JPH04311657A - Automatic starter for carburetor - Google Patents

Abstract

PURPOSE:To eliminate a pinch or the like by providing an operating rod protruding/receding by the volume change of thermal expansion material and a transmission rod for transmitting the change of the operating rod to a choke valve and a throttle valve in such a way as to convert stroke change into rotational change in the state of facing each other at the end faces thereof to perform transmission. CONSTITUTION:An output rod 13 protruding/receding by the volume change of thermal expansion material is protruded from the lower end of a wax case 12 with thermal expansion material filled therein, and the stroke of a operating rod is changed according to the movement of the output rod 13. A transmission rod 20 is provided, in correspondence with the operating rod 14, at a cylindrical collar 17 rotatably supported at the fitting boss of a carburetor body 1. A first lever 19 with a circular elongated groove 9A formed therein is fitted concentrically, and a second lever 21 with a female screw hole 21A opened in correspondence with the elongated hole 19A is rotatably disposed at the outer periphery of the collar 17. Cam parts 21B, 21C opposed to the engaging parts 7, 11 of a choke lever 6 and a throttle lever 10 are then formed at the second lever 21.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a carburetor that adjusts and controls the amount and concentration of air-fuel mixture supplied to an engine, and in particular controls the opening of a choke valve and throttle valve when starting an engine. This invention relates to an automatic starting device for a carburetor that is automatically controlled according to the engine ambient temperature.

0002

2. Description of the Related Art A conventional automatic starting device for a carburetor is known, for example, in Japanese Patent Application No. 61-19782. According to this, a connecting lever having a connecting shaft and a control lever having a choke cam part, a throttle cam part, and a locking part are respectively arranged rotatably with respect to the shaft, and the connecting lever and the control lever are are mechanically connected by a locking part when rotated in one direction, and elastically connected by the elastic force of a spring when rotated in the other direction, while the operating rod of the heat-sensitive responsive member and the connecting shaft of the connecting lever are The end of the operating rod is inserted into a through hole drilled in the connecting shaft so that it protrudes, and a nut is screwed onto one end of the operating rod that holds the connecting shaft, and a spring is compressed at the other end. A rod and a connecting shaft are sandwiched and connected using a nut and a spring.

0003

SUMMARY OF THE INVENTION This conventional automatic starting device for a carburetor has the following problems.

(1) The operating rod is inserted into the through hole of the connecting shaft, and the linear movement of the operating rod is converted into rotational movement of the connecting lever via the connecting shaft. Therefore, the inner wall of the through hole and the outer periphery of the operating rod may come into contact with each other due to the different movement directions. For this reason, the number of testing steps required to select materials for contact parts (operating rods, connecting shafts) that can maintain durability increases, which is not desirable in terms of development efficiency.

(2) Drilling a through hole in the connecting shaft increases the number of machining steps, and placing a nut and spring on the operating rod across the connecting shaft means that the end of the operating rod The spring is inserted, the operating rod is then inserted into the through hole of the connecting shaft, and the end of the operating rod that protrudes from the through hole is screwed with a nut. This results in high manufacturing costs.

[0006]

[Means for Solving the Problems] The automatic starting device for a carburetor according to the present invention improves development efficiency by reducing the number of testing steps required to select the material of the contact part that converts the linear movement of the operating rod into the rotational force of the lever. It is an object of the present invention to provide the above-mentioned device, which has a small number of parts, a small number of assembly steps, and is inexpensive to manufacture.

According to the present invention, in order to achieve the above-mentioned object, a heat-expandable material is hermetically sealed inside, and a change in stroke is applied to the outside in accordance with the movement of the output rod due to a change in the volume of the heat-expandable material. A heat-sensitive member with an operating rod for output is integrally attached to a cylindrical collar rotatably supported by a mounting boss installed upright on the vaporizer body, and the heat-sensitive member has an operating rod that outputs output. A first lever is rotatably arranged on the outer periphery of the collar and includes a transmission rod and a long groove concentrically bored in an arc shape with respect to the center of the collar. A second throttle cam portion comprising: a female threaded hole opening corresponding to the throttle lever; a choke cam portion abutting a first engaging portion provided on the choke lever; and a throttle cam portion abutting a second engaging portion provided on the throttle lever. Consisting of a lever and an operation spring whose one end is locked to the carburetor body and the other end is locked to the first lever or the second lever and biases the transmission rod of the first lever toward the operation rod, The first lever and the second lever are fixed together with a screw that is screwed into the female screw hole of the second lever through the long groove of the first lever, and the outer part of the transmission rod of the first lever is fixed by the operating spring. It is placed in contact with the end of the operating rod.

[0008]

[Operation] The end of the operating rod regulated by the heat sensitive member comes into contact with the outer side of the transmission rod of the first lever by the spring force of the operating spring, thereby transmitting the output of the heat sensitive member to the first lever. Ru.

On the other hand, the first lever and the second lever are integrally fixed by a screw that is screwed into the female thread of the second lever through the long groove of the first lever, and the first lever and the second lever are synchronously connected to each other. The rotation angle of the choke lever is regulated by the choke cam portion of the second lever that rotates to maintain the desired choke valve opening degree, and the rotation angle of the throttle lever is regulated by the throttle cam portion of the second lever to maintain the desired throttle valve opening. Maintain the valve opening.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic starting device for a carburetor according to the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a side view including a sectional view, and FIG. 2 is a sectional view of a main part taken along line A-A in FIG. 1. In the description, upper, lower, left, and right refer to the figures, and are not limited thereto.

Reference numeral 1 denotes a carburetor body through which an intake passage 2 passes, and a float chamber body 3 in which fuel is stored is disposed below the carburetor body 1.

A choke valve 4 for opening and closing the intake passage 2 is arranged on the upstream side of the intake passage 2, and this choke valve 4 is integrally attached to a choke shaft 5 rotatably supported by the carburetor body 1. Ru. A choke lever 6 is integrally attached to the end of the choke shaft 5 that protrudes to the side of the carburetor body 1, and a first engaging portion 7 such as a roller is protruded from the choke lever 6. Further, the choke lever 6 is given an elastic force in the opening direction of the choke valve 4 by a spring (not shown). In this example, choke valve 4
The opening direction is clockwise and the closing direction is counterclockwise.

A throttle valve 8 for opening and closing the intake passage 2 is disposed in the intake passage 2 downstream of the choke valve 4 (on the right side in the figure), and this throttle valve 8 is rotatably supported by the carburetor body 1. It is integrally attached to the throttle shaft 9. A throttle lever 10 is integrally attached to the end of the throttle shaft 9 that protrudes to the side of the carburetor body 1, and a second engaging portion 11 such as a roller is protruded from the throttle lever 10. Further, the throttle lever 10 is given an elastic force in the closing direction of the throttle valve 8 by a spring (not shown). In this example, the opening direction of the throttle valve 8 is counterclockwise, and the closing direction is clockwise.

[0014] S is a heat-sensitive response member and is constituted by the following. That is, 12 is a wax case in which a heat-expandable material such as paraffin or silicone is hermetically sealed, and from the lower end of this wax case 12 is an output rod 13 that converts the volume change of the heat-expandable material into a stroke. stand out. The protrusion dimension of the output rod 13 increases as the volume of the thermally expandable material increases due to a rise in temperature. An operating rod 14 that can move synchronously with the output rod 13 is disposed opposite the lower end of the output rod 13.

Wax case 12 containing the output rod 13
, the operating rod 14 is connected to the lower case 15 and the upper case 1.
6 and the inner step 15A of the lower case 15 and the upper flange 1 of the operating rod 14.
4A, the operating rod 1 is
4 and the output rod 13 are always in contact with each other and move together. By attaching the lower case 15 to the flange portion 1A of the carburetor body 1, the heat sensitive response member S is fixedly disposed on the carburetor body 1. In this state, the lower end 14B of the operating rod 14 is placed on the side of the carburetor main body 1.

17 is a mounting boss 1B of the carburetor main body 1
It is a cylindrical collar that is rotatably supported on the collar 17. Specifically, the inner collar 18 having a flange 18A is inserted into the inner hole of the collar 17, and the inner collar 1
8 with screws N and screwed onto the boss 1B, the direction of rotation of the collar 17 is guided by the outer periphery of the inner collar 18, and the flange 18A of the inner collar 18 and the mounting boss 1B
The movement of the collar 17 in the thrust direction was regulated by this.

A first lever 19 is integrally attached to the collar 17, and the first lever 19 has an operating rod 1.
A rod-shaped transmission rod 20 is disposed to protrude from the lower end 14B of the collar 17, and an arcuate long groove 19A is formed concentrically with the center of the collar 17 as a reference.

Reference numeral 21 denotes a second lever rotatably disposed around the outer periphery of the collar 17, and this second lever 21 has a female threaded hole 21A opened corresponding to the long groove 19A of the first lever 19. At the same time, a choke cam portion 21B facing the first engaging portion 7 of the choke lever 6 and a throttle cam portion 21C facing the second engaging portion 11 of the throttle lever 10 are formed.

The choke cam portion 21B opens the choke valve 4 which is in the closed state when the second lever 21 is rotated counterclockwise, and closes the choke valve 4 which is in the open state when the second lever 21 is rotated clockwise. Cam profile.

The throttle cam portion 21C is configured to close the open throttle valve 8 when the second lever 21 rotates counterclockwise, and open the closed throttle valve 8 when the second lever 21 rotates clockwise. Cam profile.

Reference numeral 22 denotes a screw that passes through the long groove 19A of the first lever 19 and is screwed into the female screw hole 21A of the second lever 21. By screwing this screw 22, the first lever 19 and the second lever are screwed together. It can be fixed integrally with the lever 21.

23 has one end locked to the carburetor main body 1,
It is an operation spring whose other end is locked to the second lever 21 (or the first lever 19) and which presses the transmission rod 20 to the lower end 14B of the operation rod 14. In this example, the second lever 21 (including the first lever 19) is applied with a counterclockwise rotational force by the operation spring 23. (This operating spring 23 is shown in FIG. 2.)

[0023]
According to the automatic starting device for a carburetor having such a configuration, when the heat-sensitive member S is disposed on the collar portion 1A of the carburetor main body 1,
The operating rod 14 can be placed on the side of the carburetor main body 1,
At this time, by controlling the protrusion dimension of the output rod 13 in a constant temperature state, the lower end portion 14B of the operating rod 14 can be accurately positioned in a constant temperature state. (The protrusion dimension of the output rod 13 under a constant temperature condition is usually controlled by recessing the head of the wax case 12.)

In this state, the first lever 19 is rotated counterclockwise, and the lower end 1 of the transmission rod 20 and the operating rod 14 is rotated.
4B and maintain this state with a jig or the like.

Next, in order to obtain the desired choke valve opening and throttle valve opening in the same temperature state as in the constant temperature state described above, the second lever 21 is rotated to determine its position, and the choke lever 6 is rotated. The first engaging part 7 is brought into contact with the choke cam part 21B, while the second engaging part 11 of the throttle lever 10 is brought into contact with the throttle cam part 21C,
This state is maintained using a jig or the like. This choke cam part 21
B. The cam profile of the throttle cam portion 21C is determined in advance through testing, and these cam portions are accurately formed by pressing the second lever 21.

Next, the first lever 19 in the above state and the second
To fix the lever 21, at this time, a screw 22 is screwed into the female screw hole 21A of the second lever 21 through the long groove 19A of the first lever 19. Therefore, the first lever 19
and the second lever 21 can be integrally attached, and at this time, the first lever 19 and the second lever 21 are attached to the operating spring 2.
3, the transmission rod 20 always comes into contact with the lower end portion 14B of the operating rod 14 with elastic force, while the choke cam portion 21B comes into contact with the first engagement portion 7. Thus, the throttle cam portion 21C comes into contact with the second engaging portion 11.

Therefore, the stroke movement of the operating rod 14 of the heat-sensitive responsive member S is transmitted from the lower end 14B of the operating rod 14 to the transmission rod 20, causing the first lever 19 to rotate and the second lever 21 to rotate synchronously. and choke cam part 2.
1B, the first engaging portion 7 controls the choke valve opening, and the throttle cam portion 21C and the second engaging portion 11 control the throttle valve opening.

[0028]

As described above, according to the automatic starting device for a carburetor of the present invention, stroke changes are converted into rotation while the operating rod and the transmission rod are in contact with each other at their end faces, so that the transmission portion This eliminates twisting and the like in the contact parts, increasing the degree of freedom in selecting materials for the operating and transmission rods, and making it easier to test the durability of the contact parts, which particularly improves development efficiency.

[0029] Also, since there is no need to provide a through hole to guide the operating rod, the number of machining steps can be reduced, and there is no longer a need to place nuts and springs across the connecting shaft as in the past. This made it possible to reduce the number of parts and assembly man-hours, thereby reducing manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a side view including a sectional view showing an embodiment of an automatic starting device for a carburetor of the present invention.

FIG. 2 is a sectional view of a main part taken along line AA in FIG. 1;

[Explanation of symbols]

1. Vaporizer body 6. Choke lever 7 First engaging part 10 Throttle lever 11 Second engaging part 13 Output rod 14 Operation lever 17 Color 19 First lever 19A Long groove 20 Transmission rod 21 Second lever 21A Female screw hole 22 Screws 23 Operation spring

Claims (1)

[Claims] 1. A heat-sensitive response device comprising an operating rod 14 in which a heat-expandable material is hermetically sealed and outputs a change in stroke to the outside in response to movement of the output rod 13 due to a change in volume of the heat-expandable material. It is integrally attached to the member S and a cylindrical collar 17 that is rotatably supported by the mounting boss 1B installed upright on the vaporizer main body 1, and is arranged corresponding to the operating rod 14 of the heat-sensitive member S. A first lever 19 including a transmission rod 20 and a long groove 19A formed in an arc shape concentrically with respect to the center of the collar 17 is rotatably arranged on the outer periphery of the collar 17. A female threaded hole 21A opens correspondingly to the inside of the long groove 19A, a choke cam portion 21B contacts a first engaging portion 7 provided on the choke lever 6, and contacts a second engaging portion 11 provided on the throttle lever 10. A second lever 21 includes a throttle cam portion 21C, one end of which is locked to the carburetor main body 1, and the other end of which is locked to the first lever 19 or the second lever.
It consists of an operation spring 23 that is locked to the lever 21 and presses and urges the transmission rod 20 of the first lever 19 toward the operation rod 14, and the first lever 19 and the second lever 21 are connected to the long groove of the first lever 19. The screw 22 is screwed into the female threaded hole 21A of the second lever 21 via the lever 19A, and the operation spring 23 brings the outside of the transmission rod 20 of the first lever 19 into contact with the end of the operation rod 14. An automatic starting device for vaporizers that comes in contact with each other.