Flow resistance setting tool

Abstract

The flow resistance setting tool of the present application is provided with a main body, a pipe, a press contact plate, and a screw. The main body has a groove whose bottom portion is flat, and pipe through holes formed at both sides of the groove near the bottom portion. The pipe is inserted into the pipe through holes in such a way as to pass above the bottom portion of the groove. The press contact plate is configured to sandwich the pipe by the bottom portion of the groove. Furthermore, the pipe side surface of the press contact plate is a convex curved surface whose interval from the bottom portion of the groove varies in the length direction of the pipe. The screw adjusts the interval between the bottom portion of the groove and the press contact plate.

Description

Technical Field

[0001] This invention relates to a flow resistance setting tool used to verify the accuracy of a leak tester. Background Technology

[0002] For workpieces installed on a leak tester (objects for verifying airtightness), a small leak test is conducted to ensure the specified airtightness. In this test, the workpiece is brought to test pressure at atmospheric pressure, and the pressure change within the workpiece is measured to confirm whether the leakage rate per unit time meets the specified value. Alternatively, the workpiece, with its internal pressure at atmospheric pressure, is placed in a sealed container, and the pressure inside the container is set to test pressure. The pressure change within the sealed container is measured to confirm whether the leakage rate per unit time meets the specified value.

[0003] To ensure the accuracy of the calculated leakage per unit time, a flow resistance setting tool is used.

[0004] As a flow resistance setting tool, technologies shown in Patent Documents 1-3 are known. Furthermore, flow resistance setting tools are sometimes also referred to as flow resistance setting nozzles, leak master units, or masternozzles. As a leak tester, technologies shown in Patent Documents 4 and 5 are known, for example.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2004-084944

[0008] Patent Document 2: Japanese Patent Application Publication No. 2013-170653

[0009] Patent Document 3: Japanese Patent Application Publication No. 2021-032286

[0010] Patent Document 4: International Publication No. 2014 / 184895

[0011] Patent Document 5: Japanese Patent Application Publication No. 2025-001810 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] If P1 is set as the test pressure, and V is set as the test pressure... e Let Q be the equivalent internal volume (the volume of space where the gas at the test pressure may exist), Q be the leakage amount per unit time, ΔP be the change in test pressure after t seconds, P0 be atmospheric pressure, and the temperature be constant. Then the following formula holds true.

[0014]

[0015] If we transform the equation to calculate the leakage rate Q per unit time, then we have:

[0016]

[0017] To accurately determine the leakage amount Q, it is necessary not only to accurately calculate the pressure change ΔP, but also the equivalent internal volume V. e This is also important. If the type of workpiece changes, the equivalent internal volume V... e Changes have occurred. However, the conventional flow resistance setting tools shown in Patent Documents 1-3 are mounted on the leak tester instead of the workpiece. Therefore, in conventional flow resistance setting tools, there is a problem that the equivalent internal volume V, which depends on the type of workpiece, cannot be confirmed or adjusted. e Regarding the accuracy of leakage measurement, a brief explanation is needed. Even for workpieces of the same type, slight differences in volume can occur due to manufacturing errors. However, volume differences caused by errors between workpieces of the same type do not pose a problem for the accuracy of leakage measurement. However, if the workpieces are of different types, there will be inherent differences in their designed volume, thus becoming a problem for the accuracy of leakage measurement.

[0018] To consider the equivalent internal volume V of each type of workpiece e This paper considers a method for preparing workpieces with leakage amounts close to specified values ​​for each type of workpiece. It is easy to obtain a leak-free workpiece (normal workpiece) that fully meets the specified value, regardless of the type of workpiece. However, it is difficult to specifically manufacture workpieces with small leakage amounts (slightly leaking workpieces) that have approximately the specified value. The present invention was made in view of this situation, and its object is to provide a small flow resistance setting tool that can be mounted on a workpiece.

[0019] Methods for solving problems

[0020] The flow resistance setting tool of the present invention comprises a body, a pipe, a crimping plate, and a screw. The body has a groove with a flat bottom portion and pipe through holes formed on two opposing sides near the bottom portion of the groove. The pipe is inserted into the pipe through holes by passing through the top of the bottom portion of the groove.

[0021] The crimping plate is configured to clamp the pipe by the bottom portion of the groove. Furthermore, the pipe-side surface of the crimping plate is a convex curved surface whose spacing from the bottom portion of the groove varies along the length of the pipe. Screws are used to adjust the spacing between the bottom portion of the groove and the crimping plate.

[0022] Invention Effects

[0023] The flow resistance setting tool according to the present invention, since it is configured to clamp the pipe by the bottom portion of the groove and the convex curved surface of the pressing plate, can be miniaturized. Because it is a small flow resistance setting tool, it can also be mounted on a workpiece. Attached Figure Description

[0024] Figure 1 This is the main view of the flow resistance setting tool.

[0025] Figure 2 This is a top view of the main body.

[0026] Figure 3 It is a cross-sectional view of the main body at line AA.

[0027] Figure 4 This is a side view of the main body observed from direction B.

[0028] Figure 5 These are the three views of the pressure plate.

[0029] Figure 6 This is the front view of the sealing component clamping part. Detailed Implementation

[0030] Hereinafter, embodiments of the present invention will be described in detail. Furthermore, structural parts with the same function will be given the same reference numerals, and repeated descriptions will be omitted.

[0031] [Example]

[0032] Figure 1 This is a front view of the flow resistance setting tool of the present invention. Figure 2 This is a top view of the main body. Figure 3 This is a sectional view of the main body at line AA. Figure 4 This is a side view of the subject taken from direction B. Figure 5 Three views of the pressure plate. Figure 6 This is a front view of the sealing component clamping element. The flow resistance setting tool 10 includes a body 100, a pipe 200, a clamping plate 300, and screws 400.

[0033] The main body 100 has a groove 110 with a flat bottom portion 111, and through holes 120 formed on two opposing sides 112 near the bottom portion 111 of the groove 110. The main body 100 can be a cylindrical metal with the through hole 120 as its length direction. For example, it can be made of stainless steel. Furthermore, the groove 110 can be formed by cutting. The outer diameter of the main body 100 can be about 7 mm, and the length can be about 20 mm.

[0034] The pipe 200 is inserted into the pipe through hole 120 by passing above the bottom portion 111 of the groove 110. The pipe 200 and the main body 100 can be made of the same material. For example, the pipe 200 can be made of stainless steel with an outer diameter of 0.4~0.8mm, an inner diameter of 0.2~0.4mm, and a length of about 10mm. The pipe through hole 120 can be inserted into the pipe 200, and only needs to be of a small diameter.

[0035] The flow resistance setting tool 10 may also include a sealing member 500 that blocks the gap between the pipe through hole 120 and the pipe 200, and a sealing member clamping member 600 that fixes the sealing member 500. The sealing member 500 may, for example, use an O-ring. The sealing member clamping member 600 may also have a step 610 for mounting the sealing member 500. Furthermore, the main body 100 also has a sealing member hole 140 for receiving the sealing member 500 and the sealing member clamping member 600. External threads may be formed on the outer surface of the sealing member clamping member 600, and internal threads may be formed on the inner surface of the sealing member hole 140.

[0036] The main body 100 may also have a mounting hole 150 at one end along its length. An internal thread may be formed on the inner surface of the mounting hole 150. A measuring joint is mounted on the mounting hole 150, for example, when the flow resistance setting tool 10 is used for flow measurement.

[0037] The crimping plate 300 is configured to clamp the pipe 200 by the bottom portion 111 of the groove 110.

[0038] Furthermore, the pipe-side surface 310 of the crimp plate 300 is a convex curved surface whose spacing from the bottom portion of the groove varies along the length of the pipe. The crimp plate 300 has two holes 320 for screws. The body 100 has two screw holes 130 in the bottom portion 111 of the groove 110 opposite to the holes 320. Screws 400 adjust the spacing between the bottom portion 111 of the groove 110 and the crimp plate 300. There may also be two screws 400. M2 screws can be used for the screws 400. Figure 1 The image shows an example of a flat-head screw with a cross-shaped hole.

[0039] In the flow resistance setting tool 10, a screw 400 is used to flatten the pipe 200 to achieve a leakage rate close to a specified value. Since the leakage rate is set to be very small, the pipe 200 needs to be flattened to the point of almost no gaps. On the other hand, if a small screw is used for the screw 400 in order to miniaturize the flow resistance setting tool 10, it would be difficult to apply the force required to flatten the pipe 200. According to the flow resistance setting tool 10, the pipe 200 is clamped by the bottom portion 111 of the groove 110 and the convex curved surface of the crimping plate 300, thus reducing the area where stress is applied, and even with a small screw, the force required to flatten the pipe 200 can be applied.

[0040] Furthermore, since the groove 110 forming the main body 100 can be formed by cutting, it can be machined even when the main body 100 is reduced in size. Therefore, the flow resistance setting tool 10 can be miniaturized. Since the flow resistance setting tool 10 can be miniaturized, it can also be mounted on a workpiece. If the flow resistance setting tool 10 is mounted on a normal workpiece, it can be made into a workpiece with a leakage amount close to the specified value. Moreover, if the leakage amount is checked and adjusted using a workpiece with the flow resistance setting tool 10 mounted, the equivalent internal volume V can be the same as when a workpiece with known leakage is mounted. e Confirm and adjust.

[0041] Explanation of reference numerals in the attached figures

[0042] 10 Flow resistance setting tool; 100 Body; 110 Groove; 111 Bottom section; 112 Side; 120 Pipe through hole; 130 Screw hole; 140 Sealing component hole; 150 Mounting hole; 200 Pipe; 300 Crimping plate; 310 Surface; 320 Hole; 400 Screw; 500 Sealing component; 600 Sealing component clamping part; 610 Step.

Claims

1. A flow resistance setting tool, characterized in that, have: The main body has a groove with a flat bottom portion and through holes formed on two opposite sides near the bottom portion of the groove. The pipe is inserted into the through hole of the pipe through the bottom portion of the groove; A crimping plate configured to clamp the pipe with the bottom portion of the groove; Screws are used to adjust the gap between the bottom portion of the groove and the pressure plate; The surface of the pressure plate on the pipe side is a convex curved surface whose interval with the bottom portion of the groove varies along the length of the pipe.

2. The flow resistance setting tool as described in claim 1, characterized in that, There are two screws. The pressure plate has two holes for the screws to pass through. The main body has two screw holes at the bottom portion of the groove opposite to the hole.

3. The flow resistance setting tool as described in claim 1 or 2, characterized in that, The main body is a cylindrical metal with the length direction of the pipe through hole as the reference direction. The groove is formed by cutting.

4. The flow resistance setting tool as described in any one of claims 1 to 3, characterized in that, It also has: A sealing component that blocks the gap between the pipe through hole and the pipe; A sealing component clamping element is used to fix the sealing component; The main body also has a sealing component hole for receiving the sealing component and the sealing component clamping member.

5. The flow resistance setting tool as described in claim 3, characterized in that, The main body also has a mounting hole at one end in the length direction.

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