Seal ring defect detection structure

Abstract

To provide a structure for reliably detecting a defect of a seal ring to be attached to a water supply cap of a radiator.SOLUTION: At least one gap 7 is formed between a seal ring 6 and a plug 4 in a state where the seal ring 6 has a defect. The inside and the outside of a tank 1 are in communication via the at least one gap.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a plug that is detachably attached to a tank of a heat exchanger used in a radiator or the like, and to a structure for detecting damage to a seal ring attached to the outer periphery of the shaft of the plug. [Background technology]

[0002] FIG. 4 shows a conventional heat exchanger used as a radiator, in which (A) is an exploded view of the main parts of the tank 1a and the plug 4a, (B) is a front view showing the plug 4a attached to the filler neck 10a of the tank 1a, and (C) is a bottom view of the plug 4a. The heat exchanger, which serves as a radiator for cooling engine coolant, has a filler neck 10a protruding from the upper end of a tank 1a, a communication hole (not shown) formed in the filler neck 10a, and a seating surface 3a formed on the edge of the communication hole. A plug 4a is detachably screwed into the communication hole. The plug 4a has a flange-shaped surface 8a formed on the lower side of a head 5a, and a shaft portion consisting of a male screw is provided below the head 5a. Furthermore, an annular groove is formed on the outer periphery of the lower end of the shaft portion, and a seal ring 6a is attached thereto. Then, the plug 4a is screwed into the communication hole of the filler neck 10a of the tank 1a, and the lower surface 8a of the head 5a is brought into contact with the seating surface 3a of the filler neck 10a. Summary of the Invention [Problem to be solved by the invention]

[0003] The above-mentioned radiator plug 4a may sometimes be attached to the tank 1a in a state where the seal ring that should be fitted in the annular groove is not fitted thereto (hereinafter, referred to as a state where the seal ring is missing). In this case, when a gas such as He is poured into the tank 1a and a seal leak inspection is performed, if the lower surface 8a of the head 5a of the plug 4a and the seating surface 3a of the filler neck 10a are in close contact with each other, the leak may not be detected. In other words, in such a situation, it is difficult to detect the defective state of the seal ring in the heat exchanger inspection process. If the seal ring, which ensures the original sealing function, becomes missing and then the adhesion of the contact surface decreases due to a change in external force (thermal effects, etc.), a problem will occur in which the cooling water inside the tank leaks from the plug.

[0004] Therefore, an object of the present invention is to provide a structure that can reliably detect the defect in the seal ring in an inspection process even if the defect is in the above-mentioned state. [Means for solving the problem]

[0005] The present invention described in claim 1 is a heat exchanger in which a seating surface 3 is formed on the hole edge of a communication hole 2 of a tank 1 of the heat exchanger, a head 5 of a plug 4 inserted into the communication hole 2 abuts against the seating surface 3, and a seal ring 6 is interposed between the communication hole 2 and the plug 4, This is a structure for detecting a loss of a seal ring in a heat exchanger, in which, when a plug 4 is inserted into a communication hole 2 and the seal ring 6 is missing, at least one gap 7 communicating between the inside and outside of the tank 1 is formed between the communication hole 2 and the plug 4.

[0006] The present invention as set forth in claim 2 provides a structure for detecting a seal ring defect in a heat exchanger as set forth in claim 1, The gap 7 is a detection structure for detecting defects in a seal ring of a heat exchanger, which is formed by a groove 9 continuing from the outer peripheral edge of the contact surface 8 of the head 5 of the plug 4 to the communication hole 2.

[0007] The present invention as set forth in claim 3 provides a structure for detecting a seal ring defect in a heat exchanger as set forth in claim 2, This is a structure for detecting defects in a seal ring of a heat exchanger, in which the cross-sectional area of ​​the groove 9 is narrower toward the center of the head 5 than at the outer periphery. Effect of the Invention

[0008] In the invention described in claim 1, when the sealing ring 6 is missing, at least one gap 7 that communicates between the inside and outside of the tank 1 is formed between the communication hole 2 and the plug 4. Therefore, when the inside of the tank 1 is pressurized, fluid flows out from the gap 7, and the damage to the seal ring 6 can be reliably detected.

[0009] In the invention described in claim 2, in the above configuration, the gap 7 is formed as a groove 9 continuing from the outer periphery of the contact surface 8 of the head 5 of the plug 4 to the through hole 2. Therefore, even if the head 5 of the plug 4 and the seating surface 3 of the communication hole 2 are in a pressed contact state, the inside and outside of the tank 1 are communicated through the groove 9, and any damage to the seal ring 6 can be reliably detected.

[0010] According to a third aspect of the present invention, in the above-mentioned configuration, the cross-sectional area of ​​the groove 9 is narrower toward the center of the head 5 than at the outer circumferential edge. This makes it possible to increase the flow resistance of the groove 9 toward the center, thereby preventing excessive outflow of fluid from the tank 1 to the outside when the seal ring 6 is damaged. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 shows a plug 4 used in a heat exchanger of the present invention, in which (A) is a front view, (B) is an enlarged view of part B in (A), (C) is a bottom view of the same, (D) is an enlarged view of part D in (C), and (E) is a cross-sectional view taken along the line EE in (A). [Diagram 2] 1A is a front view showing the state in which the plug 4 is seated in the communication hole of the filler neck 10 of the tank 1, FIG. 1B is an enlarged view of part B in FIG. 1A, and FIG. 1C is a cross-sectional view taken along line CC in FIG. [Diagram 3] 1A is a bottom view showing the release path of gas 16, and FIG. 1B is a longitudinal sectional view showing the same embodiment. [Figure 4] 1A is an exploded view of the essential parts of a conventional plug 4, (B) is a front view of the essential parts showing the plug 4 in a seated state, and (C) is a bottom view of the plug 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a plug 4 used in the detection structure of the present invention, where (A) is a front view, (B) is an enlarged view of part B in FIG. 1(A), (C) is a bottom view, (D) is an enlarged view of part D in FIG. 1(C), and (E) is a cross-sectional view taken along the line EE in FIG. 1(A). Fig. 2 shows the fitted state of the plug 4 used in the detection structure and the filler neck 10 of the tank 1, Fig. 2(A) is a front view of the main part, Fig. 2(B) is an enlarged view of part B in Fig. 2(A), and Fig. 2(C) is a cross-sectional view taken along the line CC in Fig. 2(A). Fig. 3 is an explanatory diagram showing the operation of the present invention, Fig. 3(A) is a bottom view, and Fig. 3(B) is a cross-sectional view.

[0013] The present invention relates to a structure for detecting a defect in a plug that is detachably attached to a tank of a heat exchanger, specifically, a seal ring 6 of a plug having a seal ring attached to the outer periphery of its shaft. As shown in Fig. 2 as an example, the plug 4 is attached to a filler neck 10 formed in a tank 1 at the top of the heat exchanger. A communication hole 2 that communicates between the inside and outside of the tank 1 is formed in the filler neck 10 so that the plug 4 can be fitted in. A seating surface 3 is formed on the edge of the communication hole 2. In this example, an internal thread is formed on the inner peripheral surface of the communication hole 2. The tank 1 is, for example, a box-shaped tank body with one end open, and a header plate that closes the opening of the tank body, which are fitted together. The communication hole 2 is formed in the bottom or side of the tank body. The plug 4 has a head 5 and a shaft portion, and an annular groove 15 is formed on the outer periphery of the end of the shaft portion of the plug, and normally a seal ring 6 is attached to the annular groove 15 .

[0014] In this example, an external thread 13 is formed on the outer periphery of the shaft portion, and this external thread is screwed into the internal thread of the communication hole 2, and the plug 4 is removably fitted into the tank communication hole 2. When the plug 4 is fitted into the tank communication hole 2, the head 5 of the plug 4 abuts against the seating surface 3 of the tank communication hole 2. Then, when the seal ring 6 is fitted into the annular groove 15 as described above, the gap between the inner surface of the tank communication hole 2 and the outer periphery of the shaft portion of the plug 4 is blocked by the seal ring 6. In this state, as shown in FIG. 2, the cooling water and steam in the tank 1 are not released to the outside.

[0015] In this embodiment, a structure is shown that can reliably detect the missing state of the seal ring 6 in an inspection process when the seal ring 6 is missing due to forgetting to attach the seal ring 6, etc. In this structure, at least one gap 7 that communicates between the inside and outside of the tank 1 is formed. On the inside side of the tank of the communication hole 2, when the seal ring 6 is missing from the annular groove 15 of the plug 4, a gap 7 is formed between the inner surface of the communication hole 2 and the peripheral portion of the annular groove 15 of the shaft portion of the plug 4. At the middle of the communication hole 2, a small gap 7 is formed between the external threads 13 of the shaft portion of the plug 4 and the internal threads of the communication hole 2 which are screwed thereto. 1, on the seating surface 3 side of the communication hole 2, the lower surface 8 of the head 5 of the plug 4 is recessed toward the top side of the head 5, forming a groove 9 that continues from the outer periphery of the head 5 to the communication hole 2, and a gap 7 is formed between the seating surface 3 of the communication hole 2 and the groove 9 of the plug 4. The inside and outside of the tank 1 communicate with each other via this groove 9. By providing the groove 9 in the plug 4, the gap 7 on the seating surface 3 side of the communication hole 2 can be formed by simply changing the shape of the plug 4 without changing the shape of the tank 1.

[0016] Due to the structure of the gap 7 formed as described above, when pressurized gas for inspection such as He is supplied into the tank 1, the gas 16 flows through the gaps 7 at various locations, such as the outer periphery of the plug 4 and the inner periphery of the communication hole 2 of the tank 1, and is released to the outside, as shown in Figure 3. By detecting the gas 16, it is possible to detect a missing state of the seal ring 6 in the annular groove 15 of the plug 4.

[0017] As shown in FIG. 1(B), the groove 9 formed in the plug 4 is preferably shaped like a taper 14 whose cross-sectional area is narrower toward the center of the head 5 than at the outer periphery. In this example, the shape of the taper 14 of the groove 9 is such that the arc length becomes shorter toward the center of the head 5, as shown in Fig. 1(D), and the recess depth of the groove 9 becomes shallower toward the center of the head 5, as shown in Fig. 1(E). By forming the groove 9 with the taper 14 in this manner, the flow resistance of the groove 9 can be made greater toward the center, thereby preventing excessive outflow of fluid from the tank 1 to the outside when the seal ring 6 is damaged. The shape of the taper 14 described above is preferably the shape of FIG. 1(B) which has the features of both FIG. 1(D) and FIG. 1(E), but it may be possible to adopt the features of either FIG. 1(D) or FIG. 1(E) alone.

[0018] (Modification) In the above embodiment, a defect in the seal ring 6 of the upper tank of the radiator is detected, but the present invention is not limited to this, and the same means can be used to detect the defect in the plug 4 of the lower tank. Furthermore, although the present invention has been described with reference to a tank for cooling engine coolant as a heat exchanger, the present invention can also be applied to tanks of various other heat exchangers. In this example, one groove 9 is provided on the surface 8 of the head 5 of the plug 4, but two or more grooves 9 may be provided. Furthermore, the position of the groove 9 may be anywhere between the annular groove 15 of the seal ring 6 and the head 5 of the plug 4. As in the above embodiment, it is optimal to provide the groove 9 on the lower surface 8 of the head 5 of the plug 4. However, this is not limited to this embodiment, and the groove 9 may be provided on the seating surface 3 of the communication hole 2 of the tank. The groove 9 may also be provided on both the lower surface 8 of the head 5 of the plug 4 and the seating surface 3 of the communication hole 2. In the above embodiment, a screw-on structure is adopted as the optimal structure for the plug 4 to be removably inserted into the tank communication hole 2, but the insertion structure is not limited to this and any known structure can be adopted as appropriate. [Industrial Applicability]

[0019] The present invention can be used as a detection structure for detecting damage to a water supply cap, an air vent plug, a drain cock, or other plug attached to a tank for a heat exchanger such as an engine coolant radiator, particularly a plug having a seal ring attached to the shaft portion of the plug. [Explanation of symbols]

[0020] 1 Tank 2 Communication hole 3. Seating surface 4. Stopper 5 head 6 Seal ring 7. Gap 8 sides 9 grooves 10 Filler Neck 13 External thread 14 Taper 15 Annular groove 16 Gas

Claims

[Claim 1] A heat exchanger in which a seating surface (3) is formed on the edge of a communication hole (2) in a tank (1) of the heat exchanger, a head (5) of a plug (4) inserted into the communication hole (2) is brought into contact with the seating surface (3), and a seal ring (6) is interposed between the communication hole (2) and the plug (4), With a plug (4) fitted into the communication hole (2) and with the seal ring (6) missing, at least one gap (7) communicating between the inside and outside of the tank (1) is formed between the communication hole (2) and the plug (4); The gap (7) is formed on the contact surface (8) of the head (5) of the plug (4) by a groove (9) that continues from the outer periphery to the communication hole (2); A structure for detecting defects in a seal ring of a heat exchanger, in which the cross-sectional area of ​​a groove (9) is narrower toward the center of the head (5) than at the outer periphery.

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