A camshaft structure with adjustable fuel supply advance angle

Abstract

The present invention belongs to the technical field of diesel engines, and relates to a camshaft structure with an adjustable fuel supply advance angle, wherein an oil pump cam with a fuel injection pump is fixedly mounted on a rotating shaft on the front side of the camshaft, and the position where the camshaft and the timing gear are connected consists of two shaft sections with different shaft diameters, an annular groove and a first threaded hole for assembly and disassembly, and the two shaft sections are transitioned through a slot; the timing gear is provided with a high-pressure oil pipe interface, an annular oil groove placed at the center of gravity and two second threaded holes convenient for fixing with the camshaft, and the shaft sections are sequentially a first shaft section and a second shaft section, and the diameter of the first shaft section close to the oil pump cam side is larger than that of the second shaft section, and the timing gear is interference fit with the first shaft section and clearance fit with the second shaft section, and the camshaft structure realizes that the assembly and disassembly of the camshaft assembly and the adjustment of the fuel supply advance angle can be completed by using a specific camshaft assembly structure, an external hydraulic device and special tools.

Description

Technical Field

[0001] The invention belongs to the technical field of diesel engine assembly, adjustment and equipment maintenance, and relates to a camshaft structure with adjustable fuel supply advance angle. Background Art

[0002] With the rapid development of economic construction, diesel engines are increasingly widely used in various fields of economic construction such as automobiles, engineering machinery, ships and power generation due to their advantages of large power range, good economy and high reliability. For diesel engines, the fuel supply advance angle is a very important parameter. The diesel engine fuel supply advance angle refers to the angle at which the high-pressure oil pump supplies fuel in advance when the fuel injector injects fuel before the diesel engine compression stroke piston reaches the top dead center. The reason why the diesel engine supplies fuel in advance is to better atomize the fuel. Too large or too small a fuel supply advance angle has a great impact on the power and economy of the diesel engine.

[0003] During the development of diesel engines, in order to meet the performance requirements of diesel engines, the fuel supply advance angle needs to be constantly adjusted. Diesel engines should have different fuel supply advance angles under different working conditions, and the fuel supply advance angle needs to be adjusted. The higher the speed of the diesel engine, the larger the fuel supply advance angle is required; the lower the speed, the smaller the fuel supply advance angle is required, so that the diesel engine can have the best power and economy.

[0004] At present, the adjustment methods of diesel engine fuel supply advance angle are as follows: Figure 1 As shown: the timing gear (Ⅰ) and the camshaft (Ⅱ) are connected by bolts (Ⅲ), the oil pump cam (Ⅳ) on the camshaft (Ⅱ) drives the injection pump (Ⅴ) to inject oil, and the fuel supply advance angle is adjusted by changing the thickness of the adjustment gasket (Ⅵ). This adjustment method has the following two problems:

[0005] 1. The camshaft and the timing gear are connected by bolts. Their relative position relationship is fixed and cannot be adjusted. The fuel advance angle cannot be adjusted by adjusting the relative position relationship between the camshaft and the timing gear.

[0006] 2. The fuel supply advance angle is adjusted by changing the thickness of the adjusting gasket. The grinding and replacement of the adjusting gasket requires the removal of the fuel injection pump of each cylinder and the accessories connected to it, which is labor-intensive, time-consuming and inefficient. Summary of the invention

[0007] In view of this, in order to solve the problems existing in the above-mentioned fuel supply advance angle adjustment process, the present invention provides a camshaft structure with adjustable fuel supply advance angle.

[0008] To achieve the above-mentioned purpose, the present invention provides a camshaft structure with an adjustable oil supply advance angle, comprising a camshaft and a timing gear used in conjunction with the camshaft; an oil pump cam with an oil injection pump is fixedly installed on the rotating shaft on the front side of the camshaft, and the connection position between the camshaft and the timing gear is composed of two shaft sections with different shaft diameters, an annular groove and a first threaded hole for disassembly and assembly, and the two shaft sections are transitioned through a slot; the timing gear is provided with a high-pressure oil pipe interface, an annular oil groove placed at the center of gravity and two second threaded holes for easy fixation with the camshaft, the shaft sections are successively the first shaft section and the second shaft section, the diameter of the first shaft section close to the oil pump cam side is larger than that of the second shaft section, and the timing gear has an interference fit with the first shaft section and a clearance fit with the second shaft section.

[0009] Furthermore, the high-pressure oil pipe interface can be detachably connected to a high-pressure oil pipe carrying high-pressure oil.

[0010] Furthermore, when the fuel supply advance angle is adjusted, it also includes a pressing sleeve pressed on the rear end of the camshaft, and suitable bolts are inserted into the pressing sleeve, the first threaded hole and the second threaded hole to fix the pressing sleeve, the camshaft and the timing gear.

[0011] Furthermore, the pressing sleeve, the first threaded hole and the bolts in the second threaded hole are threadedly connected with adjusting nuts for adjusting the tightness between the pressing sleeve and the camshaft.

[0012] Furthermore, an O-ring is installed in the annular oil groove.

[0013] Furthermore, when the timing gear is disassembled, it also includes a pulling block fixed at the rear of the timing gear and a bolt for fixing the pulling block and the timing gear, and a bolt is also fixedly installed in the middle of the pulling block.

[0014] Furthermore, it also includes a cushion block stuck in the first threaded hole.

[0015] The beneficial effects of the present invention are:

[0016] 1. The camshaft structure with adjustable fuel advance angle disclosed in the present invention, when the fuel advance angle needs to be adjusted, the camshaft is fixed by a pressing sleeve, the high-pressure oil pipe interface on the timing gear is connected to the high-pressure oil, and the flywheel linked with the timing gear is rotated to the required crankshaft angle, the high-pressure oil is unloaded, and the O-ring, pressing sleeve, adjusting nut and bolt are removed to complete the adjustment of the fuel advance angle. The entire camshaft structure utilizes interference fit to achieve the connection between the camshaft and the timing gear, and utilizes a camshaft and timing gear with a specific structure to achieve the adjustment of the fuel advance angle. It is a specific camshaft and timing gear connection structure that can quickly and easily adjust the fuel advance angle.

[0017] 2. The camshaft structure with adjustable oil advance angle disclosed in the present invention, when disassembling the timing gear, install the O-ring, gasket, pull block and bolts for fixing the pull block and the timing gear in sequence, connect the timing gear to high-pressure oil, turn the bolt in the middle of the pull block to move the timing gear away from the camshaft, and when the timing gear exits the shaft section, remove the high-pressure oil, remove the camshaft and timing gear, and complete the disassembly. By using a specific camshaft assembly structure, an external hydraulic device and special tools, the disassembly and assembly of the camshaft assembly and the adjustment of the oil advance angle are realized; a lot of work is reduced, work efficiency is improved, and it has the advantages of simple structure, low cost, and easy operation.

[0018] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0020] Figure 1 It is an assembly diagram of a timing gear and a camshaft in the prior art;

[0021] Figure 2 It is an assembly diagram of the timing gear and the camshaft of the present invention;

[0022] Figure 3 It is a structural schematic diagram of the camshaft of the present invention;

[0023] Figure 4 It is a schematic structural diagram of the timing gear of the present invention;

[0024] Figure 5 It is a schematic diagram of the installation structure of the press sleeve when adjusting the fuel supply advance angle of the present invention;

[0025] Figure 6 This is a state diagram of the camshaft structure when the fuel supply advance angle is adjusted according to the present invention;

[0026] Figure 7 This is a state diagram of the camshaft structure when the timing gear of the present invention is disassembled.

[0027] Figure numerals: camshaft 1, annular groove 11, first threaded hole 12, first shaft section 13, second shaft section 14, slot 15, timing gear 2, high-pressure oil pipe interface 21, annular oil groove 22, second threaded hole 23, sealing ring 3, pressing sleeve 4, adjusting nut 5, bolt 6, oil pump cam 7, fuel injection pump 8, pull block 9, gasket 10. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0029] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0030] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] In this patent, the fuel supply advance angle refers to the crankshaft angle of the piston from the top dead center when the injector starts to spray fuel.

[0032] Interference fit refers to a fit in which the difference between the size of the hole and the size of the mating shaft is a negative fit. After assembly, elastic pressure is generated on the surface of the parts, thereby obtaining a tight connection.

[0033] like Figures 2 to 7The camshaft structure with adjustable oil supply advance angle shown in the figure comprises a camshaft 1 and a timing gear 2 used in conjunction with the camshaft 1; an oil pump cam 7 with an oil injection pump 8 is fixedly mounted on the rotating shaft on the front side of the camshaft 1; the connection position of the camshaft 1 and the timing gear 2 is composed of two shaft sections with different shaft diameters, an annular groove 11 and a first threaded hole 12 for disassembly and assembly, and the two shaft sections are transitioned through a slot 15; the timing gear 2 is provided with a high-pressure oil pipe interface 21, an annular oil groove 22 placed at the center of gravity and two second threaded holes 23 for easy fixation with the camshaft 1, and a high-pressure oil pipe with high-pressure oil can be detachably connected to the high-pressure oil pipe interface 21. The shaft sections are the first shaft section 13 and the second shaft section 14 in sequence, the diameter of the first shaft section 13 close to the oil pump cam 7 is larger than that of the second shaft section 14, and the timing gear 2 has an interference fit with the first shaft section 13 and a clearance fit with the second shaft section 14.

[0034] When the fuel supply advance angle is adjusted, the pressing sleeve 4 is also included, which is pressed on the rear end of the camshaft 1. Appropriate bolts 6 are inserted into the pressing sleeve 4, the first threaded hole 12 and the second threaded hole 23 to fix the pressing sleeve 4, the camshaft 1 and the timing gear 2. An O-ring 3 is installed in the annular oil groove 22. The bolts 6 in the pressing sleeve 4, the first threaded hole 12 and the second threaded hole 23 are threadedly connected with an adjusting nut 5 for adjusting the tightness of the pressing sleeve 4 and the camshaft 1.

[0035] When it is necessary to adjust the oil advance angle, first install the O-ring 3 into the annular groove 11, connect the high-pressure oil to the high-pressure oil pipe interface 21 of the timing gear 2, and at the same time, turn the nut to move the timing gear 2 toward the camshaft 1 until the pressing sleeve 4 contacts the end face of the camshaft 1, and then rotate the flywheel linked to the timing gear 2 to rotate it to the required crankshaft angle, unload the high-pressure oil, and remove the O-ring 3, the pressing sleeve 4, the adjusting nut 5 and the bolt 6 to complete the adjustment of the oil advance angle. The entire camshaft 1 structure utilizes interference fit to achieve the connection between the camshaft 1 and the timing gear 2, and utilizes the camshaft 1 and the timing gear 2 of a specific structure to achieve the adjustment of the oil advance angle. It is a specific connection structure between the camshaft 1 and the timing gear 2, which can quickly and easily adjust the oil advance angle.

[0036] When the timing gear 2 is disassembled, it also includes a pull block 9 fixed to the rear of the timing gear 2 and a bolt 6 for fixing the pull block 9 and the timing gear 2. The middle of the pull block 9 is also fixedly mounted with a bolt 6. A cushion block 10 is placed in the first threaded hole 12.

[0037] When disassembling the timing gear 2, install the O-ring 3 into the annular groove 11 in sequence, insert the gasket 10 into the first threaded hole 12, fix the pull block 9 on the timing gear 2 through the bolt 6, connect the timing gear 2 to the high-pressure oil, turn the bolt 6 in the middle of the pull block 9 to move the timing gear 2 away from the camshaft 1, and when the timing gear 2 exits the shaft section, remove the high-pressure oil, remove the camshaft 1 and the timing gear 2, and complete the disassembly. The camshaft 1 and the timing gear 2 are disassembled and assembled using hydraulic devices and special tooling, and the camshaft 1 assembly is disassembled and assembled and the oil supply advance angle is adjusted using a specific camshaft 1 assembly structure, an external hydraulic device and special tools; a lot of work is reduced, work efficiency is improved, and it has the advantages of simple structure, low cost, and easy operation.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A camshaft structure with adjustable fuel supply advance angle, characterized in that: It comprises a camshaft and a timing gear used in conjunction with the camshaft; an oil pump cam with an oil injection pump is fixedly mounted on the rotating shaft on the front side of the camshaft; the position where the camshaft and the timing gear are connected consists of two shaft sections with different shaft diameters, an annular groove and a first threaded hole for disassembly and assembly, and the two shaft sections are transitioned through a slot; the timing gear is provided with a high-pressure oil pipe interface, an annular oil groove placed at the center of gravity and two second threaded holes for easy fixation with the camshaft, the shaft sections are sequentially the first shaft section and the second shaft section, the diameter of the first shaft section close to the oil pump cam side is larger than the second shaft section, the timing gear has an interference fit with the first shaft section and a clearance fit with the second shaft section; When the fuel supply advance angle is adjusted, it also includes a pressing sleeve pressed on the rear end of the camshaft, and suitable bolts are inserted into the pressing sleeve, the first threaded hole and the second threaded hole to fix the pressing sleeve, the camshaft and the timing gear; the high-pressure oil pipe interface can be detachably connected to the high-pressure oil pipe with high-pressure oil; the annular groove is equipped with an O-ring; When adjusting the oil advance angle, first install the O-ring into the annular groove, connect the high-pressure oil to the high-pressure oil pipe interface of the timing gear, and at the same time, turn the nut to move the timing gear toward the camshaft until the sleeve contacts the end face of the camshaft, and then rotate the flywheel linked to the timing gear to rotate it to the required crankshaft angle.

2. The camshaft structure with adjustable fuel supply advance angle as claimed in claim 1, characterized in that: The pressing sleeve, the first threaded hole and the bolts in the second threaded hole are threadedly connected with adjusting nuts for adjusting the tightness between the pressing sleeve and the camshaft.

3. The camshaft structure with adjustable fuel supply advance angle as claimed in claim 1, characterized in that: When the timing gear is disassembled, it also includes a pull block fixed at the rear of the timing gear and a bolt for fixing the pull block and the timing gear. A bolt is also fixedly installed in the middle of the pull block.

4. The camshaft structure with adjustable fuel supply advance angle as claimed in claim 3, characterized in that: Also included is a spacer block that is clamped in the first threaded hole.

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