Gas meter and ultrasonic welding method applied to gas meter

Abstract

The invention relates to the technical field of gas meter design, in particular to a gas meter and an ultrasonic welding method applied to the gas meter. Comprising a gas meter body, the gas meter body comprises a first plastic part and a second plastic part, the first plastic part is provided with a first annular welding face, and the second plastic part is provided with a second annular welding face; the ultrasonic welding structure comprises a welding rib which is annular and arranged on the first annular welding face, and the welding rib is suitable for being connected to the second annular welding face in an ultrasonic welding mode. In the application, the at least two annular welding ribs with different heights and thicknesses are arranged on the first annular welding surface of the first plastic part, so that the welding ribs can generate differentiated fusion behaviors due to geometric dimension difference in the ultrasonic welding process, and multiple and non-uniform sealing lines are formed on the welding interface.

Description

Technical Field

[0001] This invention relates to the field of gas meter design technology, and more specifically to a gas meter and an ultrasonic welding method applied to the gas meter. Background Technology

[0002] When connecting plastic components on a gas meter, such as the plastic casing and plastic display window, certain levels of sealing and reliability are required.

[0003] The connection method for plastic parts can be ultrasonic welding. Existing ultrasonic welding has a welding rib, which has a single natural vibration frequency. In different vibration environments, when the environmental vibration is similar to or the same as the natural vibration frequency of the welding rib, the welding rib is prone to cracking, thus losing its connection function. Summary of the Invention

[0004] In view of this, the present invention provides a gas meter and an ultrasonic welding method applied to the gas meter, so as to solve the problem that the weld tendons are prone to cracking due to the single inherent vibration frequency of the existing ultrasonic welding of gas meters.

[0005] In a first aspect, the present invention provides a gas meter, comprising: The gas meter body includes a first plastic part and a second plastic part, the first plastic part having a first annular welding surface and the second plastic part having a second annular welding surface; An ultrasonic welding structure includes a welding rib, which is annular and disposed on a first annular welding surface. The welding rib is adapted to be connected to a second annular welding surface by ultrasonic welding. The welded ribs are at least two in number and arranged sequentially, with each welded rib having a different height and thickness.

[0006] In this application, by providing at least two annular welding ribs with different heights and thicknesses on the first annular welding surface of the first plastic part, the welding ribs can exhibit differentiated melting behaviors due to their geometrical differences during ultrasonic welding, thereby forming multiple, non-uniform sealing lines at the welding interface. Furthermore, because the height and thickness of the welding ribs differ, the inherent vibration frequencies of each sealing line are different. Under different vibration environments, the welding ribs can maintain their connection, achieving reliable sealing and connection.

[0007] In one optional embodiment, the welding rib is a collar structure, protruding from the first annular welding surface and surrounding the first annular welding surface.

[0008] In this application, each welding rib is arranged along the first annular welding surface, and the ring structure can form multiple annular sealing lines to achieve multi-level sealing. By surrounding the first annular welding surface, the welding ribs can enclose the area to be sealed, forming a sealing structure.

[0009] In one alternative implementation, the height and thickness of the weld ribs increase sequentially from the inner ring to the outer ring.

[0010] In this application, the height and thickness of the weld ribs increase sequentially from the inner ring to the outer ring, enabling a gradual melting and compaction process from the outside to the inside during ultrasonic welding. The taller and thicker weld ribs on the outer ring contact and begin to melt first, initially forming a sealing base. Subsequently, the shorter and narrower weld ribs on the inner ring melt and fill under greater pressure, thus strengthening the seal and mechanical strength.

[0011] In one alternative implementation, the height and thickness of the weld rib decrease sequentially from the inner ring to the outer ring.

[0012] In this application, the height and thickness of the weld reinforcement decrease sequentially from the inner ring to the outer ring. The inner ring weld reinforcement first contacts the second ring welding surface and bears the main welding pressure, establishing a sealing barrier. Subsequently, the outer ring weld reinforcement fuses outside the formed sealing frame, strengthening the external seal.

[0013] In one alternative embodiment, the first plastic part is a top cover, and the second plastic part is a base; And / or, the first plastic component is a plastic display window, and the second plastic component is a top cover.

[0014] In this application, the ultrasonic welding structure of this application can be used in the connection between the base and the top cover, and also in the connection between the plastic display window and the top cover.

[0015] In one alternative implementation, the gap between two adjacent weld beads is greater than a preset spacing.

[0016] In this application, the gap between two adjacent weld beads is set to be greater than a preset spacing. Maintaining sufficient spacing between beads effectively prevents the molten material generated by adjacent weld beads from interfering with or sticking together during ultrasonic welding, ensuring that each weld bead can be independently and fully fused with the second annular welding surface. Sufficient gap also provides space for the flow and re-solidification of molten plastic, preventing welding stress from being unable to be released or internal cracks from forming due to insufficient space.

[0017] In one alternative implementation, it further includes: An overflow groove, which is annular, is disposed on the second annular welding surface. The welding rib is located inside the overflow groove and is suitable for connection to the bottom end of the overflow groove by ultrasonic welding.

[0018] In this application, an annular overflow groove is provided on the second annular welding surface, and the welding rib is located in the overflow groove and connected to the bottom of the groove. The overflow groove provides a space to accommodate the molten plastic material during ultrasonic welding, allowing excess molten material to flow into the groove without overflowing onto the welding surface and affecting the flatness of the welding surface.

[0019] In one alternative embodiment, the total volume of the weld reinforcement is not greater than the volume of the glue overflow groove.

[0020] In this application, the total volume of the weld bead is no greater than the volume of the overflow groove, ensuring that the molten plastic generated after the weld bead melts can be completely contained by the overflow groove without generating excessive internal pressure or causing the molten material to overflow. Sufficient containment space allows the welding process to utilize more welding energy and time to achieve a deeper fusion depth without worrying about overflow, thereby improving weld strength and sealing quality.

[0021] Secondly, the present invention also provides an ultrasonic welding method for use on gas meters, applicable to gas meters as described above, comprising the following steps: S1, the welding rib on the first annular welding surface is abutted against the second annular welding surface; S2, using the first frequency and the first amplitude, ultrasonic welding is performed on the welding rib and the second annular welding surface for the first time; S3, using the second frequency and the second amplitude, ultrasonic welding is performed on the welding rib and the second annular welding surface for the second time; Wherein, the first frequency is greater than the second frequency, and the first amplitude is greater than the second amplitude.

[0022] In this application, welding is performed in stages using different frequencies and amplitude parameters. First, a higher frequency and larger amplitude are used to melt the surface of the weld bead, forming an initial seal. Then, a lower frequency and smaller amplitude are used to promote deeper penetration of the molten plastic for a strong fusion. This step-by-step differentiated energy input strategy, by controlling the welding parameters at different stages, optimizes energy transfer and absorption within the material, reduces the heat-affected zone, and avoids over-welding or under-welding. This ensures welding efficiency while improving the overall performance and long-term reliability of the welded joint.

[0023] In one alternative implementation, the first frequency is 20 kHz to 30 kHz, and the second frequency is 15 kHz to 20 kHz.

[0024] In this application, a higher first frequency facilitates the rapid concentration and conversion of ultrasonic energy on the plastic surface, causing the top of the higher weld bead to melt and flow rapidly, forming a continuous and dense surface sealing layer in a short time. Subsequently, a lower second frequency allows the ultrasonic energy to be transmitted more smoothly and deeply to the weld bead, thereby creating a weld area with high mechanical strength.

[0025] In one alternative implementation, the first amplitude is 45 μm to 55 μm, and the second amplitude is 25 μm to 35 μm.

[0026] In this application, the larger first amplitude provides strong mechanical vibration during the initial welding stage, effectively breaking down the intermolecular barriers on the contact surfaces and accelerating the frictional heating and material melting process at the top of the weld bead. Subsequently, the smaller second amplitude provides a gentler and more continuous vibration mode, which helps the weld bead form a stronger mechanical connection. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of the first plastic part in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of the second plastic part in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the gas meter body structure according to Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the assembly of the base shell and the base in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the structure of the first sealing assembly in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the first sealing gasket structure in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the upper cover structure of Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the structure of the second sealing assembly in Embodiment 1 of the present invention. Figure 9 This is a schematic diagram of the structure before ultrasonic welding in Embodiment 2 of the present invention; Figure 10 This is a schematic diagram of the structure after ultrasonic welding in Embodiment 2 of the present invention; Figure 11This is a schematic diagram of the ultrasonic welding arrangement structure in Embodiment 2 of the present invention; Figure 12 This is a schematic diagram illustrating the principle of Embodiment 2 of the present invention.

[0029] Explanation of reference numerals in the attached figures: 1. First plastic part; 2. First annular welding surface; 3. Second plastic part; 4. Second annular welding surface; 5. Welding rib; 6. Glue overflow groove; 7. Ultrasonic welding equipment; 8. Base shell; 9. Base; 10. Top cover; 11. First sealing gasket; 12. First screw; 13. Contact rib position; 14. Second sealing gasket; 15. Sealing rib; 16. Groove; 17. Second screw. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The following is combined Figures 1 to 12 The following describes embodiments of the present invention.

[0032] Example 1 like Figures 1 to 2 As shown, the present invention provides a gas meter, comprising: The gas meter body includes a first plastic part 1 and a second plastic part 3. The first plastic part 1 has a first annular welding surface 2, and the second plastic part 3 has a second annular welding surface 4. The first plastic part 1 can be a plastic display window, and the second plastic part 3 can be a plastic top cover 10. The plastic top cover 10 can be provided with a recessed mounting platform for installing the plastic display window. The second annular welding surface 4 can be the surface of the mounting platform. The first annular welding surface 2 of the first plastic part 1 can be opposite to and adapted to the second annular welding surface 4, and the first annular welding surface 2 is attached to the second annular welding surface 4. The gas meter body may also include a base shell 8, a plastic base 9, and a plastic top cover 10 connected in sequence. The first plastic part 1 can be the top cover 10, and the second plastic part can be the base 9. An ultrasonic welding structure is suitable for connecting the base 9 and the top cover 10.

[0033] The ultrasonic welding structure includes a welding rib 5, which is annular and disposed on the first annular welding surface 2. The welding rib 5 is adapted to be connected to the second annular welding surface 4 by ultrasonic welding. The welding rib 5 can be a triangular structure, or a structure with a pointed tip, or a general columnar structure. This embodiment is not limited to these.

[0034] In this embodiment, there are at least two weld ribs 5, arranged sequentially, with each weld rib 5 having a different height and thickness. In this embodiment, the number of weld ribs 5 can be two, and the sequential arrangement refers to the sequential nesting of each annular weld rib 5. It should be noted that the height is the length of the weld rib 5 from the first annular welding surface 2 to the second annular welding surface 4, and the thickness is the tangential width of the weld rib 5, i.e., the width perpendicular to its length. The natural vibration frequency of the weld rib 5 can be adjusted by setting the height and width.

[0035] In this application, by providing at least two annular welding ribs 5 with different heights and thicknesses on the first annular welding surface 2 of the first plastic part 1, the welding ribs 5 can exhibit differentiated melting behavior due to differences in geometric dimensions during ultrasonic welding, thereby forming multiple, non-uniform sealing lines at the welding interface. Furthermore, because the heights and thicknesses of the welding ribs 5 differ, the inherent vibration frequencies of each sealing line are different. Under different vibration environments, the welding ribs 5 can maintain their connection, achieving reliable sealing and connection.

[0036] In one optional embodiment, the welding rib 5 is a ring structure, protruding from the first annular welding surface 2 and surrounding the first annular welding surface 2. Surrounding the first annular welding surface 2 allows the welding rib 5 to enclose the area to be sealed, forming a sealing structure. Specifically, it can be a concentric ring. The axes of symmetry of the welding ribs 5 coincide, they have the same shape, but different sizes. The welding rib 5 is not necessarily a circular ring; its specific ring shape should be determined according to the actual structure of the plastic display window. The welding rib 5 can be set on the plastic display window, and is positioned at the edge of the plastic display window, such as... Figure 9 As shown, it is opposite to the second annular welding surface 4.

[0037] In this application, the concentric ring shape ensures that the welding force is evenly distributed on the first annular welding surface 2 and the second annular welding surface 4, avoiding local stress concentration and uneven welding caused by the eccentricity or asymmetry of the welding rib 5. The symmetrical geometric layout allows ultrasonic energy to be evenly transmitted on the welding surface, promoting the formation of a continuous and complete fusion zone between the welding rib 5 and the second annular welding surface 4, further ensuring the continuity and tightness of the sealing line and preventing leakage paths from the welding interface.

[0038] In one optional embodiment, the height and thickness of the weld ribs 5 increase sequentially from the inner ring to the outer ring. The height of the weld ribs 5 located near the outer ring is greater than the height of the weld ribs 5 located near the inner ring.

[0039] In this application, the height and thickness of the welding ribs 5 increase sequentially from the inner ring to the outer ring, enabling a melting and compaction process that penetrates progressively from the outside to the inside during ultrasonic welding. The higher outer ring welding ribs 5 contact and begin to melt first, initially forming a sealing base. Subsequently, the lower inner ring welding ribs 5 melt and fill under greater pressure, thus strengthening the seal and mechanical strength.

[0040] In one optional embodiment, the height and thickness of the weld ribs 5 decrease sequentially from the inner ring to the outer ring. The height of the weld ribs 5 located near the inner ring is greater than the height of the weld ribs 5 located near the outer ring.

[0041] In this application, the height and thickness of the welding rib 5 decrease sequentially from the inner ring to the outer ring. The inner ring welding rib 5 first contacts the second annular welding surface 4 and bears the main welding pressure, initially establishing a sealing barrier. Subsequently, the outer ring welding rib 5 fuses with the existing sealing frame, strengthening the external seal.

[0042] In one optional embodiment, the first plastic part 1 is a top cover 10, and the second plastic part 3 is a base 9. The top cover 10 may have a first annular welding surface 2, located at its edge. The welding rib 5 protrudes from the first annular welding surface 2. The base 9 has a second annular welding surface 4, located at its edge. The first annular welding surface 2 and the second annular welding surface 4 are positioned opposite each other. The welding rib 5 is connected to the second annular welding surface 4 by ultrasonic welding. Before welding, the welding rib 5 abuts against the second annular welding surface 4. During welding, the welding rib 5 melts and fills the spaces between adjacent welding ribs 5, forming a welding surface, thus firmly connecting the top cover 10 and the base 9.

[0043] And / or, the first plastic part 1 is a plastic display window, and the second plastic part 3 is a top cover 10. The plastic display window can be disposed on the top cover 10, which has a mounting groove for mounting the display window. The plastic display window may have a first annular welding surface 2, and the welding rib 5 protrudes from the plastic display window. The top cover 10 has a second annular welding surface 4, which may be located at the edge of the mounting groove. The first annular welding surface 2 and the second annular welding surface 4 are arranged opposite to each other. The welding rib 5 can be connected to the second annular welding surface 4 by ultrasonic welding. Before welding, the welding rib 5 abuts against the second annular welding surface 4. During welding, the welding rib 5 melts and fills the spaces between adjacent welding ribs 5, forming a welding surface, thus firmly connecting the plastic display window and the top cover 10.

[0044] In one optional embodiment, the gap between two adjacent welded ribs 5 is greater than a preset spacing. The preset spacing can be 1 mm.

[0045] In this application, the gap between two adjacent welding ribs 5 is set to be greater than a preset spacing. Maintaining sufficient spacing between the ribs effectively prevents the molten material generated by adjacent welding ribs 5 from interfering with or adhering to each other during ultrasonic welding, ensuring that each welding rib 5 can independently and fully fuse with the second annular welding surface 4. Sufficient gap also provides space for the flow and re-solidification of molten plastic, preventing welding stress from being unable to be released or internal cracks from occurring due to insufficient space.

[0046] In one alternative implementation, it further includes: An overflow groove 6, which is annular, is disposed on the second annular welding surface 4. The welding rib 5 is located within the overflow groove 6 and is suitable for connection to the bottom end of the overflow groove 6 via ultrasonic welding. The overflow groove 6 is disposed on the second plastic part 3. The height of the welding rib 5 should exceed the depth of the overflow groove 6, so that the top end of the welding rib 5 can rub against the bottom end of the overflow groove 6, thereby generating molten plastic and realizing ultrasonic welding.

[0047] In this application, an annular overflow groove 6 is provided on the second annular welding surface 4, and the welding rib 5 is located inside the overflow groove 6 and connected to the bottom of the groove. The overflow groove 6 can provide a space to accommodate the molten plastic material during ultrasonic welding, so that excess molten material can flow into the groove without overflowing onto the welding surface and affecting the flatness of the welding surface.

[0048] In one optional embodiment, the total volume of the welding rib 5 is not greater than the volume of the glue overflow groove 6.

[0049] In this application, the total volume of the welding rib 5 is no greater than the volume of the overflow groove 6, ensuring that the molten plastic produced after the welding rib 5 melts can be completely contained by the overflow groove 6 without generating excessive internal pressure or causing the molten material to overflow. Sufficient containment space allows the welding process to use more welding energy and time to achieve a deeper fusion depth without worrying about overflow, thereby improving welding strength and sealing quality.

[0050] In addition, such as Figures 3 to 8 As shown, the base shell 8 and the base 9 are connected by a first sealing assembly, and the base 9 and the top cover 10 are connected by a second sealing assembly; the first sealing assembly includes a first sealing gasket 11, which is located between the edge of the base shell 8 and the edge of the base 9, wherein the base shell 8 and the base 9 are connected by a first screw 12. In one optional embodiment, the first screw 12 penetrates the base 9 and the first sealing gasket 11, and is screwed to the base shell 8. The base 9 and the base shell 8 may have opposing connection holes, and the connection holes on the base shell 8 are screwed to the first screw 12. The first sealing gasket 11 may have a sealing hole opposite to the connection hole. The first screw 12 penetrates both the sealing hole and the connection hole. In this application, the first screw 12 penetrates the base 9 and the first sealing gasket 11 before being screwed to the base shell 8, enabling simultaneous connection and sealing. The through-type design allows the screw to directly apply a uniform axial clamping force to the first sealing gasket 11 during tightening, ensuring sufficient compression deformation of the sealing gasket on the contact surface between the base shell 8 and the base 9, thereby forming a continuous sealing interface.

[0051] In one optional embodiment, the first screw 12 and the first sealing gasket 11 are interference-fitted. The interference amount between the first screw 12 and the first sealing gasket 11 can be from 10% to 30%. A sealing hole for the first screw 12 to pass through can be provided on the first sealing gasket 11, and the sealing hole and the first screw 12 are interference-fitted. Because the first screw 12 and the first sealing gasket 11 are interference-fitted, when the first screw 12 is fitted into the sealing hole on the first sealing gasket 11, the first screw 12 can compress the first sealing gasket 11, causing the first sealing gasket 11 to form raised ribs on the mating surfaces with the base shell 8 and the base 9, respectively.

[0052] In this application, the raised ribs are in close contact with the relatively rigid surfaces of the base shell 8 and the base 9. Under the tightening force of the first screw 12, the base shell 8, the base 9, and the first sealing gasket 11 can form a sealing structure for the gas meter.

[0053] In one optional embodiment, a contact rib 13 is provided on the contact surface of the base 9 that contacts the nut, and the contact rib 13 surrounds the first screw 12. The cross-section of the contact rib 13 near the base 9 is larger than the cross-section near the nut of the first screw 12.

[0054] In this application, when the nut is tightened downwards, the gradually widening cross-section of the contact rib 13 allows the top of the contact rib 13 to withstand higher concentrated stress, easily generating sufficient deformation to fill any micro-gaps and form a sealing structure. The lower part of the contact rib 13 is wider, which can prevent the contact rib 13 from buckling or excessively crushing under high pressure, ensuring the stability of the seal. The contact rib 13 of this application has a wedge effect, which allows the sealing structure to have a self-reinforcing tendency when subjected to internal pressure or external impact, helping to maintain long-term sealing effect and improving the durability of the sealing interface under temperature cycling or mechanical vibration conditions.

[0055] like Figure 8As shown, the second sealing assembly includes a second sealing gasket 14 and a sealing rib 15. The second sealing gasket 14 is disposed on the base 9, and the sealing rib 15 is disposed on the upper cover 10. The end structure of the sealing rib 15 is smaller than the bottom structure and abuts against the second sealing gasket 14. The base 9 and the upper cover 10 are connected by a second screw 17. It should be noted that the end of the sealing rib 15 that abuts against the second sealing gasket 14 is the end, and the root of the sealing rib 15 is the bottom. Specifically, the end of the sealing rib 15 can be a triangular structure with a pointed tip facing the second sealing gasket 14. The end of the sealing rib 15 can also have a pointed tip and extend gradually along the sealing rib 15, with the cross-section gradually increasing. This embodiment is not limited to this.

[0056] In one alternative implementation, such as Figure 8 As shown, the second sealing assembly further includes: A groove 16 is provided on the base 9, and the second sealing gasket 14 is disposed within the groove 16. The groove 16 and the second sealing gasket 14 placed therein can be a clearance fit.

[0057] In this application, the second sealing assembly provides positioning and accommodating space for the sealing gasket by providing a groove 16 on the base 9 and placing the second sealing gasket 14 therein. The groove 16 ensures that the sealing gasket will not shift laterally or twist during assembly and use, guaranteeing that it remains in the preset sealing position. The sealing gasket accommodated in the groove 16 is laterally constrained by the groove wall. When the sealing rib 15 of the upper cover 10 is pressed in, the deformation of the sealing gasket mainly occurs in a controllable vertical direction, thereby forming a uniform and predictable compression sealing band.

[0058] It should be noted that the second screw 17 may not penetrate the second sealing gasket 14, and threaded holes for the second screw 17 may be provided on the base 9 and the top cover 10. The second screw 17 may be located on the groove 16 near the inner side of the gas meter, or on the groove 16 near the outer side of the gas meter.

[0059] Example 2 like Figures 9 to 12 As shown, the present invention also provides an ultrasonic welding method for use on gas meters, applicable to gas meters as described above, comprising the following steps: S1, the welding rib 5 on the first annular welding surface 2 is abutted against the second annular welding surface 4; S2, using a first frequency and a first amplitude, ultrasonic welding is performed on the welding rib 5 and the second annular welding surface 4 for a first time; welding can be performed using an ultrasonic welding device 7, which can be aligned with the first annular welding surface 2 and the second annular welding surface 4. The first time can be from 0.2 seconds to 0.5 seconds.

[0060] S3, using a second frequency and a second amplitude, ultrasonic welding is performed on the welding rib 5 and the second annular welding surface 4 for a time of a second time; the second time can be from 0.5 seconds to 1.0 seconds.

[0061] Wherein, the first frequency is greater than the second frequency, and the first amplitude is greater than the second amplitude.

[0062] In this application, welding is performed in stages using different frequencies and amplitude parameters. First, a higher frequency and larger amplitude are used to melt the surface layer of the weld bead 5, forming an initial seal. Subsequently, a lower frequency and smaller amplitude are used to promote deeper penetration of the molten plastic for a robust fusion. This step-by-step differentiated energy input strategy, by controlling the welding parameters at different stages, optimizes energy transfer and absorption within the material, reduces the heat-affected zone, and avoids over-welding or under-welding. This ensures welding efficiency while improving the overall performance and long-term reliability of the welded joint.

[0063] In one optional implementation, the first frequency is 20 kHz to 30 kHz, and the second frequency is 15 kHz to 20 kHz. Alternatively, the first and second frequencies can be the same, for example, 20 kHz, and differentiation can be achieved by adjusting the amplitude, for example, the first amplitude and the second amplitude. Differentiation can also be achieved by adjusting the welding time, for example, the first time and the second time.

[0064] In this application, a higher first frequency facilitates the rapid concentration and conversion of ultrasonic energy on the plastic surface, causing the top of the higher weld rib 5 to melt and flow rapidly, forming a continuous and dense surface sealing layer in a short time. Subsequently, a lower second frequency allows the ultrasonic energy to be transmitted more smoothly and deeply to the weld rib 5, thereby creating a weld area with high mechanical strength.

[0065] In one alternative implementation, the first amplitude is 45 μm to 55 μm, and the second amplitude is 25 μm to 35 μm. Specifically, the first amplitude can be 50 μm, and the second amplitude can be 30 μm.

[0066] In this application, the larger first amplitude provides strong mechanical vibration during the initial welding stage, effectively breaking down the intermolecular barriers on the contact surfaces and accelerating the frictional heating and material melting process at the top of the higher weld bead 5. Subsequently, the smaller second amplitude provides a gentler and more continuous vibration mode, which helps the weld bead 5 form a stronger mechanical connection.

[0067] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A gas meter, characterized in that, include: The gas meter body includes a first plastic part (1) and a second plastic part (3), the first plastic part (1) having a first annular welding surface (2) and the second plastic part (3) having a second annular welding surface (4); An ultrasonic welding structure includes a welding rib (5), which is annular and disposed on the first annular welding surface (2). The welding rib (5) is adapted to be connected to the second annular welding surface (4) by ultrasonic welding. There are at least two weld ribs (5), which are arranged in sequence, and each weld rib (5) has a different height and thickness.

2. The gas meter according to claim 1, characterized in that, The welding rib (5) is a collar structure, protruding on the first annular welding surface (2) and surrounding the first annular welding surface (2).

3. The gas meter according to claim 1, characterized in that, From the inner ring to the outer ring, the height and thickness of the welded rib (5) increase sequentially; Alternatively, from the inner ring to the outer ring, the height and thickness of the welded rib (5) decrease sequentially.

4. The gas meter according to claim 1, characterized in that, The first plastic part (1) is the top cover (10), and the second plastic part (3) is the base (9); And / or, the first plastic part (1) is a plastic display window, and the second plastic part (3) is a top cover (10).

5. The gas meter according to claim 1, characterized in that, The gap between two adjacent welded tendons (5) is greater than the preset spacing.

6. The gas meter according to any one of claims 1 to 5, characterized in that, Also includes: The overflow groove (6) is annular and is set on the second annular welding surface (4). The welding rib (5) is located inside the overflow groove (6) and is suitable for connection to the bottom end of the overflow groove (6) by ultrasonic welding.

7. The gas meter according to claim 6, characterized in that, The total volume of the welding rib (5) is not greater than the volume of the glue overflow groove (6).

8. An ultrasonic welding method applied to a gas meter, suitable for the gas meter as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1, the welding rib (5) on the first annular welding surface (2) is abutted against the second annular welding surface (4); S2, using the first frequency and the first amplitude, ultrasonic welding is performed on the welding rib (5) and the second annular welding surface (4) for the first time; S3, using the second frequency and the second amplitude, ultrasonic welding is performed on the welding rib (5) and the second annular welding surface (4) for the second time; Wherein, the first frequency is greater than the second frequency, and the first amplitude is greater than the second amplitude.

9. The ultrasonic welding method for gas meters according to claim 8, characterized in that, The first frequency is 20 kHz to 30 kHz, and the second frequency is 15 kHz to 20 kHz.

10. The ultrasonic welding method applied to a gas meter according to claim 8, characterized in that, The first amplitude is 45 μm to 55 μm, and the second amplitude is 25 μm to 35 μm.

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