CN201835885U

CN201835885U - Motor start decompressor

Info

Publication number: CN201835885U
Application number: CN2010205796965U
Authority: CN
Inventors: 梅家军; 高进; 谭清; 陈桂林
Original assignee: CHONGQING RUNTONG DONGLI Co Ltd
Current assignee: CHONGQING RUNTONG TECHNOLOGY CO., LTD.
Priority date: 2010-10-26
Filing date: 2010-10-26
Publication date: 2011-05-18
Anticipated expiration: 2020-10-26

Abstract

The utility model discloses a motor start decompressor, which comprises a camshaft, an exhaust cam on the camshaft and a driving gear mounted on the camshaft. Two pin bosses perpendicular to an axis of the camshaft are integrally arranged on one end surface of the driving gear opposite to the exhaust cam, and a penetrating through hole is arranged on the end surface of the driving gear in a direction which is perpendicular to the direction of the axis of one of the pin boss; an integrally formed centrifugal swinging block is pin-jointed with the pin bosses and can rotate along a pin shaft, the centrifugal swinging block is divided into a driving end and a driven end, and the driven end penetrates the through hole and is positioned between a limit lug boss of the exhaust cam and the other end surface of the driving gear to perform circular arc movement; a reposition torsion spring is arranged on the pin shaft to enable the driving end to move close to the camshaft under the torque force of the reposition torsion spring, so as to drive the driven end to be positioned in the position of the limit lug boss and limit an air valve for reaching the lowermost close position of the air valve. The motor start decompressor has the advantages of simple structure and process, reliable performance and low cost.

Description

A kind of engine start decompressor

Technical field

The utility model relates to a kind of engine start decompressor, especially is applied in the startup decompressor on the general small-size gasoline engine camshaft.

Background technique

Because general small-size petrol engine claimed structure is simple, cost is low, and often adopts hand starting.During startup, if too big in the cylinder pressure of timing points, operating load is bigger during the engine start running, can produce serious bounce-back, and it is injured to cause operator.Therefore, decompressor need be set and suitably reduce the normal start-up operation of in-cylinder pressure in order to motor.Prior art generally is arranged on its decompressor between the actuation gear and exhaust cam of camshaft; Utilize centrifugal principle, engine speed is lower during startup, and centrifugal block for clutch use can be with the slight jack-up of exhaust cam, thereby reduces cylinder pressure; Behind engine start, the centrifugal block for clutch use of high speed rotating leaves the exhaust cam positive stop lug boss and inoperative under action of centrifugal force.But the installation of the centrifugal block for clutch use of above-mentioned prior art adopts the mode of screw-nut, pin back-up ring and so on to fix usually, it is more to relate to part, assembly process process is poor, causes starting decompressor or more complicated, can not satisfy higher compact structure and low-cost requirement.

Summary of the invention

The purpose of this utility model provides a kind of more reliable engine start decompressor, is convenient to assembling simultaneously, reduces cost.

Engine start decompressor described in the utility model comprises the exhaust cam on camshaft, the camshaft and is installed in actuation gear on the camshaft that actuation gear is also adjacent with exhaust cam near the axle head of camshaft.Be wholely set axis and two perpendicular key seats of camshaft axis on the opposing end face of actuation gear and exhaust cam; With the end face of the actuation gear of the axial Vertical direction of one of them key seat on be provided with one and run through through hole; Integrated centrifugal block for clutch use also can be rotated around bearing pin on key seat by pin joint, centrifugal block for clutch use is that the boundary is divided into drive end and driven end with the bearing pin, and driven end passes between the other end that through hole is limited in the positive stop lug boss of exhaust cam and actuation gear and does circular motion; Reduction torsion spring is set on the bearing pin, the one end is abutted against mutually with the end face of actuation gear, thereby the other end is abutted against mutually with the drive end of centrifugal block for clutch use and make drive end to being limited in the positive stop lug boss position and arriving minimum valve-closing position at this restriction valve near camshaft direction motion drive driven end by its torsion.The utility model is taked two key seats and is connected with a bearing pin on the Placement of centrifugal block for clutch use, key seat on camshaft, had both been increased centrifugal block for clutch use installation, reliability of operation by one-body molded, had also reduced the cost of material of key seat.Simultaneously for making centrifugal block for clutch use when starting, be limited in the positive stop lug boss position, prior art is to use an extension spring to realize, its distance, reliability is relatively poor, the utility model is provided with a reduction torsion spring for overcoming this defective on the bearing pin that connects centrifugal block for clutch use, realized the function of prior art extension spring in limited space, both increase the reliability that resets, saved suitable space again.

Working principle is: when ato unit, the engine output shaft rotating speed is not high, the rotating speed of camshaft is not high yet, the centrifugal force that drive end produced of centrifugal block for clutch use is little, be not enough to overcome reduction torsion spring power, the centrifugal block for clutch use driven end can not close valve near the end face of exhaust cam fully, the engine start load is less, and start-up operation is comparatively light.After the motor proper functioning, the rotating speed of camshaft also improves, and the drive end of centrifugal block for clutch use overcomes reset torsion spring torque force because of centrifugal force, thereby drive the spacing end face that driven end leaves positive stop lug boss, decompressor no longer works, and valve can be closed fully, and motor enters normal operation.

Further, for the through hole that the driven end that makes things convenient for centrifugal block for clutch use passes on the actuation gear disc is installed easily, when motor normally moves that driven end is spacing on the end face of actuation gear near row institute cam again simultaneously, via design becomes a long strip hole, wherein be slightly larger than the width of driven end end near its width of an end of key seat, the width of the other end is slightly less than the width of driven end end.During assembling, driven end passes through hole from the slightly wide end of through hole and installs; During normal working of engine, though driven end terminal under the drive of drive end centrifugal force to the motion of actuation gear end face, because of the slightly narrow end of through hole can not be by limited.

By another technological scheme, centrifugal block for clutch use is designed to U-shaped, wherein U-shaped opening one end extends to form driven end, the end of driven end forms the bending side that coincide with the positive stop lug boss end face, reach the purpose of decompression with this, two opening ends at U-shaped form pin-and-hole so that centrifugal block for clutch use is installed on the key seat simultaneously.Because whole centrifugal block for clutch use is integrated, and two pin joint points are arranged again, has increased the operational reliability of getting rid of piece greatly; Drive end adopts the U-shaped structure, has also reduced the shared space length of drive end, has saved the space.Be the effect that the centrifugal force that increases centrifugal block for clutch use decompressor when realizing that better motor normally moves lost efficacy, the design is provided with balancing weight in the U-shaped bottom of centrifugal block for clutch use.

Being provided with of reduction torsion spring, preferred its of the utility model passes bearing pin and is installed between two key seats, like this purpose that can reach the most reliable, save the space most.

Engine start decompressor described in the utility model, by integrated two key seats, be designed to the centrifugal block for clutch use of U-shaped, and being connected two reduction torsion springs between the key seat with same bearing pin of pin joint centrifugal block for clutch use, the utility model patent has realized that decompressor moves more reliability, part and still less, more saves space, more material saving, the simpler purpose of assembling.

Description of drawings

Now in conjunction with the accompanying drawings the utility model is described in further details.

Fig. 1: the structural arrangements schematic representation of engine start decompressor described in the utility model;

The left view of Fig. 2: Fig. 1;

The worm's eye view of Fig. 3: Fig. 1, during ato unit, the position of centrifugal block for clutch use;

The sectional view of Fig. 4: Fig. 2

When the worm's eye view of Fig. 5: Fig. 1, motor normally move, the position of centrifugal block for clutch use.

Embodiment

As Fig. 1-shown in Figure 5, engine start decompressor of the present utility model comprises camshaft 19, suit actuation gear 1, exhaust cam 5 and intake cam 20 on the camshaft 19; Actuation gear 1 is timing gear again; Wherein, actuation gear 1 is near camshaft axle head and adjacent with exhaust cam 5; Produce a positive stop lug boss 17 on the exhaust cam 5 simultaneously.

Actuation gear 1 is wholely set two

key seats

11 and 24 at gear face 12 faces, opens pin-and-holes in the middle of this actuation gear key seat 11 respectively, actuation gear 1 on gear disc, have the wide end of an end narrow run through through hole 13.

Reduction torsion spring 3 pass bearing pin 4 by pin joint between two key seats.

Centrifugal block for clutch use 2 is one-body molded, is shaped as U-shaped, is divided into the extension driven end 8 of an end of drive end 7 and U-shaped opening, and drive end is provided with counterweight 28 in the bottom of U-shaped, is respectively equipped with pin-and-hole 9 in two port position of U-shaped.

During assembling, the first step: reduction torsion spring 3 pretensions 1～3 are enclosed as pretension torsion, the one end is abutted against near one of them opening end of U-shaped opening of centrifugal block for clutch use 2, and place together between the

key seat

11 and 24 on actuation gear 1 end face 12 with centrifugal block for clutch use 2, the other end of reduction torsion spring is abutted against on the end face 12 of actuation gear 1; Second step: the pin-and-hole, key seat 24, reduction torsion spring 3, another pin-and-hole of centrifugal block for clutch use 2, the key seat 11 that the riveted joint end of bearing pin 4 are passed centrifugal block for clutch use 2 respectively; The 3rd one: the riveted joint end riveted joint with bearing pin 4 prevents that it from coming off, and finishes assembling.

After assembling was finished, centrifugal block for clutch use 2 can freely rotate around bearing pin 4.At camshaft 19 during the static or slow-speed of revolution, when being ato unit, centrifugal block for clutch use 2 does not have centrifugal force or its centrifugal force to be not enough to overcome the torsion that resets of reduction torsion spring 3, the driven end 8 of centrifugal block for clutch use 2 is against the end face (as Fig. 3) of the positive stop lug boss 17 of exhaust cam 5, the end of the driven end 8 of centrifugal block for clutch use 2 is unseat the valve 6 a little, press thereby reduce cylinder, be convenient to start.

Behind the engine start, camshaft 19 rotating speeds are tending towards normal, the centrifugal force of centrifugal block for clutch use 2 is enough to overcome the resetting torsion of reduction torsion spring 3 and makes the drive end rotation of centrifugal block for clutch use, drive centrifugal block for clutch use 2 driven end 8 motions and away from positive stop lug boss 17 positions of exhaust cam 5; At this moment, near the end face 25 of actuation gear 1 and keep static (as Fig. 5), the driven end 8 of centrifugal block for clutch use 2 no longer to contact valve 6, motor enters proper functioning to the driven end 8 of centrifugal block for clutch use 2 under action of centrifugal force.

Behind engine misses, the rotating speed of camshaft 19 is 0rpm, and the centrifugal force of centrifugal block for clutch use 2 is 0, under the effect of reduction torsion spring 3, centrifugal block for clutch use 2 rotations, its driven end 8 abuts against positive stop lug boss 17 places of exhaust cam 5 again and keeps static (as Fig. 4), prepares for starting next time.The gap of the pushing end 8 restriction valve-closing valve port positions of centrifugal block for clutch use 2 is 0.7～1.0mm.

Claims

1. engine start decompressor, comprise the exhaust cam on camshaft, the camshaft and be installed in actuation gear on the camshaft, actuation gear is also adjacent with exhaust cam near the axle head of camshaft, it is characterized in that: be wholely set axis and perpendicular key seat (11) and (24) of camshaft axis on the opposing end face (12) of described actuation gear (1) and exhaust cam (5); With the end face of the actuation gear of the axial Vertical direction of one of them key seat on consistent reach through hole (13) is set; An integrated centrifugal block for clutch use (2) is gone up and can be rotated around bearing pin (4) at key seat (11) and (24) by pin joint, centrifugal block for clutch use (2) is that the boundary is divided into drive end (7) and driven end (8) with bearing pin (4), and driven end (8) passes between the other end (27) that through hole (13) is limited in the positive stop lug boss (17) of exhaust cam (5) and actuation gear (1) and does circular motion; One reduction torsion spring (3) is set on the bearing pin (4), the one end is abutted against mutually with the end face (12) of actuation gear, the other end be abutted against mutually with the drive end (7) of centrifugal block for clutch use (2) and make drive end (7) by its torsion thus be limited in positive stop lug boss (17) position and arrive minimum valve-closing position to drive driven end (8) near camshaft direction motion at this restriction valve (6).

2. engine start decompressor according to claim 1, it is characterized in that: described through hole (13) is a long strip hole, wherein its width of an end near key seat is slightly larger than the terminal width of driven end (8), and the width of the other end is slightly less than the terminal width of driven end (8).

3. engine start decompressor according to claim 1, it is characterized in that: the drive end (7) of described centrifugal block for clutch use (2) is a U-shaped, pin-and-hole is set at the opening two ends of U-shaped, a wherein end of U-shaped opening extends to form driven end (8) and passes through hole (13), and the end of driven end (8) forms the bending side that coincide with positive stop lug boss (17) end face.

4. engine start decompressor according to claim 3 is characterized in that: the U-shaped bottom of described centrifugal block for clutch use (2) is provided with counterweight (28).

5. engine start decompressor according to claim 1 is characterized in that: described reduction torsion spring (3) passes bearing pin (4) and is set between key seat (11) and (24).