Patent Publication Number: US-11022074-B2

Title: Throttle and choke control linkage mechanism of diaphragm type carburetor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims all benefits accruing under 35 U.S.C. § 119 from China Patent Application No. 201821203633.2, filed on Jul. 27, 2018, in the China National Intellectual Property Administration, the content of which is hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to the field of carburetor, in particular, to a throttle and choke control linkage mechanism of carburetor. 
     BACKGROUND 
     The carburetor is a mechanical device that mixes a ratio of gasoline with air under the vacuum generated by operation of an engine. At present, there are many types of carburetors on the market, and their structures are different. The functions and principles of carburetors are basically the same, mainly based on controlling the mixture of air and fuel entering the engine, and the flow of the mixture is determined by the throttle. An opening angle of the throttle is determined by pulling a throttle trigger of the engine, resulting in controlling the amount of mixture entering the engine. 
     Referring to  FIGS. 37 to 49 , a throttle and choke control linkage mechanism of a carburetor of the prior art is provided. When a choke lever on an engine is pulled, a choke handle  13  will rotate counterclockwise. Since the choke handle  13  and a choke shaft  7  are connected to each other by a non-circular portion, the choke shaft  7  will rotate together with a choke valve  9  fixed on the choke shaft  7  by a screw  8 . At the same time, a stopper  13 - 1  of the choke handle  13  will touch a portion  11 - 1  of a fast idle handle  11 , in order to push the fast idle handle  11  to overcome the torsion of a torsional spring  10  and then rotate counterclockwise. Under the tension of the choke lever, when the choke valve  9  is closed to a certain position, the fast idle handle  11  contacts a portion  5 - 1  of a throttle grip  5 , in order to push a throttle shaft  1  and a throttle  3  fixed on the throttle shaft  1  by another screw  2  to gradually open with gradual closing of the choke valve  9 . The portion  5 - 1  will fall into a ratchet  11 - 2  to generate a coupling. In order to ensure the portion  5 - 1  of the throttle grip  5  can fall into the ratchet  11 - 2  of the fast idle handle  11 , the choke valve  9  and a main body choke hole  14 - 1  must not be completely closed. It is also impossible to close in the operation: when there is no over-travel, the portion  5 - 1  of the throttle grip  5  cannot fall into the ratchet  11 - 2  of the fast idle handle ( 11 ). In order to make sure that the fast idle handle  11  and the throttle grip  5  are coupled, there must be the over-travel (as shown in  FIG. 42 ). At this time, the choke valve  9  and the main body choke hole  14 - 1  on a main body  14  are affected by the torsional spring on the fast idle handle, the choke valve cannot be completely closed and sealed, that is, a gap is generated during the over-travel. Due to an accumulated tolerance of each element, the position of the choke valve  9  is inconsistent. As shown in  FIGS. 42 to 44 , when the choke valve is fully closed under an external force, the fast idle handle and the throttle grip are interlocked, and there is a gap between the idle handle and the throttle grip. As shown in  FIGS. 45 to 47 , when the external force is released, the choke shaft  7  will be pushed back under the torsion of the torsional spring, causing the choke valve to open a part, thereby affecting the starting performance of the engine. After a fast idle linkage, there will be gaps in different sizes between the choke valve and an air intake of the main body, and the choke valve cannot be completely closed, resulting in a difference in an air intake amount when the engine is started and the starting performance of the engine. 
     Referring to  FIGS. 48 and 49 , another throttle and choke control linkage mechanism of another carburetor in prior art is provided. The difference between the throttle and choke control linkage mechanism in  FIGS. 48 and 49  and the throttle and choke control linkage mechanism in  FIGS. 37 to 47  is that the fast idle handle has a bevel on an upper portion in  FIG. 48 . The choke lever (not shown) on the engine pulls the choke handle  13 , and the connecting portion of the choke handle  13  and the choke shaft  7  is provided with a flat shape to drive the choke shaft  7  and the choke valve  9  fixed by a screw  8  to rotate together. At the same time, a stopper  13 - 1  is in contact with the portion  11 - 1  of the fast idle handle  11  on the choke handle  13  to push the fast idle handle  11  and overcome the torsion of the torsional spring  10 . Under the tension of the choke lever, when the choke valve  9  is rotated to a certain position, the fast idle handle  11  contacts an arm  5 - 1  of the throttle grip  5  and pushes the throttle shaft  1  and the throttle  3  fixed by a screw  2  to gradually open with the gradual closing of the choke valve  9 . When the arm  5 - 1  of the throttle grip  5  slides along a surface of  11 - 3  of the fast idle handle  11  to a bevel  11 - 2  of the fast idle handle  11 , the arm  5 - 1  of the throttle grip  5  will contact the bevel  11 - 2  of the fast idle handle  11  and generate an initial coupling. The choke handle  13  is continually pulled. When the choke valve  9  and the main body  14  are completely closed, the arm  5 - 1  of the throttle grip  5  is located on the bevel  11 - 2  of the fast idle handle  11  and slides to a certain point (as shown in  FIG. 32 ), and at this time, an opening angle of the throttle  3  depends on the position of the arm  5 - 1  of the throttle grip  5  sliding on the bevel  11 - 2  of the fast idle handle  11 . An accumulated tolerance of each element will result in that the position of the arm ( 5 - 1 ) of the mass-produced throttle handle ( 5 ) on the bevel  11 - 2  of the fast idle handle ( 11 ) will be inconsistent, so the opening angle of the throttle  3  is relatively inconsistent. The fast idle handle  11  will rotate counterclockwise to drive the choke valve  9  closed under the action of the throttle grip  5 . However, due to manufacturing errors, the position of the throttle  3  is uncertain, which will affect the starting performance of the engine. Due to the accumulated tolerance of each element, the opening angle of throttle has a large difference after the fast idle linkage, resulting in poor consistency of engine starting and large engine speed dispersion when starting after fast idling. 
     In prior art, there will be gaps of different sizes between a choke valve and a throttle of the main body, which cannot be completely closed, resulting in a difference in the amount of mixture entering the engine when starting the engine, the starting performance of the engine, and the opening angle of the throttle. Therefore, there are large differences in engine starting consistency and engine speed at the time of quick idling after starting. 
     SUMMARY 
     An embodiment of the present disclosure includes a throttle and choke control linkage mechanism for a carburetor including a choke shaft rotatably installed with a choke valve, a throttle shaft rotatably installed with a throttle, a choke handle fixed on the choke shaft and configured for rotating the choke valve from a fully opened position to a fully closed position or from the fully closed position to the fully opened position, a throttle grip fixed on the throttle shaft and configured for rotating the throttle from an idling position to an opened position, and a fast idle handle being able to rotate freely around the choke shaft, the fast idle handle further carrying a first end of a torsional spring, which has a second end connected with the choke shaft. When the choke handle is pulled, the choke valve is rotated from the fully opened position to the fully closed position. The fast idle handle is disposed on the choke shaft which is deflected by the torsional spring and rotatable along a first path. The throttle grip is rotatable along a second path which is coplanar and intersects with the first path. The fast idle handle is provided with a locking recess configured for locking the throttle grip. When the choke handle departs from the throttle grip, the throttle is at the idling position and the throttle grip is locked within the locking recess. The choke handle is further provided with a first surface which is able to link with the throttle grip. When the choke handle is linked with the throttle grip, the choke valve is at the fully closed position, and the throttle is opened with an angle larger than the idling position. 
     Furthermore, when the choke handle is linked with the throttle grip, the throttle grip is not locked by the locking recess, and there is a gap between the throttle grip and the fast idle handle. 
     Furthermore, the choke shaft and the throttle grip are linked with each other via the torsional spring. 
     Furthermore, at least one of the choke handle and the fast idle handle is provided with a convex portion, the fast idle handle is contacted with the choke handle under the torsional spring, when the choke handle is pulled, the choke valve is rotated from the fully opened position to the fully closed position, the fast idle handle and the choke handle will rotate, and the choke handle is finally linked with the throttle grip. 
     Furthermore, the fast idle handle is rotatably fixed on the choke shaft. 
     Furthermore, the fast idle handle comprises a first through hole with a cylindrical shape, the fast idle handle further has a first peak. 
     Furthermore, when the fast idle handle rotates until the first peak contacts a sixth edge of the throttle grip, the throttle is located at a maximum throttle angle, and a fifth edge of the throttle grip has not yet entered into the locking recess of the fast idle handle. 
     Furthermore, the choke shaft penetrates through the first through hole of the fast idle handle, and the fast idle handle freely rotate about the choke shaft. 
     Furthermore, a choke shaft sleeve is disposed on a bottom side of the fast idle handle and sleeved around the choke shaft. 
     Furthermore, the choke handle comprises a third surface. When the choke handle is rotated to enable the fast idle handle to rotate, the third surface touches a third peak of the throttle grip, a part of a fifth edge of the throttle grip contacts with a ninth edge of the fast idle handle and is not located in the locking recess. 
     Furthermore, the throttle grip is provided with a first linkage shaft configured for engaging the fast idle handle. When the fast idle handle rotates and the first peak contacts with the first linkage shaft, the throttle is rotated to a maximum throttle angle by the throttle grip. 
     Furthermore, the throttle grip is further provided with a second linkage shaft configured for engaging the choke handle. When the choke handle rotates until the second linkage shaft touch a first surface of the choke handle, the first linkage shaft contacts with a ninth edge of the fast idle handle, but not contact the locking recess. 
     Compared with the prior art, the choke handle is further provided with the first surface which is able to link with the throttle grip. When the choke handle is linked with the throttle grip, the choke valve is at the fully closed position, the throttle is opened with the angle larger than the idling position. Therefore, it is easier to start the engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a throttle and choke control linkage mechanism in an embodiment of the present disclosure. 
         FIG. 2  is an exploded view of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 3  is an exploded view of a throttle shaft of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 4  is an exploded view of a choke shaft of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 5  is a perspective view of a choke valve at a fully opened position and a throttle at a fully closed position of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 6  is a perspective view of a choke handle of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 7  is a perspective view of a fast idle handle of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 8  is a perspective view of a choke handle and a fast idle handle of the throttle and choke control linkage mechanism in  FIG. 1 , which are in a contacting state. 
         FIG. 9  is a perspective view of a choke valve at a closed position and a throttle at an opened position of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 10  is an enlarged view of a fast idle handle of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 11  is a perspective view of a throttle grip of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 12  is a perspective view of a fast idle handle and a throttle grip of the throttle and choke control linkage mechanism in  FIG. 1 , which are just in a contacting state. 
         FIG. 13 a    is a perspective view of a throttle rotating to a maximum opening angle of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 13 b    is a perspective view of a fast idle handle and a throttle grip of the throttle and choke control linkage mechanism in  FIG. 13   a.    
         FIG. 14 a    is a perspective view of a fast idle handle rotating counter-clockwise at working of the throttle and choke control linkage mechanism in  FIG. 13   a.    
         FIG. 14 b    is a perspective view of the fast idle handle, a throttle grip and a choke handle touching with each other of the throttle and choke control linkage mechanism in  FIG. 14   a.    
         FIG. 15 a    is a perspective view of a choke valve at a fully closed position of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 15 b    is a perspective view of a fast idle handle, a throttle grip and a choke handle touching with each other of the throttle and choke control linkage mechanism in  FIG. 15   a.    
         FIG. 16 a    is a perspective view of a fast idle handle rotating clockwise and stopping of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 16 b    is a perspective view of the fast idle handle, a throttle grip and a choke handle touching with each other of the throttle and choke control linkage mechanism in  FIG. 16   a.    
         FIG. 17 a    is a perspective view of a throttle grip rotating and passing a second peak, until contacting with a fast idle handle of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 17 b    is a perspective view of the throttle grip, the fast idle handle and a choke handle contacting with each other of the throttle and choke control linkage mechanism in  FIG. 17   a.    
         FIG. 18 a    is a perspective view of a fast idle handle and a throttle grip in a linked state of the throttle and choke control linkage mechanism in  FIG. 1 , when a choke valve is at a fully opened position. 
         FIG. 18 b    is a perspective view of the throttle grip, the fast idle handle and the choke handle of the throttle and choke control linkage mechanism in  FIG. 18   a.    
         FIG. 19  is a perspective view of a fast idle handle and a throttle handle in a critical state of the throttle and choke control linkage mechanism in  FIG. 1 , when a throttle rotates from an idling position to a fully opened position. 
         FIG. 20 a    is a perspective view of a choke valve and a throttle handle both being fully opened of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 20 b    is a perspective view of the choke valve and a fast idle handle contacting with each other of the throttle and choke control linkage mechanism in  FIG. 20   a.    
         FIG. 21  is a perspective view of a throttle and choke control linkage mechanism in another embodiment of the present disclosure. 
         FIG. 22  is an exploded view of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 23  is an exploded view of a throttle shaft of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 24  is an exploded view of a choke shaft of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 25  is a perspective view of a choke handle of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 26  is a perspective view of a throttle grip of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 27  is a perspective view of a choke valve at a fully opened position and a throttle at a fully closed position of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 28 a    is a perspective view of a choke handle and a fast idle handle of the throttle and choke control linkage mechanism in  FIG. 1 , which are in a linked state. 
         FIG. 28 b    is a perspective view of a choke handle and a fast idle handle of the throttle and choke control linkage mechanism in  FIG. 28 a   , which are in a contacting state. 
         FIG. 29 a    is a perspective view of a throttle rotating to a maximum opening angle (critical state) of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 29 b    is a perspective view of a fast idle handle and a throttle grip in the critical state of the throttle and choke control linkage mechanism in  FIG. 29   a.    
         FIG. 30 a    is a perspective view of a choke handle and a throttle grip of the throttle and choke control linkage mechanism in  FIG. 21 , which just contact each other. 
         FIG. 30 b    is a perspective view of a choke handle and a throttle grip of the throttle and choke control linkage mechanism in  FIG. 21 , which are in a linked state. 
         FIG. 30 c    is a perspective view of a fast idle handle and a throttle grip of the throttle and choke control linkage mechanism in  FIG. 21 , which are in a linked state. 
         FIG. 31 a    is a perspective view of a choke valve at a fully closed position of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 31 b    is a perspective view of a throttle grip and a choke valve being in a linked state of the throttle and choke control linkage mechanism in  FIG. 31   a.    
         FIG. 31 c    is a perspective view of a throttle grip and a fast idle handle being in a linked state of the throttle and choke control linkage mechanism in  FIG. 31   a.    
         FIG. 32 a    is a perspective view of a throttle grip touching with a choke handle and a fast idle handle of the throttle and choke control linkage mechanism in  FIG. 21 , when the choke valve is rotated clockwise. 
         FIG. 32 b    is a perspective view of the throttle grip touching with the choke handle of the throttle and choke control linkage mechanism in  FIG. 32   a.    
         FIG. 32 c    is a perspective view of the throttle grip touching with the fast idle handle of the throttle and choke control linkage mechanism in  FIG. 32   a.    
         FIG. 33 a    is a perspective view of the throttle grip stopped to rotate of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 33 b    is a perspective view of the throttle grip and a choke handle in a linked state of the throttle and choke control linkage mechanism in  FIG. 21 . 
         FIG. 34  is a perspective view of a throttle grip locked by a fast idle handle of the throttle and choke control linkage mechanism in  FIG. 21 , when a choke valve is at a fully opened position. 
         FIG. 35  is a perspective view of a fast idle handle and a throttle handle in a critical state of the throttle and choke control linkage mechanism in  FIG. 21 , when a throttle rotates from an idling position to a fully opened position. 
         FIG. 36  is a perspective view of a choke valve and a throttle handle both being fully opened of the throttle and choke control linkage mechanism in  FIG. 1 . 
         FIG. 37  is a perspective view of a carburetor of the prior art. 
         FIG. 38  is a perspective view of a throttle handle of the carburetor in  FIG. 37 . 
         FIG. 39  is a perspective view of a choke handle of the carburetor in  FIG. 37 . 
         FIG. 40  is a perspective view of a fast idle handle of the carburetor in  FIG. 37 . 
         FIG. 41  is a cross-sectional view of a main body of the carburetor in  FIG. 37 . 
         FIG. 42  is a perspective view of the carburetor in an over travel state in  FIG. 37 . 
         FIG. 43  is a perspective view of the carburetor in  FIG. 37 , in a return state under torsional spring of a choke valve. 
         FIG. 44  is a perspective view of the carburetor with the choke valve fully closed in  FIG. 37 . 
         FIG. 45  is a perspective view of the carburetor in  FIG. 37 , in which the choke shaft is reversely pushed under the action of the torsion spring after the external force is lost, causing the choke valve to open partly. 
         FIG. 46  is a perspective view of another carburetor of the prior art. 
         FIG. 47  is a perspective view of a fast idle handle of the carburetor in  FIG. 46 . 
         FIG. 48  is a perspective view of the carburetor in  FIG. 46  in a linked state. 
         FIG. 49  is a perspective view of the carburetor in  FIG. 46  with the choke valve fully closed. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will be further described in detail below with reference to the drawings and specific embodiments, in order to better understand the objective, the technical solution and the advantage of the present disclosure. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the disclosure. 
     It should be noted that when an element is referred to as being “fixed” to another element, it may be directly attached to the other element or a further element may be presented between them. When an element is considered to be “connected” to another element, it may be directly connected to the other element or connected to the other element through a further element (e.g., indirectly connected). The terms as used herein “vertical”, “horizontal”, “left”, “right”, and the like, are for illustrative purposes only and are not meant to be the only orientation. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as a skilled person in the art would understand. The terminology used in the description of the present disclosure is for the purpose of describing particular embodiments and is not intended to limit the disclosure. 
     Referring to  FIG. 1 , an embodiment of the present disclosure includes a carburetor  100   100  including a main body  14  and a throttle and choke control linkage mechanism  20 . The throttle and choke control linkage mechanism  20  is mounted on the main body  14 . 
     The carburetor  100  can be a diaphragm type carburetor  100 . The carburetor  100  can be other types. 
     In this embodiment, the carburetor  100  is the diaphragm type carburetor  100 , the throttle and choke control linkage mechanism  20  is a throttle and choke control linkage mechanism of the diaphragm type carburetor  100 . The structure and working process of the throttle and choke control linkage mechanism  20  will be represented hereinafter. 
     Referring to  FIG. 2 , the throttle and choke control linkage mechanism  20  can include a throttle shaft  1 , a throttle  3 , a throttle grip  5 , a choke shaft  7 , a choke valve  9 , a fast idle handle  11  and a choke handle  13 . The throttle and choke control linkage mechanism  20  is an integrated structure formed by the throttle  3 , the choke valve  9 , and a cold start and quick idle setting mechanism of a throttle-choke. Referring to  FIG. 4 , the choke shaft  7  can be installed with a choke handle  13 , a torsional spring  12 , a fast idle handle  11 , and a choke shaft sleeve  10  and a choke valve  9  from top to bottom. The choke handle  13  is provided with a third through hole  13   g  configured for accommodating an end of the choke shaft  7 . The choke handle  13  can be linked with the end of the choke shaft  7 . An inner surface of the third through hole  13   g  can include a seventh non-circular surface  13   a  and an eighth non-circular surface  13   b  opposite to each other. When the choke valve  9  is fully closed, the throttle  3  is opened with an angle, the throttle grip  5  and the fast idle handle  11  are not in a linking state and there is a gap between the throttle grip  5  and the fast idle handle  11 . The choke valve  9  can be fully closed and have a good consistency. When an engine is started and a “POP” sound is made, the choke valve  9  is opened, the choke handle  13  will detach from the throttle grip  5 , and at the same time, the throttle grip  5  will be coupled with the fast idle handle  11 , so a throttle angle can have a good consistency, greatly improving a starting performance and a fast idle speed of the engine. 
     When the choke valve  9  is rotated from an opened position to a fully closed position, the throttle  3  can automatically be opened to a position greater than a fast idling position, making the starting of the engine easier. 
     The choke shaft  7  is able to rotate and mount with the choke valve  9 . The choke handle  13  is configured for rotating the choke valve  9  from a fully opened position to the fully closed position or from the fully closed position to the fully opened position, and fixed on the choke shaft  7 . The throttle grip  5  can carry a torsional spring (not shown), be configured for rotating the throttle  3  from a fully closed position to a fully opened position and fixed on the throttle shaft  1 . The fast idle handle  11  can carry a torsional spring  12  and be able to rotate freely around the choke shaft  7 . 
     In an embodiment, referring to  FIG. 4 , the end of the choke shaft  7  includes a fifth non-circular surface  7   a  and a sixth non-circular surface  7   b  opposite to each other. The seventh non-circular surface  13   a  and the eighth non-circular surface  13   b  of the third through hole  13   g  of the choke handle  13  can be respectively coupled with the fifth non-circular surface  7   a  and the sixth non-circular surface  7   b , so the choke handle  13  can drive the choke shaft  7  to rotate together. 
     Referring to  FIG. 3 , the throttle grip  5  can include a second through hole  5   k . The second through hole  5   k  includes a third non-circular surface  5   i  and a fourth non-circular surface  5   j  opposite to each other. An end of the throttle shaft  1  can include a first non-circular surface  1   a  and a second non-circular surface  1   b  opposite to each other. The first non-circular surface  1   a  and the second non-circular surface  1   b  are respectively coupled to the third non-circular surface  5   i  and the fourth non-circular surface  5   j  of the second through hole  5   k . That is, the end of the throttle shaft  1  can be located within the second through hole  5   k  and is fastened to the throttle grip  5  by the upper screw  6 . 
     The throttle shaft  1  can be provided with an annular groove  1   c , and a shield ring  4  can be disposed in the annular groove  1   c.    
     Referring to  FIG. 4 , the choke shaft  7  can include a fifth non-circular surface  7   a , a sixth non-circular surface  7   b  and a cylindrical surface  7   c.    
     Referring to  FIG. 4 , the fast idle handle  11  can include a first through hole  11   h . The first through hole  11   h  can have a cylindrical shape and include an inner surface  11   g . Referring to  FIG. 7 , the fast idle handle  11  can further have a locking recess  11   c , a ninth edge  11   d , a first peak  11   e , a tenth edge  11   f , a seventh edge  11   a  and an eighth edge  11   b . Referring to  FIG. 11 ,  FIG. 13 a    and  FIG. 13 b   , when the fast idle handle  11  rotates until the first peak  11   e  contacts the sixth edge  5   f  of the throttle grip  5 , the throttle  3  is located at a maximum throttle angle, and a fifth edge  5   e  of the throttle grip  5  has not yet entered into the locking recess  11   c  of the fast idle handle  11 . 
     In the present embodiment, the choke shaft  7  penetrates through the first through hole  11   h  of the fast idle handle  11 , and the cylindrical surface  7   c  can contact the inner surface  11   g  of the first through hole  11   h . The fast idle handle  11  can freely rotate about the choke shaft  7 . 
     Furthermore, a choke shaft sleeve  10  can be disposed on a bottom side of the fast idle handle  11  and sleeved around the choke shaft  7  (shown in  FIG. 4 ). 
     Referring to  FIG. 2 , the fast idle handle  11  can be disposed on the choke shaft  7  which is deflected by the torsional spring  12 . The fast idle handle  11  can rotate along a first path which is coplanar and intersects with a second path of rotating of the throttle grip  5 . 
     At least one of the choke handle  13  and the fast idle handle  11  has a convex portion operatively connected with one of the choke handle  13  and the fast idle handle  11 . The choke handle  13  rotates and makes the choke valve  9  close, causing the fast idle handle  11  to rotate toward an engaged position. 
     Referring to  FIG. 8 , the choke handle  13  is provided with a first convex portion  13   h , and the fast idle handle  11  is provided with a second convex portion  11   i.    
     The choke valve  9  can rotate from the fully opened position to the fully closed position or from the fully closed position to the fully opened position by the rotating of the choke handle  13  and the choke shaft  7 . 
     The throttle  3  can be fixed to the throttle shaft  1  by a bolt  2 . 
     It can be shown that the choke valve  9  can rotate from the fully opened position to the fully closed position in  FIG. 5 - FIG. 8 . 
     The choke handle  13  can include a plurality of surfaces. The plurality of surfaces of the choke handle  13  are configured for inter-connecting with the throttle grip  5 . Referring to  FIG. 8 , when the choke valve  9  is at the fully opened position, the seventh edge  11   a  of the fast idle handle  11  contacts closely with a second surface  13   c  of the choke handle  13  under a torsion of the torsional spring  12 . That is, there is no gap between the second convex portion  11   i  and the first convex portion  13   h , which contacts with each other. When the choke valve  9  rotates from the fully opened position to the fully closed position, that is, the choke handle  13  is rotated counter-clockwise, the fast idle handle  11  is driven to rotate counter-clockwise by the choke handle  13 . 
     It can be shown that the throttle  3  can rotate from an idling position to an opened position in  FIG. 9 - FIG. 12 . 
     When the tenth edge  11   f  of the fast idle handle  11  rotates and contacts with the third edge  5   c  of the throttle grip  5 , the throttle grip  5  and the throttle  3  are correspondingly driven to rotate clockwise, the throttle  3  will gradually rotate from an idling position to an opened position. 
     It can be shown that the throttle  3  rotates to the maximum throttle angle from  FIG. 13 a    and  FIG. 13   b.    
     When the tenth edge  11   f  of the fast idle handle  11  drives the throttle grip  5  to rotate, the first peak  11   e  contacts with the third edge  5   c  of the throttle grip  5 , such that the throttle grip  5  and the throttle  3  will be driven to rotate clockwise. The throttle  3  rotates from the idling position to the fully opened position. When the first peak  11   e  contacts with the sixth edge  5   f  of the throttle grip  5 , the throttle  3  has the maximum throttle angle. 
     Referring to  FIG. 14 a    and  FIG. 14 b   , when the choke handle  13  is continuously pulled, the fast idle handle  11  continuously rotates counter-clockwise, the fifth edge  5   e  of the throttle grip  5  will move toward the ninth edge  11   d  of the fast idle handle  11 . And at the same time, the third peak  5   b  of the throttle grip  5  will touch a first surface  13   d  of the choke handle  13 . 
     Referring to  FIG. 15 a    and  FIG. 15 b   , the choke handle  13  will rotate continuously, such that the fast idle handle  11  continuously rotates until the choke valve  9  closes fully. Then, the third peak  5   b  of the throttle grip  5  is completely engaged with a middle of the first surface  13   d  of the choke handle  13 . There are gaps between the fifth edge  5   e  and the ninth edge  11   d  and between the sixth edge  5   f  and the locking recess  11   c , which are not in contact with each other. 
     Referring to  FIG. 16 a    and  FIG. 16 b   , the choke handle  13  drives the choke valve  9  to rotate clockwise, the first surface  13   d  will pull the throttle grip  5  to rotate clockwise. The fast idle handle  11  will rotate clockwise together under the torsion of the torsional spring  12 , until that the ninth edge  11   d  touches and is stopped by the fifth edge  5   e  of the throttle grip  5 . Then, the fast idle handle  11  will not rotate clockwise. 
     Referring to  FIG. 17 a    and  FIG. 17 b   , the choke handle  13  is pulled to rotate clockwise, a third surface  13   e  of the choke handle  13  will pass over the third peak  5   b  of the throttle grip  5  and slide along a first edge  5   a  of the throttle grip  5  until it departs from the first edge  5   a . The throttle grip  5  will rotate counter-clockwise under the torsion of the torsional spring until it is locked within the locking recess  11   c  of the fast idle handle  11 . Then, the throttle grip  5  will stop to rotate counter-clockwise. 
     Referring to  FIG. 18 a    and  FIG. 18 b   , the choke handle  13  is continuously pulled to rotate clockwise, a third surface  13   e  of the choke handle  13  will departs completely from the first edge  5   a  of the throttle grip  5  until the choke valve  9  rotates clockwise to the fully opened position. At this time, the choke valve  9  is in contact with a block portion  14   a  of the main body  14 . The sixth edge  5   f  of the throttle grip  5  is completely locked within the locking recess  11   c  of the fast idle handle  11 . 
     Referring to  FIG. 19 , when the throttle  3  rotates from the idling position to the opened position, that is, the throttle grip  5  is pulled clockwise, the sixth edge  5   f  contacts with the first peak  11   e  of the fast idle handle  11 , and the throttle grip  5  can be in a critical state. 
     It can be shown that an end state of the throttle and choke control linkage mechanism from  FIG. 20 a    to  FIG. 20   b.    
     The throttle  3  is continuously operated. The throttle grip  5  continues to rotate clockwise, the first peak  11   e  of the fast idle handle  11  detaches from the sixth edge  5   f . The fast idle handle  11  will rotate clockwise under the torsion of the torsional spring, until the seventh edge  11   a  of the fast idle handle  11  contacts the second surface  13   c  of the choke handle  13 . The movement of the throttle and choke control linkage mechanism ends. 
     In another embodiment, referring to  FIG. 21  to  FIG. 24 , another throttle and choke control linkage mechanism in a carburetor  200  is provided. The structure and connection relationship between the various components of the carburetor  200  is substantially the same as that of the carburetor  100 , except for the structures of the throttle grip  5  and the choke handle  13 . Therefore, the structures of the throttle grip  5  and the choke handle  13 , and working process of the carburetor  200  will be explained. 
     Referring to  FIG. 25 , the first surface  13   d  is further provided with a concave portion  131 . The concave portion  131  is configured for linking with the throttle grip  5 . 
     Referring to  FIG. 26 , the throttle grip  5  is provided with a first linkage shaft  5   g  and a second linkage shaft  5   h . The first linkage shaft  5   g  is configured for engaging the fast idle handle  11 , and the second linkage shaft  5   h  is configured for engaging the choke handle  13 . 
     Preferably, the first linkage shaft  5   g  and the second linkage shaft  5   h  are vertically disposed on the throttle grip  5 , that is, an axis of the first linkage shaft  5   g  can be vertical to a surface of the throttle grip  5  and parallel to an axis of the second linkage shaft  5   h . Of course, in other embodiments, the axis of the first linkage shaft  5   g  and the axis of the second linkage shaft  5   h  may not be disposed in parallel. 
     Referring to  FIG. 27 ,  FIG. 28 a   ,  FIG. 28 b   ,  FIG. 29 a   ,  FIG. 29 b   ,  FIG. 30 a   ,  FIG. 30 b   ,  FIG. 30 c   ,  FIG. 31 a   ,  FIG. 31 b   , and  FIG. 31 c   , it shows a process of the choke valve  9  from a fully opening position to a fully closing position. 
     When the choke valve  9  is at the fully opening position, the seventh edge  11   a  of the fast idle handle  11  is in close contact with the first face  13   c  of the choke handle  13  by the torsion of the torsional spring  12  (as shown in  FIG. 20 b   ). When the choke valve  9  is rotated from the fully opening position to the fully closed position, that is, when the choke handle  13  is pulled to rotate counterclockwise, the fast idle handle  11  can be driven to rotate counterclockwise by the choke handle  13 . 
     Specifically, referring to  FIG. 28 a    to  FIG. 28 b   , a process of the throttle  3  from the idling position to the opened position is showed. 
     When the tenth edge  11   f  of the fast idle handle  11  rotates and contacts with the first linkage shaft  5   g  of the throttle grip  5 , the throttle grip  5  and the throttle  3  are driven to rotate clockwise, and the throttle  3  will gradually rotate from the idling position to the opened position. 
     It can be shown that the throttle  3  rotates to the maximum throttle angle from  FIG. 29 a    and  FIG. 29   b.    
     When the tenth edge  11   f  of the fast idle handle  11  drives the throttle grip  5  to rotate, the first peak  11   e  contacts with the first linkage shaft  5   g  of the throttle grip  5 , such that the throttle  3  rotates from the idling position to the fully opened position. When the first peak  11   e  contacts with the first linkage shaft  5   g  of the throttle grip  5 , the throttle  3  has the maximum throttle angle. 
     Referring to  FIG. 30 a   ,  FIG. 30 b   , and  FIG. 30 c   , when the choke handle  13  is continuously pulled, the fast idle handle  11  continuously rotates counter-clockwise, the first linkage shaft  5   g  of the throttle grip  5  will move to the ninth edge  11   d  of the fast idle handle  11 , but not contact the locking recess  11   c . And at the same time, the second linkage shaft  5   h  of the throttle grip  5  will touch the first surface  13   d  of the choke handle  13 . 
     Referring to  FIG. 31 a   ,  FIG. 31 b   , and  FIG. 31 c   , the choke handle  13  will rotate continuously, such that the fast idle handle  11  continuously rotates until the choke valve  9  closes fully. Then, the second linkage shaft  5   h  of the throttle grip  5  is completely engaged with the concave portion  131  of the first surface  13   d . There are gaps between the first linkage shaft  5   g  and the ninth edge  11   d  and between the first linkage shaft  5   g  and the locking recess  11   c , which are not in contact with each other. 
     Referring to  FIG. 32 a   ,  FIG. 32 b    and  FIG. 32 c   , the choke handle  13  drives the choke valve  9  to rotate clockwise, the second surface  13   e  will pull the throttle grip  5  to rotate clockwise. The fast idle handle  11  will rotate clockwise together under the torsion of the torsional spring  12 , until that the ninth edge  11   d  touches and is stopped by the first linkage shaft  5   g  of the throttle grip  5 . Then, the fast idle handle  11  will not rotate clockwise. 
     Referring to  FIG. 33 a    and  FIG. 33 b   , the choke handle  13  is pulled to rotate clockwise, a third surface  13   e  of the choke handle  13  will not contact with the second linkage shaft  5   h . At the time, the throttle grip  5  will rotate counter-clockwise under the torsion of the torsional spring until it is locked within the locking recess  11   c  of the fast idle handle  11  (as shown in  FIG. 34 ). Then the throttle grip  5  will stop to rotate counter-clockwise. 
     Referring to  FIG. 34 , the choke handle  13  is continuously pulled to rotate clockwise, a third surface  13   e  of the choke handle  13  will departs completely from the second linkage shaft  5   h  of the throttle grip  5  until the choke valve  9  rotates clockwise to the fully opened position. At this time, the choke valve  9  is in contact with the block portion  14   a  of the main body  14 . The first linkage shaft  5   g  of the throttle grip  5  is completely locked within the locking recess  11   c  of the fast idle handle  11 , and there is a gap between the second convex portion  11   i  and the first convex portion  13   h.    
     Referring to  FIG. 35 , when the throttle  3  rotates from the idling position to the opened position, that is, the throttle grip  5  is pulled clockwise, the first linkage shaft  5   g  contacts with the first peak  11   e  of the fast idle handle  11 , and the throttle grip  5  can be in the critical state. 
     It can be shown that an end state of the throttle and choke control linkage mechanism from  FIG. 36 . 
     The throttle  3  is continuously operated. The throttle grip  5  continues to rotate clockwise, the first peak  11   e  of the fast idle handle  11  detaches from the first linkage shaft  5   g . The fast idle handle  11  will rotate clockwise under the torsion of the torsional spring, until the seventh edge  11   a  of the fast idle handle  11  contacts with the second surface  13   c  of the choke handle  13 , and there is no gap between the second convex portion  11   i  and the first convex portion  13   h . The movement of the throttle and choke control linkage mechanism ends. 
     The technical features of the above-described embodiments may be combined in any combination. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, all should be considered as the scope of this disclosure. 
     The above-described embodiments are merely illustrative of several embodiments of the present disclosure, and the description thereof is relatively specific and detailed, but is not to be construed as limiting the scope of the disclosure. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the disclosure. Therefore, the scope of the disclosure should be determined by the appended claims.