential ribs 5a are preferably arranged at equal intervals in the axial direction. The circumferential ribs 5a are arranged at least in the axial center of the body 2.

[0021] The protruding height of the circumferential ribs 5a (the amount of protrusion radially outward from the outer circumferential surface of the body 2) is, for example, about 2 mm to 5 mm, and the rib width is, for example, about 1 mm to 5 mm. The number and dimensions of the circumferential ribs 5a are determined appropriately based on the pressure resistance required of the silencer 1, etc.

[0022] In this embodiment, circumferential ribs 5b are provided on the inner peripheral surface of the body 2 so as to extend continuously in the circumferential direction. The main purpose of these circumferential ribs 5b is to improve the sound deadening effect, but they also have the effect of reinforcing the body 2. In this embodiment, multiple circumferential ribs 5b are arranged at intervals in the axial direction. It is preferable that the circumferential ribs 5b are arranged at equal intervals in the axial direction. The circumferential ribs 5b can be provided as desired.

[0023] The protruding height of the circumferential ribs 5b (the amount of protrusion radially inward from the inner circumferential surface of the body 2) is, for example, about 2 mm to 5 mm, and the rib width is, for example, about 1 mm to 5 mm. The number and dimensions of the circumferential ribs 5b are determined appropriately based on the sound-deadening properties required of the silencer 1, etc.

[0024] The cross-sectional shape of the circumferential ribs 5a, 5b is not limited to a semicircular shape or other shape with an arc-shaped apex, but may be a triangular shape, a square shape, or other polygonal shape, etc. Having an arc-shaped apex is advantageous in improving the durability of the circumferential ribs 5a, 5b.

[0025] As in this embodiment, the circumferential ribs 5a and 5b are preferably arranged to be offset in the axial direction. That is, the circumferential ribs 5a and 5b should be arranged so that they do not overlap in the axial direction. If the circumferential ribs 5a and 5b were arranged so that they overlap in the axial direction, the amount of resin in the body portion 2 would be excessively unevenly distributed, which would be disadvantageous for successful injection molding of the segments 6A and 8A.

[0026] An example of a procedure for manufacturing this silencer 1 will now be described.

[0027] First, the segments 6A and 8A shown in Fig. 3 are manufactured by a known resin molding method. For example, the segments 6A and 8A may be injection molded using a known injection molding machine. When the segments 6A and 8A are injection molded, the circumferential ribs 5a and 5b are also molded integrally at the same time.

[0028] Next, as shown in Fig. 5, the opposing surfaces 7, 9 of the divided bodies 6A, 8A are brought into a pressure-bonded state. In this state, ultrasonic waves are applied to at least one of the opposing surfaces 7, 9 using an ultrasonic welding device 10, thereby welding the opposing surfaces 7, 9 together. In this way, the divided bodies 6A, 8A are joined and integrated together, and the silencer 1 is manufactured.

[0029] More specifically, various known types of ultrasonic welding device 10 can be used, and the device has a horn 11 that emits ultrasonic waves and a receiving base 12. The other divided body 8A is held and fixed by the receiving base 12. The facing surface 7 of one divided body 6A is brought into contact with the facing surface 9 of this divided body 8A. Here, by fitting the convex engaging portion 7a into the concave engaging portion 9a, the facing surfaces 7, 9 can be accurately positioned and brought into contact with each other while preventing misalignment.

[0030] Next, a horn 11 is brought into contact with the end face of the pipe portion 4 of one of the segments 6A, and pressure is applied to the segment 6A toward the other segment 8A, bringing the opposing surfaces 7, 9 into a pressure-bonded state. Thereafter, the positions (axial positions) of the segments 6A, 8A are maintained. Next, ultrasonic waves are emitted from the horn 11 and applied to one of the segments 6A for a predetermined period of time, whereby the ultrasonic waves are propagated and applied to the opposing surfaces 7, 9. The applied ultrasonic waves cause minute vibrations, which heat and melt the resins of the opposing surfaces 7, 9. The molten resin on the opposing surfaces 7, 9 then cools and hardens, welding the opposing surfaces 7, 9 together.

[0031] The frequency of the applied ultrasonic waves is, for example, 15 kHz to 200 kHz, more preferably 20 kHz to 40 kHz. The amplitude is, for example, 5 μm to 50 μm, and the duration of application of the ultrasonic waves is, for example, 0.5 seconds to 5 seconds. The optimal ranges for the ultrasonic frequency, amplitude, application duration, and pressure applied to the opposing surfaces 7 and 9 vary slightly depending on the specifications of the segments 6A and 8A. Therefore, preliminary tests are conducted to determine these optimal ranges, and the opposing surfaces 7 and 9 are welded together using the determined optimal ranges.

[0032] The vibrations generated on the opposing surfaces 7 and 9, which are welded by applying ultrasonic waves, are very small, which is advantageous in preventing burrs from being generated by the molten resin. In other words, it becomes possible to omit the finishing work on the joints of the segments 6A and 8A (the parts corresponding to the opposing surfaces 7 and 9).

[0033] In this embodiment, each of the divided bodies 6A, 8A has a shape in which the silencer 1 is divided into two along a direction perpendicular to the axial direction, so the joint area between the divided bodies 6A, 8A (the area of ​​the opposing surfaces 7, 9) is minimized. This is advantageous for more uniformly joining the opposing surfaces 7, 9. If there is variation in the joint strength of the joints, damage will be concentrated in areas with low joint strength, so being able to more uniformly join the opposing surfaces 7, 9 greatly contributes to improving durability.

[0034] The opposing surfaces 7, 9 protrude more radially outward than the surrounding body portion 2, increasing the bonding area between them. The engagement portions 7a, 9a also increase the bonding area between the opposing surfaces 7, 9. This is advantageous for improving the bonding strength between the segments 6A, 8A.

[0035] In this silencer 1, the body portion 2 and the pipe portion 4 are connected via the expanded portion 3, so that when internal pressure acts during use of the silencer 1, it is possible to prevent excessive stress from occurring locally in the region between the body portion 2 and the pipe portion 4. The circumferential rib 5a resists the internal pressure acting on the silencer 1, so it is possible to prevent excessive stress from occurring locally. Therefore, with this silencer 1, it is possible to ensure sufficient pressure resistance against internal pressure even though it is made of lightweight resin.

[0036] As shown in Fig. 2, in the piping system of an automotive air conditioner, refrigerant C flows into one pipe section 4, passes through expanded section 3, body section 2, and expanded section 3, and flows out of the other pipe section 4, repeatedly circulating. In expanded section 3, refrigerant C flows along the inner circumferential surface. In this embodiment, the circulating refrigerant C is interfered with by circumferential ribs 5b protruding from the inner circumferential surface of body section 2, thereby canceling out the noise and pulsation caused by the circulating refrigerant C, thereby further reducing the noise and pulsation.

[0037] The circumferential ribs 5b may be arranged in the axial direction with different protruding heights. The circumferential ribs 5b are not limited to the protruding direction perpendicular to the axial direction as in the above-described embodiment, but may be protruding at an angle toward the other axial side (the other pipe portion 4 side from which the refrigerant C flows out).

[0038] As shown in Fig. 6, it is also possible to use divided bodies 6A, 8A that are divided into two so that the peripheral walls of the opposing surfaces 7, 9 of each body overlap in the wall thickness direction (the left-right direction in Fig. 6) over the entire circumferential length. The divided bodies 6A, 8A in Fig. 6 differ from the divided bodies 6A, 8A in Fig. 3 only in the specifications of the opposing surfaces 7, 9, and the other specifications are the same.

[0039] The procedure for manufacturing silencer 1 using divided bodies 6A and 8A is substantially the same as the procedure for manufacturing silencer 1 illustrated in Figures 1 and 2. As illustrated in Figure 7, with opposing surfaces 7 and 9 of divided bodies 6A and 8A pressed together, ultrasonic waves are applied from horn 11 to at least one of the opposing surfaces 7 and 9, thereby welding the opposing surfaces 7 and 9 together.

[0040] 7, the peripheral walls of the opposing surfaces 7, 9 overlap in the wall thickness direction over the entire circumferential length, so that one opposing surface 7 is convex and the other opposing surface 9 is concave, and they fit together in the axial direction. This is advantageous for suppressing misalignment of the divided bodies 6A, 8A (opposing surfaces 7, 9) and crimping them together before applying ultrasonic waves.

[0041] The peripheral wall of the other opposing surface 9 covers the outer periphery of the peripheral wall of one opposing surface 7 over the entire circumferential length. Therefore, the joining area between the opposing surfaces 7, 9 is increased compared to when the peripheral walls of the opposing surfaces 7, 9 are butted together over the entire circumferential length with no overlap in the wall thickness direction. This is advantageous for improving the joining strength between the segments 6A, 8A.

[0042] 8, in addition to the circumferential ribs 5a, axial ribs 5c extending in the axial direction can also be provided protrudingly on the outer peripheral surface of the body portion 2. The axial ribs 5c are molded integrally with the divided bodies 6A and 8A at the same time when the divided bodies 6A and 8A are injection molded.

[0043] The axial ribs 5c are preferably arranged at least in the axial center of the body portion 2, in the range where the circumferential ribs 5a are arranged. The protruding height and rib width of the axial ribs 5c are the same as those of the circumferential ribs 5a. Three or more axial ribs 5c are arranged at equal intervals around the circumferential direction of the body portion 2, and preferably, for example, three to twelve axial ribs. By providing the axial ribs 5c in addition to the circumferential ribs 5a, it is advantageous to further improve the durability of the body portion 2 (silencer 1).

[0044] Instead of the axial ribs 5c shown in Fig. 8, as shown in Fig. 9, diagonal ribs 5d may be provided on the outer peripheral surface of the body 2, extending at an angle of, for example, 30° to 60° relative to the axial direction. The diagonal ribs 5d are molded integrally with the segments 6A and 8A simultaneously when they are injection molded. The protruding height and width of the diagonal ribs 5d are set to be the same as those of the circumferential ribs 5a.

[0045] The silencer 1 of the embodiment shown in Fig. 10 is manufactured by joining and integrating two divided bodies 6A, 8A shown in Fig. 11. Each divided body 6A, 8A has a shape in which the silencer 1 is divided into two bodies transverse to the axial direction. More specifically, each divided body 6A, 8A has a shape in which the silencer 1 is divided into two bodies along a direction in which the silencer 1 is uniformly inclined with respect to the axial direction (inclination angle B is about 80°). This inclination angle B can be set, for example, in the range of 60° or more and less than 90°.

[0046] In the silencer 1 shown in FIG. 10, the opposing surfaces 7, 9 of the respective divided bodies 6A, 8A are not divided into two along a direction perpendicular to the axial direction. This silencer 1 does not have a circumferential rib 5b, but it can also be configured to have a circumferential rib 5b. In other words, this silencer 1 differs from the silencer 1 shown in FIGS. 1 and 2 in the specifications of the opposing surfaces 7, 9. The other specifications of this silencer 1 are substantially the same as those of the silencer 1 shown in FIGS. 1 and 2. The various arrangements described for the silencer 1 shown in FIGS. 1 and 2 can also be applied to this silencer 1.

[0047] The procedure for manufacturing this silencer 1 is substantially the same as the procedure for manufacturing the silencer 1 illustrated in Figures 1 and 2. First, the divided bodies 6A and 8A illustrated in Figure 11 are manufactured by resin injection molding. Next, as illustrated in Figure 12, the opposing surfaces 7 and 9 of the divided bodies 6A and 8A are pressed together, and ultrasonic waves are applied to at least one of the opposing surfaces 7 and 9 using an ultrasonic welding device 10 to weld the opposing surfaces 7 and 9 together. In this way, the divided bodies 6A and 8A are joined and integrated to manufacture the silencer 1.

[0048] 12, the peripheral walls of the opposing surfaces 7, 9 overlap in the wall thickness direction, but in other cross-sectional views, the peripheral walls of the opposing surfaces 7, 9 are butted together but not overlapped in the wall thickness direction. In other words, the peripheral walls of the opposing surfaces 7, 9 do not overlap in the wall thickness direction over the entire circumferential length.

[0049] In this embodiment, the opposing surfaces 7, 9 extend in a direction that is uniformly inclined and transverse to the axial direction, which increases the area of ​​the opposing surfaces 7, 9 compared to the specification in which the opposing surfaces 7, 9 extend in a direction perpendicular to the axial direction as shown in Figure 1. This increases the bonding area between the opposing surfaces 7, 9, which is advantageous for improving the bonding strength between the segments 6A, 8A.

[0050] As shown in Fig. 13, it is also possible to use divided bodies 6A, 8A that are divided into two so that the peripheral walls of the opposing surfaces 7, 9 of each body overlap in the wall thickness direction (left and right direction in Fig. 13) over the entire circumferential length. The divided bodies 6A, 8A in Fig. 13 differ from the divided bodies 6A, 8A in Fig. 11 only in the specifications of the opposing surfaces 7, 9, and the other specifications are the same.

[0051] The procedure for manufacturing this silencer 1 is substantially the same as the procedure for manufacturing the silencer 1 illustrated in Fig. 7. As illustrated in Fig. 14, with the opposing surfaces 7, 9 of the divided bodies 6A, 8A pressed together, ultrasonic waves are applied from a horn 11 to at least one of the opposing surfaces 7, 9, thereby welding the opposing surfaces 7, 9 together.

[0052] 14, the peripheral walls of the opposing surfaces 7, 9 overlap in the wall thickness direction over the entire circumferential length, so that one opposing surface 7 is concave and the other opposing surface 9 is convex, and they fit together in the axial direction. This is advantageous for suppressing misalignment of the divided bodies 6A, 8A (opposing surfaces 7, 9) and crimping them together before applying ultrasonic waves.

[0053] The peripheral wall of one opposing surface 7 covers the outer periphery of the peripheral wall of the other opposing surface 9 over the entire circumferential length. As a result, the areas of the opposing surfaces 7, 9 are larger than when the peripheral walls of the opposing surfaces 7, 9 are butted together over the entire circumferential length with no overlap in the wall thickness direction. This increases the bonding area between the opposing surfaces 7, 9, which is advantageous for improving the bonding strength between the segments 6A, 8A.

[0054] The silencer 1 of the embodiment illustrated in Figures 15 to 17 is manufactured by joining and integrating two divided bodies 6B, 8B illustrated in Figures 18 and 19. Each divided body 6B, 8B has a shape in which the silencer 1 is divided into two along the axial direction. In addition, the peripheral walls of the opposing surfaces 7, 9 are butted together in a non-overlapping manner in the wall thickness direction over the entire axial length.

[0055] That is, this silencer 1 differs from the silencer 1 illustrated in FIGS. 1 and 2 in the specifications of the opposing surfaces 7, 9 (the division direction of the segments 6B, 8B). The segments 6B, 8B do not have circumferential ribs 5b, but they can also be designed to have circumferential ribs 5b. The other specifications of this silencer 1 are substantially the same as those of the silencer 1 illustrated in FIGS. 1 and 2. The various arrangements described for the silencer 1 illustrated in FIGS. 1 and 2 can also be applied to this silencer 1.

[0056] The procedure for manufacturing this silencer 1 is substantially the same as the procedure for manufacturing the silencer 1 illustrated in Figures 1 and 2. First, the divided bodies 6B and 8B illustrated in Figures 18 and 19 are manufactured by resin injection molding. Next, as illustrated in Figure 20, the opposing surfaces 7 and 9 of the divided bodies 6B and 8B are pressed together, and ultrasonic waves are applied to at least one of the opposing surfaces 7 and 9 using an ultrasonic welding device 10 to weld the opposing surfaces 7 and 9 together. In this way, the divided bodies 6B and 8B are joined and integrated to manufacture the silencer 1.

[0057] In this embodiment, the opposing surfaces 7, 9 extend along the axial direction, which increases the area of ​​the opposing surfaces 7, 9 compared to specifications in which the opposing surfaces 7, 9 extend along a direction transverse to the axial direction. This increases the bonding area between the opposing surfaces 7, 9, which is advantageous for improving the bonding strength between the segments 6B, 8B.

[0058] As shown in Fig. 21, it is also possible to use divided bodies 6A, 8A that are divided into two so that the peripheral walls of the opposing surfaces 7, 9 overlap in the wall thickness direction over the entire axial length. The divided bodies 6A, 8A in Fig. 21 differ from the divided bodies 6A, 8A in Fig. 19 only in the specifications of the opposing surfaces 7, 9, and the other specifications are the same.

[0059] The procedure for manufacturing this silencer 1 is substantially the same as the procedure for manufacturing the silencer 1 illustrated in Fig. 20. As illustrated in Fig. 22, with the opposing surfaces 7, 9 of the divided bodies 6A, 8A pressed together, ultrasonic waves are applied from a horn 11 to at least one of the opposing surfaces 7, 9, thereby welding the opposing surfaces 7, 9 together.

[0060] 22, the peripheral walls of the opposing surfaces 7, 9 overlap in the wall thickness direction over the entire axial length, so that one opposing surface 7 is convex and the other opposing surface 9 is concave, and they fit together in the circumferential direction. This is advantageous for suppressing misalignment of the divided bodies 6A, 8A (opposing surfaces 7, 9) and crimping them together before applying ultrasonic waves.

[0061] The peripheral wall of the other opposing surface 9 covers the outer periphery of the peripheral wall of one opposing surface 7 over the entire axial length. This increases the area of ​​the opposing surfaces 7, 9 compared to when the peripheral walls of the opposing surfaces 7, 9 are butted together without overlapping in the wall thickness direction over the entire axial length. This increases the bonding area between the opposing surfaces 7, 9, which is advantageous for improving the bonding strength between the segments 6B, 8B.

[0062] In the above-described various embodiments for manufacturing the silencer 1, ultrasonic waves are used to weld the opposing surfaces 7, 9 together, but the opposing surfaces 7, 9 can also be welded together by applying slide vibration instead of ultrasonic waves. Therefore, a method for manufacturing the silencer 1 using the slide vibration welding device 13 will be described below.

[0063] 1 and 2, the opposing surfaces 7 and 9 of the divided bodies 6A and 8A are brought into a pressure-bonded state as shown in Fig. 23. In this state, a slide vibration welding device 13 is used to apply slide vibration to one of the opposing surfaces 7, thereby welding the opposing surfaces 7 and 9 together.

[0064] Although the segments 6A and 8A in FIG. 23 do not have circumferential ribs 5b, they can also be configured to have circumferential ribs 5b. Since sliding vibrations along the opposing surfaces 7 and 9 are applied to the segment 6A, it is desirable that the opposing surfaces 7 and 9 be flat in the sliding direction. For this reason, the segments 6A and 8A in FIG. 23 do not have the engaging portions 7a and 9a shown in FIG. 3. Other specifications of this silencer 1 are substantially the same as those of the silencer 1 shown in FIGS. 1 and 2. The various arrangements described for the silencer 1 shown in FIGS. 1 and 2 can also be applied to this silencer 1.

[0065] Various known types of slide vibration welding device 13 can be used, and include a sliding head 14 that slides, a holding portion 14a that holds one of the divided bodies 6A and is slidably vibrated by the sliding head 14, and a holding base 15. The other divided body 8A is held and fixed by the holding base 15. The opposing surface 7 of one divided body 6A held by the holding portion 14a is brought into contact with the opposing surface 9 of the other divided body 8A held and fixed by the holding base 15, and the divided body 6A is pressed toward the other divided body 8A, thereby crimping the opposing surfaces 7 and 9 together. Thereafter, the axial positions of the respective divided bodies 6A and 8A are maintained.

[0066] Then, by causing the slide head 14 to slide back and forth along the opposing surfaces 7 and 9, slide vibration is applied to the holding portion 14a and one of the divided bodies 6A (opposing surface 7) for a predetermined time. This slide vibration causes the opposing surfaces 7 and 9 to rub against each other, causing the resins in each to heat up and melt. The molten resin on the opposing surfaces 7 and 9 then cools and hardens, welding the opposing surfaces 7 and 9 together.

[0067] The frequency of the applied slide vibration is, for example, 200 kHz to 250 kHz. The amplitude is, for example, 0.5 mm to 2.0 m, and the duration of application of the ultrasonic waves is, for example, 0.5 seconds to 5 seconds. The optimal ranges for the ultrasonic frequency, amplitude, application duration, and pressure applied to the opposing surfaces 7 and 9 vary slightly depending on the specifications of the segments 6A and 8A. Therefore, preliminary tests should be conducted to determine these optimal ranges, and the segments 6A and 8A can be welded together using the determined optimal ranges.

[0068] It is desirable that the area of ​​the opposing surfaces 7, 9 that rub against each other due to the sliding vibration be as large as possible. In the method of applying sliding vibration, the opposing surfaces 7, 9 slide relatively against each other at high speed, making it possible to more quickly weld the opposing surfaces 7, 9 together over a wide area.

[0069] 10 in which the opposing surfaces 7, 9 extend at a uniform incline relative to the axial direction, is manufactured by applying a sliding vibration to one of the opposing surfaces 7 using a slide vibration welding device 13 while the opposing surfaces 7, 9 of the respective segments 6A, 8A are pressed together, as illustrated in FIG. 24. This joins and integrates the respective segments 6A, 8A to manufacture the silencer 1. The vibration direction of the applied sliding vibration is along the opposing surfaces 7, 9, so that one segment 6A is held by a holder 14a in a state inclined relative to the slide head 14, and the other segment 8A is held and fixed by a holder 15 in a state inclined relative to the slide head 14.

[0070] 15 to 17 in which the opposing surfaces 7, 9 extend along the axial direction, the opposing surfaces 7, 9 of the silencer 1 of each divided body 6B, 8B are pressed together, as shown in Fig. 25. In this state, a slide vibration is applied to one of the opposing surfaces 7 using a slide vibration welding device 13, thereby welding the opposing surfaces 7, 9 together. In this embodiment, the vibration direction of the slide vibration applied to one divided body 6B is perpendicular to the axial direction.

[0071] 15 to 17, the vibration direction of the slide vibration may be set to the axial direction when manufacturing the silencer 1 illustrated in Fig. 15 to 17 using the slide vibration welding device 13. That is, in this case, the opposing surfaces 7, 9 are pressed together as illustrated in Fig. 26, and then the slide vibration welding device 13 is used to apply axial slide vibration to one of the opposing surfaces 7, thereby welding the opposing surfaces 7, 9 together.

[0072] When the silencer 1 is manufactured using the slide vibration welding device 13, the various arrangements described in the case where the ultrasonic welding device 10 is used can also be applied.

[0073] As in the various embodiments of the silencer 1 described above, ultrasonic or sliding vibration is applied to at least one of the opposed surfaces 7, 9 in the crimped state to weld the opposed surfaces 7, 9 together, so the joining portions of the respective divided bodies 6A (6B), 8A (8B) are not limited to being cylindrical, and even if they have other shapes, the respective divided bodies 6A (6B), 8A (8B) can be joined together and integrated. Therefore, this manufacturing method is highly versatile, as it can manufacture silencers 1 of various shapes made of resin that are lightweight and have sufficient pressure resistance against internal pressure.

[0074] In addition, in the method of welding the opposing surfaces 7, 9 together using the ultrasonic welding device 10, the opposing surfaces 7, 9 only vibrate slightly, so it is also possible to form the opposing surfaces 7, 9 into a zigzag shape that fits together. Therefore, the method of applying ultrasonic waves is more advantageous than the method of applying sliding vibration for manufacturing silencers 1 with a wider variety of shapes. [Explanation of symbols]

[0075] 1 silencer 2. Torso 3 Expanded section 4 Pipe section 5a, 5b Circumferential rib 5c Axial rib 5d diagonal rib 6A, 6B One of the divisions 7 Opposite Surface 7a Engagement part 8A, 8B Other divided body 9 Opposite Surface 9a Engagement part 10 Ultrasonic welding equipment 11 Horn 12 Cradle 13 Slide vibration welding device 14 Slide Head 14a Holding part 15 Holding stand C Refrigerant

Claims

1. A method for manufacturing a resin silencer to be connected to piping of an automotive air conditioner, the silencer having a cylindrical body portion and pipe portions connected to both axial ends of the body portion via expanded pipe portions and having a smaller diameter than the body portion, The silencer is molded by resin molding into a divided body having a shape divided into two parts across the axial direction or along the axial direction, A method for manufacturing a resin silencer in which the opposing surfaces of each divided body are pressed together, and then ultrasonic or sliding vibration is applied to at least one of the opposing surfaces to weld the opposing surfaces together and join the divided bodies together into a single unit.

2. 2. The method for manufacturing a resin silencer according to claim 1, wherein each of the divided bodies is formed by dividing the silencer into two bodies along a direction perpendicular to the axial direction.

3. 2. The method for manufacturing a resin silencer according to claim 1, wherein each of the divided bodies is formed by dividing the silencer into two bodies along a direction that is uniformly inclined relative to the axial direction.

4. 2. The method for manufacturing a resin silencer according to claim 1, wherein each of the divided bodies is a divided body in which the silencer is divided into two along the axial direction.

5. A method for manufacturing a resin silencer according to any one of claims 2 to 4, wherein engaging portions that engage with each other are formed on each of the opposing surfaces, and the ultrasonic waves are applied to each of the opposing surfaces in a state where the engaging portions are engaged with each other and the opposing surfaces are pressed together.

6. 5. The method for manufacturing a resin silencer according to claim 2, wherein, with the opposing surfaces pressed against each other, one of the opposing surfaces is fixed in a predetermined position, and a sliding vibration having a frequency of 200 Hz or more and 250 Hz or less and an amplitude of 2.0 mm or less is applied to the other opposing surface.

7. 4. A method for manufacturing a resin silencer according to claim 2 or 3, wherein each divided body is a divided body shaped so that the peripheral walls of each of the opposing surfaces are butted together in a non-overlapping manner in the wall thickness direction over the entire circumferential length.

8. 4. A method for manufacturing a resin silencer according to claim 2 or 3, wherein each divided body is a divided body having a shape in which the peripheral walls of the opposing surfaces are divided into two so as to overlap in the wall thickness direction over the entire circumferential length.

9. 5. A method for manufacturing a resin silencer as described in claim 4, wherein each divided body is a divided body shaped so that the peripheral walls of each opposing surface are butted together in a non-overlapping manner in the wall thickness direction over the entire axial length.

10. 5. A method for manufacturing a resin silencer as described in claim 4, wherein each divided body is a divided body shaped so that the peripheral walls of each opposing surface are overlapped in the wall thickness direction over the entire axial length.

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