Durability test device and method for an automotive exhaust gas pressure sensor

Abstract

The present invention discloses a durability test device and method for an automotive exhaust gas pressure sensor. The test device includes a pressure sensor test sample, a medium pressure barrel, a constant temperature box, a pressure sensor, an intake shut-off valve, a pressure monitor, an exhaust shut-off valve, and a simulated power device. Among them, one side of the medium pressure barrel is connected to an intake pipe, on which a pressure sensor and an intake shut-off valve are provided. The other side is connected to the simulated power device through a pipeline, and still another side is connected to one end of the exhaust shut-off valve. The other end of the exhaust shut-off valve is connected to the pressure sensor test sample. The pressure sensor test sample and the medium pressure barrel are located in the constant temperature box. The pressure monitor is electrically connected to the pressure sensor test sample and the pressure sensor respectively. The test device and method of the present invention meet the test requirements, and the test device has a simple structure, low test energy consumption, and good test effects.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive parts, and particularly to a durability test device and method for an automotive exhaust gas pressure sensor. Background Art

[0002] At present, semiconductor pressure sensors combine advanced micro-machining technologies and can output accurate, high-precision analog output signals proportional to the input pressure. Their characteristics of low cost and high performance greatly meet the strict requirements of OEM customers. The sensors adopt standard packaging forms and can measure gauge pressure, absolute pressure, differential pressure, etc. within a certain pressure range. In the plastic packaging of pressure sensors, the bonding process conditions of the sensing chip and bonding are usually wire bonding between gold wires and aluminum pads. After the sensing chip is bonded, the component is covered by silicone gel. This packaging can prevent and reduce oxidation and corrosion in the air. Due to the high temperature, large air pressure fluctuations, and especially the presence of strong corrosive substances such as NO compounds in automotive exhaust gas, a part of the gas will penetrate the silicone gel covering layer and corrode the internally bonded components. In particular, the bonding between the gold wire and the aluminum pad (Au / Al) in the component has no passivation protection layer, and the corrosion reaction can be accelerated under the action of high temperature and air pressure vibration, resulting in the failure of the bonding point. Once the automotive exhaust gas pressure sensor is damaged, the exhaust gas pressure cannot be monitored in time, and no timely response can be made to exhaust pipe blockage faults caused by blockage of the particulate adsorption device, damage to the three-way catalytic converter, blockage of the heat-resistant material filled in the muffler, and poor drainage caused by cold in northern regions, resulting in phenomena such as engine idle speed jitter, weak acceleration, "backfire" in the intake pipe during acceleration, sudden acceleration flameout, and inability to start. Therefore, it is necessary for users to master the service life of the sensor and replace the automotive exhaust gas pressure sensor in time to avoid engine failures caused by sensor damage. Existing detection devices generally use engines to provide exhaust gas for testing. Although this detection method is effective, for long-term testing, the engine has high energy consumption and the generated exhaust gas causes great environmental pollution. Summary of the Invention

[0003] A durability test device for an automotive exhaust gas pressure sensor includes a pressure sensor test sample, a medium pressure barrel, a constant temperature box, a pressure sensor, an intake cut-off valve, a pressure monitor, an exhaust cut-off valve, and a simulation power device. Among them: one side of the medium pressure barrel is connected to an intake pipe, on which a pressure sensor and an intake cut-off valve are provided; the other side is connected to the simulation power device through a pipeline, and still another side is connected to one end of the exhaust cut-off valve. The other end of the exhaust cut-off valve is connected to the pressure sensor test sample. The pressure sensor test sample and the medium pressure barrel are located in the constant temperature box. The pressure monitor is electrically connected to the pressure sensor test sample and the pressure sensor respectively.

[0004] An endurance test device for an automotive exhaust gas pressure sensor, wherein: the simulation power device includes a cylinder block, on which an upper body of a pressure pump is provided. Inside the upper body of the pressure pump, there are two medium chambers. Horizontally arranged between the two medium chambers is a rubber diaphragm. The middle part of the rubber diaphragm is clamped by an upper spring support piece and a lower spring support piece. The top end of the upper spring support piece is connected to one end of an upper spring, the other end of the upper spring is connected to the top end of the medium chamber, the bottom end of the lower spring support piece is connected to one end of a lower spring, and the other end of the lower spring is connected to the bottom end of the medium chamber. At the top of the upper body of the pressure pump, there is a pressure output pipe. One end of the pressure output pipe is connected to the medium chamber, and the other end is connected to a medium pressure barrel through a pipeline. The cylinder block is fixedly connected to the bottom shell of the pressure pump by bolts. At the top of one side of the bottom shell of the pressure pump, there is a breather port of the bottom shell of the pressure pump. The inner cavity of the cylinder block is communicated with the medium chamber through a pressure transmission hole. Inside the inner cavity of the cylinder block, there is a piston. The piston is movably connected to one end of a rocker arm through a fixed shaft on the rocker arm. The other end of the rocker arm is movably connected to a cam through a fixed shaft under the rocker arm. The cam is connected to one end of a transmission shaft by a shaft pin. The cam is located inside the bottom shell of the pressure pump. The other end of the transmission shaft passes through the inner wall of the bottom shell of the pressure pump and is fixedly connected to a motor through a coupling.

[0005] An endurance test device for an automotive exhaust gas pressure sensor, wherein: on one side of the upper body of the pressure pump, there is a pressure adjustment hole. One end of the pressure adjustment hole is connected to the medium chamber, and the other end is provided with a pressure adjustment cover plate.

[0006] An endurance test method for an automotive exhaust gas pressure sensor, wherein: this test method uses an endurance test device for an automotive exhaust gas pressure sensor to conduct the test, including the following steps:

[0007] (1) First, fill a certain amount of gas simulating automotive exhaust gas into the medium pressure barrel and maintain a certain pressure.

[0008] (2) Then turn on the constant temperature box to make it work at a constant temperature, and keep the gas simulating automotive exhaust gas in the medium pressure barrel at the required test temperature.

[0009] (3) Then turn on the simulation power device and adjust it so that the gas pressure fluctuation in the medium pressure barrel reaches a level close to automotive emissions.

[0010] (4) Finally, open the outlet shut-off valve to conduct the test on the test sample of the pressure sensor.

[0011] The technical effects and advantages of the present invention: By using a motor to drive the piston to move to generate air pressure fluctuations, simulating the pressure vibration during engine exhaust; using a diaphragm to transmit pressure and isolate the medium in the test chamber; using a pressure monitor to observe the condition of the test piece and the pressure condition of the medium online; using a constant temperature box to accelerate the simulation of temperature corrosion and aging environment; the test device has a simple structure, relatively low energy consumption compared to engine bench tests, and good test effects. Description of the Drawings

[0012] Figure 1 This is the system diagram of the present invention.

[0013] Figure 2 This is the front view of the simulated power device of the present invention.

[0014] Figure 3 This is the left view of the simulated power device of the present invention.

[0015] In the figure: 1 pressure sensor test specimen, 2 medium pressure barrel, 3 constant temperature box, 4 pressure sensor, 5 inlet cut-off valve, 6 pressure monitor, 7 outlet cut-off valve, 8 simulated power device, 9 pressure output pipe, 10 upper spring support plate, 11 rubber diaphragm, 12 lower spring support plate, 13 pressure adjustment hole, 14 pressure adjustment cover plate, 15 pressure transmission hole, 16 cylinder block, 17 lower fixed shaft of rocker arm, 18 cam, 19 upper body of pressure pump, 20 medium chamber, 21 upper spring, 22 lower spring, 23 piston, 24 upper fixed shaft of rocker arm, 25 breather port of pressure pump bottom shell, 26 rocker arm, 27 transmission shaft, 28 pressure pump bottom shell, 29 motor. Detailed implementation manners

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0017] Please refer to Figure 1 , a durability test device for an automotive exhaust gas pressure sensor, comprising a pressure sensor test specimen 1, a medium pressure barrel 2, a constant temperature box 3, a pressure sensor 4, an inlet cut-off valve 5, a pressure monitor 6, an outlet cut-off valve 7 and a simulated power device 8, wherein: one side of the medium pressure barrel 2 is connected to an intake pipe, the intake pipe is provided with a pressure sensor 4 and an inlet cut-off valve 5, the other side is connected to the simulated power device 8 through a pipeline, and still another side is connected to one end of the outlet cut-off valve 7. The other end of the outlet cut-off valve 7 is connected to the pressure sensor test specimen 1. The pressure sensor test specimen 1 and the medium pressure barrel 2 are located in the constant temperature box 3. The pressure monitor 6 is electrically connected to the pressure sensor test specimen 1 and the pressure sensor 4 respectively.

[0018] Please refer to Figure 2 and Figure 3, wherein, the simulation power device 8 includes a cylinder block 16, a pressure pump upper body 19 is provided on the cylinder block 16, two medium cavities 20 are provided in the pressure pump upper body 19, a rubber diaphragm 11 is transversely arranged between the two medium cavities 20, and the rubber diaphragm 11 can effectively isolate the gas in the medium pressure barrel 2 to prevent leakage. The middle part of the rubber diaphragm 11 is pressed by an upper spring support piece 10 and a lower spring support piece 12. The top end of the upper spring support piece 10 is connected to one end of an upper spring 21, the other end of the upper spring 21 is connected to the top end of the medium cavity 20, the bottom end of the lower spring support piece 12 is connected to one end of a lower spring 22, and the other end of the lower spring 22 is connected to the bottom end of the medium cavity 20. The arrangement of the upper spring 21 and the lower spring 22 can prevent the rubber diaphragm 11 from being torn by the air pressure vibration generated during the movement of the piston 23. A pressure output pipe 9 is provided at the top end of the pressure pump upper body 19. One end of the pressure output pipe 9 is connected to the medium cavity 20, and the other end is connected to the medium pressure barrel 2 through a pipeline. The cylinder block 16 is fixedly connected to a pressure pump bottom shell 28 by bolts. A pressure pump bottom shell breathing port 25 is provided at the top of one side of the pressure pump bottom shell 28. The inner cavity of the cylinder block 16 is communicated with the medium cavity 20 through a pressure transmission hole 15. A piston 23 is provided in the inner cavity of the cylinder block 16. The piston 23 is movably connected to one end of a rocker arm 26 through a rocker arm upper fixed shaft 24. The other end of the rocker arm 26 is movably connected to a cam 18 through a rocker arm lower fixed shaft 17. The cam 18 is connected to one end of a transmission shaft 27 by a shaft pin. The cam 18 is located in the pressure pump bottom shell 28. The other end of the transmission shaft 27 passes through the inner wall of the pressure pump bottom shell 28 and is fixedly connected to a motor 29 through a coupling.

[0019] Wherein, a pressure regulating hole 13 is provided on one side of the pressure pump upper body 19. One end of the pressure regulating hole 13 is connected to the medium cavity 20, and a pressure regulating cover plate 14 is provided at the other end. The pressure fluctuation in the medium pressure barrel 2 is regulated by regulating the pressure at the bottom end of the medium cavity 20 separated by the rubber diaphragm 11.

[0020] A durability test method for an automotive exhaust gas pressure sensor, wherein: This test method uses a durability test device for an automotive exhaust gas pressure sensor for testing. First, turn on the constant temperature box 3 to work, maintain the temperature inside the constant temperature box 3, close the outlet cut-off valve 7, open the inlet cut-off valve 5 to fill the medium pressure barrel 2 with gas simulating automotive exhaust gas, and the pressure sensor 4 monitors the pressure inside the medium pressure barrel 2. When the pressure monitor 6 shows that the specified pressure is reached, close the inlet cut-off valve 5, open the simulated power device 8, and the motor 29 drives the piston 23 to move through the cam 18 and the rocker arm 26 to generate air pressure fluctuations. These air pressure fluctuations are transmitted to the inside of the medium pressure barrel 2 through the rubber diaphragm 11. The pressure change inside the medium pressure barrel 2 drives the pressure fluctuation of the pressure sensor 4. By adjusting the pressure regulating cover plate 14, the pressure fluctuation monitored by the pressure sensor 4 inside the medium pressure barrel 2 is made to approach the normal automotive exhaust gas emission level. At this time, open the outlet cut-off valve 7, monitor the pressure change of the pressure sensor test sample 1 through the pressure monitor 6, and start recording the time. Until the pressure monitor 6 monitors that the pressure change of the pressure sensor test sample 1 is abnormal, record the time, and the durability time of the pressure sensor test sample 1 can be calculated. Compared with the traditional method of using the engine operation to generate exhaust gas to test the pressure sensor test sample, the present invention can reduce fuel consumption, reduce environmental pollution, use a motor instead, only consume part of the electric energy, and is easy to adjust to the optimal state, with convenient monitoring and good test results.

Claims

1. A durability test device for an automotive exhaust gas pressure sensor, comprising a pressure sensor test sample (1), a medium pressure barrel (2), a constant temperature box (3), a pressure sensor (4), an intake shut-off valve (5), a pressure monitor (6), an exhaust shut-off valve (7), and a simulated power device (8). Characterized in that: One side of the medium pressure barrel (2) is connected to an intake pipe, on which a pressure sensor (4) and an intake shut-off valve (5) are provided. The other side is connected to the simulated power device (8) through a pipeline, and still another side is connected to one end of the exhaust shut-off valve (7). The other end of the exhaust shut-off valve (7) is connected to the pressure sensor test sample (1). The pressure sensor test sample (1) and the medium pressure barrel (2) are located in the constant temperature box (3). The pressure monitor (6) is electrically connected to the pressure sensor test sample (1) and the pressure sensor (4) respectively; The simulated power device (8) includes a cylinder block (16), on which a pressure pump upper body (19) is provided. Inside the pressure pump upper body (19), there are two medium cavities (20). A rubber diaphragm (11) is horizontally arranged between the two medium cavities (20). The middle of the rubber diaphragm (11) is pressed by an upper spring support plate (10) and a lower spring support plate (12). The top end of the upper spring support plate (10) is connected to one end of an upper spring (21), and the other end of the upper spring (21) is connected to the top end of the medium cavity (20). The bottom end of the lower spring support plate (12) is connected to one end of a lower spring (22), and the other end of the lower spring (22) is connected to the bottom end of the medium cavity (20). A pressure output pipe (9) is provided at the top end of the pressure pump upper body (19). One end of the pressure output pipe (9) is connected to the medium cavity (20), and the other end is connected to the medium pressure barrel (2) through a pipeline. The cylinder block (16) is fixedly connected to a pressure pump bottom shell (28) by bolts. On one side of the top of the pressure pump bottom shell (28), there is a pressure pump bottom shell breather port (25). The inner cavity of the cylinder block (16) is communicated with the medium cavity (20) through a pressure transfer hole (15). A piston (23) is provided in the inner cavity of the cylinder block (16). The piston (23) is movably connected to one end of a rocker arm (26) through a rocker arm upper fixed shaft (24). The other end of the rocker arm (26) is movably connected to a cam (18) through a rocker arm lower fixed shaft (17). The cam (18) is pin-connected to one end of a transmission shaft (27). The cam (18) is located inside the pressure pump bottom shell (28). The other end of the transmission shaft (27) passes through the inner wall of the pressure pump bottom shell (28) and is fixedly connected to a motor (29) through a coupling.

2. A durability test device for an automotive exhaust gas pressure sensor according to claim 1, Characterized in that: One side of the pressure pump upper body (19) is provided with a pressure adjustment hole (13). One end of the pressure adjustment hole (13) is connected to the medium cavity (20), and the other end is provided with a pressure adjustment cover plate (14).

3. A durability test method for an automotive exhaust gas pressure sensor, Characterized in that: The durability test device for an automotive exhaust gas pressure sensor as described in any one of claims 1-2 comprises the following steps: First, a certain amount of simulated automotive exhaust gas is filled into the medium pressure barrel (2) and a certain pressure is maintained; then the constant temperature chamber (3) is turned on to operate at a constant temperature so that the simulated automotive exhaust gas in the medium pressure barrel (2) is maintained at the required test temperature; then the simulated power device (8) is turned on and adjusted so that the gas pressure fluctuation in the medium pressure barrel (2) approaches the level during normal automotive emissions; finally, the outlet cut-off valve (7) is opened to conduct a test on the pressure sensor test sample (1).

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