CN2858970Y - Small four-stroke gasoline engine - Google Patents

Abstract

The utility model discloses a small four-stroke gasoline engine comprising a body, a crankshaft, a connecting rod, a piston and a bearing. Wherein the cylinder head, cylinder body, upper and lower crankcases form an integral component. Two bearing seats mounted with bearings are disposed in the upper and lower crankcases at the same side with the crankshaft. The crankshaft is supported on the bearing with cantilever type, and the piston is disposed inside the cylinder body. One end of the connecting rod connects with the crankshaft and the other end connects with the piston. The side face of the component opposite to the bearing seat is provided with an inclined joint surface, by which an oil pan is mounted on the component. The lower rocker arm, timing cam, crankshaft, connecting rod and piston of the valve mechanism can also be mounted conveniently by the joint surface. In the utility model, the cylinder head, cylinder body, upper and lower crankcases form an integral component, and reduces the machining die to be one set. Thereby omits the mounting bolts, reduces mounting cost, and increases mounting precision.

Description

Mini four-stroke gasoline engine

One, technical field

The utility model relates to a kind of petrol engine, a kind of specifically mini four-stroke gasoline engine.

Two, background technique

Petrol engine is a kind of gasoline-fueled spark ignition type internal combustion engine.Press the difference of gas distribution system, petrol engine can be divided into two-stroke gasoline engine and four-stroke gasoline engine two classes.Particularly mini four-stroke gasoline engine is because compact structure, easy to use and extensively be used as the motive force of machinery such as light-duty vehicle, spray duster device, chain saw, small generator, water pump, mowing machine for four-stroke gasoline engine, and global Annual output is approximately 3,000 ten thousand.Mini four-stroke gasoline engine adopts the reciprocating piston type structure, and it generally is made up of seven parts such as body, connecting rod, gas distribution system, oil supply system, lubrication system, cooling system and ignition systems.Body part wherein mainly comprises cylinder head, cylinder block, upper and lower crankcase and oil sump.Petrol engine both domestic and external in decades manufacturer mostly adopts split type housing construction on the mini four-stroke gasoline engine of its production, promptly make these several parts of cylinder head, cylinder block, upper and lower crankcase and oil sump respectively, link to each other with bolt again, form the body of petrol engine.It is simple to do processing like this, so the method is used till today.But this method need be made five secondary moulds in advance, relies on mould that these five parts are carried out machining again, combines at last, and in large-scale production, its manufacturing and installation cost are higher.

Along with being growing more intense of petrol engine industry competition, each producer all improves in the design to petrol engine, in the hope of minimizing cost under the constant prerequisite of product quality guaranteeing, so following several new model in the combination of body, occurred:

1. form by four parts: cylinder head, cylinder block and upper crankcase one, lower crankcase, oil sump;

2. form cylinder head and cylinder block one, upper crankcase, lower crankcase, oil sump by four parts;

3. form cylinder head, cylinder block and upper crankcase one, lower crankcase and oil sump one by three parts;

4. form cylinder head, cylinder block and upper crankcase one, lower crankcase, oil sump by three parts;

5. form cylinder head and cylinder block one, upper and lower crankcase one, oil sump by three parts;

At present, the manufacturer of the mini four-stroke gasoline engine that various countries are main all adopts one to two kind of tissue in aforesaid several scheme to produce basically, can reduce cost in various degree like this.But the body that adopts these design proposals to produce still comprises three to four parts, needs equally to make corresponding mould, and cost of production is still higher.It is an integrated member that each producer is not designed to body cylinder head, cylinder block, upper crankcase and lower crankcase, reason with the oil sump stack mounting is again: because the restriction of structure, the attachment face of oil sump and organism component can only be located at the bottom of this member, and this has just produced two problems:

1. the lower shake-changing arm of distribution device, timing cam can't normal mounting;

2. bent axle, connecting rod and piston can't be installed.

How to address these problems, the component of further integrated body, making petrol engine compacter, more economical is the present direction of making great efforts of designer of various countries manufacturer.

Three, summary of the invention

1, goal of the invention: the purpose of this utility model provides and is a kind ofly guaranteeing to make housing construction compacter, the mini four-stroke gasoline engine that cost of production is lower under the constant condition of every performance.

2, technological scheme: mini four-stroke gasoline engine described in the utility model, it comprises body, bent axle, connecting rod, piston and bearing, wherein body from top to bottom is respectively a cylinder head, cylinder block, upper crankcase, lower crankcase and oil sump, last, be provided with the bearing support of two correspondences in the lower crankcase, described Bearing Installation is in bearing support, bent axle is supported on the bearing, piston is arranged in the cylinder block, one end of connecting rod connects bent axle, the other end connects piston, it is characterized in that: described cylinder head, cylinder block, upper crankcase and lower crankcase are an integrated member, two bearing supports are arranged on the homonymy of bent axle, bent axle is cantilever type to be supported, and is provided with the junction plane of inclination in the member side relative with bearing support, and oil sump is installed on the member by this junction plane.

Because cylinder head, cylinder block, upper crankcase and lower crankcase are designed to an integrated member, and two bearing supports are arranged on the homonymy of bent axle, the two end supports structure that two strong points in traditional type are located at crankshaft two end becomes the cantilever structure that two strong points are located at the bent axle homonymy, the mounting point of bent axle and bearing and connecting rod all concentrates on a side of member like this, thereby the installation junction plane that can oil sump be set in the opposite side rather than the bottom surface of member, by this junction plane installation personnel the lower shake-changing arm and the timing cam of distribution device, bent axle can be installed very easily, the problem that connecting rod and piston can't be installed has also obtained solution.

For easy for installation, connecting rod adopts bearing shell formula split connecting rod, this is owing to cylinder head, cylinder block, upper crankcase and lower crankcase in the utility model are integrated members, in the process that piston, connecting rod are installed, can run into structural obstruction like this, adopt bearing shell formula split connecting rod can finish installation easily.

3, beneficial effect: the utility model compared with prior art has following characteristics: cylinder head, cylinder block, upper crankcase and lower crankcase are integrated members in (1) the utility model, to process required three so originally and be reduced to a pair to the fourth officer mould, and saved and originally be used for cylinder head, cylinder block, all fastening screws of upper and lower crankcase, greatly reduced manufacture cost and installation cost; (2) the installation junction plane that oil sump is set in a side rather than the bottom surface of member can be installed the lower shake-changing arm and the timing cam of distribution device very easily by this junction plane installation personnel, and the problem that bent axle, connecting rod and piston can't be installed has also obtained solution; (3) the installation junction plane with four to six original parts is reduced to two, has reduced cumulative error, has improved installation precision; (4) bent axle adopts cantilever structure, and existing relatively bent axle has reduced material consumption, the corresponding cost that reduced; (5) guaranteeing to make motor compacter, more economical under the constant prerequisite of the every performance of petrol engine.

Four, description of drawings

Fig. 1 is a schematic diagram of the present utility model;

Fig. 2 is the main sectional view of integrated member in the utility model;

Fig. 3 is the left sectional view of integrated member in the utility model;

Fig. 4 is an integrated member and sectional view after oil sump combines in the utility model.

Five, embodiment

As Fig. 1, Fig. 2, Fig. 3 and shown in Figure 4, mini four-stroke gasoline engine described in the utility model, comprise body, bent axle 1, connecting rod 2, piston 3 and bearing 4, body from top to bottom is respectively a cylinder head 5, cylinder block 6, upper crankcase 7, lower crankcase 8 and oil sump 9, wherein cylinder head 5, cylinder block 6, upper crankcase 7 and lower crankcase 8 are an integrated member 11, last, be provided with the bearing support 10 of two correspondences in the lower crankcase, these two bearing supports 10 all are arranged on the homonymy of bent axle 1, bearing 4 is installed in the bearing support 10, bent axle 1 is supported on the bearing 4, because two bearing supports 10 all are arranged on the homonymy of bent axle 1, make bent axle 1 be the cantilever type supporting structure, piston 3 is arranged in the cylinder block 6, connecting rod 2 adopts bearing shell formula split connecting rod, and the one end is connected on the axle journal of bent axle 1, and the other end is connected on the piston 3, side at the member 11 relative with bearing support 10 is provided with junction plane 12, and oil sump 9 is installed on the member 11 by this junction plane 12.

In the installation process, for the installation of lower shake-changing arm and cam, the gear chamber of it can being packed into from member 11 sides (perpendicular to the front) guarantees not produce with other part in the installation process and interferes, and with screw it is fastened on the body inwall again, makes its reliable operation.For the installation of bent axle 1, connecting rod 2 and piston 3 assemblies, be to go up connecting rod and piston 3 cylinder of packing into earlier, will go up connecting rod again and be inserted in crankpin, upper and lower strut is fastened on the crank pin of bent axle 1 at last, finish installation.

Claims (2)

1, a kind of mini four-stroke gasoline engine, it comprises body, bent axle (1), connecting rod (2), piston (3) and bearing (4), wherein body from top to bottom is respectively a cylinder head (5), cylinder block (6), upper crankcase (7), lower crankcase (8) and oil sump (9), in upper crankcase (7) and lower crankcase (8), be provided with the bearing support (10) of two correspondences, described bearing (4) is installed in the bearing support (10), bent axle (1) is supported on the bearing (4), piston (3) is arranged in the cylinder block (6), one end of connecting rod (2) connects bent axle (1), the other end connects piston (3), it is characterized in that: described cylinder head (5), cylinder block (6), upper crankcase (7) and lower crankcase (8) are an integrated member (11), two bearing supports (10) are arranged on the homonymy of bent axle (1), bent axle (1) is cantilever type to be supported, be provided with the junction plane (12) of inclination in the side of the member (11) relative with bearing support (10), oil sump (9) is installed on the member (11) by this junction plane (12).

2, mini four-stroke gasoline engine according to claim 1 is characterized in that: described connecting rod (1) is a bearing shell formula split connecting rod.