Double-channel hydraulic tappet

Abstract

The double-channel hydraulic tappet comprises a shell (1), an upper plunger (2), a lower plunger (5), a base plate (4) and a one-way valve steel ball (6), the upper plunger, the lower plunger and the base plate are all installed in the shell, the base plate (4) is located between the upper plunger and the lower plunger, an opening (21) is formed in the lower end of the upper plunger (2), and the one-way valve steel ball (6) is arranged in the opening (21). The lower end of the upper plunger is sealed through a base plate (4); the lower plunger is provided with an oil return groove (15) and an oil return hole (14), the oil return hole (14) is communicated with the oil return groove (15), a low-pressure cavity (10) is formed between the lower plunger (5) and the base plate (4), and the oil return hole (14) is communicated with the high-pressure cavity (11) and the low-pressure cavity (10) through a gap between the lower plunger (5) and the shell (1). The rocker arm is simple and reliable in structure, compact in assembly and easy and convenient to machine, and can play a role in adjusting the gap between the cam and the rocker arm and providing engine oil with different pressures for the rocker arm so as to change the working state of the rocker arm.

Description

Technical Field

[0001] The utility model relates to an engine accessory, in particular to a double-channel hydraulic tappet which can be used for a variable valve timing system. Background Art

[0002] The existing common hydraulic lash adjuster only uses a single oil circuit to supply oil to a single oil chamber, which eliminates the gap between the valve and the cam to reduce the impact when the valve rocker arm is driven by the cam to swing. The hydraulic lash adjuster used to provide a certain pressure to the rocker arm for the oil drive mechanism to switch the working condition has a closed surface on the bottom of the ball head plunger of the upper section of the hydraulic tappet, and it is difficult to discharge the waste generated by punching during the manufacturing process. Therefore, it is necessary to improve the structure of the existing hydraulic lash adjuster to optimize the working method and make it easier to process and manufacture. Utility Model Content

[0003] In order to solve the problems existing in the prior art, the utility model provides a dual-channel hydraulic tappet, which can automatically compensate for the valve working clearance and adjust the valve opening time by adjusting the oil supply state.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is a dual-channel hydraulic tappet, including a shell, an upper plunger, a lower plunger, a pad and a one-way valve, the lower plunger is a hollow structure, and the lower plunger, the one-way valve and the bottom of the shell together form a high-pressure chamber; the upper plunger, the lower plunger and the pad are all installed inside the shell, the pad is located between the upper plunger and the lower plunger, an opening is provided at the lower end of the upper plunger, and the lower end of the upper plunger is sealed by the pad; an oil return groove and an oil return hole are provided on the lower plunger, the oil return hole and the oil return groove are connected, a low-pressure chamber is formed between the lower plunger and the pad, and the oil return hole connects the high-pressure chamber and the low-pressure chamber through the gap between the lower plunger and the shell.

[0005] The utility model adopts a dual-channel hydraulic tappet with a segmented plunger, which is installed in a guide hole on the engine cylinder head, and the ball head is connected to the ball groove of the valve rocker arm. The upper plunger and the lower plunger are separated by a pad to ensure that the oil circuits between the upper and lower plungers are separated. The upper plunger has an oil inlet hole on the side, and the lower end of the upper plunger is sealed by the pad. After the oil enters the upper plunger, it flows directly upward. The bottom of the upper plunger is opened, and the upper and lower plungers are separated by the pad, which is convenient for processing and realizes the adjustment function.

[0006] In one embodiment of the utility model, an upper oil hole is formed at the upper end of the upper plunger, and an opening is formed at the bottom of the lower end of the upper plunger.

[0007] In an embodiment of the present invention, at least one oil inlet hole is provided on a side of the upper plunger.

[0008] In one embodiment of the utility model, an oil return groove and at least one oil return hole are provided on the straight wall at the lower end of the outer cylindrical surface of the lower plunger, and the oil return groove is a circumferential annular groove. The lower plunger is provided with an oil return groove and an oil return hole, and when the oil in the high-pressure chamber flows out, it can return to the oil storage chamber through the oil return hole, thereby ensuring that the hydraulic tappet works normally in the initial stage of engine oil supply.

[0009] In one embodiment of the utility model, at least one oil inlet groove is provided on the top of the lower plunger. At the same time, the lower plunger has an oil inlet groove, and the oil enters the oil storage chamber and enters the high-pressure chamber downward under the action of the pressure difference.

[0010] In an embodiment of the present invention, an annular groove is provided on the inner circle of the shell.

[0011] In an embodiment of the utility model, the annular groove includes an upper annular groove and a lower annular groove, a first oil hole is opened at the upper annular groove, and a second oil hole is opened at the upper portion of the lower annular groove.

[0012] In one embodiment of the utility model, the upper plunger, the backing plate and the lower plunger are restricted in the housing by a retaining spring.

[0013] This technical solution has the following beneficial effects:

[0014] The utility model adopts a hydraulic clearance adjuster structure of a segmented plunger, and a pad is set between the upper plunger and the lower plunger to ensure the separation of the upper and lower oil paths. An oil return hole is opened on the lower plunger to form a passage between the high-pressure chamber and the low-pressure chamber, solving the problem of difficult oil return in the initial stage of engine startup. A hole is opened at the lower end of the upper plunger to ensure the discharge of processing waste. Further, a ring groove is added on the inner circle of the housing to reduce the amount of grinding. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of an embodiment of the utility model;

[0016] Figure 2 It is a structural schematic diagram of an upper plunger in an embodiment of the utility model;

[0017] Figure 3 This is another structural schematic diagram of the upper plunger in one embodiment of the utility model;

[0018] Figure 4 It is a structural schematic diagram of a lower plunger in one embodiment of the utility model. DETAILED DESCRIPTION

[0019] Below is a combination of the embodiments and the attached Figures 1 to 4 The utility model is further described.

[0020] A dual-channel hydraulic tappet adopts a hydraulic clearance adjuster structure of a segmented plunger, which is installed in a guide hole on an engine cylinder head, and a ball head is connected to a ball groove of a valve rocker arm.

[0021] like Figure 1 As shown, a dual-channel hydraulic tappet for automatic adjustment of engine clearance of variable valve timing VVT includes a housing 1, an upper plunger 2, a pad 4 and a lower plunger 5. One end of the housing 1 is open, the lower end of the upper plunger 2 contacts the pad 4, the lower end of the pad 4 contacts the upper end surface of the upper plunger 5, the lower end of the upper plunger is sealed by the pad 4, and the upper plunger and the lower plunger are separated by the pad, so as to ensure the oil circuit separation between the upper and lower plungers. The lower ends of the upper plunger 2, the pad 4 and the upper plunger 5 are placed inside the housing 1 and the outer circumference is matched with the inner wall of the housing 1. The upper plunger 2, the pad 4 and the upper plunger 5 are limited in the housing 1 by the retaining spring 3 and do not fall out.

[0022] The outer circumferential surface of the housing 1 is provided with two annular grooves, an upper annular groove and a lower annular groove, to reduce the amount of processing. The upper annular groove is provided with a first oil hole 19, and the lower annular groove is provided with a first oil hole 20. High-pressure oil is supplied to the upper end through the first oil hole 19, the oil inlet hole 12 and the upper end oil hole 18 to form an oil circuit.

[0023] like Figure 2-3 As shown, the upper end of the upper plunger 2 is provided with an upper end oil hole 18, the side of the upper plunger 2 is provided with at least one oil inlet hole 12, the lower end surface of the upper plunger 2 is in contact with the upper end surface of the pad 4, and the upper plunger is pressed on the pad 4 by pressure to form a sealing area, which is separated from the low-pressure chamber 10. The bottom of the upper plunger 2 is provided with an opening 21 to facilitate the discharge of waste during processing. Figure 2 The schematic diagram of the upper plunger structure is provided with an oil inlet hole. Figure 3 It is a schematic diagram of the upper plunger structure with two oil inlet holes.

[0024] The upper plunger 5 is a hollow structure and contains a low-pressure chamber 10. A one-way valve is provided at the bottom opening of the upper plunger 5. The one-way valve includes a one-way valve steel ball, a one-way valve spring, and a spring seat 7. A one-way valve spring seat 7 is provided at the bottom of the one-way valve steel ball 6, and a one-way valve spring 8 for support is provided between the one-way valve steel ball 6 and the one-way valve spring seat 7. The one-way valve spring seat 7 is supported by a plunger return spring 9 inside the housing 1. The upper plunger 5, the one-way valve steel ball 6 and the bottom of the housing 1 together form a high-pressure chamber 11. An oil return groove 15 is provided on the straight wall at the lower end of the outer cylindrical surface of the upper plunger 5. At least one oil return hole 14 is opened at the oil return groove 15, and the oil return groove 15 is connected to the oil return hole 14. In this embodiment, the oil return groove 15 is a circumferential annular groove. Each of the oil return holes 14 communicates with the high-pressure chamber 11 and the low-pressure chamber 10 through the gap between the upper plunger 5 and the housing 1. At least one oil inlet groove 13 is provided at the upper end of the upper plunger 5 , and the low-pressure oil enters the tappet low-pressure chamber 10 through the first oil hole 20 and the oil inlet groove 13 .

[0025] The utility model specifically relates to a double-oil supply columnar hydraulic tappet that can be used in a variable valve timing system, which can automatically compensate for the valve working clearance and adjust the valve opening time by adjusting the oil supply state. The utility model has a simple and reliable structure, compact assembly, and is easy to process, and can effectively save space in the cylinder head. It can simultaneously play the two roles of adjusting the clearance between the cam and the rocker arm and providing the rocker arm with oil of different pressures to change its working state.

[0026] The above specific embodiments are only used to explain the utility model, not to limit the utility model. Any changes and substitutions made to the utility model without creative labor within the scope of protection of the concept and claims of the utility model shall fall within the scope of protection of the utility model patent.

Claims

1. A dual-channel hydraulic tappet, comprising a housing (1), an upper plunger (2), a lower plunger (5), a backing plate (4) and a one-way valve, wherein the lower plunger (5) is a hollow structure, and the lower plunger (5), the one-way valve and the bottom of the housing (1) together form a high-pressure chamber (11), characterized in that: The upper plunger (2), the lower plunger (5) and the gasket (4) are all installed inside the shell, the gasket (4) is located between the upper plunger and the lower plunger, the lower end of the upper plunger (2) is provided with an opening (21), and the lower end of the upper plunger is sealed by the gasket (4); the lower plunger (5) is provided with an oil return groove (15) and an oil return hole (14), the oil return hole (14) and the oil return groove (15) are connected, a low-pressure chamber (10) is formed between the lower plunger (5) and the gasket (4), and the oil return hole (14) is connected to the high-pressure chamber (11) and the low-pressure chamber (10) through the gap between the lower plunger (5) and the shell (1).

2. The dual-channel hydraulic tappet according to claim 1, characterized in that: An upper oil hole (18) is provided at the upper end of the upper plunger (2), and an opening (21) is provided at the bottom of the lower end of the upper plunger (2).

3. The dual-channel hydraulic tappet according to claim 1, characterized in that: At least one oil inlet hole (12) is provided on the side of the upper plunger (2).

4. The dual-channel hydraulic tappet according to claim 1, characterized in that: An oil return groove (15) and at least one oil return hole (14) are provided on the straight wall at the lower end of the outer cylindrical surface of the lower plunger (5), and the oil return groove (15) is a circumferential annular groove.

5. The dual-channel hydraulic tappet according to claim 1, characterized in that: At least one oil inlet groove (13) is provided on the top of the lower plunger (5).

6. The dual-channel hydraulic tappet according to claim 1, characterized in that: An annular groove is provided on the inner circle of the shell (1).

7. The dual-channel hydraulic tappet according to claim 6, characterized in that: The annular groove comprises an upper annular groove and a lower annular groove. A first oil hole (19) is opened at the upper annular groove, and a second oil hole (20) is opened at the upper portion of the lower annular groove.

8. The dual-channel hydraulic tappet according to any one of claims 1 to 7, characterized in that: The upper plunger (2), the backing plate (4) and the lower plunger (5) are restricted in the housing (1) by means of a retaining spring (3).

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