Overhead cam valve mechanism durability test device

Abstract

The utility model relates to a durability test device for an overhead cam valve mechanism, which comprises a workbench, a cylinder cover, a supporting assembly and a driving assembly, and the cylinder cover is arranged above the workbench; the supporting assembly comprises a damping piece, and the cylinder cover is connected with the workbench through the damping piece. The driving assembly comprises a motor, a bearing seat, an elastic membrane and a connecting shaft assembly, the motor is installed on the workbench, and the output end of the motor is connected with a cam shaft driving gear of the valve mechanism through the bearing seat, the elastic membrane and the connecting shaft assembly in sequence; according to the test device, the durability test of the overhead cam valve mechanism can be carried out through the cylinder cover and the valve mechanism installed on the cylinder cover, complete machine conditions are not needed, in the durability test process, vibration transmitted to the workbench by the valve mechanism can be reduced through the damping piece, and meanwhile, the durability of the overhead cam valve mechanism is improved through the elastic membrane. And the centering error between the bearing seat and the connecting shaft assembly can be adapted, and the axial impact vibration and circumferential angular vibration of the rotating shaft of the valve mechanism can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of automotive engine testing technology, and in particular to a durability testing device for an overhead cam valve train mechanism. Background Technology

[0002] The valve train is an important mechanism for controlling the intake and exhaust phases of the engine. The overhead camshaft is the most common form. At the same time, the in-cylinder braking of the engine can also be controlled by the cam, rocker arm and other structures of the valve train. Therefore, the valve train is an important structural basis for the intake and exhaust phases and in-cylinder braking of the engine.

[0003] The valve train has a complex structure with numerous parts, and its high-speed rotation poses risks of mechanical damage such as impact loads and wear. Therefore, it is necessary to test the operational coordination function and mechanical reliability of the valve train. Utility Model Content

[0004] In view of this, it is necessary to provide a durability testing device for an overhead cam valve train mechanism to test the operational coordination function and mechanical reliability of the valve train mechanism.

[0005] This utility model provides a durability testing device for an overhead camshaft valve train mechanism, including a worktable, a cylinder head, a support assembly, and a drive assembly. The cylinder head is disposed above the worktable and is used to install the valve train mechanism. The support assembly includes a shock absorber, and the cylinder head is connected to the worktable via the shock absorber. The drive assembly includes a motor, a bearing housing, an elastic diaphragm, and a connecting shaft assembly. The motor is mounted on the worktable, and the output end of the motor is sequentially connected to the camshaft drive gear of the valve train mechanism via the bearing housing, the elastic diaphragm, and the connecting shaft assembly.

[0006] Furthermore, the shock absorber includes multiple rubber pads or multiple shock-absorbing springs installed between the cylinder head and the worktable.

[0007] Furthermore, the support assembly also includes a connecting plate, the top of which is fixedly connected to the bottom of the cylinder head, and the bottom of which is connected to the worktable via the shock absorber.

[0008] Furthermore, the support assembly also includes an oil collection tray disposed at the bottom of the connecting plate and fixedly connected to the workbench.

[0009] Furthermore, the support assembly also includes a plurality of inlet and outlet oil seats mounted on the connecting plate.

[0010] Furthermore, the drive assembly also includes a torque meter, and the output end of the motor is connected to the bearing housing via the torque meter.

[0011] Furthermore, the connecting shaft assembly includes a connecting flange, a shaft flange, a drive shaft, an idler shaft, and an idler wheel connected in sequence. The connecting flange is connected to the elastic diaphragm, and the idler wheel is connected to the camshaft drive gear of the valve train mechanism.

[0012] Furthermore, the connecting shaft assembly also includes a positioning washer, a first bolt, an oil seal, and a second bolt. The first bolt passes through the connecting flange, the positioning washer, and the shaft flange in sequence. The positioning washer has annular protrusions on both sides, and the two annular protrusions engage with annular grooves formed on opposite sides of the connecting flange and the shaft flange, respectively. The oil seal is sleeved on the drive shaft, and the shaft flange is connected to the oil seal and the drive shaft via the second bolt.

[0013] Furthermore, the connecting shaft assembly also includes a bearing, a positioning sleeve, and an end face gasket. The bearing and the positioning sleeve are both sleeved on the idler wheel shaft. The bearing engages with an annular groove formed on the idler wheel. One side of the positioning sleeve is coaxially embedded in the idler wheel, and one side of the positioning sleeve is connected to the end face gasket. The other side of the positioning sleeve abuts against the bearing. The idler wheel is connected to the camshaft drive gear of the valve train mechanism via the end face gasket.

[0014] Furthermore, the device also includes a guide seat, a positioning screw, and a positioning nut. The guide seat is mounted on the elastic diaphragm, and the positioning screw passes sequentially through the bearing housing, the guide seat, and the connecting flange, and is connected to the positioning nut.

[0015] Compared with existing technologies, this test device, through the cylinder head and the valve train installed on it, and driven by the drive assembly, can conduct durability tests on the overhead cam valve train mechanism. It does not require whole machine conditions and is different from component testing conditions, ensuring the integrity and durability of the system structure. During the above-mentioned durability test, the vibration transmitted from the valve train mechanism to the worktable can be reduced by setting up shock absorbers. At the same time, the set elastic diaphragm can adapt to the alignment error between the bearing housing and the connecting shaft assembly, and reduce the rotational axial impact vibration and circumferential angular vibration of the valve train mechanism. Attached Figure Description

[0016] Figure 1 A schematic diagram of a portion of the overall structure of the durability testing device for the top-mounted cam valve mechanism provided in this embodiment of the utility model;

[0017] Figure 2 A schematic diagram of another part of the overall structure of the overhead cam valve timing mechanism durability testing device provided in this embodiment of the utility model;

[0018] Figure 3This is a schematic diagram of the connecting shaft assembly in the durability testing device for the top-mounted cam valve train provided in an embodiment of the present invention.

[0019] Figure 4 This is a schematic diagram of the installation of the elastic diaphragm in the durability testing device for the top-mounted cam valve mechanism provided in this embodiment of the utility model. Detailed Implementation

[0020] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0021] Those skilled in the art will understand that, in this specification, the term "comprising" is an open-ended expression, meaning that the stated feature is present but other features are excluded. Directional terms such as "upper," "lower," "left," and "right" refer to exemplary directions based on the accompanying drawings. Features specified as "first" or "second" implicitly include one or more of that feature. Singular expressions can also be used in plural forms. "Multiple" means two or more. The terms "installed," "connected," and "linked" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection via an intermediate medium, and it can be a connection within two components. Furthermore, "linked" can include wireless connections.

[0022] Traditional durability testing equipment for overhead camshaft valve trains is typically a complete engine valve train testing device, meaning it incorporates the structure of the entire engine. Durability testing of the valve train is performed using a running engine. This testing process includes testing the entire valve train as well as its components (such as camshafts, rocker arms, valves, and springs). By running the entire engine, the durability of the valve train or its internal components can be tested. However, the cost of a complete engine structure is high, hindering forward development.

[0023] During the aforementioned durability test of the overhead camshaft valve train, cylinder head vibration affects the stability of its internal valve train operation, as well as its coaxiality (i.e., circumferential angular vibration). It can also cause axial impact on the valve train. If these vibrations are not addressed, they will affect the service life of the testing device. Therefore, only low-speed, short-term functional tests can be performed; long-term durability testing is not possible. Therefore, if... Figure 1-2As shown, this utility model embodiment provides a durability testing device for an overhead cam valve train mechanism, including a worktable 100, a cylinder head 200, a support assembly 300, and a drive assembly 400. The cylinder head 200 is disposed above the worktable 100 and is used to install the valve train mechanism. The support assembly 300 includes a shock absorber 310, and the cylinder head 200 is connected to the worktable 100 via the shock absorber 310. The drive assembly 400 includes a motor 410, a bearing housing 420, an elastic diaphragm 430, and a connecting shaft assembly 440. The motor 410 is mounted on the worktable 100, and the output end of the motor 410 is connected to the camshaft drive gear of the valve train mechanism in sequence via the bearing housing 420, the elastic diaphragm 430, and the connecting shaft assembly 440.

[0024] During implementation, the test device, through the cylinder head 200 and the valve train installed on it, and driven by the drive assembly 400, can conduct durability tests on the overhead cam valve train mechanism. It does not require whole-machine conditions and is different from component testing conditions, ensuring the integrity and durability of the system structure. During the above-mentioned durability test, the vibration transmitted from the valve train mechanism to the worktable 100 can be reduced by setting the damping component 310. At the same time, the elastic diaphragm 430 can accommodate the alignment error between the bearing housing 420 and the connecting shaft assembly 440, and reduce the rotational axial impact vibration and circumferential angular vibration of the valve train mechanism.

[0025] In this embodiment, the top surface of the workbench 100 is used to install and place the support assembly 300 and the drive assembly 400, since the support assembly 300 and the drive assembly 400 need to be installed sequentially along a horizontal axis.

[0026] In one embodiment, a structure such as a pad or a height-adjustable support frame can be added to the bottom of the drive assembly 400 to ensure that the output ends of the connecting shaft assembly 440 and the valve distribution assembly are coaxially arranged.

[0027] In another embodiment, the top surface of the worktable 100 includes a first support surface and a second support plane. The cylinder head 200 is mounted on the first support surface via a support assembly 300, and the drive assembly 400 is mounted on the second support surface. There may be a height difference between the first support surface and the second support surface to facilitate the coaxial arrangement of the output ends of the connecting shaft assembly 440 and the valve train assembly.

[0028] In this embodiment, the cylinder head 200 is disposed above the workbench 100 and is used to install the valve train mechanism. The cylinder head 200 is a sample of the top cover part of the engine.

[0029] In one embodiment, a T-slot is provided on the workbench 100, and the bottom of the cylinder head 200 is slidably connected to the T-slot for easy assembly and disassembly. Specifically, a slider is provided at the bottom of the cylinder head 200, and the slider is slidably connected to the T-slot. The T-slot includes a vertically arranged first strip groove and a horizontally arranged second strip groove. The bottom of the first strip groove is connected to the middle part of the second strip groove. The slider is T-shaped and slidably connected to the T-slot. The T-slot extends in a horizontal direction perpendicular to the axial direction of the cylinder head 200.

[0030] When placing the cylinder head 200, simply insert the slider at the bottom of the cylinder head 200 into the T-slot. When disassembling, simply remove the slider from the T-slot to remove the cylinder head 200.

[0031] The support assembly 300 in this embodiment includes a damper 310, through which the cylinder head 200 is connected to the worktable 100. The damper 310 eliminates circumferential vibrations transmitted from the valve train to the cylinder head 200.

[0032] In one embodiment, the damper 310 includes a plurality of rubber pads or a plurality of damping springs mounted between the cylinder head 200 and the worktable 100.

[0033] When the damping component 310 consists of multiple rubber pads, the rubber pads can absorb the vibration of the cylinder head 200 along its circumferential direction; when the damping component 310 is a damping spring, the setting direction of the damping spring can be controlled to absorb the vibration of the cylinder head 200 along its circumferential direction. This reduces the impact of vibration on the connection between the cylinder head 200, the valve train mechanism, and the drive assembly 400, effectively improving the service life of the overhead cam valve train durability test device in this embodiment.

[0034] Of course, in other embodiments, the shock absorber 310 can also be implemented by combining a rubber pad and a shock absorber spring.

[0035] In one embodiment, the support assembly 300 further includes a connecting plate 320, the top of which is fixedly connected to the bottom of the cylinder head 200, and the bottom of which is connected to the worktable 100 via a shock absorber 310. The connecting plate 320 provides cylinder bores and oil inlet and return passages for each cylinder of the cylinder head 200. Specifically, the support assembly 300 also includes a plurality of oil inlet and return seats 340 mounted on the connecting plate 320, which can provide inlet and return oil circulation for the valve train.

[0036] Because there is oil leakage in the valve train mechanism inside the cylinder head 200, in order to avoid oil contamination of the workbench 100 surface and affecting the test process, in one embodiment, the support assembly 300 further includes an oil collection tray 330 disposed at the bottom of the connecting plate 320 and fixedly connected to the workbench 100. The oil collection tray 330 facilitates the collection of leaking oil.

[0037] The drive assembly 400 in this embodiment includes a motor 410, a bearing housing 420, an elastic diaphragm 430, and a connecting shaft assembly 440. The motor 410 is mounted on the worktable 100, and the output end of the motor 410 is connected to the camshaft drive gear of the valve train mechanism in sequence via the bearing housing 420, the elastic diaphragm 430, and the connecting shaft assembly 440.

[0038] Among them, the motor 410 provides power to the valve train, the bearing housing 420 bears the axial load of the valve train, and the elastic diaphragm 430 can adapt to the alignment error between the bearing housing 420 and the connecting shaft assembly 440, as well as reduce the rotational axial impact vibration and circumferential angular vibration of the valve train.

[0039] In one embodiment, the drive assembly 400 further includes a torque meter 411, and the output terminal of the motor 410 is connected to the bearing housing 420 via the torque meter 411. The torque meter 411 connected to the output terminal of the motor 410 can measure torque. A torque meter 411 of model Aigo HP-100 can be used to measure torque, which is a structure that those skilled in the art can conceive of, and will not be described or explained in detail here.

[0040] like Figure 3 As shown, in one embodiment, the connecting shaft assembly 440 includes a connecting flange 441, a shaft flange 443, a drive shaft 445, an idler shaft 446, and an idler 449 connected in sequence. The connecting flange 441 is connected to the elastic diaphragm 430, and the idler 449 is connected to the camshaft drive gear of the valve train mechanism.

[0041] In one embodiment, the connecting shaft assembly 440 further includes a positioning washer 442, a first bolt, an oil seal 444, and a second bolt. The first bolt passes through the connecting flange 441, the positioning washer 442, and the shaft flange 443 in sequence. The positioning washer 442 has annular protrusions on both sides, and the two annular protrusions engage with the annular grooves formed on opposite sides of the connecting flange 441 and the shaft flange 443, respectively. The oil seal 444 is sleeved on the drive shaft 445, and the shaft flange 443 is connected to the oil seal 444 and the drive shaft 445 via the second bolt.

[0042] Among them, the oil seal 444 cooperates with the end cap 210 of the cylinder head 200 to provide sealing oil to the end face of the valve train.

[0043] In one embodiment, the connecting shaft assembly 440 further includes a bearing 447, a positioning sleeve 448, and an end face gasket 4410. The bearing 447 and the positioning sleeve 448 are both sleeved on the idler shaft 446. The bearing 447 is engaged with an annular groove formed on the idler 449. One side of the positioning sleeve 448 is coaxially built into the idler 449. One side of the positioning sleeve 448 is connected to the end face gasket 4410, and the other side of the positioning sleeve 448 abuts against the bearing 447. The idler 449 is connected to the camshaft drive gear of the valve train mechanism via the end face gasket 4410.

[0044] The idler shaft 446 is supported by bearing 447 and radially positions the idler 449. An oil passage is designed in between to provide lubrication (the oil passage is connected to the oil hole of the end cover 210 of the cylinder head 200). The positioning bushing 448 provides axial positioning for the idler shaft 446. The end face gasket 4410 can prevent the idler 449 from rotating and rubbing against the cylinder head 200. The idler 449 is connected to the camshaft drive gear of the valve train mechanism and drives the valve train mechanism to run under the drive of the motor 410.

[0045] like Figure 4 As shown, in one embodiment, the device further includes a guide seat 431, a positioning screw, and a positioning nut. The guide seat 431 is mounted on the elastic diaphragm 430, and the positioning screw passes sequentially through the bearing seat 420, the guide seat 431, and the connecting flange 441, and is connected to the positioning nut. The guide seat 431 has an annular stepped structure.

[0046] In another embodiment, there are multiple guide seats 431, positioning screws, and positioning nuts. The elastic diaphragm 430 has multiple first connecting holes and multiple second connecting holes, which are arranged alternately along the circumference of the elastic diaphragm 430. Multiple guide seats 431 are respectively installed in the multiple first connecting holes and multiple second connecting holes. Some positioning screws pass through the guide seats 431 installed in the multiple first connecting holes and the bearing seat 420 and are connected to the positioning nuts. Other positioning screws pass through the guide seats 431 installed in the multiple second connecting holes and the connecting flange 441 and are connected to the positioning nuts. The elastic diaphragm 430 and guide seats 431 can achieve circumferential positioning constraint between the bearing seat 420 and the connecting flange 441.

[0047] Understandably, the aforementioned valve train is an overhead cam valve train, which uses either a toothed belt or a chain drive. The advantages of a toothed belt are that it requires no lubrication and has low operating noise, although its lifespan is slightly shorter compared to a chain. Compared to a toothed belt, a chain drive requires lubrication and has higher transmission noise, but its advantages are reliability and a lifespan comparable to that of the engine. The valve train is driven by the drive assembly 400 to test the durability of the valve train or its internal components.

[0048] To facilitate the assessment of the durability of the valve train, the test apparatus in this embodiment is also equipped with monitoring devices for conditional parameters such as oil temperature and pressure (T, P), as well as monitoring devices for operating conditional parameters such as drive speed (n), drive angle vibration (ΔP), drive torque (T), and cylinder head 20° vibration (a), and a detection device for valve displacement (s). The monitoring and detection of the above parameters can provide conditions for assessing durability.

[0049] It is understood that the above-mentioned monitoring and detection devices can collect data through various corresponding sensors, which is a structure that can be conceived by those skilled in the art, and will not be elaborated or explained in detail here.

[0050] Example 1: A durability test is conducted on the entire valve train. The valve train is installed on the cylinder head 200 and connected to the connecting shaft assembly 440. The valve train is driven to move by the motor 410. After the valve train has been working for a certain period of time, the durability of the valve train can be determined by detecting the overall working condition of the valve train.

[0051] Example 2: A durability test is performed on the cam in the valve train. The valve train is installed on the cylinder head 200 and connected to the connecting shaft assembly 440. The valve train is driven to move by the motor 410. After the valve train has been working for a certain period of time, the durability of the cam can be determined by detecting the working condition of the cam.

[0052] Example 3: Durability test of rocker arm in valve train mechanism. The valve train mechanism is installed on cylinder head 200 and connected to connecting shaft assembly 440. The valve train mechanism is driven to move by motor 410. After the valve train mechanism has been working for a certain period of time, the durability of cam can be judged by detecting the working condition of rocker arm.

[0053] Example 4: A durability test is performed on the valves in the valve train. The valve train is installed on the cylinder head 200 and connected to the connecting shaft assembly 440. The valve train is driven to move by the motor 410. After the valve train has been working for a certain period of time, the durability of the cam can be determined by detecting the working condition of the valves.

[0054] Understandably, durability tests can also be performed on other components in the valve train.

[0055] Compared with existing technologies, this test device, through the cylinder head 200 and the valve train installed on it, and driven by the drive assembly 400, can conduct durability tests on the overhead cam valve train mechanism. It does not require whole-machine conditions and is different from component testing conditions, ensuring the integrity and durability of the system structure. During the above-mentioned durability test, the vibration transmitted from the valve train mechanism to the worktable 100 can be reduced by setting the damping component 310. At the same time, the elastic diaphragm 430 can accommodate the alignment error between the bearing housing 420 and the connecting shaft assembly 440, and reduce the rotational axial impact vibration and circumferential angular vibration of the valve train mechanism.

[0056] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A durability testing device for a top-mounted cam valve timing mechanism, characterized in that, include: Workbench; Cylinder head, which is located above the workbench and is used to install the valve train mechanism; A support assembly, including a shock absorber, wherein the cylinder head is connected to the worktable via the shock absorber; The drive assembly includes a motor, a bearing housing, an elastic diaphragm, and a connecting shaft assembly. The motor is mounted on the worktable, and the output end of the motor is connected to the camshaft drive gear of the valve train via the bearing housing, the elastic diaphragm, and the connecting shaft assembly in sequence.

2. The durability testing device for the top-mounted cam valve train mechanism according to claim 1, characterized in that, The shock absorber includes multiple rubber pads or multiple shock absorber springs installed between the cylinder head and the worktable.

3. The durability testing device for the top-mounted cam valve train mechanism according to claim 1, characterized in that, The support assembly also includes a connecting plate, the top of which is fixedly connected to the bottom of the cylinder head, and the bottom of which is connected to the worktable via the shock absorber.

4. The durability testing device for the top-mounted cam valve train mechanism according to claim 3, characterized in that, The support assembly also includes an oil collection tray disposed at the bottom of the connecting plate and fixedly connected to the workbench.

5. The durability testing device for the top-mounted cam valve train mechanism according to claim 4, characterized in that, The support assembly also includes multiple inlet and outlet oil seats mounted on the connecting plate.

6. The durability testing device for the top-mounted cam valve train mechanism according to claim 1, characterized in that, The drive assembly also includes a torque meter, and the output end of the motor is connected to the bearing housing via the torque meter.

7. The durability testing device for the top-mounted cam valve train mechanism according to claim 1, characterized in that, The connecting shaft assembly includes a connecting flange, a shaft flange, a drive shaft, an idler shaft, and an idler wheel connected in sequence. The connecting flange is connected to the elastic diaphragm, and the idler wheel is connected to the camshaft drive gear of the valve train.

8. The durability testing device for the top-mounted cam valve timing mechanism according to claim 7, characterized in that, The connecting shaft assembly further includes a positioning washer, a first bolt, an oil seal, and a second bolt. The first bolt passes through the connecting flange, the positioning washer, and the shaft flange in sequence. The positioning washer has annular protrusions on both sides, and the two annular protrusions engage with annular grooves formed on opposite sides of the connecting flange and the shaft flange. The oil seal is sleeved on the drive shaft, and the shaft flange is connected to the oil seal and the drive shaft via the second bolt.

9. The durability testing device for the top-mounted cam valve train mechanism according to claim 7, characterized in that, The connecting shaft assembly also includes a bearing, a positioning sleeve, and an end face gasket. The bearing and the positioning sleeve are both sleeved on the idler wheel shaft. The bearing engages with an annular groove formed on the idler wheel. One side of the positioning sleeve is coaxially embedded in the idler wheel, and one side of the positioning sleeve is connected to the end face gasket. The other side of the positioning sleeve abuts against the bearing. The idler wheel is connected to the camshaft drive gear of the valve train mechanism via the end face gasket.

10. The durability testing device for the top-mounted cam valve train mechanism according to claim 7, characterized in that, The device also includes a guide seat, a positioning screw, and a positioning nut. The guide seat is mounted on the elastic diaphragm, and the positioning screw passes through the bearing housing, the guide seat, and the connecting flange in sequence, and is connected to the positioning nut.

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