Variable timing device for diesel engine intake valve

Abstract

This invention discloses a variable timing device for a diesel engine intake valve, comprising a housing, an upper push rod, a lower push rod, a spring, a roller, and a hydraulic unit. The upper end of the housing has an oil inlet, an oil outlet, and a return oil outlet, and the middle of the housing has a transverse lubricating oil channel. The upper push rod is located in the oil chamber at the upper end of the housing, with a piston in the middle of the upper push rod positioned between the oil inlet and the oil outlet. The lower push rod is located in the cavity at the lower end of the housing, opposite to the upper push rod. The spring is fitted onto the middle of the lower push rod, and the roller is located in a groove at the bottom of the lower push rod, with its outer ring supported on the outer contour of the cam on the camshaft. The hydraulic unit is located on one side of the upper end of the housing. This invention adopts a two-section structure for the intake push rod, and the return oil path is controlled by a two-position, one-way solenoid valve. This allows for both normal intake timing and delayed intake timing during valve timing, achieving precise control of the valve opening and closing with high accuracy and stability.

Description

Technical Field

[0001] This invention relates to a timing device for a diesel engine intake valve, and more particularly to a variable timing device for a diesel engine intake valve, belonging to the technical field of diesel engine parts. Background Technology

[0002] Diesel engine valve timing refers to the timing of the opening and closing of diesel engine valves to ensure that the valve opening and closing are synchronized with the piston movement. Correct valve timing improves combustion efficiency, reduces energy loss, and ensures the normal operation of the diesel engine. To ensure accurate valve timing, diesel engines are typically equipped with a camshaft and a valve timing mechanism. The cams on the camshaft convert rotational motion into linear motion through the valve timing mechanism to control the opening and closing of the valves. Currently, valve timing optimization technology is widely used in the diesel engine field, but existing valve timing mechanisms still have drawbacks such as low timing accuracy and poor timing stability. Summary of the Invention

[0003] The purpose of this invention is to provide a diesel engine intake valve variable timing device that is simple in structure, highly accurate, and has good stability.

[0004] This invention is achieved through the following technical solution:

[0005] A variable valve timing device for a diesel engine intake valve includes a housing, an upper push rod, a lower push rod, a spring, a roller, and a hydraulic unit. The housing has an oil inlet and an oil outlet on one side of its upper end, and an oil return port on the other side. A transverse lubricating oil channel is located in the middle of the housing. The upper push rod is positioned within an oil chamber at the upper end of the housing, with a piston in its middle located between the oil inlet and outlet, and slidably connected to the oil chamber wall at the upper end of the housing. The lower push rod is positioned within a cavity at the lower end of the housing, opposite to the upper push rod, and slidably connected to the cavity wall at the lower end of the housing. The spring is fitted onto the middle of the lower push rod, with both ends fixed to a step on the lower push rod and the top wall of the cavity at the lower end of the housing, respectively. The roller is positioned within a groove at the bottom of the lower push rod, fixed to a pin, with both ends of the pin supported on opposite sides of the groove. The outer ring of the roller is supported on the outer contour of a cam on a camshaft. The hydraulic unit is located on one side of the upper end of the housing.

[0006] The objectives of this invention can also be further achieved through the following technical measures.

[0007] The aforementioned variable valve timing device for diesel engine intake valves includes a hydraulic unit comprising a solenoid valve, a check valve, and multiple pipelines. The solenoid valve is located on one side of the upper end of the housing, and the check valve is installed inside the piston side of the upper push rod. The oil inlet pipe is connected to the oil inlet of the housing. When the solenoid valve is activated, the oil outlet of the housing is connected to the inlet of the solenoid valve through the oil outlet pipe, and the outlet of the solenoid valve is connected to the oil inlet pipe. The two ends of the first return oil pipe on the lower side of the oil outlet pipe are respectively connected to the oil outlet pipe and one end of the lubricating oil passage in the middle of the housing. The other end of the lubricating oil passage in the middle of the housing is connected to the return oil port of the housing through the second return oil pipe.

[0008] The aforementioned variable timing device for diesel engine intake valves, wherein the solenoid valve is a two-position one-way solenoid valve.

[0009] The aforementioned variable timing device for diesel engine intake valve, wherein the upper push rod includes a vertical rod and a piston, the piston is fixed on the middle of the vertical rod, and the upper and lower ends of the vertical rod are slidably connected to the top cover of the housing and the through hole in the middle of the housing, respectively.

[0010] The aforementioned variable timing device for diesel engine intake valves, wherein the lower push rod has an inverted T-shaped structure, the upper end of the lower push rod is slidably connected to the through hole in the middle of the housing, and the upper end of the lower push rod is provided with a transverse lubricating hole.

[0011] This invention adopts a two-section structure of upper and lower pushrods for the intake pushrod, and the total length of the two sections is variable. At the same time, the opening and closing of the return oil circuit is controlled by a two-position one-way solenoid valve. In this way, during the valve timing process, two functions can be realized: normal intake timing and delayed intake timing. This achieves the effect of precise control of valve opening and closing, high control accuracy, accurate valve timing, and good stability, thereby ensuring the normal operation of the diesel engine.

[0012] The advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments, which are given by way of example only with reference to the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the solenoid valve in the on state of the present invention;

[0014] Figure 2 This is a schematic diagram of the solenoid valve in the open circuit state of the present invention. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] like Figure 1 and Figure 2As shown, the present invention is mounted on a diesel engine frame using fasteners. The invention includes a housing 1, an upper push rod 2, a lower push rod 3, a spring 4, a roller 5, and a hydraulic unit 6. The upper left side of the housing 1 has an oil inlet 11 and an oil outlet 12, the upper right side of the housing 1 has an oil return port 13, and the middle of the housing 1 has a transverse lubricating oil channel 14. The upper push rod 2 is located in the oil chamber at the upper end of the housing 1. The upper push rod 2 includes a vertical rod 21 and a piston 22. The piston 22 is fixed to the middle of the vertical rod 21. The upper and lower ends of the vertical rod 21 are slidably connected to the housing top cover 15 and the through hole in the middle of the housing 1, respectively. The piston 22 is located between the oil inlet 11 and the oil outlet 12 and is slidably and sealingly connected to the oil chamber wall at the upper end of the housing 1. The lower push rod 3 is located in the cavity at the lower end of the housing 1, opposite to the upper push rod 2. The lower push rod 3 has an inverted T-shaped structure. The upper end of the lower push rod 3 is slidably connected to the through hole in the middle of the housing 1. The upper end of the lower push rod 3 is provided with a transverse lubricating hole 31. The lower end of the lower push rod 3 is slidably connected to the cavity wall at the lower end of the housing 1. The spring 4 is fitted on the middle part of the lower push rod 3. The two ends of the spring 4 are respectively fixed to the step of the lower push rod 3 and the top wall of the cavity at the lower end of the housing 1. The roller 5 is located in the groove at the bottom of the lower push rod 3 and is fixed on the pin 32. The two ends of the pin 32 are respectively supported on both sides of the groove. The outer ring of the roller 5 is supported on the outer contour of the cam 7 on the camshaft.

[0017] The hydraulic unit 6 is located on one side of the upper end of the housing 1, and includes a solenoid valve 61, a check valve 62, and multiple pipelines. The solenoid valve 61 is a two-position, one-way solenoid valve, located on the upper left side of the housing 1. The check valve 62 is installed inside the piston 22 in the middle of the upper push rod 2. The oil inlet pipe 63 is connected to the oil inlet 11 of the housing 1. When the solenoid valve 61 is turned on, the oil outlet 12 of the housing 1 is connected to the inlet of the solenoid valve 61 through the oil outlet pipe 64, and the outlet of the solenoid valve 61 is connected to the oil inlet pipe 63. The two ends of the first return oil pipe 65 below the oil outlet pipe 64 are connected to the oil outlet pipe 64 and the left end of the lubricating oil passage 14 in the middle of the housing 1, respectively. The right end of the lubricating oil passage 14 in the middle of the housing 1 is connected to the return oil port 13 of the housing 1 through the second return oil pipe 66.

[0018] like Figure 1 As shown, solenoid valve 61 is in the ON state. When the lower push rod 3 moves upward with cam 7, the lower push rod 3 pushes the upper push rod 2 upward synchronously, and the two do not separate. The total length of the push rods remains the same, and the intake valve is open. When the upper push rod 2 and the lower push rod 3 move downward with cam 7, the oil circuit state is as follows: Figure 1 As indicated by the arrow, lubricating oil enters the upper part of the oil chamber through the oil inlet 11, enters the lower part of the oil chamber through the one-way valve 62, and forms a circuit through the solenoid valve 61 via the oil outlet 12. At this time, the lubricating oil in the lower part of the oil chamber flows out smoothly, and the downward movement of the upper push rod 2 is unobstructed until the upper and lower push rods finish moving downward with the cam 7. The intake valve is then closed, and the upper and lower push rods maintain a basically synchronous descent. Throughout the entire process, the total length of the push rods remains unchanged, which is the normal intake timing.

[0019] like Figure 2 As shown, solenoid valve 61 is in the open circuit state. When the upper push rod 2 and the lower push rod 3 move upward with the cam 7, they do not separate, and the total length of the push rods remains unchanged. When the upper push rod 2 and the lower push rod 3 move downward with the cam 7, the oil circuit state is as follows: Figure 2 As indicated by the arrow, lubricating oil enters the upper part of the oil chamber through the oil inlet 11 and enters the lower part of the oil chamber through the one-way valve 62. Since the solenoid valve 61 is closed, a circuit cannot be formed, and the lubricating oil in the lower part of the oil chamber cannot flow out. At this time, the lower push rod 3 moves down normally with the cam 7, while the downward movement of the upper push rod 2 is hindered by the lubricating oil pressure in the lower part of the oil chamber. The upper and lower push rods separate, and the total length of the push rods increases until the lower push rod 3 moves down with the cam 7 and returns to the cam base circle. The transverse lubricating oil hole 31 at the upper end of the lower push rod 3 is connected to the lubricating oil channel 14 in the middle of the housing 1. The lubricating oil in the lower part of the oil chamber flows into the upper part of the oil chamber through the oil outlet 12, the first return oil pipe 65, the lubricating oil channel 14, the lubricating oil hole 31, the second return oil pipe 66, and the return oil port 13, forming a circuit. At this time, the lubricating oil in the lower part of the oil chamber can flow out smoothly, and the upper push rod 2 can continue to move down, and the total length of the push rod returns to its original length. During the process of the upper push rod 2 being obstructed from descending, the intake valve remains open until the upper push rod 2 resumes its downward movement and the intake valve closes. This is the delayed intake timing.

[0020] In addition to the above embodiments, the present invention may have other implementation methods. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A variable timing device for a diesel engine intake valve, characterized in that: The system includes a housing, an upper push rod, a lower push rod, a spring, rollers, and a hydraulic unit. The housing has an oil inlet and an oil outlet on one side of its upper end, and an oil return port on the other side. A transverse lubricating oil channel is located in the middle of the housing. The upper push rod is positioned within an oil cavity at the upper end of the housing, with a piston in its middle located between the oil inlet and outlet, and slidably connected to the wall of the oil cavity at the upper end of the housing. The lower push rod is positioned within a cavity at the lower end of the housing, opposite to the upper push rod, and slidably connected to the cavity wall at the lower end of the housing. The spring is fitted onto the middle of the lower push rod, with both ends fixed to a step on the lower push rod and the top wall of the cavity at the lower end of the housing, respectively. The roller is positioned within a groove at the bottom of the lower push rod, and is fixed to a pin, with both ends of the pin supported on either side of the groove. The outer ring of the roller is supported on the outer contour of the cam on the camshaft; the lower push rod has an inverted T-shaped structure, and the upper end of the lower push rod is slidably connected to the through hole in the middle of the housing. The upper end of the lower push rod is provided with a transverse lubricating hole; the hydraulic unit is located on one side of the upper end of the housing. The hydraulic unit includes a solenoid valve, a check valve, and multiple pipelines. The solenoid valve is located on one side of the upper end of the housing, and the check valve is installed inside the piston side in the middle of the upper push rod; the oil inlet pipe is connected to the oil inlet of the housing. When the solenoid valve is turned on, the oil outlet of the housing is connected to the inlet of the solenoid valve through the oil outlet pipe, and the outlet of the solenoid valve is connected to the oil inlet pipe; the two ends of the first return oil pipe on the lower side of the oil outlet pipe are respectively connected to the oil outlet pipe and one end of the lubricating channel in the middle of the housing. The other end of the lubricating channel in the middle of the housing is connected to the return oil port of the housing through the second return oil pipe.

2. The variable timing device for diesel engine intake valve as described in claim 1, characterized in that: The solenoid valve is a two-position one-way solenoid valve.

3. The variable timing device for diesel engine intake valve as described in claim 1, characterized in that: The upper push rod includes a vertical rod and a piston. The piston is fixed on the middle part of the vertical rod, and the upper and lower ends of the vertical rod are slidably connected to the top cover of the housing and the through hole in the middle of the housing, respectively.

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