Two-cylinder engine crankshaft

Abstract

The utility model relates to a two-cylinder engine crankshaft. The utility model relates to a double-shaft double-shaft bearing which comprises a first main shaft neck, a second main shaft neck, a third main shaft neck, a first balance block, a second balance block, a third balance block and a fourth balance block, a first connecting rod neck is connected between the first balance block and the second balance block, a second connecting rod neck is connected between the third balance block and the fourth balance block, and a flange is coaxially arranged at the outer end of the first main shaft neck. The third main shaft neck is used for being connected with a power output part, gear necks and a chain wheel neck are coaxially arranged at the outer end of the third main shaft neck, a flat square is arranged at the outer end of the chain wheel neck, the two gear necks are sequentially and fixedly sleeved with a balance shaft driving gear and a timing chain wheel, and a signal panel is further coaxially fixed to the outer side face of the first balance block. The in-phase double-cylinder gasoline engine has the advantages of being simple in manufacturing process, easy to maintain, compact in structure, small in vibration amplitude and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of engine crankshafts, especially a two-cylinder engine crankshaft. BACKGROUND

[0002] The more the cylinder number of engine is, the stronger its power is, but the corresponding production process is more complex.In some special occasions, such as motorcycles, agricultural equipment, range extenders, etc., they do not have high requirements on the power of engine, but have higher requirements on the size, weight, production cost, fuel economy, maintenance difficulty, etc.of engine, so two-cylinder engine has irreplaceability in low-cost, small space, medium-low load scenarios.However, two-cylinder engine naturally has the defect of difficult balance of first-order inertia force, so how to reduce vibration and noise has become a problem for two-cylinder engine production enterprises. SUMMARY

[0003] The utility model provides a kind of two-cylinder engine crankshaft;Solve the problem that two-cylinder engine naturally has first-order inertia force difficult balance in prior art.

[0004] The above technical problems of the utility model are mainly solved by the following technical scheme: a two-cylinder engine crankshaft, comprising: first main journal, second main journal and third main journal, three main journals are coaxial, the inner end of the first main journal is connected with first balance block, the two ends of the second main journal are connected with second balance block and third balance block respectively, the inner end of the third main journal is connected with fourth balance block, the first balance block and the second balance block are connected with first connecting rod neck, the third balance block and the fourth balance block are connected with second connecting rod neck, two connecting rod necks are coaxially arranged, the center line of connecting rod neck and main journal is coplanar design, the outer end of the first main journal is coaxially provided with flange, the outer cylindrical surface thereof is matched with crankshaft rear oil seal, seals the rear end of engine, a plurality of screw holes are provided on the end face of the flange for connecting power output parts, the outer end of the third main journal is coaxially provided with gear neck and sprocket neck, and the shaft diameter is stepwisely reduced, so that a step for limiting can be formed, the outer end of the sprocket neck is provided with flat square, balance shaft drive gear and timing sprocket are sequentially fixedly sleeved on two gear necks, and the outer side surface of the first balance block is also coaxially fixed with signal disc.

[0005] Further, three main journals are used to cooperate with crankshaft hole on engine cylinder block to support crankshaft, two connecting rod necks are rotationally matched with connecting rod to convert reciprocating motion of piston into rotary motion of crankshaft.The function of flat square is to cooperate with inner rotor of oil pump to drive oil pump to rotate.The upper and lower surfaces of flat square are concentric arc surfaces, and the left and right surfaces are symmetrical planes with respect to the center surface of crankshaft.A second positioning hole is provided in the center of the end surface of flat square, and the second positioning hole is used to accurately position oil pump.Signal disc is used to provide crankshaft position signal for ECU.

[0006] Further, a first oil channel through the first balance block is arranged between the first main journal and the first connecting rod journal, so that the oil in the bearing oil groove of the first main journal enters the surface of the first connecting rod journal through the first oil channel to provide cooling and lubrication for the first connecting rod journal.

[0007] Therefore, compared with the prior art, the utility model has the following characteristics: 1. The utility model is applicable to the in-phase double-cylinder gasoline engine, has the advantages of simple manufacturing process, easy maintenance and compact structure, and the balance block and the balance shaft driving gear are arranged, the balance shaft driving gear can be used to drive the balance shaft to rotate, and the balance shaft and the balance block are combined to offset the vibration generated during the operation of the engine. BRIEF DESCRIPTION OF DRAWINGS

[0008] ATTACHED Figure 1 It is a structural schematic diagram of the utility model;

[0009] ATTACHED Figure 2 It is a disassembled view of the utility model;

[0010] ATTACHED Figure 3 It is a structural schematic diagram of the utility model after the signal disc, the balance shaft driving gear and the timing sprocket are disassembled;

[0011] ATTACHED Figure 4 It is attached Figure 3 The structural view from another perspective;

[0012] ATTACHED Figure 5 It is attached Figure 3 The center face sectional view. DETAILED DESCRIPTION

[0013] The technical scheme of the utility model will be further specifically described below by combining with the drawings.

[0014] In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0015] Embodiment 1: see Figure 1 , Figure 2 and Figure 3 , a two-cylinder engine crankshaft, comprising: a first main journal 12, a second main journal 14 and a third main journal 16, the three main journals are coaxial, the inner end of the first main journal is connected with a first balance block 25, the two ends of the second main journal are respectively connected with a second balance block 26 and a third balance block 27, the inner end of the third main journal is connected with a fourth balance block 29, a first connecting rod journal 13 is connected between the first balance block and the second balance block, a second connecting rod journal 15 is connected between the third balance block and the fourth balance block, the two connecting rod journals are coaxially arranged, the center line of the connecting rod journal and the main journal is coplanar design, the outer end of the first main journal is coaxially provided with a flange 11, the outer cylindrical surface of which cooperates with the rear oil seal of the crankshaft to seal the rear end of the engine, six screw holes 21 are provided on the end face of the flange for connecting power output parts, the outer end of the third main journal is coaxially provided with a gear journal 17 and a sprocket journal 18, and the shaft diameter is stepwise reduced, so that a step for limiting is formed, a flat square 19 is provided on the outer end of the sprocket journal, a balance shaft drive gear 3 and a timing sprocket 4 are sequentially and fixedly sleeved on the two gear journals, the balance shaft drive gear 3 and the timing sprocket 4 need to be heated during installation, so as to be press-fitted on the gear journal and the sprocket journal, a signal disc is further coaxially fixed on the outer side surface of the first balance block, and the signal disc 2 is fixed on the first balance block by three screws 5.

[0016] The three main journals are used to cooperate with the crankshaft hole on the engine cylinder block to support the crankshaft, and the two connecting rod journals are rotatably connected with the connecting rods to convert the reciprocating motion of the piston into the rotary motion of the crankshaft. The flat square is used to cooperate with the inner rotor of the oil pump to drive the oil pump to rotate. The upper and lower surfaces of the flat square are concentric arc surfaces, and the left and right surfaces are symmetrical planes relative to the center surface of the crankshaft. See Figure 4 , a second positioning hole 31 is provided at the center of the end surface of the flat square, which is used to accurately position the oil pump. The signal disc is used to provide the crankshaft position signal for the ECU.

[0017] Specifically, see Figure 5 , a first oil passage 22 passing through the first balance block is provided between the first main journal and the first connecting rod journal, so that the oil in the bearing oil groove of the first main journal enters the surface of the first connecting rod journal through the first oil passage to provide cooling and lubrication for the first connecting rod journal; a second oil passage 30 passing through the fourth balance block is provided between the third main journal and the second connecting rod journal, so that the oil in the bearing oil groove of the third main journal enters the surface of the second connecting rod journal through the second oil passage to provide cooling and lubrication for the second connecting rod journal.

[0018] Specifically, see Figure 3 , two balance holes 24 and 28 are respectively provided on the side of the first balance block and the fourth balance block away from the connecting rod journal, which are used to meet the requirements of dynamic balance of the crankshaft.

[0019] For details, see Figure 4 The outer surface of the fourth balance block is provided with a first positioning hole 32 and a etched surface 33. The etched surface is used to register relevant information of the crankshaft. The positioning tool pin is inserted into the first positioning hole. The balance shaft drive gear is provided with a third positioning hole corresponding to the first positioning hole. When installing the balance shaft drive gear, it is necessary to ensure that it is aligned with the tool pin and the gear neck at the same time so that the balance shaft drive gear can be accurately pressed onto the gear neck.

[0020] For details, see Figure 3 The four balance blocks have a fan-shaped structure, with any two adjacent balance blocks forming a symmetrical structure. The fan-shaped angle of the balance blocks is between 84° and 90°. The distance between the two sides of the first and second balance blocks, and the distance between the two sides of the third and fourth balance blocks are all 90mm. The outer diameter of the four balance blocks is 160mm.

[0021] This invention can be modified in many ways, as will be apparent to those skilled in the art, and such modifications are not considered to depart from the scope of this invention. All such modifications that are obvious to those skilled in the art are included within the scope of these claims.

Claims

1. A crankshaft for a two-cylinder engine, characterized in that, include: The system comprises a first main journal, a second main journal, and a third main journal. The inner end of the first main journal is connected to a first balance block. The two ends of the second main journal are respectively connected to a second balance block and a third balance block. The inner end of the third main journal is connected to a fourth balance block. A first connecting rod journal connects the first and second balance blocks, and a second connecting rod journal connects the third and fourth balance blocks. The two connecting rod journals are coaxially arranged. The outer end of the first main journal is coaxially provided with a flange, and the end face of the flange is provided with several screw holes. The outer end of the third main journal is coaxially provided with a gear journal and a sprocket journal, and the shaft diameter decreases in a stepped manner. The outer end of the sprocket journal is provided with a flat square. A balance shaft drive gear and a timing sprocket are sequentially fixedly fitted onto the two gear journals. A signal disk is also coaxially fixed to the outer surface of the first balance block.

2. The crankshaft for a two-cylinder engine according to claim 1, characterized in that: A first oil passage passing through the first balance block is provided between the first main journal and the first connecting rod journal, and a second oil passage passing through the fourth balance block is provided between the third main journal and the second connecting rod journal.

3. The crankshaft for a two-cylinder engine according to claim 1, characterized in that: The first and fourth balance blocks have several balance holes on the side away from the connecting rod neck.

4. The crankshaft for a two-cylinder engine according to claim 1, characterized in that: The fourth balancing block has a first positioning hole and an engraved surface on its outer side; the flat square has a second positioning hole at the center of its end face.

5. The crankshaft for a two-cylinder engine according to claim 1, characterized in that: The four balance blocks are in a fan-shaped structure, with any two adjacent balance blocks forming a symmetrical structure. The fan-shaped angle of the balance blocks is between 84° and 90°.

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