An airtightness detection device and detection method for die-castings

Abstract

The present invention discloses an airtightness detection device and a detection method for die-castings, belonging to the technical field of airtightness detection. The airtightness detection device includes a heating component and a detection component. The heating component includes a high-frequency heater and a heating box, and the high-frequency heater is located in the heating box. The detection component includes a first air source, a stop valve, a heat preservation box, a mercury box, a leak detector and a second air source. An air inlet pipe and an air outlet pipe are inserted into the heat preservation box. The first air source, the stop valve and the other end of the air inlet pipe are connected in sequence. A partition plate is inserted downward from the top of the mercury box, and mercury is filled in the mercury box. A first chamber and a second chamber are respectively formed by enclosing between the liquid level of the mercury, the partition plate and the mercury box. The first chamber is connected to the other end of the air outlet pipe, and the second chamber, the leak detector and the second air source are connected in sequence. An airtightness detection device for die-castings provided by an embodiment of the present invention can improve the reliability of the airtightness detection data of die-castings.

Description

Technical Field

[0001] The present invention belongs to the technical field of airtightness detection, and more specifically, relates to an airtightness detection device and method for die-castings. Background Art

[0002] With the advent of the automotive electrification era, the airtightness requirements for automotive aluminum alloy components are getting higher and higher. For example, the requirements for the sealing of electronic control housings, battery covers, and motor covers are becoming increasingly stringent.

[0003] Traditional methods usually adopt room-temperature airtightness detection and cannot test the airtightness state of die-castings after high temperatures are generated under the actual vehicle operation conditions. Moreover, for the heated products, the heat exchange between their temperature and the gas (which makes the detection gas become high-temperature gas) will also have an adverse impact on the detection results of the leak detector, all of which will lead to relatively low reliability of the airtightness detection data of the final die-castings. Summary of the Invention

[0004] In view of the above defects or improvement requirements of the prior art, the present invention provides an airtightness detection device and method for die-castings, aiming to not only detect the airtightness of the to-be-tested die-castings under high-temperature conditions, but also avoid the high-temperature gas from affecting the detection results of the leak detector, thereby improving the reliability of the airtightness detection data of die-castings.

[0005] In a first aspect, the present invention provides an airtightness detection device for die-castings, and the airtightness detection device includes a heating component and a detection component;

[0006] The heating component includes a high-frequency heater and a heating box, and the high-frequency heater is located in the heating box;

[0007] The detection component includes a first air source, a stop valve, a heat preservation box, a mercury box, a leak detector, and a second air source. An air inlet pipe and an air outlet pipe are inserted into the heat preservation box. One end of the air inlet pipe and one end of the air outlet pipe are both located inside the heat preservation box, and one end of the air inlet pipe and one end of the air outlet pipe are both used for being inserted into both ends of the through hole of the to-be-tested die-casting. The first air source, the stop valve, and the other end of the air inlet pipe are sequentially connected. A partition is inserted downward from the top of the mercury box, and the mercury box is filled with mercury. The liquid level height of the mercury is higher than the bottom of the partition and lower than the top of the mercury box. A first chamber and a second chamber are respectively formed by enclosing between the liquid level of the mercury, the partition, and the mercury box. The first chamber is connected to the other end of the air outlet pipe, and the second chamber, the leak detector, and the second air source are sequentially connected.

[0008] Optionally, the detection component further includes a pressure regulating valve, and the pressure regulating valve is arranged between the first air source and the stop valve.

[0009] Optionally, sealing plugs are coaxially sleeved at one end of the intake pipe and one end of the exhaust pipe, and each of the sealing plugs is used to be inserted into both ends of the through hole of the die casting to be tested.

[0010] Optionally, the inner cavity of the heat preservation box is provided with infrared resistance wires to heat the inner cavity of the heat preservation box.

[0011] Optionally, a pressure gauge is inserted on the exhaust pipe to monitor the pressure in the exhaust pipe, and the pressure gauge is located outside the mercury box and the heat preservation box.

[0012] Optionally, the gas in the first gas source and the second gas source is nitrogen or helium.

[0013] In a second aspect, the present invention provides a detection method for an airtightness detection device for die castings. The detection method is based on the airtightness detection device for die castings described in the first aspect, and the detection method includes:

[0014] Place the die casting to be tested in the heating box, and heat the die casting to be tested through the high-frequency heater;

[0015] Carry the heated die casting to be tested to the heat preservation box for heat preservation, and insert one end of the intake pipe and one end of the exhaust pipe into both ends of the through hole of the die casting to be tested;

[0016] Open the stop valve and the leak detector, inflate the first chamber and the second chamber respectively through the first gas source and the second gas source, then close the stop valve to maintain pressure, and make the liquid level of the mercury corresponding to the first chamber not higher than the liquid level of the mercury corresponding to the second chamber;

[0017] Before and after the set time, detect the pressure difference before and after in the second chamber through the leak detector.

[0018] The beneficial effects brought by the technical solution provided by the embodiments of the present invention are:

[0019] For a hermeticity detection device for die-castings provided by an embodiment of the present invention, when detecting the hermeticity of a to-be-detected die-casting, first, place the to-be-detected die-casting in a heating box, and heat the to-be-detected die-casting through a high-frequency heater, so as to simulate a high-temperature state of the to-be-detected die-casting during operation by heating the to-be-detected die-casting through the high-frequency heater. Next, transport the heated to-be-detected die-casting to a heat preservation box for heat preservation, and insert one end of an air inlet pipe and one end of an air outlet pipe into both ends of a through hole of the to-be-detected die-casting, so as to facilitate subsequent inflation of the through hole in the to-be-detected die-casting. Next, open a stop valve and a leak detector, inflate a first chamber and a second chamber respectively through a first gas source and a second gas source, then close the stop valve to keep pressure, and make the liquid level of the mercury corresponding to the first chamber not higher than the liquid level of the mercury corresponding to the second chamber (make the pressure of the first chamber greater than the pressure of the second chamber). Due to the blocking effect of the mercury in the mercury box, the gas blown out by the first gas source can only enter the first chamber after passing through the to-be-detected die-casting and will not directly enter the leak detector, thus avoiding high-temperature gas directly entering the leak detector and affecting the detection reliability of the leak detector. Finally, before and after a set time, detect the pressure difference before and after in the second chamber through the leak detector. When a leak occurs in the through hole of the to-be-detected die-casting, the pressure in the first chamber will decrease, resulting in the mercury on the right side of a partition gradually flowing into the left side of the partition, making the volume of the second chamber increase. According to the ideal gas state equation, the pressure corresponding to the second chamber will decrease, so that the pressure difference between the second chamber before and after can be conveniently detected through the leak detector, which is the leakage amount of the to-be-detected die-casting, and the hermetic state of the to-be-detected die-casting can be described.

[0020] That is to say, a hermeticity detection device for die-castings provided by an embodiment of the present invention can not only detect the hermetic state of a to-be-detected die-casting in a high-temperature state, but also avoid high-temperature gas affecting the detection result of the leak detector, thereby improving the reliability of the hermeticity detection data of the to-be-detected die-casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of a hermeticity detection device for die-castings provided by an embodiment of the present invention;

[0022] Figure 2 is a flowchart of a detection method of a hermeticity detection device for die-castings provided by an embodiment of the present invention.

[0023] The meanings represented by each symbol in the figure are as follows:

[0024] 1. Heating assembly; 11. High-frequency heater; 12. Heating box; 2. Detection assembly; 21. First air source; 22. Cut-off valve; 23. Insulation box; 231. Intake pipe; 232. Exhaust pipe; 2321. Pressure gauge; 233. Sealing plug; 234. Infrared resistance wire; 24. Mercury box; 241. Partition board; 242. Mercury; 25. Leak detector; 26. Second air source; 27. First chamber; 28. Second chamber; 29. Pressure regulating valve; 100. Die casting to be pressure-tested. Detailed implementation manners

[0025] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various implementation manners of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] Figure 1 is a schematic structural diagram of an airtightness detection device for die castings provided by an embodiment of the present invention. As Figure 1 shown, the airtightness detection device includes a heating assembly 1 and a detection assembly 2.

[0027] The heating assembly 1 includes a high-frequency heater 11 and a heating box 12, and the high-frequency heater 11 is located in the heating box 12.

[0028] The detection assembly 2 includes a first air source 21, a cut-off valve 22, an insulation box 23, a mercury box 24, a leak detector 25 and a second air source 26. An intake pipe 231 and an exhaust pipe 232 are inserted into the insulation box 23. One end of the intake pipe 231 and one end of the exhaust pipe 232 are both located inside the insulation box 23, and one end of the intake pipe 231 and one end of the exhaust pipe 232 are both used to be inserted into both ends of the through hole of the die casting 100 to be tested. The first air source 21, the cut-off valve 22 and the other end of the intake pipe 231 are connected in sequence. A partition board 241 is inserted downward from the top of the mercury box 24, and the mercury box 24 is filled with mercury 242. The liquid level height of the mercury 242 is higher than the bottom of the partition board 241 and lower than the top of the mercury box 24. A first chamber 27 and a second chamber 28 are respectively formed by enclosing between the liquid level of the mercury 242, the partition board 241 and the mercury box 24. The first chamber 27 is connected to the other end of the exhaust pipe 232, and the second chamber 28, the leak detector 25 and the second air source 26 are connected in sequence.

[0029] For a hermeticity detection device for die-castings provided by an embodiment of the present invention, when performing hermeticity detection on a to-be-detected die-casting 100, first, place the to-be-detected die-casting 100 in a heating box 12, and heat the to-be-detected die-casting 100 through a high-frequency heater 11, so as to heat the to-be-detected die-casting 100 through the high-frequency heater 11 to simulate the high-temperature state of the to-be-detected die-casting 100 during operation. Next, transport the heated to-be-detected die-casting 100 to a heat preservation box 23 for heat preservation, and insert one end of an air inlet pipe 231 and one end of an air outlet pipe 232 into both ends of a through hole of the to-be-detected die-casting 100, so as to facilitate subsequent inflation of the through hole in the to-be-detected die-casting 100. Then, open a stop valve 22 and a leak detector 25, inflate a first chamber 27 and a second chamber 28 respectively through a first air source 21 and a second air source 26, then close the stop valve 22 to maintain pressure, and make the liquid level of mercury 242 corresponding to the first chamber 27 not higher than the liquid level of mercury 242 corresponding to the second chamber 28 (make the pressure of the first chamber 27 greater than the pressure of the second chamber 28). Due to the blocking effect of the mercury 242 in a mercury box 24, the gas blown out by the first air source 21 can only enter the first chamber 27 after passing through the to-be-detected die-casting 100, and will not directly enter the leak detector 25, thereby avoiding high-temperature gas directly entering the leak detector 25 and affecting the detection reliability of the leak detector 25. Finally, before and after a set time, detect the pressure difference before and after in the second chamber 28 through the leak detector 25. When there is a leak in the through hole of the to-be-detected die-casting 100, the pressure in the first chamber 27 will decrease, resulting in the mercury 242 on the right side of a partition plate 241 gradually flowing into the left side of the partition plate 241, making the volume of the second chamber 28 increase. According to the ideal gas state equation, the pressure corresponding to the second chamber 28 will decrease, so as to conveniently detect the pressure difference between the second chamber 28 before and after through the leak detector 25, which is the leakage amount of the to-be-detected die-casting 100, and the hermetic state of the to-be-detected die-casting 100 can be described.

[0030] That is to say, a hermeticity detection device for die-castings provided by an embodiment of the present invention can not only detect the hermetic state of the to-be-detected die-casting 100 in a high-temperature state, but also avoid high-temperature gas affecting the detection result of the leak detector 25, thereby improving the reliability of the hermeticity detection data of the to-be-detected die-casting 100.

[0031] It is easy to understand that the high-frequency heater 11 can improve the heating speed by using high-frequency heating, and can make the temperature of the to-be-detected die-casting 100 rise from the core to the periphery to the set temperature simultaneously in a short time.

[0032] It should be noted that the leak detector 25 controls the air intake amount of the second air source 26 by setting specific parameters, so as to accurately control the air pressure in the second chamber 28.

[0033] In this embodiment, the detection component 2 further includes a pressure regulating valve 29, which is arranged between the first gas source 21 and the stop valve 22. The pressure regulating valve 29 can accurately control the intake pressure of the first gas source 21 to avoid damaging the pressure casting 100 to be tested due to excessive intake pressure.

[0034] Exemplarily, a pressure gauge 2321 is inserted on the air outlet pipe 232 to monitor the pressure inside the air outlet pipe 232, and the pressure gauge 2321 is located outside the mercury box 24 and the heat preservation box 23. The pressure gauge 2321 can display the pressure maintaining pressure of the first chamber 27 in real time to avoid damaging the pressure casting 100 to be tested due to excessive pressure in the first chamber 27.

[0035] In this embodiment, sealing plugs 233 are coaxially sleeved at one end of the intake pipe 231 and one end of the air outlet pipe 232, and each sealing plug 233 is used to be inserted into both ends of the through hole of the pressure casting 100 to be tested. The sealing plug 233 plays a role in sealing the pressure casting 100 to be tested to avoid leakage at the connection between the intake pipe 231 and the air outlet pipe 232 and the pressure casting 100 to be tested.

[0036] In one implementation manner of the present invention, the inner cavity of the heat preservation box 23 is provided with an infrared resistance wire 234 to heat the inner cavity of the heat preservation box 23.

[0037] In the above implementation manner, the infrared resistance wire 234 can heat and keep warm the inner cavity of the heat preservation box 23 to avoid heat loss of the pressure casting 100 to be tested, and the simulation effect is better.

[0038] Exemplarily, the gas in the first gas source 21 and the second gas source 26 is nitrogen or helium. Nitrogen or helium has better stability.

[0039] Figure 2 It is a flowchart of a detection method for an airtightness detection device for pressure castings provided by an embodiment of the present invention. As Figure 2 shown, the detection method is the above-mentioned airtightness detection device for pressure castings, and the detection method includes:

[0040] S201. Place the pressure casting 100 to be tested in the heating box 12 and heat the pressure casting 100 to be tested through the high-frequency heater 11.

[0041] S202. Carry the heated pressure casting 100 to be tested to the heat preservation box 23 for heat preservation, and insert one end of the intake pipe 231 and one end of the air outlet pipe 232 into both ends of the through hole of the pressure casting 100 to be tested.

[0042] It should be noted that the heated pressure casting 100 to be tested can be carried to the heat preservation box 23 by a manipulator.

[0043] S203. Open the stop valve 22 and the leak detector 25, inflate the first chamber 27 and the second chamber 28 through the first gas source 21 and the second gas source 26 respectively, and close the stop valve 22 to maintain the pressure, so that the liquid level of the mercury 242 corresponding to the first chamber 27 is not higher than the liquid level of the mercury 242 corresponding to the second chamber 28.

[0044] S204. Before and after the set time, detect the pressure difference before and after in the second chamber 28 through the leak detector 25.

[0045] Exemplarily, when there is a leak in the through hole of the pressure casting 100 to be tested, the pressure in the first chamber 27 will decrease, causing the mercury 242 on the right side of the partition 241 to gradually flow into the left side of the partition 241, increasing the volume of the second chamber 28. According to the ideal gas state equation, the pressure corresponding to the second chamber 28 will decrease, so that the pressure difference before and after in the second chamber 28 can be conveniently detected through the leak detector 25, which can illustrate the airtight state of the pressure casting 100 to be tested.

[0046] That is to say, for the detection method of the airtightness detection device for pressure castings provided by the present invention, after heating the pressure casting 100 to be tested, the airtight state after heating of the pressure casting 100 to be tested can be effectively simulated under the actual vehicle operation state, and the airtightness value can be effectively detected, providing reliable data support for the components to be assembled into the vehicle in the future.

[0047] Those skilled in the art can easily understand that the above are only the preferred embodiments of the present invention, and are not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An airtightness detection device for die-castings, characterized in that, The airtightness detection device includes a heating component (1) and a detection component (2); The heating component (1) includes a high-frequency heater (11) and a heating box (12), and the high-frequency heater (11) is located in the heating box (12); The detection component (2) includes a first air source (21), a stop valve (22), a heat preservation box (23), a mercury box (24), a leak detector (25) and a second air source (26). An air inlet pipe (231) and an air outlet pipe (232) are inserted into the heat preservation box (23). One end of the air inlet pipe (231) and one end of the air outlet pipe (232) are both located inside the heat preservation box (23), and one end of the air inlet pipe (231) and one end of the air outlet pipe (232) are both used for being inserted into both ends of the through hole of the die casting to be tested (100). The first air source (21), the stop valve (22) and the other end of the air inlet pipe (231) are sequentially communicated. A partition plate (241) is inserted downward from the top of the mercury box (24), and mercury (242) is filled in the mercury box (24). The liquid level height of the mercury (242) is higher than the bottom of the partition plate (241) and lower than the top of the mercury box (24). A first chamber (27) and a second chamber (28) are respectively enclosed among the liquid level of the mercury (242), the partition plate (241) and the mercury box (24). The first chamber (27) is communicated with the other end of the air outlet pipe (232), and the second chamber (28), the leak detector (25) and the second air source (26) are sequentially communicated. The leak detector controls the air intake of the second air source.

2. The airtightness detection device for die-castings according to claim 1, wherein, The detection component (2) further includes a pressure regulating valve (29), and the pressure regulating valve (29) is arranged between the first air source (21) and the stop valve (22).

3. The airtightness detection device for die-castings according to claim 1, wherein, Sealing plugs (233) are coaxially sleeved at one end of the air inlet pipe (231) and one end of the air outlet pipe (232), and each sealing plug (233) is used for being inserted into both ends of the through hole of the die casting to be tested (100).

4. An airtightness detection device for die-cast parts according to any one of claims 1-3, characterized in that, The inner cavity of the heat preservation box (23) has an infrared resistance wire (234) to heat the inner cavity of the heat preservation box (23).

5. A hermeticity detection device for die-castings according to any one of claims 1-3, characterized in that, A pressure gauge (2321) is inserted into the air outlet pipe (232) to monitor the pressure in the air outlet pipe (232), and the pressure gauge (2321) is located outside the mercury box (24) and the heat preservation box (23).

6. A hermeticity detection device for die-castings according to any one of claims 1-3, characterized in that, The gases in the first air source (21) and the second air source (26) are nitrogen or helium.

7. A detection method for an airtightness detection device of die-castings, characterized in that, The detection method is based on an airtightness detection device for die castings according to any one of claims 1-6, and the detection method includes: Placing the die casting to be tested (100) in the heating box (12) and heating the die casting to be tested (100) through the high-frequency heater (11); Transfer the heated die casting to be measured (100) to the heat preservation box (23) for heat preservation, and insert one end of the air inlet pipe (231) and one end of the air outlet pipe (232) into both ends of the through hole of the die casting to be measured (100). Open the stop valve (22) and the leak detector (25), charge the first chamber (27) and the second chamber (28) respectively through the first gas source (21) and the second gas source (26), then close the stop valve (22) to keep the pressure, and make the liquid level of the mercury (242) corresponding to the first chamber (27) not higher than the liquid level of the mercury (242) corresponding to the second chamber (28). Before and after the set time, detect the pressure difference before and after in the second chamber (28) through the leak detector (25).

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