CN2864106Y

CN2864106Y - Start decompressor of engine

Info

Publication number: CN2864106Y
Application number: CN 200620109742
Authority: CN
Inventors: 马涛
Original assignee: Chongqing Zongshen Technology Development and Research Co Ltd
Current assignee: Chongqing Zongshen Engine Manufacturing Co Ltd
Priority date: 2006-01-10
Filing date: 2006-01-10
Publication date: 2007-01-31
Anticipated expiration: 2016-01-10

Abstract

The present utility model discloses a start decompressor of engine, including a camshaft and a exhaust cam and drive gears on the camshaft, where a pin seat is disposed on the end face of the drive gears; a centrifugal decompression swing block is instlled on the pin seat capable of swinging, and divided into a pusher end and a counterbalance end; the pin shaft is composed of a head and a pole, on the end of which is provided with a concave pit, anamorphically clipped on the side of the pin seat hole when installed; the counterbalance end connects the spring, while the pusher end extends to the end face of the exhaust cam and restricts the valve here to arrive the location of the closed valve hole; the reset spring force and the centrifugal force generated on the counterbalance end are respectively made the pusher end to go to or leave the end face of the exhaust cam. The present utility model, makes use of the feature that the plastic-made driving gear is convenient to mold, to install the centrifugal decompression swing block by installing a pin seat on the drive gear, and use the deformation concave pit of the pole terminal of the pin shaft to make it posible to press or knock flat the head using tools such as a clamp of a hammer during installation,install deformation can be used to or a tool such as pressure or knock flat head, the pin shaft clipped to not extricate, which is vey convenient in technics, hereby reducing the cost.

Description

A kind of engine start decompressor

Technical field

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

Technical background

The general small-size petrol engine is because structural requirement is simple, cost is low, often adopt hand starting, the gear of drive cam shaft also replaces with engineering plastics, too big at the engine cylinder pressure of timing points position in order to prevent to start, cause serious startup bounce-back, need be increased in the relief valve unit that can reduce cylinder pressure under the engine start rotating speed on the motor, simultaneously, when the motor proper functioning, this relief valve unit is ineffective again, no longer reduces cylinder and presses.The startup decompressor form that can reach above-mentioned requirements in the prior art is very many, the general petrolic startup decompressor of general small-size is arranged on the actuation gear of camshaft and the position between the exhaust cam, piece is got rid of in a centrifugal decompression, utilize centrifugal principle, get rid of piece when starting low speed and back down exhaust cam slightly, get rid of piece during normal operation high speed and push away the gas cam and inoperative of beginning to rehearse, reach above-mentioned technical requirements by centrifugal force.But the installation of piece is got rid of in the centrifugal decompression of above-mentioned prior art, adopts screw-nut, pin ring washer and so on mode to fix usually, because part is very little, assembly process process is poor, and starts decompressor or more complicated, can not satisfy the low requirement of higher compact structure and cost.

The model utility content

The purpose of this utility model provides a kind of engine start decompressor, in the time of can making with plastics with camshaft drive gear, is convenient to assembling, reduces cost.

Engine start decompressor described in the utility model comprises exhaust cam and actuation gear on camshaft and its, and exhaust cam closes on actuation gear, the end face one of its actuation gear be provided with key seat; Centrifugal decompression is got rid of piece and is installed on the key seat with bearing pin and can swings around bearing pin, and is divided into pushing end and counterweight end so that the bearing pin both sides to be installed; Bearing pin is made up of head and bar portion, and bar portion termination is provided with the pit that is used to be out of shape, and distortion forms protruding base and is stuck in limit, key seat hole during installation; Described counterweight end connects Returnning spring, and Returnning spring one end hangs on the actuation gear; Described pushing end extends to the exhaust cam end face and arrives the minimum valve port position of closing at this restriction valve; The centrifugal force that Returnning spring power and counterweight end produce make respectively pushing end axially near and leave the end face of exhaust cam.

Actuation gear is made with plastics, can mold very easily and key seat is installed centrifugal decompression is installed gets rid of piece, and the distortion pit that the bar portion termination of bearing pin is installed makes when installing can flatten or strike gently homalocephalus portion with the instrument of clamp or hammer and so on, forming protruding base blocks bearing pin and does not deviate from, very convenient on the technology, thus reduce cost.Working principle is: when ato unit, the engine output shaft rotating speed is not high, the rotating speed of camshaft is not high yet, it is little that the centrifugal force that the counterweight end of piece produced is got rid of in centrifugal decompression, be not enough to overcome the Returnning spring pulling force, the end face of piece pushing end near exhaust cam got rid of in centrifugal decompression, and valve can not be closed fully, and be less when the cylinder of motor is pressed with respect to the valve complete shut-down at this moment; This moment, motor reacted on start end---and people's the limbs or the strength of starting electrical machinery are also less, make to compare sensation engine start leicht fallen D/A easily easily.And after the motor proper functioning, the engine output shaft rotating speed improves, the rotating speed of camshaft also improves, centrifugal decompression is got rid of the centrifugal force that the counterweight end of piece produced and is overcome the Returnning spring pulling force, make pushing end leave the end face of exhaust cam, decompressor is inoperative, and valve can be closed fully, this moment, the cylinder of motor pressed recovery normal, and engine performance is had no effect.

In the such scheme, can open the hole near the gear web the key seat; The through hole that the counterweight end passes through the gear web is connected with Returnning spring, and Returnning spring hangs on the rivet of other end of actuation gear.Actuation gear is made with plastics, also can mold gear web through hole very easily, the through hole that the bigger counterweight end of volume ratio that piece is got rid of in centrifugal decompression passes through the gear web is arranged in the other end of actuation gear with Returnning spring, be arranged in actuation gear and the exhaust cam side can be saved axial space compared with prior art, allow compact structure, make the part of whole device can be very small and exquisite, simple, cost be low.

On the other end web of actuation gear described in the such scheme annular groove can be set, web through hole, counterweight end and Returnning spring are arranged in this annular groove.The effect of annular groove has three, one, counterweight end and Returnning spring are placed in one, and reduce axial dimension, its two, plastic gear is not a slab, is convenient to improve the injection moulding quality, promptly increases manufacturability, its three, weight reduction reduces cost.

Piece is got rid of in described centrifugal decompression can be by the steel plate bending forming, and its counterweight end bends to described annular groove after passing through web.Use the steel plate impact briquetting, very convenient cost is low, and when the counterweight end was bigger, bending can reduce axial dimension in annular groove.

Described counterweight end can be provided with the spring hanging hole and be connected with Returnning spring.The convenient connection.

Camshaft described in the scheme is positioned at exhaust cam and the actuation gear section can also process chamfered edge, and centrifugal decompression is got rid of in the piece swing, and its pushing end is moved along this chamfered edge.Process just to allow behind the chamfered edge and leave certain camshaft radial space position, other the outer parts of pushing end that make centrifugal decompression get rid of piece do not interfere with valve, and piece is got rid of in centrifugal decompression can the highi degree of accuracy manufacturing, reduces cost.

The preferable 0.8-1.0mm of being chosen as in gap of the pushing end restriction valve-closing valve port position of piece is got rid of in centrifugal decompression described in the scheme.

Engine start decompressor described in the utility model, utilize the characteristics of the actuation gear convenient formation of plastics manufacturing, with the installation key seat of actuation gear centrifugal decompression is installed and gets rid of piece, and the distortion pit that the bar portion termination of bearing pin is installed makes when installing can flatten or strike gently homalocephalus portion with the instrument of clamp or hammer and so on, forming protruding base blocks bearing pin and does not deviate from, very convenient on the technology, thus reduce cost.And counterweight end, Returnning spring of centrifugal decompression being got rid of piece etc. are arranged in the other end of actuation gear, have saved axial space compared with prior art, allow compact structure, make the part of whole device can be very small and exquisite, simple, and cost is low.

Description of drawings

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

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

Fig. 2 is the plan view of Fig. 1;

Fig. 3 is the I portion zoomed-in view of Fig. 2;

Fig. 4 is the left view of Fig. 1;

Fig. 5 is that the A of Fig. 4 is to view;

Fig. 6 is the J portion zoomed-in view of Fig. 4.

Embodiment

As Fig. 1---shown in Figure 6, engine start decompressor of the present utility model, comprise camshaft 1, one processes exhaust cam 12 and intake cam 11 on the camshaft 1, the actuation gear 2 of having gone back suit on the camshaft 1, actuation gear 2 is timing gear again, uses nylon material injection moulding, and exhaust cam 12 closes on actuation gear 2.

Close at actuation gear 2 on the end face of exhaust cam 12, one inject a key seat 4, have the pin-and-hole of installation to play axle bed on the key seat 4, actuation gear 2 has through hole 21 on the gear web on key seat 4 limits.

Centrifugal decompression is got rid of piece 3 by the steel plate bending forming, centrifugal decompression is got rid of piece 3 usefulness bearing pins 5 and is through on the key seat 4, bearing pin 5 is made up of head 51 and bar portion 52, as Fig. 2, shown in Figure 3, bar portion 52 terminations are provided with the pit 53 that is used to be out of shape, during installation with clamp to chuck portion 51 and bar portion 52 terminations because pit 53 end intensity are low, produce plastic deformation and form protruding base 54 and be stuck in key seat limit, 4 hole and fixed position.Centrifugal decompression is got rid of piece 3 and can be swung around bearing pin 5, and is divided into pushing end 31 and counterweight end 32 so that bearing pin 5 both sides to be installed; The centrifugal decompression that key seat 4 is installed get rid of piece 3 swaying directions satisfy make pushing end 31 axial leave or near the end face of exhaust cam 12.

The counterweight end 32 that piece 3 is got rid of in centrifugal decompression passes through the other end of the through hole 21 of gear web to actuation gear 2, this end face web is provided with an annular groove 22, counterweight end 32 is processed with the end that a spring hanging hole 33 connects Returnning spring 6, the other end of Returnning spring 6 then hangs on the rivet 7 of actuation gear 2 webs, web through hole 21, counterweight end 32 and Returnning spring 6 are arranged in annular groove 22, wherein, counterweight end 32 bends in annular groove 22 after passing through web.

Returnning spring 6 is a draught spring, and the power of Returnning spring 6 makes the end face of pushing end 31 near exhaust cam 12, and the centrifugal force that counterweight end 32 produces then makes pushing end 31 leave the end face of exhaust cam 12; As shown in Figure 6, described pushing end 31 extends to the lower end surface of exhaust cam 12, in this position, makes valve 9 can not arrive extreme lower position, has stayed valve port gap 8.

As Fig. 4, shown in Figure 6, camshaft 1 is positioned at exhaust cam 12 and actuation gear also is processed with chamfered edge 13 for 2 sections, and centrifugal decompression is got rid of in piece 3 swings, and its pushing end 31 is moved along this chamfered edge 13.The gap 8 that the pushing end 31 restriction valve-closing valve port positions of piece 3 are got rid of in centrifugal decompression is 0.8-1.0mm.

Claims

1, a kind of engine start decompressor comprises exhaust cam and actuation gear on camshaft and its, and exhaust cam closes on actuation gear, it is characterized in that: the end face one of described actuation gear (2) be provided with key seat (4); Centrifugal decompression is got rid of that piece (3) is installed in bearing pin (5) that key seat (4) is gone up and can be around bearing pin (5) swing, and is divided into pushing end (31) and counterweight end (32) so that bearing pin (5) both sides to be installed; Bearing pin (5) is made up of head (51) and bar portion (52), and bar portion (52) termination is provided with the pit (53) that is used to be out of shape, and distortion forms protruding base (54) and is stuck in key seat (4) limit, hole during installation; Described counterweight end (32) connects Returnning spring (6), and Returnning spring (6) one ends hang on the actuation gear (2); Described pushing end (31) extends to exhaust cam (12) end face and arrives the minimum valve port position of closing at this restriction valve (9); The centrifugal force that Returnning spring (6) power and counterweight end (32) produce make respectively pushing end (31) axially near and leave the end face of exhaust cam (12).

2, engine start decompressor according to claim 1 is characterized in that: have through hole (21) near the gear web the described key seat (4); The through hole (21) that counterweight end (32) passes through the gear web is connected with Returnning spring (6); Above-mentioned Returnning spring (6) hangs on the rivet (7) of other end of actuation gear (2).

3, engine start decompressor according to claim 2, it is characterized in that: the other end web of described actuation gear (2) is provided with annular groove (22), and web through hole (21), counterweight end (32) and Returnning spring (6) are arranged in this annular groove (22).

4, engine start decompressor according to claim 3 is characterized in that: described centrifugal decompression is got rid of piece (3) by the steel plate bending forming, and its counterweight end (32) bends to described annular groove (22) after passing through web.

5, engine start decompressor according to claim 4 is characterized in that: described counterweight end (32) is provided with spring hanging hole (33) and is connected with Returnning spring (6).

6, engine start decompressor according to claim 1, it is characterized in that: described camshaft (1) is positioned at exhaust cam (12) and actuation gear (2) section is processed with chamfered edge (13), centrifugal decompression is got rid of in piece (3) swing, and its pushing end (31) is moved along this chamfered edge (13).

7, according to the described arbitrary engine start decompressor of claim 1-6, it is characterized in that: the gap (8) that pushing end (31) the restriction valve-closing valve port position of piece (3) is got rid of in described centrifugal decompression is 0.8-1.0mm.