Diesel engine cylinder head sealing test tool device and test method

Abstract

The present application belongs to the technical field of sealing test, and particularly relates to a diesel engine cylinder head sealing test tool device and a test method, which comprises a tool frame, the surface of the tool frame is used for placing a diesel engine cylinder, a support plate is fixed above the tool frame, a pressing mechanism is arranged on the support plate, and a test mechanism is connected below the pressing mechanism; the test mechanism comprises a cylinder pressure gauge, a pipeline, a one-way valve and a sealing rubber head, the pressing mechanism comprises a rocking wheel, a rotating shaft, a screw rod, an arc-shaped disc, a T-shaped block, a connecting rod and a spring, the pipeline is connected below the cylinder pressure gauge, the one-way valve is arranged in the pipeline, and the sealing rubber head is sleeved outside the lower end of the pipeline, the device solves the problem that the rotating shaft bearing is installed on the support plate and the sealing property in the test process cannot be improved, so that the test data is inaccurate.

Description

Technical Field

[0001] This invention belongs to the technical field of sealing test, specifically relating to a tooling device and test method for testing the sealing performance of a diesel engine cylinder head. Background Technology

[0002] The engine cylinder head is the most complex component of a diesel engine, bearing the heaviest mechanical and thermal loads. It is a complex box-shaped part with intake and exhaust valve seats, valve guide holes, and fuel injector mounting holes. It is frequently in contact with high-temperature, high-pressure combustion gases, thus requiring it to withstand significant thermal and mechanical loads. Leaks in the cylinder head will lead to oil leaks, causing pressure fluctuations within the engine and preventing normal operation. To ensure product quality during manufacturing, cylinder pressure gauges are typically used to test the cylinder head's airtightness. Airtightness testing instruments usually employ rubber joints, which are suitable for diesel engines and can be pressed into the corresponding spark plug holes. Repeated testing and insertion / removal of spark plug holes by rubber joints leads to severe wear. Inaccurate test data is often caused by aging or severe wear of the rubber joint. Current technology requires pausing the test and replacing the rubber joint, failing to improve sealing during the test and significantly reducing testing efficiency. This phenomenon has become a pressing problem for those in the field to solve. Summary of the Invention

[0003] The purpose of this invention is to provide a tooling and testing method for testing the sealing performance of a diesel engine cylinder head, so as to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a diesel engine cylinder head sealing test fixture and test method, comprising a fixture frame, the surface of which is used to place a diesel engine cylinder, a support plate fixed above the fixture frame, and a clamping mechanism provided on the support plate, and a test mechanism connected below the clamping mechanism; the test mechanism includes a cylinder pressure gauge, a pipe, a one-way valve, and a sealing head, the clamping mechanism includes a rocker wheel, a rotating shaft, a screw, an arc-shaped disc, a T-shaped block, a connecting rod, and a spring, the pipe is connected below the cylinder pressure gauge, and the one-way valve is disposed inside the pipe, and the sealing head is sleeved on the outer side of the lower end of the pipe.

[0005] The present invention further illustrates that the rotating shaft bearing is mounted on the support plate, and its right end is fixed to the rocker wheel. The rotating shaft has a threaded hole inside, and the threaded hole is threadedly connected to the screw. The left end of the screw is threadedly connected to the arc-shaped disk. The T-shaped block is connected to the cylinder pressure gauge bearing through the connecting rod and is located below the arc-shaped disk. The spring is located between the bottom of the T-shaped block and the inner side of the support plate, and is sleeved on the outer side of the connecting rod. After the rotating shaft rotates, the outer end of the arc-shaped disk contacts the upper surface of the T-shaped block, and the edge of the T-shaped block is arc-shaped.

[0006] The present invention further illustrates that a protrusion is provided at the right end of the screw, and a locking block is slidably connected to the outside. A plug is fixed to the left side of the locking block. A hole is provided on the surface of the rocker wheel, and the plug is inserted into the hole. After the screw rotates, the position of the arc-shaped disk moves.

[0007] The present invention further illustrates that the outer side of the pipe is threaded, and a toothed disc is threadedly connected to the outer side. A nut is provided above the toothed disc, and a groove is provided above the sealing head. A spring is provided in the groove, and the upper end of the spring is in contact with the lower surface of the toothed disc.

[0008] The present invention further illustrates that the inner bearing of the tooling frame is connected to a gear column, and the outer side of the connecting rod is fixed with a gear disc two, both of which mesh with the gear column.

[0009] The present invention further illustrates that the outer side of the screw is threaded with a second nut, and the second nut is in contact with the left side of the arc-shaped disk. A limit block is provided on the right side of the arc-shaped disk, and the limit block is fixed to the outer side of the screw.

[0010] The present invention further explains that after the T-shaped block rotates, it disengages from the arc-shaped disk, and the arc-shaped disk is divided into several different models according to its own length.

[0011] The present invention further describes the test method as follows: Step S1, preheating the diesel engine to ensure it reaches normal operating temperature; Step S2, disconnecting the fuel and ignition systems, turning off the ignition switch, and disconnecting the diesel pump and ignition system; Step S3, removing all spark plugs or injectors; Step S4, pressing the sealing rubber head of the cylinder pressure gauge into the spark plug hole of the cylinder being tested; Step S5, fully opening the throttle and starting the diesel engine, rotating its internal crankshaft for 3-5 seconds, and reading the cylinder pressure gauge reading; Step S6, repeating the measurement, measuring each cylinder once, and then comparing the data. If the cylinder pressure is lower than 80% of the standard value, there is a sealing problem; otherwise, there is no sealing problem.

[0012] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention conducts cylinder head sealing tests by inserting and removing the sealing rubber head into and out of the spark plug hole of the cylinder. The entire operation process is simple and the measurement efficiency is high. Inserting the sealing rubber head into the spark plug hole can ensure sealing performance and improve the accuracy of test data. By adjusting the position of the arc-shaped plate, the force of the sealing rubber head inserted into the spark plug hole is increased, thereby improving the sealing performance during the test and ensuring the accuracy of the test. Furthermore, by adjusting the position of the arc-shaped plate, the sealing rubber head can be used for a long time until it is completely scrapped, which greatly extends the service life of the sealing rubber head and makes full use of it, thereby reducing the replacement frequency and reducing costs. After the position of the arc-shaped plate is adjusted, the operator can fix the screw by sliding the locking block to prevent the arc-shaped plate and the T-shaped block from being affected by the screw and rotating when they are pressed against each other, thus preventing the arc-shaped plate from failing to press down the T-shaped block and ensuring the smooth progress of the test. When the sealing head is inserted into the spark plug hole and its wear is relatively severe, in order to further improve the sealing performance, the spring is forced outward to open the sealing head, thereby increasing the adhesion strength between the sealing head and the inner wall of the spark plug hole, thus strengthening the sealing performance, fully avoiding errors in the test data, and improving the test accuracy. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the pressing mechanism and testing mechanism of the present invention; Figure 3 This is a schematic diagram of the internal structure of the sealing head and rotating shaft of the present invention; Figure 4 This is a partial structural schematic diagram of the clamping mechanism of the present invention; Figure 5 This is an exploded view of the testing mechanism of the present invention; Figure 6 This is an exploded view of the clamping mechanism of the present invention; Figure 7 This is a schematic diagram of Embodiment 3 of the present invention; Figure 8 This is a plan view of the present invention; Figure 9 This is a schematic diagram of several arc-shaped disks of the present invention; In the diagram: 1. Tooling frame; 2. Support plate; 21. Cylinder pressure gauge; 22. Pipe; 221. Gear disc one; 23. Sealing head; 231. Spring; 24. Rocker wheel; 25. Rotating shaft; 251. Screw; 252. Arc-shaped disc; 253. Locking block; 26. T-shaped block; 27. Connecting rod; 271. Gear disc two; 28. Spring; 3. Gear column. Detailed Implementation

[0014] The following detailed, non-limiting description of the technical solution of the present invention, in conjunction with preferred embodiments and accompanying drawings, is provided. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0015] Please see Figures 1-9 The present invention provides a technical solution: a diesel engine cylinder head sealing test fixture and test method, including a fixture frame 1, the surface of the fixture frame 1 is used to place the diesel engine cylinder, a support plate 2 is fixed above the fixture frame 1, and a pressing mechanism is provided on the support plate 2, and a test mechanism is connected below the pressing mechanism. The testing mechanism includes a cylinder pressure gauge 21, a pipe 22, a one-way valve, and a sealing head 23. The clamping mechanism includes a rocker wheel 24, a rotating shaft 25, a screw 251, an arc-shaped disc 252, a T-shaped block 26, a connecting rod 27, and a spring 28. The pipe 22 is connected below the cylinder pressure gauge 21, and the one-way valve is located inside the pipe 22. The sealing head 23 is sleeved on the outer side of the lower end of the pipe 22.

[0016] The rotating shaft 25 is mounted on the support plate 2, and its right end is fixed to the rocker wheel 24. The rotating shaft 25 has a threaded hole inside, and the threaded hole is threaded to the screw 251. The left end of the screw 251 is threaded to the arc-shaped disk 252. The T-shaped block 26 is connected to the cylinder pressure gauge 21 bearing through the connecting rod 27 and is located below the arc-shaped disk 252. The spring 28 is located between the bottom of the T-shaped block 26 and the inner side of the support plate 2, and is sleeved on the outer side of the connecting rod 27. After the rotating shaft 25 rotates, the outer end of the arc-shaped disk 252 contacts the upper surface of the T-shaped block 26, and the edge of the T-shaped block 26 is arc-shaped. Before measurement, the operator rotates the rocker wheel 24, which drives the arc-shaped disk 252 to rotate via the shaft 25. The arc-shaped disk 252 rotates until it contacts the T-shaped block 26 and they press against each other. The T-shaped block 26 moves downward under force, and the spring 28 deforms under force. At the same time, the T-shaped block 26 drives the cylinder pressure gauge 21 downward via the connecting rod 27, thereby inserting the sealing head 23 into the spark plug hole of the cylinder through the pipe 22. During the measurement, the internal pressure of the cylinder enters the cylinder pressure gauge 21 through the pipe 22. The cylinder sealing performance is measured by the reading displayed on the cylinder pressure gauge 21. After the test is completed, the rocker wheel 24 is rotated in the opposite direction, causing the arc-shaped disk 252 to disengage from the T-shaped block 26. The reaction force generated by the spring 28 resets it, thereby causing the sealing head 23 to be pulled out of the spark plug hole. The whole operation process is simple, the measurement efficiency is high, and the insertion of the sealing head 23 into the spark plug hole can ensure the sealing performance and improve the accuracy of the test data.

[0017] The right end of the screw 251 is provided with a protrusion, and a locking block 253 is slidably connected to the outside. A plug rod is fixed on the left side of the locking block 253. The surface of the rocker wheel 24 is provided with a hole, and the plug rod is inserted into the hole. After the screw 251 rotates, the position of the arc-shaped disk 252 moves. Example 1: Repeated insertion and removal of the sealing head 23 from the spark plug hole causes wear. In this case, the operator can pull the locking block 253, causing the insertion rod to be pulled out of the hole in the rocker wheel 24. Then, rotating the locking block 253 causes the screw 251 to rotate. The screw 251 rotates and moves within the threaded hole of the rotating shaft 25, thereby moving the arc-shaped disk 252. After the arc-shaped disk 252 moves to the left, when the rotating shaft 25 is rotated again, the arc-shaped disk 252 and the T-shaped block 26 are pressed against each other, increasing the downward stroke of the T-shaped block 26. This simultaneously increases the force with which the sealing head 23 inserts into the spark plug hole, thereby improving the sealing performance during the test and ensuring the test results are met. The accuracy of the test is improved, and by adjusting the position of the arc-shaped disk 252, the sealing head 23 can be used for a long time until it is completely scrapped. The service life of the sealing head 23 is greatly extended, making full use of it, thereby reducing the replacement frequency and reducing costs. After the position of the arc-shaped disk 252 is adjusted, the operator can slide the locking block 253 to slide it through the protrusion of the screw 251 and insert the rod back into the hole. This can fix the screw 251 and prevent the arc-shaped disk 252 from rotating due to the influence of the screw 251 when it is pressed against the T-shaped block 26. This also prevents the arc-shaped disk 252 from failing to press the T-shaped block 26, ensuring the smooth progress of the test.

[0018] The outer side of the pipe 22 is threaded, and a toothed disc 221 is connected to the outer thread. A nut is provided above the toothed disc 221. A groove is provided above the sealing head 23, and a spring piece 231 is provided in the groove. The upper end of the spring piece 231 is in contact with the lower surface of the toothed disc 221. Example 2: When the sealing head 23 is inserted into the spark plug hole and its wear is relatively severe, in order to further improve the sealing performance, the operator turns the nut one to make the gear plate one 221 rotate. The gear plate one 221 moves downward while rotating through the threaded part of the pipe 22, squeezing the spring plate 231. The spring plate 231 is forced outward to open the sealing head 23, thereby increasing the adhesion strength between the sealing head 23 and the inner wall of the spark plug hole, thus strengthening the sealing performance, fully avoiding errors in the test data, and improving the test accuracy.

[0019] The inner bearing of the tooling frame 1 is connected to the gear column 3, and the outer side of the connecting rod 27 is fixed with the gear disc 271. Both the gear disc 221 and the gear disc 271 mesh with the gear column 3. Example 3: Figure 7 As shown, the first gear 221 rotates, driving the gear column 3 to rotate. The gear column 3, through meshing, drives the second gear 271 to rotate, thereby driving the connecting rod 27 to rotate. After the connecting rod 27 rotates, it drives the T-block 26 to rotate, causing the T-block 26 to disengage from the arc-shaped disk 252. At this time, because the spring piece 231 in embodiment 2 squeezes the sealing head 23 outward, it presses it tightly into the spark plug hole, increasing the friction intensity between the two. Through the friction between the sealing head 23 and the inner wall of the spark plug hole, it can be ensured that the sealing head 23 will not disengage from the spark plug hole. Therefore, the operator does not need to hold the crank 24, freeing their hands to better observe the reading of the cylinder pressure gauge 21, and can also pick up other diesel engine cylinders to be tested and place them aside, which relatively improves the efficiency of the test.

[0020] The screw 251 is threaded with a nut 2 on its outer side, and the nut 2 is in contact with the left side of the arc-shaped disk 252. A limit block is provided on the right side of the arc-shaped disk 252, and the limit block is fixed to the outer side of the screw 251.

[0021] After the T-shaped block 26 rotates, it disengages from the arc-shaped disk 252. The arc-shaped disk 252 is divided into several different models according to its own length. Example 4: Figure 7 As shown, when the height of the oil extraction machine cylinder changes due to model issues, the sealing head 23 cannot be pressed into the spark plug hole. In this case, the arc-shaped disc 252 needs to be replaced. Alternatively, if the arc-shaped disc 252 is severely worn, it can also be replaced. In embodiment three, after the T-shaped block 26 disengages from the arc-shaped disc 252, the operator loosens nut two and then rotates the arc-shaped disc 252 to remove it from the screw 251, thereby replacing the arc-shaped disc 252. The model of the arc-shaped disc 252 is as follows: Figure 9 As shown, the arc-shaped disc 252 is replaced and adjusted according to the height of the cylinder to be tested later, and the operation is simple; The entire device has a simple structure and is suitable for large-scale cylinder sealing tests. Regardless of the cylinder model or spark plug hole size, the same test fixture can be used, making it widely applicable. It eliminates the need to manufacture several different types of fixtures based on the different test objects, greatly reducing manufacturing costs.

[0022] The test methods include: Step S1: Preheat the diesel engine to ensure it reaches normal operating temperature; Step S2: Disconnect the fuel and ignition systems, turn off the ignition switch, and disconnect the diesel pump and ignition system; Step S3: Remove all spark plugs or fuel injectors; Step S4: Press the sealing rubber head 23 of the cylinder pressure gauge 21 into the spark plug hole of the cylinder being tested; Step S5: Fully open the throttle and start the diesel engine, allowing the internal crankshaft to rotate for 3-5 seconds, and read the reading on cylinder pressure gauge 21. Step S6: Repeat the measurement. Measure each cylinder 2-3 times and then compare the data. Compare the cylinder pressure values. If the cylinder pressure is lower than 80% of the standard value, there is a sealing problem; otherwise, there is no sealing problem.

[0023] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, 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, and therefore should not be construed as a limitation of this invention.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features, and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fixture for testing the sealing performance of a diesel engine cylinder head, comprising a fixture frame (1), characterized in that: The surface of the tooling frame (1) is used to place the diesel engine cylinder. A support plate (2) is fixed above the tooling frame (1), and a clamping mechanism is provided on the support plate (2). A test mechanism is connected below the clamping mechanism. The test mechanism includes a cylinder pressure gauge (21), a pipe (22), a one-way valve, and a sealing head (23). The clamping mechanism includes a rocker wheel (24), a rotating shaft (25), a screw (251), an arc-shaped disc (252), a T-shaped block (26), a connecting rod (27), and a spring (28). The pipe (22) is connected below the cylinder pressure gauge (21), and the one-way valve is located inside the pipe (22). The sealing head (23) is sleeved on the outer side of the lower end of the pipe (22). The rotating shaft (25) is mounted on the support plate (2) and its right end is fixed to the rocker wheel (24). The rotating shaft (25) has a threaded hole inside and is threaded to the screw (251). The left end of the screw (251) is threaded to the arc-shaped disk (252). The T-shaped block (26) is connected to the cylinder pressure gauge (21) bearing through the connecting rod (27) and is located below the arc-shaped disk (252). The spring (28) is located between the bottom of the T-shaped block (26) and the inner side of the support plate (2) and is sleeved on the outer side of the connecting rod (27). After the rotating shaft (25) rotates, the outer end of the arc-shaped disk (252) contacts the upper surface of the T-shaped block (26). The edge of the T-shaped block (26) is arc-shaped. The right end of the screw (251) is provided with a protrusion, and a locking block (253) is slidably connected to the outside. A plug is fixed on the left side of the locking block (253). The surface of the rocker wheel (24) is provided with a hole, and the plug is inserted into the hole. After the screw (251) rotates, the position of the arc-shaped disk (252) moves. The outer side of the pipe (22) is threaded, and a toothed disc (221) is connected to the outer thread. A nut is provided above the toothed disc (221). A groove is provided above the sealing head (23), and a spring piece (231) is provided in the groove. The upper end of the spring piece (231) is in contact with the lower surface of the toothed disc (221).

2. The diesel engine cylinder head sealing test fixture according to claim 1, characterized in that: The tooling frame (1) has a gear column (3) connected to the inner bearing, and a gear disc (271) is fixed to the outer side of the connecting rod (27). Both the gear disc (221) and the gear disc (271) mesh with the gear column (3).

3. The diesel engine cylinder head sealing test fixture according to claim 2, characterized in that: The screw (251) is threaded with a nut, and the nut is in contact with the left side of the arc-shaped disk (252). A limit block is provided on the right side of the arc-shaped disk (252), and the limit block is fixed to the outside of the screw (251).

4. The diesel engine cylinder head sealing test fixture according to claim 3, characterized in that: After the T-shaped block (26) rotates, it disengages from the arc-shaped disk (252). The arc-shaped disk (252) is divided into several different models according to its own length.

5. A test method for a diesel engine cylinder head sealing test fixture, as described in claim 1, characterized in that: The test method includes: Step S1: Preheat the diesel engine to ensure it reaches normal operating temperature; Step S2: Disconnect the fuel and ignition systems, turn off the ignition switch, and disconnect the diesel pump and ignition system; Step S3: Remove all spark plugs or fuel injectors; Step S4: Press the sealing rubber head (23) of the cylinder pressure gauge (21) into the spark plug hole of the cylinder being tested; Step S5: Fully open the throttle and start the diesel engine, allowing the internal crankshaft to rotate for 3-5 seconds, and read the reading on the cylinder pressure gauge (21); Step S6: Repeat the measurement. Measure each cylinder 2-3 times and then compare the data. Compare the cylinder pressure values. If the cylinder pressure is lower than 80% of the standard value, there is a sealing problem; otherwise, there is no sealing problem.

Images