Pressure balance pressure testing tool for end face sealing of workpiece

Abstract

The application discloses a pressure balance pressure testing tool for workpiece end face sealing, which comprises a cylinder, a piston is slidably arranged in the cylinder, the piston can abut against a pressure testing interface of a pressure testing workpiece to press and seal the pressure testing interface, a balance cavity is formed between the piston and the inner wall of the cylinder, a first pressure injection channel is arranged on the cylinder and is communicated with the balance cavity, a second pressure injection channel is arranged on the piston and is communicated with the inside of the pressure testing workpiece, and the area of the piston in contact with the pressure medium in the balance cavity in the direction perpendicular to the axis is greater than the area of the piston in contact with the pressure medium at the pressure testing interface in the direction perpendicular to the axis. The inside pressure of the pressure testing workpiece is utilized for sealing, so that the sealing structure of the pressure testing workpiece is still reliable under high pressure without additional force, the sealing performance is improved, and the stress area of the whole sealing structure is mainly concentrated on the end face of the pressure testing interface, and the overall structure of the pressure testing workpiece is hardly affected by external force.

Description

Technical Field

[0001] This invention relates to the field of pressure testing technology, and more specifically to a pressure balancing pressure testing fixture for sealing the end face of a workpiece. Background Technology

[0002] Pressure testing is the most effective means of re-inspecting raw materials and checking the manufacturing quality of pipe fittings, instruments, valves, and containers. It is also the primary method for testing the pressure-bearing capacity of equipment. During pressure testing, ensuring the sealing reliability and efficiency of the workpiece's end-face sealing interface, as well as the rationality of the overall stress on the workpiece, are crucial.

[0003] Currently, for high-pressure test workpieces with end-face sealing structures in China, there are two main approaches to sealing test fixtures:

[0004] like Figure 3 As shown, the test interface 20 is sealed by pressing the sealing blind plate 70 onto the end face of the flange 30 with bolts 80 or clamps. This method has the disadvantages of high labor intensity, low work efficiency, and the risk of leakage due to uneven clamping force in all directions.

[0005] like Figure 4 As shown, a lower sealing blind plate 130 is installed at the bottom of the pressure-bearing frame 110 and fixed to the pressure-bearing frame 110. An actuator 50 is installed at the upper end of the pressure-bearing frame 110. One end of the actuator 50 is connected to the pressure-bearing frame 110, and the other end is connected to the upper sealing blind plate 120 through a telescopic shaft 60. The space between the upper sealing blind plate 120 and the lower sealing blind plate 130 is the test pressure area. When testing the test workpiece 10, the test workpiece 10 is placed on the lower sealing blind plate 130, and the actuator 50 drives the upper sealing blind plate 120 to press and fix the test workpiece 10. Then, the test workpiece 10 is pressurized with a pressure medium. The problem is that the upper sealing blind plate 120 is forcibly pressed against the end face of the flange 30 to seal the test pressure interface 20. The overall structure of the test workpiece 10 is under stress, which is not suitable for workpieces with low structural strength or slender workpieces. In addition, the overall cost is high due to the presence of a large thrust test pressure fixture.

[0006] Therefore, the applicant proposes a pressure balancing test fixture for sealing the end face of a workpiece, which has good sealing effect, simple structure, convenient operation, easy manufacturing and high efficiency. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a pressure balancing test fixture for sealing the end face of a workpiece.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A pressure balancing test fixture for sealing the end face of a workpiece includes:

[0010] A cylinder, in which a piston is slidably disposed, the piston being able to abut against the test pressure interface of the test workpiece to press and seal the test pressure interface;

[0011] A balance chamber is formed between the piston and the inner wall of the cylinder. A first injection channel communicating with the balance chamber is provided on the cylinder. A second injection channel communicating with the interior of the test workpiece is provided on the piston.

[0012] The area of ​​the piston in contact with the pressure medium located in the balance chamber in the direction perpendicular to the axis is greater than the area of ​​the piston in contact with the pressure medium at the test interface in the direction perpendicular to the axis.

[0013] Furthermore, one end of the cylinder is connected to the positioning support sleeve, the other end of the positioning support sleeve has an opening, and the positioning support sleeve has a positioning cavity communicating with the opening.

[0014] Furthermore, the piston is driven by an actuator to press and seal the test port, and the actuator is mounted on the cylinder via a connecting rod.

[0015] Furthermore, a sealing gasket is installed on the side of the piston near the test port.

[0016] Furthermore, a second seal is provided between the piston and the inner wall of the cylinder.

[0017] Furthermore, the actuator is connected to the piston via a telescopic shaft, which passes through the cylinder and has a first seal between it and the cylinder.

[0018] Furthermore, one side wall of the positioning cavity and the opening penetrates one side of the positioning support sleeve.

[0019] Furthermore, the pressure testing interface is a flange-type interface, which has a flange that can be placed in the positioning cavity.

[0020] Compared with the prior art, the present invention provides a pressure balancing test fixture for sealing the end face of a workpiece, which has the following advantages:

[0021] This invention uses a piston to press and seal the test interface of the workpiece, and then injects a pressure medium into the workpiece through an injection channel. Because the balance chamber is connected to the inside of the workpiece through a second injection channel, the pressure inside the balance chamber is equal to the pressure inside the workpiece, maintaining balance. Since the contact area between the piston and the pressure medium in the balance chamber in the direction perpendicular to the axis is greater than the contact area between the piston and the pressure medium at the test interface in the direction perpendicular to the axis, the side of the piston in contact with the pressure medium in the balance chamber will generate a thrust towards the side of the piston in contact with the pressure medium at the test interface. This causes the end face of the test interface to be subjected to an inward compressive force. As the internal pressure of the workpiece increases, the compressive force on the end face of the test interface will also increase. This ensures that the sealing structure of the workpiece remains reliable under high pressure without additional force, improving sealing performance. Furthermore, the stress area of ​​the entire sealing structure is mainly concentrated on the end face of the test interface, and the overall structure of the workpiece is almost unaffected by external forces. Attached Figure Description

[0022] Figure 1 This is a cross-sectional structural diagram of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the present invention;

[0024] Figure 3 This is a structural schematic diagram of existing technology 1;

[0025] Figure 4 This is a structural schematic diagram of prior art 2.

[0026] The markings in the diagram are: 1. Cylinder; 11. Balance chamber; 2. Positioning support sleeve; 21. Positioning chamber; 22. Opening; 3. Piston; 4. First seal; 5. Second seal; 6. Connecting rod; 7. First injection channel; 8. Second injection channel; 9. Screw; 10. Test workpiece; 20. Test interface; 30. Flange; 40. Sealing gasket; 50. Actuator; 60. Telescopic shaft; 70. Sealing blind plate; 80. Bolt; 90. Washer; 100. Nut; 110. Pressure-bearing frame; 120. Upper sealing blind plate; 130. Lower sealing blind plate. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0028] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] This invention provides a pressure balancing test fixture for sealing the end face of a workpiece, as described in the following embodiment. Figure 1 and Figure 2 The device includes: a cylinder 1, a piston 3 slidably disposed inside the cylinder 1, the outer wall of the piston 3 being cylindrical, the piston 3 being able to abut against the test pressure interface 20 of the test pressure workpiece 10 to press and seal the test pressure interface 20, a balance cavity 11 being formed between the piston 3 and the inner wall of the cylinder 1, a first injection channel 7 communicating with the balance cavity 11 being provided on the cylinder 1, and a second injection channel 8 being provided on the piston 3 connecting the balance cavity 11 with the interior of the test pressure workpiece 10, so that the pressure inside the balance cavity 11 is equal to the pressure inside the test pressure workpiece 10, maintaining balance, and the area of ​​the piston 3 in contact with the pressure medium located in the balance cavity 11 in the direction perpendicular to the axis is greater than the area of ​​the piston 3 in contact with the pressure medium at the test pressure interface 20 in the direction perpendicular to the axis.

[0033] The test workpiece 10 has test interfaces 20 at both ends, and the test interfaces 20 are flange-type interfaces with flanges 30 on them.

[0034] Specifically, the area of ​​the piston 3 in contact with the pressure medium located in the balance chamber 11 in the direction perpendicular to the axis can be calculated by combining the diameter of the piston 3 in the cylinder 1 in the direction perpendicular to the axis with the formula for the area of ​​a circle (wherein, the area affected by the telescopic shaft 60 needs to be subtracted from the area of ​​the telescopic shaft 60 in contact with the piston 3). The area of ​​the piston 3 in contact with the pressure medium at the test port 20 in the direction perpendicular to the axis can be calculated by combining the internal diameter of the test port 20 with the formula for the area of ​​a circle.

[0035] The side of piston 3 in contact with the pressure medium located in the balance chamber 11 will generate a thrust towards the side of piston 3 in contact with the pressure medium at the test pressure port 20. The magnitude of the thrust is the difference between the area of ​​piston 3 in contact with the pressure medium in the balance chamber 11 in the direction perpendicular to the axis and the area of ​​piston 3 in contact with the pressure medium at the test pressure port 20 in the direction perpendicular to the axis, which is the thrust generated under the action of the pressure medium. Because the pressure inside the balance chamber 11 is equal to the pressure inside the test workpiece 10, that is, the force generated per unit area inside the balance chamber 11 and the test workpiece 10 is the same. The contact area of ​​the pressure medium is greater than the contact area of ​​the piston 3 with the pressure medium at the test interface 20 in the direction perpendicular to the axis. The pressure areas at both ends are different, resulting in a force imbalance. This causes the end faces of the flanges 30 at both ends to be subjected to inward compressive force. As the internal pressure of the test workpiece 10 increases, the compressive force on the end faces of the flanges 30 at both ends will also increase. This ensures that the sealing structure of the test workpiece 10 remains reliable under high pressure without additional force, thus improving the sealing performance. Furthermore, the stress area of ​​the entire sealing structure is mainly concentrated on the end faces of the flanges 30 at both ends, and the overall structure of the test workpiece 10 is almost unaffected by external forces.

[0036] Specifically, the second injection channels 8 are evenly spaced around the axis of the piston 3, and the number is 4 to 10. In this embodiment, the number of second injection channels 8 is 8.

[0037] When the pressure medium is injected into the test workpiece 10, the pressure medium enters the balance chamber 11 through the first injection channel 7 on the cylinder 1 at one end of the test workpiece 10, and then enters the test workpiece 10 through the second injection channel 8 on the piston 3. As the internal pressure of the test workpiece 10 increases, the pressure medium enters another balance chamber 11 through the second injection channel 8 on the piston 3 at the other end of the test workpiece 10.

[0038] Among them, refer to Figure 1In this embodiment, the piston 3 is driven by the actuator 50 to press and seal the test pressure interface 20. The actuator 50 is mounted on the cylinder 1 via the connecting rod 6. The actuator 50 is connected to the piston 3 via the telescopic shaft 60. The telescopic shaft 60 passes through the cylinder 1 and a first sealing element 4 is provided between it and the cylinder 1. The first sealing element 4 is a sealing ring. An annular groove is provided on the cylinder 1 at the position where the telescopic shaft 60 passes through the cylinder 1. The first sealing element 4 is placed in the annular groove to prevent leakage of the medium in the balance chamber 11, which would affect the internal pressure balance of the balance chamber 11 and reduce the sealing performance.

[0039] Preferably, the telescopic shaft 60 is aligned with the axis of the piston 3, ensuring uniform clamping force on all sides of the piston 3 and avoiding the risk of leakage due to uneven clamping force.

[0040] The actuator 50 is a pneumatic cylinder, hydraulic cylinder, or servo motor, which is existing technology and will not be elaborated further here. The piston 3 is driven by the telescopic shaft 60 to move inside the cylinder 1, pressing the flange 30 end face of the test workpiece 10, providing clamping force, sealing the test interface 20, improving sealing performance, preventing leakage at the flange 30 end face, and thus ensuring the smooth progress of the pressure test.

[0041] Specifically, piston 3 is connected to telescopic shaft 60 via screw 9.

[0042] Specifically, the end face of flange 30 bears two forces: one is the clamping force provided by actuator 50 (which accounts for a very small proportion of the resultant force and its direction can be controlled), and the other is the extrusion force provided by balance chamber 11.

[0043] Reference Figure 1 In this embodiment, a second sealing element 5 is provided between the piston 3 and the inner wall of the cylinder 1. The second sealing element 5 is a sealing ring. An annular placement groove is provided on the outer wall of the piston 3, and the second sealing element 5 is placed in the annular placement groove to prevent leakage of the medium in the balance chamber 11, which would affect the internal pressure balance of the balance chamber 11 and reduce the sealing performance.

[0044] Reference Figure 1 and Figure 2 In this embodiment, a sealing gasket 40 is installed on the side of the piston 3 near the test pressure port 20.

[0045] Specifically, during sealing, the sealing gasket 40 contacts the end face of the flange 30, and a sealing effect is achieved by compressing and deforming the sealing gasket 40.

[0046] Reference Figure 1 and Figure 2In this embodiment, the cylinder 1 is connected to one end of the positioning support sleeve 2, and the other end of the positioning support sleeve 2 is provided with an opening 22. The positioning support sleeve 2 is provided with a positioning cavity 21 that communicates with the opening 22.

[0047] Specifically, the diameter of the opening 22 is slightly larger than the outer wall diameter of the test workpiece 10, the diameter of the positioning cavity 21 is slightly larger than the diameter of the flange 30, and the diameter of the positioning cavity 21 is larger than the diameter of the opening 22. The flange 30 is supported by the area difference between the positioning cavity 21 and the opening 22, providing support force and maintaining the clamping force provided by the actuator 50 and the extrusion force borne by the end face of the flange 30, thus maintaining the balance of forces.

[0048] Reference Figure 1 and Figure 2 In this embodiment, one side wall of the positioning cavity 21 and the opening 22 penetrates one side of the positioning support sleeve 2, so that both the positioning cavity 21 and the opening 22 are U-shaped, which facilitates the quick installation and automatic positioning of the test workpiece 10.

[0049] Specifically, when the flange 30 is placed in the positioning cavity 21, the axes of the telescopic shaft 60, piston 3, positioning cavity 21, opening 22, sealing gasket 40, flange 30 and pressure test interface 20 are the same.

[0050] Working principle: During use, the flanges 30 at both ends of the test workpiece 10 are placed into the positioning cavities 21 of the two positioning support sleeves 2 for positioning and support. Then, the actuator 50 is activated, driving the two pistons to abut against the corresponding flanges 30 for compression and sealing, providing clamping force. When the pressure medium is injected into the test workpiece 10, one end of the first injection channel 7 of the cylinders 1 at both ends of the test workpiece 10 is opened and the other end is closed. The pressure medium enters the balance chamber 11 through the first injection channel 7 on one end of the cylinder 1 of the test workpiece 10, and then enters the test workpiece 10 through the second injection channel 8 on the piston 3. As the internal pressure of the test workpiece 10 increases, the pressure medium enters the other balance chamber 11 through the second injection channel 8 on the piston 3 at the other end of the test workpiece 10, so that the internal pressure of the balance chamber 11 is equal to the internal pressure of the test workpiece 10. To maintain balance, because the area of ​​piston 3 in contact with the pressure medium in the balance chamber 11 in the direction perpendicular to the axis is greater than the area of ​​piston 3 in contact with the pressure medium at the test port 20 in the direction perpendicular to the axis, the side of piston 3 in contact with the pressure medium in the balance chamber 11 will generate a thrust towards the side of piston 3 in contact with the pressure medium at the test port 20, so that the end faces of the flanges 30 at both ends are subjected to inward extrusion force. As the internal pressure of the test workpiece 10 increases, the extrusion force on the end faces of the flanges 30 at both ends will also increase, thereby ensuring that the sealing structure of the two ends of the test workpiece 10 remains reliable under high pressure without additional force, improving the sealing performance. Moreover, the stress area of ​​the entire sealing structure is mainly concentrated on the end faces of the flanges 30 at both ends, and the overall structure of the test workpiece 10 is almost unaffected by external forces.

[0051] The present invention has a simple structure and low cost. The test workpiece 10 can be quickly installed and automatically positioned. It uses the internal pressure of the test workpiece 10 for sealing, and the sealing effect is good.

[0052] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions also fall within the scope of protection of the present invention.

Claims

1. A pressure balancing test fixture for sealing the end face of a workpiece, characterized in that, include: A cylinder (1) is provided with a piston (3) that slides inside the cylinder (1). The piston (3) can abut against the test interface (20) of the test workpiece (10) to press and seal the test interface (20). A balance chamber (11) is formed between the piston (3) and the inner wall of the cylinder (1). A first injection channel (7) communicating with the balance chamber (11) is provided on the cylinder (1). A second injection channel (8) communicating with the inside of the test workpiece (10) is provided on the piston (3). The area of ​​the piston (3) in contact with the pressure medium located in the balance chamber (11) in the direction perpendicular to the axis is greater than the area of ​​the piston (3) in contact with the pressure medium at the test port (20) in the direction perpendicular to the axis. The cylinder (1) is connected to one end of the positioning support sleeve (2), and the other end of the positioning support sleeve (2) is provided with an opening (22). The positioning support sleeve (2) is provided with a positioning cavity (21) that communicates with the opening (22).

2. The pressure balancing test fixture for sealing the end face of a workpiece according to claim 1, characterized in that, The piston (3) is driven by the actuator (50) to press and seal the test port (20). The actuator (50) is mounted on the cylinder (1) via the connecting rod (6).

3. The pressure balancing test fixture for sealing the end face of a workpiece according to claim 1, characterized in that, A sealing gasket (40) is installed on the side of the piston (3) near the test port (20).

4. The pressure balancing test fixture for sealing the end face of a workpiece according to claim 1, characterized in that, A second seal (5) is provided between the piston (3) and the inner wall of the cylinder (1).

5. The pressure balancing test fixture for sealing the end face of a workpiece according to claim 2, characterized in that, The actuator (50) is connected to the piston (3) via a telescopic shaft (60), which passes through the cylinder (1) and is provided with a first seal (4) between itself and the cylinder (1).

6. The pressure balancing test fixture for sealing the end face of a workpiece according to claim 1, characterized in that, The side wall of the positioning cavity (21) and the opening (22) penetrates one side of the positioning support sleeve (2).

7. The pressure balancing test fixture for sealing the end face of a workpiece according to claim 6, characterized in that, The pressure test interface (20) is a flange type interface, and the flange type interface has a flange (30), which can be placed in the positioning cavity (21).

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