Double-balance-shaft system of double-cylinder engine special for range extension of micro-miniature vehicle

Abstract

The utility model relates to the technical field of engine balance shafts, in particular to a double-balance-shaft system of a special double-cylinder engine for extending the range of a microminiature vehicle, which comprises a first balance system, a second balance system and a crankshaft, a driving gear is arranged at one end of the crankshaft; the first balance system and the second balance system are arranged on the two sides of the crankshaft respectively. And the first balance system and the second balance system are driven by the driving gear. The utility model has the advantages of simple structure, low cost and small occupied space of the whole machine; the rotating inertia force is eliminated through the crank balance weight, the reciprocating inertia moment is eliminated through the double balance shafts, automobile vibration is reduced, more efficient work is achieved, and noise is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of engine balance shafts, in particular to a double balance shaft system of a double-cylinder engine specially used for a micro-sized vehicle with a range increase. Background Art

[0002] With the rapid development of the automobile industry, people's requirements for vehicle comfort are gradually increasing, and engine vibration and the noise generated by vibration have become the focus of engine design.

[0003] The function of the balance shaft is to make the engine run more smoothly, reduce the vibration of the car, and improve the overall comfort of the car. The balance shaft technology is a simple and very practical engine technology. It can effectively reduce the vibration of the whole vehicle and improve driving comfort.

[0004] Balance shafts can be divided into single balance shafts and double balance shafts. During the operation of the engine, the piston moves very fast and the movement speed is very uneven; after the car has a balance shaft, the engine will run more smoothly. However, existing small-displacement gasoline engines have the problem of large vibration and noise of the balance shaft.

[0005] Therefore, there is an urgent need for a dual balance shaft system for a twin-cylinder engine specially used for extending the range of a micro-sized vehicle. Utility Model Content

[0006] In order to overcome the problems existing in the prior art, the utility model aims to provide a dual balance shaft system for a twin-cylinder engine specially used for range extension of a micro-sized vehicle.

[0007] To achieve the above-mentioned objectives, the utility model provides the following technical solutions: a dual balancing shaft system for a two-cylinder engine specially used for a micro-sized vehicle with an extended range, comprising a first balancing system, a second balancing system and a crankshaft; a driving gear is provided at one end of the crankshaft; the first balancing system and the second balancing system are respectively provided on both sides of the crankshaft; the first balancing system and the second balancing system are driven by the driving gear; the first balancing system comprises a first balancing shaft and a first balancing gear; the second balancing system comprises a second balancing shaft and a second balancing gear; the first balancing shaft and the second balancing shaft are both eccentric structures; a plurality of through holes are respectively provided on the spoke plates of the first balancing gear and the second balancing gear, and the eccentric structure is a "concave" structure with protrusions at both ends of the axial direction and a concave middle part of the axial direction formed by removing part of the structure of a circular shaft structure along the axial direction.

[0008] The utility model is further configured as follows: the first balancing gear is arranged at one end of the first balancing shaft and meshes with the driving gear.

[0009] The utility model is further configured as follows: the second balance gear is arranged at one end of the second balance shaft and meshes with the driving gear.

[0010] The utility model is further configured as follows: the first balance shaft and the second balance shaft are parallel to the crankshaft, the first balance gear and the second balance gear are symmetrically distributed on both sides of the driving gear with the center of the driving gear as the center, and the driving gear is respectively meshed with the first balance gear and the second balance gear in reverse transmission.

[0011] The utility model is further configured as follows: a transmission chain is arranged on the first balance gear, the second balance gear and the driving gear.

[0012] The utility model is further configured as follows: a transmission ratio of the first balancing shaft, the second balancing shaft and the crankshaft is 1:1:1.

[0013] The crankshaft driving gear is respectively engaged with the first balance gear and the second balance gear in reverse transmission. When the first balance gear rotates, it drives the first balance shaft to rotate to generate reverse centrifugal force, and the second balance gear drives the second balance shaft to rotate to generate reverse centrifugal force for balancing.

[0014] The utility model is further configured as follows: a crank and a connecting rod are also arranged on the crankshaft, a connecting rod journal is arranged on the crank, the connecting rod comprises a big head end and a small head end, the big head end of the connecting rod is connected to the connecting rod journal, and the small head end of the connecting rod is connected to the piston.

[0015] The utility model is further configured as follows: a balancing block is also arranged on the crank.

[0016] The utility model can reduce the fuel consumption of the engine while miniaturizing the engine, improve the economy and reduce the pollution to the environment. The crankshaft balancing system adopts a double balancing shaft arrangement, taking into account the engine arrangement, with low cost and low vibration and noise of the whole machine.

[0017] In summary, the beneficial effects of the above technical solution of the utility model are as follows:

[0018] The utility model has a simple structure, low cost and small space occupation of the whole machine; the rotational inertia force is eliminated by the crank counterweight, the reciprocating inertia moment is eliminated by the double balance shafts, the vibration of the car is reduced to bring more efficient work, and the noise is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0021] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0022] 1. driving gear, 2. crankshaft, 20. crank, 21. connecting rod journal, 22. balancing block, 3. first balancing gear, 4. second balancing gear, 5. first balancing shaft, 6. second balancing shaft. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention, the following is a clear and complete description of the technical solution of the present invention in conjunction with the drawings of the present invention. Based on the embodiments of the present invention, other similar embodiments obtained by ordinary technicians in the field without creative work should all fall within the scope of protection of the present invention. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only referenced to the directions of the drawings. Therefore, the directional words used are used to illustrate rather than limit the creation of the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0025] The utility model is further described below in conjunction with the accompanying drawings and preferred embodiments.

[0026] Example:

[0027] like Figure 1 As shown, a preferred embodiment of the utility model is a dual balancing shaft system of a twin-cylinder engine specially used for a micro-sized vehicle with a range extender, comprising a first balancing system, a second balancing system and a crankshaft 2; a driving gear 1 is provided at one end of the crankshaft 2; the first balancing system and the second balancing system are respectively provided on both sides of the crankshaft 2; the first balancing system and the second balancing system are driven by the driving gear 1.

[0028] The first balancing system includes a first balancing shaft 5 and a first balancing gear 3; the first balancing gear 3 is arranged at one end of the first balancing shaft 5 and meshes with the driving gear 1. The second balancing system includes a second balancing shaft 6 and a second balancing gear 4; the second balancing gear 4 is arranged at one end of the second balancing shaft 6 and meshes with the driving gear 1.

[0029] The first balance shaft 5 and the second balance shaft 6 are parallel to the crankshaft 2, and the first balance gear 3 and the second balance gear 4 are symmetrically distributed on both sides of the driving gear 1 with the center of the driving gear 1 as the center. The spokes of the first balance gear 3 and the second balance gear 4 are respectively provided with a plurality of through holes.

[0030] The driving gear 1 is respectively in reverse transmission engagement with the first balancing gear 3 and the second balancing gear 4. The transmission ratio of the first balancing shaft 5, the second balancing shaft 6 and the crankshaft 2 is 1:1:1.

[0031] The first balance gear 3 , the second balance gear 4 and the driving gear 1 are provided with a transmission chain.

[0032] The first balancing shaft 5 and the second balancing shaft 6 are both eccentric structures. The eccentric structure is a "concave" structure formed by removing part of the structure of a circular shaft along the axial direction, with convex ends in the axial direction and concave in the middle part in the axial direction.

[0033] The driving gear 1 of the crankshaft 2 is respectively engaged with the first balance gear 3 and the second balance gear 4 in reverse transmission. After the first balance gear 3 rotates, it drives the first balance shaft 5 to rotate to generate reverse centrifugal force, and the second balance gear 4 drives the second balance shaft 6 to rotate to generate reverse centrifugal force for balancing.

[0034] The crankshaft 2 is also provided with a crank 20 and a connecting rod. The crank 20 is provided with a connecting rod journal 21. The connecting rod includes a large end and a small end. The large end of the connecting rod is connected to the connecting rod journal 21, and the small end of the connecting rod is connected to the piston. The crank 20 is also provided with a balancing block 22.

[0035] The working principle of the utility model and the calculation of the reciprocating inertia force according to the model parameters are as follows:

[0036] When the piston moves up and down once, the engine will vibrate twice, so the vibration frequency of the engine is related to the engine speed. In vibration theory, multiple harmonic vibrations are often used to describe the vibration of the engine.

[0037] Three forces need to be considered for balance: rotational inertia force, first-order reciprocating inertia force, and second-order reciprocating inertia force.

[0038] The rotational inertia force can be eliminated by the crank counterweight. The reciprocating inertia moment needs a balance shaft to eliminate.

[0039] The first-order reciprocating inertia force has the greatest impact on the engine, and the second-order reciprocating inertia force is omitted to simplify the calculation. First-order reciprocating inertia force:

[0040]

[0041] Where m is the mass, r is the radius, is the rotation angle, ω is the angular velocity. From the formula, it can be concluded that the magnitude of the first-order reciprocating inertia force varies with the cosine of the angle, and the direction is along the center line of the cylinder.

[0042] Since the rotational speed of the balance shaft is the same as that of the crankshaft, when comparing the reciprocating inertia force, start by comparing the mass-diameter product mr of each part.

[0043] The mass-diameter product that needs to be balanced is equal to the sum of the mass of the piston group and the mass of the connecting rod head multiplied by its rotation radius, that is:

[0044] p j *r=(m3+m4)*r

[0045] The mass-diameter product balanced by the crankshaft balance shaft is equal to the difference between the overbalanced mass-diameter product of the crank and the mass-diameter product of the connecting rod big end, that is:

[0046] p r *r=m1*r1-m2*r2

[0047] The mass-diameter product balanced by the balance shaft is equal to the sum of the mass-diameter products of the two balance shafts, that is:

[0048] p b *r=m b1 *r b1 +m b2 *r b2

[0049] Where r: crank radius; r1: distance between crank rotation center and mass center; r2: connecting rod big end rotation radius; r b1 : The radius of the first balance axis; r b2 : The radius of the second balance axis; p j : The mass that needs to be balanced; p r : The mass balanced by the crankshaft balance shaft; p b : The mass of the balance shaft; m1: The crank overbalance weight; m2: The mass of the connecting rod big end; m3: The mass of the piston group; m4: The mass of the connecting rod small end; m b1 : The mass of the first balancing shaft; m b2 : The mass of the second balance shaft.

[0050] Substitute the actual data into the calculation and get p j 646.4g, p r 417.2g, p b 263.12g;

[0051] p r +p b =417.2+263.12=680.32g

[0052] 680.32g>646.4g

[0053] That is, the reciprocating inertia force generated by the piston and the connecting rod small end can be completely balanced by the crank counterweight and the balance shaft.

[0054] Finally, it should be noted that the above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A dual balance shaft system for a twin-cylinder engine for a mini car with a range extension, characterized in that: It includes a first balancing system, a second balancing system and a crankshaft; a driving gear is arranged at one end of the crankshaft; the first balancing system and the second balancing system are respectively arranged on both sides of the crankshaft; the first balancing system and the second balancing system are driven by the driving gear; the first balancing system includes a first balancing shaft and a first balancing gear, and the second balancing system includes a second balancing shaft and a second balancing gear; the first balancing shaft and the second balancing shaft are both eccentric structures; a plurality of through holes are respectively arranged on the spoke plates of the first balancing gear and the second balancing gear, and the eccentric structure is a "concave" structure formed by removing part of the structure of a circular shaft structure along the axial direction, with the two axial ends protruding and the middle axial part concave.

2. The dual balance shaft system of the twin-cylinder engine for mini-sized vehicles with extended range according to claim 1, characterized in that: The first balance gear is disposed at one end of the first balance shaft and meshes with the driving gear.

3. The dual balance shaft system of the twin-cylinder engine for mini-sized vehicles with extended range according to claim 2, characterized in that: The second balance gear is disposed at one end of the second balance shaft and meshes with the driving gear.

4. The dual balance shaft system of the twin-cylinder engine for mini-sized vehicles with extended range as claimed in claim 3 is characterized in that: The first balance shaft and the second balance shaft are parallel to the crankshaft, and the first balance gear and the second balance gear are symmetrically distributed on both sides of the driving gear with the center of the driving gear as the center.

5. The dual balance shaft system of the twin-cylinder engine for mini-sized vehicles with extended range as claimed in claim 4, characterized in that: The first balance gear, the second balance gear and the driving gear are provided with a transmission chain.

6. The dual balance shaft system of the twin-cylinder engine for mini-sized vehicles with extended range as claimed in claim 5, characterized in that: The transmission ratio of the first balance shaft, the second balance shaft and the crankshaft is 1:1:

1.

7. The dual balance shaft system of the twin-cylinder engine for mini-sized vehicles with extended range as claimed in claim 1, characterized in that: The crankshaft is also provided with a crank and a connecting rod. The crank is provided with a connecting rod journal. The connecting rod includes a big head end and a small head end. The big head end of the connecting rod is connected to the connecting rod journal, and the small head end of the connecting rod is connected to the piston.

8. The dual balance shaft system of the twin-cylinder engine for mini-sized vehicles with extended range as claimed in claim 7, characterized in that: A balancing block is also arranged on the crank.

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