Float connection structure

Abstract

To suppress the breakage of a weld part due to impulsive force.SOLUTION: A float connection structure includes a hollow float 45, a mounting member 51 provided penetrating through the inside and the outside of the float 45 for connecting to a lever 46, a support member 55 stored in the float 45 and fixed to the float 45, a first weld part 61 for weld-joining the outward side of the mounting member 51 to an outer surface 45c of the float 45, and a second weld part 62 for weld-joining the inward side of the mounting member 51 to the support member 55. The throat thickness of the first weld part 61 is smaller than that of the second weld part 62.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The technology of the present disclosure relates to a connecting structure of a float. [Background technology]

[0002] A connecting structure for a float that rises and falls according to the liquid level is disclosed, for example, in Patent Document 1. The connecting structure disclosed in Patent Document 1 is provided in a liquid pressure-feeding device and includes a float and an attachment member joined to the float. The attachment member is welded to the float and is connected to a lever, which is the object to be connected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-43944 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the float connection structure described above, there is a risk that the mounting member may become detached from the float. That is, the welded joint connecting the float and mounting member has reduced impact strength due to thermal effects, and therefore may be damaged by an impact force acting on the storage space due to, for example, water hammer or the sudden inflow of a large amount of drain. This could result in the mounting member becoming detached from the float.

[0005] The technology disclosed herein has been developed in consideration of such circumstances, and its purpose is to suppress damage to the welded portion due to impact forces in a float connection structure in which the float and mounting member are welded together. [Means for solving the problem]

[0006] The float connection structure of the present disclosure comprises a hollow float, an attachment member, a support member, an outer weld, and an inner weld. The attachment member is provided to penetrate the float from the inside to the outside and is for connecting to an object to be connected. The support member is housed inside the float and fixed to the float. The outer weld welds the outer side of the attachment member to the outer surface of the float. The inner weld welds the inner side of the attachment member to the support member. The throat thickness of the outer weld is smaller than the throat thickness of the inner weld. [Effects of the Invention]

[0007] The float connection structure can prevent damage to the welded portion due to impact force. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing a drain trap in a closed state. [Figure 2] FIG. 2 is a cross-sectional view showing the drain trap in an open state. [Figure 3] FIG. 3 is a cross-sectional view showing the connecting structure of the float. [Figure 4] FIG. 4 is a plan view showing the float connection structure as viewed from the lever side. [Figure 5] FIG. 5 is a cross-sectional view showing a float connection structure according to a modified example. [Figure 6] FIG. 6 is a plan view showing a float connection structure according to a modified example, as viewed from the lever side. DETAILED DESCRIPTION OF THE INVENTION

[0009] Exemplary embodiments will be described in detail below with reference to the drawings. Figure 1 is a cross-sectional view showing a drain trap 100 in a closed state. Figure 2 is a cross-sectional view showing the drain trap 100 in an open state.

[0010] The drain trap 100 is installed in, for example, a steam pipe in a steam system, and prevents the outflow of steam while allowing the drain generated by condensation of the steam to flow out. The drain trap 100 is provided with a connecting structure for a float 45. Specifically, the drain trap 100 includes a housing 1, a screen 3, and a valve mechanism 4.

[0011] A flow path 2 through which the drain flows is formed in the housing 1. In this example, the flow path 2 is formed by an inlet path 21, a capture path 22, a communication path 23, a storage chamber 24, and an outlet path 25.

[0012] One end of the inlet channel 21 opens to the outside, specifically in the horizontal direction. The other end of the inlet channel 21 is connected to the capture channel 22. A screen 3 is provided in the capture channel 22. The capture channel 22 communicates with the storage chamber 24 via a communication channel 23. More specifically, one end of the capture channel 22 is connected to the inlet channel 21, and the other end of the capture channel 22 is closed by a closure plate 13. The communication channel 23 is connected to the side of the capture channel 22 and the bottom of the storage chamber 24. In other words, the capture channel 22 is located below the storage chamber 24.

[0013] Drain is temporarily stored in the storage chamber 24. One end of the outflow path 25 is connected to the storage chamber 24, more specifically, connected to a lower portion of the side of the storage chamber 24. The other end of the outflow path 25 opens to the outside, more specifically, opens horizontally. In the flow path 2, drain that has flowed into the inflow path 21 from the outside flows through the capture path 22, the communication path 23, and the outflow path 25 in this order, and then flows out to the outside.

[0014] More specifically, the housing 1 has a lower portion 11 and an upper portion 12 that are connected to each other in the vertical direction. The lower portion 11 and the upper portion 12 are joined by bolting. The lower portion 11 is formed with an inlet channel 21, a capture channel 22, a communication channel 23, and an outlet channel 25. The storage chamber 24 is formed across the lower portion 11 and the upper portion 12. The housing 1 is provided with a plurality of legs 14.

[0015] As described above, the screen 3 is provided in the capture passage 22 and captures foreign matter in the drain flowing through the capture passage 22. The screen 3 is formed in a cylindrical shape extending in the axial direction of the capture passage 22. In the capture passage 22, the drain that has flowed in from the inlet passage 21 passes through the peripheral wall of the screen 3 from the inside to the outside. As the drain passes through the peripheral wall of the screen 3, foreign matter in the drain is captured.

[0016] The valve mechanism 4 is provided in the flow path 2 and opens and closes the flow path 2. Specifically, the valve mechanism 4 is provided in the storage chamber 24 and opens and closes the connection between the storage chamber 24 and the outflow path 25. The valve mechanism 4 has a case 41 in which a valve hole 42 is formed, a valve element 43 that opens and closes the valve hole 42, and a driver 44 that drives the valve element 43.

[0017] Case 41 is disposed at a connection portion between storage chamber 24 and outflow path 25. Case 41 is provided so that its internal space communicates with the aforementioned connection portion (i.e., outflow path 25). Valve hole 42 penetrates case 41 from the inside to the outside, and communicates the internal space of case 41 with storage chamber 24. In other words, storage chamber 24 and outflow path 25 communicate with each other via valve hole 42. In this example, a pair of valve holes 42 aligned in the vertical direction are provided, and a pair of valve bodies 43 are provided to open and close each of the pair of valve holes 42.

[0018] More specifically, of the pair of valve bodies 43, the valve body 43 corresponding to the upper valve hole 42 is located in the internal space of the case 41, and the valve body 43 corresponding to the lower valve hole 42 is located outside the case 41. The pair of valve bodies 43 move up and down to open and close the pair of valve holes 42. That is, the valve body 43 closes the valve holes 42 by moving up (see the closed valve state shown in Figure 1), and opens the valve holes 42 by moving down (see the open valve state shown in Figure 2).

[0019] The driver 44 moves the pair of valve bodies 43 up and down according to the drain water level in the reservoir chamber 24. The driver 44 has a hollow float 45, a lever 46, and an operating rod 48.

[0020] The float 45 is formed in a hollow spherical shape, i.e., a spherical shell shape, and is housed in the storage chamber 24. The float 45 is made of metal. The float 45 rises and falls according to the drain water level in the storage chamber 24. The lever 46 is connected to the float 45. The lever 46 is rotatably supported by a shaft 47a provided in the storage chamber 24. The lever 46 swings around the shaft 47a as the float 45 rises and falls.

[0021] The operating rod 48 extends generally in the vertical direction, with one end connected to the lever 46 and the other end connected to the pair of valve bodies 43. More specifically, one end of the operating rod 48 is rotatably connected to a shaft 47b provided on the lever 46. The shaft 47b is provided on the lever 46 on the opposite side of the shaft 47a from the float 45 side. The operating rod 48 moves up and down in accordance with the swing of the lever 46. In other words, the valve mechanism 4 moves the pair of valve bodies 43 up and down as the operating rod 48 moves up and down in accordance with the rise and fall of the float 45.

[0022] In drain trap 100 configured in this manner, when little drain has accumulated in storage chamber 24, float 45 is located near the bottom of storage chamber 24, as shown in Figure 1. In this state, operating rod 48 and valve body 43 are raised, and valve hole 42 is closed by valve body 43. Therefore, even if steam from the steam system flows into storage chamber 24 from inlet channel 21, the steam is prevented from flowing out from storage chamber 24 to outlet channel 25. In this way, drain trap 100 prevents the flowing in steam from flowing out.

[0023] When condensate is generated in the steam system, the condensate flows into and accumulates in the storage chamber 24. As the condensate accumulates in the storage chamber 24, the float 45 rises. When the float 45 rises, the operating rod 48 and valve body 43 descend, opening the valve hole 42. This allows the condensate in the storage chamber 24 to flow out through the outflow path 25. In this way, the condensate trap 100 allows the condensate to flow out while preventing the outflow of steam.

[0024] <Float connection structure> Fig. 3 is a cross-sectional view showing the connecting structure of the float 45. Fig. 4 is a plan view showing the connecting structure of the float 45 as viewed from the lever 46 side.

[0025] The connection structure of the float 45 (hereinafter also simply referred to as the connection structure) is a structure for connecting the lever 46, which is the object to be connected, to the float 45. This connection structure includes the float 45 described above and a coupler 50. The coupler 50 is fixed to the float 45 and connected to the lever 46.

[0026] The coupler 50 has a mounting member 51 and a support member 55, both of which are made of metal.

[0027] The mounting member 51 is a member for connecting to the lever 46, and is provided so as to penetrate the float 45 from the inside to the outside. More specifically, the mounting member 51 has a substantially cylindrical shaft portion 52 and a substantially disk-shaped flange portion 53. The float 45 is formed with a through-hole 45e having substantially the same diameter as the shaft portion 52. The shaft portion 52 is inserted into the through-hole 45e. In other words, the shaft portion 52 extends in the radial direction of the float 45 and penetrates the float 45 from the inside to the outside. The flange portion 53 is integrally formed with the inner end portion of the shaft portion 52. In other words, the entire flange portion 53 is located inside the float 45. The outer diameter of the flange portion 53 is larger than the diameter of the through-hole 45e, and the flange portion 53 is provided coaxially with the shaft portion 52.

[0028] A female screw 52a is formed in the axial direction of the shaft 52. The female screw 52a is threadedly engaged with a male screw (not shown) provided on the lever 46. In other words, the shaft 52 and the lever 46 are connected by being threadedly engaged with each other.

[0029] The support member 55 supports the mounting member 51. The support member 55 is housed inside the float 45 and fixed to the float 45. Specifically, the support member 55 has a curved portion 56 that supports the mounting member 51 and a flange portion 57 that is fixed to the float 45.

[0030] The curved portion 56 is formed by bending a plate material toward the mounting member 51 (more specifically, the flange portion 53). More specifically, the curved portion 56 is formed in a generally hemispherical shell shape with a diameter smaller than that of the float 45, and is provided with its open end located on the opposite side from the mounting member 51. The flange portion 57 is formed integrally with the curved portion 56. More specifically, the flange portion 57 is provided on the outer periphery of the open end of the curved portion 56. In other words, the flange portion 57 extends radially outward from the open end of the curved portion 56.

[0031] The connecting structure includes a first weld 61 that welds the outer side of the mounting member 51 to the outer surface 45c of the float 45, and a second weld 62 that welds the inner side of the mounting member 51 to the support member 55. The connecting structure further includes a third weld 63 that welds the support member 55 to the float 45. The first weld 61 is an example of an outer weld, and the second weld 62 is an example of an inner weld.

[0032] Here, the "outer side" refers to the portion located on the outer side of the float 45, and the "inner side" refers to the portion located on the inner side of the float 45.

[0033] Specifically, the first weld 61 is provided at a corner formed by the outer side of the shaft portion 52 and the outer surface 45c of the float 45. In other words, the first weld 61 is provided on the periphery of the through hole 45e in the outer surface 45c of the float 45. The first weld 61 is a full-circumferential fillet weld that is welded around the entire circumference of the shaft portion 52.

[0034] The second weld 62 welds the flange 53 of the mounting member 51 to the curved portion 56. In other words, the second weld 62 is provided at the corner formed by the outer periphery of the flange 53 and the spherical surface of the curved portion 56. The second weld 62 is a full perimeter fillet weld that is welded around the entire circumference of the flange 53. In this manner, the mounting member 51 is joined to the support member 55.

[0035] The third weld 63 welds the flange 57 of the support member 55 to the float 45. Here, as shown in FIG. 3 , the float 45 is formed into a hollow sphere by welding two hemispherical shell-shaped segments 45a, 45b together. More specifically, the two segments 45a, 45b are welded together with the outer peripheral edge of the flange 57 sandwiched between them. That is, the third weld 63 welds the flange 57 to the outer surfaces of the two segments 45a, 45b (i.e., the outer surface 45c of the float 45). In this way, the support member 55 is fixed to the float 45.

[0036] The throat thickness of the first weld 61 is smaller than the throat thickness of the second weld 62. In other words, the weld strength of the first weld 61 is smaller than the weld strength of the second weld 62. More specifically, the second weld 62 ensures a weld strength sufficient to withstand stresses such as tensile stress, compressive stress, bending stress, and torsional stress that may occur during normal operation. Since the second weld 62 firmly secures the mounting member 51 to the support member 55 and ultimately to the float 45, the first weld 61 does not need to have the aforementioned weld strength. The first weld 61 is a seal weld that can prevent fluids such as condensate and steam from entering the float 45 through the gap between the through-hole 45e of the float 45 and the shaft portion 52.

[0037] The throat thickness of the third welded portion 63, like the throat thickness of the second welded portion 62, is greater than the throat thickness of the first welded portion 61. In other words, the weld strength of the third welded portion 63 is greater than the weld strength of the first welded portion 61. More specifically, the third welded portion 63 ensures a weld strength that can withstand stresses such as tensile stress, compressive stress, bending stress, and torsional stress that may occur during normal operation. In this way, the support member 55 is firmly fixed to the float 45 by the third welded portion 63.

[0038] According to the connecting structure configured as above, damage to the welded portion due to impact force can be suppressed.

[0039] That is, the connecting structure includes a hollow float 45, a mounting member 51 that penetrates the float 45 from the inside to the outside and connects to an object to be connected (i.e., lever 46), a support member 55 that is housed inside the float 45 and fixed to the float 45, a first weld 61 that welds the outer side of the mounting member 51 to the outer surface 45c of the float 45, and a second weld 62 that welds the inner side of the mounting member 51 to the support member 55. The throat thickness of the first weld 61 is smaller than the throat thickness of the second weld 62.

[0040] According to this configuration, the second weld 62 has a larger throat thickness than the first weld 61. In other words, the second weld 62 has a greater weld strength than the first weld 61. Therefore, the second weld 62 has a weld strength sufficient to withstand stresses such as tensile stress and compressive stress that may occur during normal operation, and the first weld 61 can be seal welded to prevent fluid from entering the float 45. In other words, the first weld 61, which does not require much weld strength, is provided outside the float 45, and the second weld 62, which requires sufficient weld strength, is provided inside the float 45.

[0041] Generally, in welds, a heat-affected zone is created where the welding heat changes the mechanical properties of the material. The heat-affected zone has high hardness and low notch toughness (impact value). Normally, the greater the throat thickness of the weld, the greater the weld strength, but the larger the area of the heat-affected zone, and the lower the impact value. A lower impact value makes the weld weaker against sudden impact forces. The first weld 61 has a small throat thickness, so the area of the heat-affected zone is also small, and the impact value is not low. The second weld 62 has a large throat thickness, so the area of the heat-affected zone is also large, and the impact value is lower.

[0042] Therefore, when an impact force acts on the storage chamber 24 due to water hammer or the sudden inflow of a large amount of drainage, the first welded portion 61 is not damaged by the impact force because its impact value is not low. On the other hand, although the second welded portion 62 has a low impact value, it is located inside the float 45 and is not subjected to the impact force. Therefore, the second welded portion 62 is also not damaged by the impact force. In this way, damage to the first welded portion 61 and the second welded portion 62 due to the impact force can be suppressed. Therefore, it is possible to suppress the attachment member 51 from coming off the float 45 due to damage to the first welded portion 61 and the second welded portion 62.

[0043] Furthermore, the support member 55 has a curved portion 56 formed by bending a plate material toward the mounting member 51. The second welded portion 62 joins the inner side of the mounting member 51 to the curved portion 56 by welding.

[0044] According to this configuration, the curved portion 56 to which the inner side of the mounting member 51 is welded is curved toward the mounting member 51, so that the length of the inner side of the mounting member 51 can be shortened as much as possible, thereby reducing material costs and weight.

[0045] Furthermore, the thickness of the float 45 is smaller than the thickness of the curved portion 56 .

[0046] This configuration further reduces material costs and weight. Specifically, since the first welded portion 61 does not require high weld strength, the thickness of the float 45 can be made thin. On the other hand, the second welded portion 62 requires sufficient weld strength, so the thickness of the curved portion 56 can be ensured appropriately. Furthermore, since the curved portion 56 is housed inside the float 45, the volume of the float 45 tends to be much larger than the volume of the curved portion 56. Thus, even if the curved portion 56, which has a small volume, is thick, the float 45, which has a very large volume, can be thin, resulting in reduced material costs and weight overall.

[0047] <<Variation>> In this modification, the configuration of the support member is changed in the connecting structure of the above embodiment. Here, differences from the above embodiment will be described. Fig. 5 is a cross-sectional view showing the connecting structure of float 45 according to the modification. Fig. 6 is a plan view showing the connecting structure of float 45 according to the modification as viewed from the lever 46 side.

[0048] The support member 58 of this modified example is housed inside the float 45 and fixed to the float 45, similar to the above embodiment. The support member 58 has a shape similar to the support member 55 of the above embodiment, except that the flange 57 is omitted. In other words, the entire support member 58 is formed into a substantially hemispherical shell shape in which a plate material is curved toward the mounting member 51 (more specifically, the flange 53), and corresponds to the curved portion 56 of the above embodiment. In this example, the support member 58 is also provided with an open end 58a located on the opposite side from the mounting member 51.

[0049] The connecting structure includes a first weld 61 and a second weld 62 similar to those of the previous embodiment, and a fourth weld 64 instead of the third weld 63 of the previous embodiment. The fourth weld 64 welds the support member 58 to the float 45. Note that the float 45 in this example is formed into a hollow sphere by directly welding together two hemispherical shell-shaped segments 45a, 45b, but the welds are not shown in the drawings.

[0050] Specifically, the fourth weld 64 welds the open end 58a of the support member 58 to the inner surface 45d of the float 45. More specifically, the fourth weld 64 is provided at a position closer to the mounting member 51 than the dividing position of the float 45. The fourth weld 64 is provided at a corner formed by the open end 58a of the support member 58 and the inner surface 45d of the float 45. The fourth weld 64 is a full-circumference fillet weld that is welded around the entire circumference of the open end 58a.

[0051] The throat thickness of the fourth weld 64, like the throat thickness of the second weld 62, is larger than the throat thickness of the first weld 61. In other words, the fourth weld 64 ensures welding strength that can withstand stresses such as tensile stress, compressive stress, bending stress, and torsional stress that may occur during normal operation. In this way, the support member 58 is firmly fixed to the float 45 by the fourth weld 64.

[0052] Furthermore, the fourth welded portion 64, like the second welded portion 62, is provided inside the float 45. Therefore, like the second welded portion 62, the fourth welded portion 64 has a low impact value, but is not subjected to impact force. Therefore, the fourth welded portion 64 is not damaged by impact force. Therefore, damage to the first welded portion 61, the second welded portion 62, and the fourth welded portion 64 due to impact force can be suppressed. As a result, it is possible to suppress detachment of the mounting member 51 from the float 45 due to damage to these welded portions 61, 62, and 64. The other configurations, actions, and effects are the same as those of the above-described embodiment.

[0053] Other Embodiments As described above, the above embodiment has been described as an example of the technology disclosed in this application. However, the technology of the present disclosure is not limited to this and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. Furthermore, the components described in the above embodiment can be combined to create new embodiments. Furthermore, the components described in the accompanying drawings and detailed description may include not only components essential for solving the problem, but also components that are not essential for solving the problem in order to exemplify the technology. Therefore, the fact that these non-essential components are described in the accompanying drawings or detailed description should not be interpreted as immediately determining that these non-essential components are essential.

[0054] For example, although the mounting member 51 has the shaft portion 52 and the flange portion 53, the flange portion 53 may be omitted. In this case, the inner side of the shaft portion 52 is welded to the curved portion 56 of the support member 55.

[0055] Furthermore, although the support members 55, 58 are fixed to the float 45 by welding, they may alternatively be fixed to the float 45 by bolting.

[0056] Furthermore, the shapes of the support members 55 and 58 are not limited to those described above. For example, the support members may be formed in the shape of a flat plate as a whole.

[0057] Furthermore, the positions at which the support members 55, 58 are fixed to the float 45 are not limited to the positions described above.

[0058] The shape of the float 45 may be an oval sphere or a rectangle, other than a sphere.

[0059] The float connection structure of the present disclosure may also be applied to devices other than the aforementioned drain trap 100. For example, this connection structure may also be applied to a liquid pumping device that pumps drain stored in a storage chamber to the outside by introducing steam. [Industrial Applicability]

[0060] As described above, the technology of the present disclosure is useful for a connecting structure of floats. [Explanation of symbols]

[0061] 45 Float 45c outer surface 46 Lever (connected object) 51 Mounting material 55 Support member 56 Curved section 58 Support member 61 First weld (outer weld) 62 Second weld (inner weld)

Claims

1. A hollow float and An attachment member that penetrates the float from the inside to the outside and is used to connect to an object to be connected; a support member housed inside the float and fixed to the float; an outer weld portion that welds the outer side of the mounting member to the outer surface of the float; an inner weld portion that welds an inner side of the mounting member to the support member, The throat thickness of the outer weld is smaller than the throat thickness of the inner weld. A float connection structure characterized by the above.

2. 2. The float connection structure according to claim 1, the support member has a curved portion formed by a plate member curved toward the mounting member, The inner welded portion welds the inner side of the mounting member to the curved portion. A float connection structure characterized by the above.

3. 3. The float connection structure according to claim 2, The thickness of the float is smaller than the thickness of the curved portion. A float connection structure characterized by the above.

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