Discharge pipe

Abstract

To provide a discharge pipe suppressing a pressure loss of a discharge liquid passing through the inside.SOLUTION: A longitudinal discharge pipe 10 includes an inflow opening 12 formed at one end, a cylindrical inner peripheral surface 16 extending in the longitudinal direction and constituting a main flow passage, and a discharge flow passage 20 formed radially outward from the inner peripheral surface 16. The discharge flow path 20 has a first opening formed on the inner peripheral surface and a discharge opening formed on the outer peripheral surface of the discharge pipe 10. An opening area of the first opening is larger than an opening area of the discharge opening.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a discharge pipe having an opening at one end and a bottom at the other end. [Background technology]

[0002] Patent Document 1 discloses a cooling structure for a rotating electric machine that is disposed above a motor stator and a generator stator and includes a coolant flow path through which a coolant flows. The coolant flow path includes an upper pipe that sprays or drips coolant onto the motor stator and the generator stator. The upper pipe is cylindrical and has a bottom, with injection holes formed on the outer circumferential surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-54108 Summary of the Invention [Problem to be solved by the invention]

[0004] In the upper pipe disclosed in Patent Document 1, the coolant passes from the opening through an internal flow path, and from the flow path through an injection hole before being sprayed to the outside, but there is a risk of pressure loss occurring when passing from the internal flow path through the injection hole.

[0005] An object of the present invention is to provide a discharge pipe that reduces pressure loss of discharge liquid passing through the inside. [Means for solving the problem]

[0006] To solve the above problems, one aspect of the present invention is a longitudinal discharge pipe comprising an inlet opening formed at one end, a cylindrical, longitudinally extending inner circumferential surface constituting a main flow path, and a discharge flow path formed radially outward from the inner circumferential surface. The discharge flow path has a first opening formed in the inner circumferential surface and a discharge opening formed in the outer circumferential surface of the discharge pipe. The opening area of ​​the first opening is larger than the opening area of ​​the discharge opening. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a discharge pipe that reduces pressure loss of the discharge liquid passing through the inside. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view of a discharge pipe according to an embodiment. [Figure 2] FIG. 2(a) is a front view of the discharge pipe of the embodiment, and FIG. 2(b) is a bottom view of the discharge pipe of the embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the discharge pipe taken along line AA in FIG. 2(a). [Figure 4] 2(b) is a cross-sectional view of the discharge pipe taken along line BB. FIG. [Figure 5] FIG. 4 is an enlarged cross-sectional view of the discharge pipe shown in FIG. 3. [Figure 6] FIG. 10 is a cross-sectional view of the discharge pipe at a position where the discharge pipe passes through the second discharge hole along the radial direction. DETAILED DESCRIPTION OF THE INVENTION

[0009] Fig. 1 is a perspective view of a discharge pipe 10 of the embodiment. Fig. 2(a) is a front view of the discharge pipe 10 of the embodiment, and Fig. 2(b) is a bottom view of the discharge pipe 10 of the embodiment. The discharge pipe 10 is provided in a cooling path that circulates a coolant, and discharges the coolant to a drive unit of a vehicle.

[0010] The discharge pipe 10 has an inlet opening 12, a bottom 14, an inner circumferential surface 16, an attachment portion 18, and a discharge flow path 20. The discharge pipe 10 is formed in a longitudinal and cylindrical shape. The attachment portion 18 attaches the discharge pipe 10 to a mounting member on the vehicle body side. The direction along the central axis of the discharge pipe 10 is referred to as the longitudinal direction.

[0011] The inlet opening 12 is formed at one end of the discharge pipe 10. The bottom portion 14 is formed at the other end of the discharge pipe 10. The thickness of the bottom portion 14 can be adjusted by the first discharge hole 20a.

[0012] The inner circumferential surface 16 is formed from the inlet opening 12 to the bottom 14, is cylindrical, and extends in the longitudinal direction, constituting a main flow path. The discharge flow path 20 has a first discharge hole 20a, a second discharge hole 20b, a third discharge hole 20c, and a recess 22. The first discharge hole 20a, the second discharge hole 20b, and the third discharge hole 20c (when not distinguished, they will be referred to as "each discharge hole") open radially outward and are located below the discharge pipe 10.

[0013] As shown in FIG. 2(b), the first discharge hole 20a, the second discharge hole 20b, and the third discharge hole 20c are formed in pairs, spaced apart in the longitudinal direction. The number and arrangement of these discharge holes may be determined depending on the structure of the object to be cooled. The recesses 22 are formed so as to recess the inner circumferential surface 16, and are formed in pairs with the same shape. When viewed in the axial direction as shown in FIG. 2(a), the recesses 22 are rectangular, and the axial cross section of the recesses 22 is also rectangular.

[0014] Of the first outlet hole 20a, the second outlet hole 20b, and the third outlet hole 20c, the second outlet hole 20b has the largest diameter. This allows the second outlet hole 20b, which is located in the center, to have the largest discharge rate. The diameter of each outlet hole may be set depending on which part of the device to be cooled.

[0015] Figure 3 is a cross-sectional view of the discharge pipe 10 taken along line AA in Figure 2(a). The recess 22 extends longitudinally from the inlet opening 12 toward the bottom 14 and is formed in a groove shape. The recess 22 increases the cross-sectional area of ​​the inner circumferential surface 16 without changing the outer diameter of the discharge pipe 10. Each discharge hole is formed in communication with the recess 22, thereby shortening the length of each discharge hole. By increasing the cross-sectional area of ​​the inner circumferential surface 16 and shortening the length of each discharge hole, it is possible to reduce pressure loss in the discharged liquid.

[0016] A plurality of discharge holes are formed at intervals in the longitudinal direction on the recess 22. This allows the discharge holes located on the recess 22 to be short, thereby suppressing pressure loss of the discharged liquid.

[0017] A plurality of recesses 22 are formed parallel to the inner circumferential surface 16. By forming a plurality of recesses 22, the cross-sectional area of ​​the inner circumferential surface 16 increases. A plurality of discharge holes are formed in each of the plurality of recesses 22. In FIG. 3, a first discharge hole 20a, a second discharge hole 20b, and a third discharge hole 20c are formed in each of a pair of recesses 22. This allows a plurality of discharge holes that discharge in different directions to be arranged on the recesses 22.

[0018] Figure 4 is a cross-sectional view of the discharge pipe 10 taken along line BB shown in Figure 2(b) A pair of first discharge holes 20a are formed radially and open in different directions.

[0019] The discharge flow path 20 is formed to penetrate radially from the first opening 32 to the discharge opening 28. The first opening 32 is formed in the inner circumferential surface 16. The discharge opening 28 is formed in the outer circumferential surface of the discharge pipe 10. The first discharge hole 20a has a second opening 30 between the first opening 32 and the discharge opening 28. The first opening 32, the second opening 30, and the discharge opening 28 are positioned overlapping in the radial direction. The second opening 30 and the discharge opening 28 may be coaxial and have the same opening area. The second discharge hole 20b and the third discharge hole 20c also have a second opening 30 and a discharge opening 28, respectively.

[0020] Here, the molding of the discharge pipe 10 will be described. To form the discharge pipe 10, a mold that forms the surface of the discharge pipe 10, a core pin that forms the inner peripheral surface 16, and slide pins that form each discharge hole are used. The core pin has a protrusion that forms the recess 22. The core pin is placed inside the mold, and with the protrusion of the slide pin abutting against the inner surface of the mold, a resin material is injected into the mold to form the discharge pipe 10. The discharge pipe 10 is removed from the mold, and the core pin and slide pin are removed, completing the molding of the discharge pipe 10.

[0021] The core pin has a protrusion, which improves its rigidity and stabilizes its position. The slide pin can support the core pin when the resin material is poured into the mold. The core pin has a flat protrusion, which makes it easier to bring the flat end face of the slide pin into contact with the protrusion. The core pin is less likely to bend even when the slide pin is pressed against it because its rigidity has been improved by the protrusion.

[0022] The first discharge hole 20a, located at the deepest part of the recess 22, is connected to a curved surface extending from the recess 22 to the bottom 14. In the inner circumferential surface 16, the side facing the inlet opening 12 is referred to as the front, and the side facing the bottom 14 is referred to as the back. This structure will be explained with reference to new drawings.

[0023] Figure 5 is an enlarged cross-sectional view of the discharge pipe 10 shown in Figure 3. A rounded surface 14a is formed on the lower part of the bottom portion 14. The rounded surface 14a is smoothly curved toward the boundary edge 26 of the recess 22. The recess 22 has a curved surface 22a that is smoothly curved from the boundary edge 26 to the circumferential edge 24 of the first discharge hole 20a.

[0024] The curved surface 22a is located at the innermost end 22b of the recess 22 on the bottom 14 side, and is curved with rounded corners. The curved surface 22a is formed in an arc shape along the circumferential edge 24 of the first discharge hole 20a. The first discharge hole 20a is disposed at the innermost end 22b of the recess 22, with part of the circumferential edge 24 continuing to the curved surface 22a. As a result, the innermost first discharge hole 20a is connected to the curved surface 22a, thereby reducing pressure loss of the discharged liquid.

[0025] Pressure drops may occur at the back of the discharge pipe 10, which may make it difficult for the discharge liquid to come out of the first discharge hole 20a located at the very back. Furthermore, increasing the diameter of the first discharge hole 20a increases the discharge rate when no pressure drop occurs. By suppressing the pressure loss at the deepest first discharge hole 20a, the effects of pressure drop can be reduced, allowing the first discharge hole 20a to discharge a constant rate of discharge liquid.

[0026] 3, the width of the recess 22 is set to match the largest diameter of the second discharge hole 20b among the diameters of the first discharge hole 20a, the second discharge hole 20b, and the third discharge hole 20c. The second discharge hole 20b is formed to fill the width of the recess 22. By matching the width of the recess 22 to the second discharge hole 20b, which has the largest diameter, it is possible to ensure a contact surface for the slide pin during molding, while preventing the width of the recess 22 from becoming too large and reducing the rigidity of the discharge pipe 10.

[0027] As shown in FIG. 5, the width of the recess 22 narrows toward the innermost end 22b, and is matched to the diameter of the first discharge hole 20a.

[0028] 6 is a cross-sectional view of the discharge pipe 10 at a position radially passing through the second discharge hole 20b. The first opening 32 is defined by the edge of the recess 22 on the inner circumferential surface 16 and is formed on the inner circumferential surface 16. The discharge flow path 20 penetrates radially from the first opening 32 to the discharge opening 28.

[0029] The recess 22 has a step 22c located between the first opening 32 and the discharge opening 28. The step 22c is located on the bottom surface of the recess 22. The step 22c forms the second opening 30 by the inner peripheral edge of the step 22c. The recess 22 is formed so as to recess the inner peripheral surface 16 from the first opening 32 to the step 22c. This reduces pressure loss when the discharge liquid passes through the discharge flow path 20 by passing through the recess 22, which has a larger opening than the second discharge hole 20b. The second opening 30 and the discharge opening 28 are arranged coaxially. The opening areas of the second opening 30 and the discharge opening 28 are the same, but may be different.

[0030] The opening area of ​​the first opening 32 is larger than the opening area of ​​the discharge opening 28. This makes it possible to reduce pressure loss of the discharged liquid compared to when a uniform cylindrical discharge flow path is formed that extends directly from the inner circumferential surface 16.

[0031] The opening area of ​​the first opening 32 is larger than the opening area of ​​the second opening 30. The recess 22 serves as a guide for the discharged liquid to flow to the second opening 30, and is less susceptible to the influence of vortices that are generated when the discharged liquid flows to the second opening 30. Therefore, it is possible to suppress pressure loss.

[0032] The present invention is not limited to the above-described embodiments, and various modifications such as design changes may be made to the embodiments based on the knowledge of those skilled in the art, and such modified embodiments may also be included within the scope of the present invention.

[0033] In the embodiment, the recess 22 is formed in a groove shape, but this is not limiting. For example, the recess 22 may be a cylindrical shape recessed from the inner circumferential surface 16. In this embodiment, the recess 22 is formed coaxially with the first discharge hole 20a, the second discharge hole 20b, and the third discharge hole 20c. In this modification, the opening area of ​​the first opening 32 is also formed to be larger than the opening area of ​​the discharge opening 28. [Explanation of symbols]

[0034] 10 discharge pipe, 12 inlet opening, 14 bottom, 14a curved surface, 16 inner peripheral surface, 18 mounting portion, 20 discharge flow path, 20a first discharge hole, 20b second discharge hole, 20c third discharge hole, 22 recess, 22a curved surface, 22c stepped portion, 24 peripheral edge, 26 boundary edge, 28 discharge opening, 30 second opening, 32 first opening.

Claims

1. A longitudinal discharge pipe, an inlet opening formed at one end; a cylindrical inner circumferential surface extending in a longitudinal direction and constituting a main flow path; a discharge flow path formed radially outward from the inner circumferential surface, The discharge flow path is a first opening formed in the inner circumferential surface; a discharge opening formed on the outer peripheral surface of the discharge pipe, The discharge pipe is characterized in that the opening area of ​​the first opening is larger than the opening area of ​​the discharge opening.

2. The discharge flow path is a step portion located between the first opening and the discharge opening; a second opening formed by the step portion, 2. The discharge pipe according to claim 1, wherein an opening area of ​​the first opening is larger than an opening area of ​​the second opening.

3. 3. The discharge pipe according to claim 2, wherein the discharge flow path has a recess formed so as to recess the inner circumferential surface from the first opening to the stepped portion.

4. Further, a bottom portion is formed on the other end side.

4. The discharge pipe of claim 3, wherein the recess extends longitudinally from the inlet opening toward the bottom.

5. 5. The discharge pipe according to claim 4, wherein the width of the recess is set to the largest diameter among the diameters of the plurality of discharge openings.

6. The recess has a curved surface that is rounded at a deep end portion on the bottom side, the discharge flow path is disposed at the inner end portion with a part of its periphery continuing to the curved surface, The discharge pipe according to claim 4 , wherein the curved surface is formed in an arc shape along the outer periphery of the second opening.

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