JPH066222Y2 - Vaporizer starter - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a vaporizer for controlling the concentration and amount of an air-fuel mixture supplied to an engine, and particularly to a vaporizer for supplying a rich air-fuel mixture at the time of starting the engine. Related to the starting device.

[Conventional technology]

A conventional generally used starter for a carburetor for a two-cycle engine will be described with reference to FIG.

In FIG. 1, an intake passage 2 penetrates the inside of the carburetor main body 1, and a float chamber main body 3 is arranged on a side portion of the carburetor main body 1. It A valve seat 5 is connected to the fuel inlet H and opens in the float chamber 4. A float valve 6 is movably arranged corresponding to the valve seat 5, and further the float valve 6 is provided.
Is arranged in the float chamber 4 and is arranged corresponding to the float arm 7 of the float 9 rotatably supported by the pin 8 by the float arm 7. The float arm 7 is rotated by the rotation of the float 9 with respect to the pin 8, and the float valve 6 controls the opening and closing of the valve seat 5.

Further, 10 is a main nozzle as a main fuel system, the tip of which is projected into the intake passage 2 and opened, and the other end is arranged below a constant liquid level XX formed in the float chamber 4. Connected to the main fuel jet 11. Reference numeral 12 is a throttle valve that controls the opening and closing of the intake passage 2.

Reference numeral 20 is a diaphragm made of an elastic member such as a rubber material, which is separated from the float chamber 4 and is divided into a starting fuel pump chamber 21 and an atmosphere chamber 22.
21 is formed by the diaphragm 50 and the concave portion of the float chamber main body 3, and the atmosphere chamber 22 is formed by the diaphragm 50 and the cover 23. In addition, J is an air hole which connects the air chamber 22 to the atmosphere.

Then, the following paths are opened in the starting fuel pump chamber 21. That is, 24 is a starting fuel inflow passage which has a suction side check valve 25 therein and communicates with a portion below the constant liquid surface of the float chamber 4, and the starting fuel inflow passage corresponds to the suction side check valve 25. As a result, a suction valve seat 26 is formed, and the suction side check valve 25 is pressed against the suction valve seat 26 by a spring 27.

28, one end opens in the substantially central portion of the starting fuel pump chamber 21,
The other end is a starting fuel discharge passage opened to the intake passage 2 on the engine side (left side in the drawing) from the throttle valve 12, and the discharge valve seat 29 is closed by being pressed by a spring 30 in the starting fuel discharge passage. A discharge side check valve 31 is arranged.

A valve seat 32 is formed at the opening end of the starting fuel discharge passage to the starting fuel pump chamber 21.

Further, 33 is an opening / closing valve portion provided integrally with the diaphragm 50, and this opening / closing valve portion 33 is a valve seat at the end of the starting fuel discharge passage 28.
The valve seat 32 is arranged corresponding to 32, and opens and closes the valve seat 32 according to the movement of the diaphragm 50, thereby controlling the opening and closing of the starting fuel discharge passage 28. Further, the operating rod 34 is integrally arranged on the diaphragm 50, and by moving the operating rod 34, the diaphragm 50 and the on-off valve portion 33 move in synchronization.

N is the operating rod 34 (including the diaphragm 50 and the opening / closing valve section 33)
Position regulating member for holding the engine at a substantially intermediate portion between the first state in which it is fully pressed toward the starting fuel pump chamber 21 side and the second state in which it is fully pulled toward the atmosphere chamber 22 side (fully pulled to the left in the figure). Specifically, a groove 34A is formed in the operating rod 34, and the groove 34A is provided when the operating rod 34 is operated to an intermediate position.
And a spring (36) for pressing the ball (35) which applies a pressing force orthogonal to the operating rod (34) with elastic force.

Reference numeral 37 is a spring that is contracted in the atmosphere chamber 22 and has one end locked to the cover 23 and the other end locked to the diaphragm 50 to press the diaphragm 50 toward the starting fuel pump chamber 21.

When the intermediate position restricting member N is operated, the ball 35 is moved by the spring 36 into the groove 34A of the operating rod 34.
The pressing force acting in the direction perpendicular to the longitudinal axis Y-Y of 34 is such that the spring in the intermediate position state of the operating rod 34.
This is larger than the pressing force of the operating rod 34 in the longitudinal direction Y-Y of the operating rod 34, whereby the operating rod 34 can be held at the intermediate position.

Then, regarding the starting in a state where the engine ambient temperature is low, prior to the starting operation of the engine, first, the operating rod 34 is pulled fully to the left in the figure against the spring force of the spring 37. The on-off valve section 33 also moves to the left in synchronization with the operating rod 34,
The opening / closing valve portion 33 opens the valve seat 32 and increases the volume of the starting fuel pump chamber 21.

According to this, the suction side check valve 25 opens the suction valve seat 26, and the discharge side check valve 31 closes the discharge valve seat 29.

Therefore, by this operation, the fuel stored in the floating chamber 4 is sucked into the starting fuel pump chamber 21.

Next, the pulling operation force to the left with respect to the operating rod 34 is released. According to this, the operating rod 34 is moved toward the starting fuel pump chamber 21 side (to the right side) in the figure by the spring force of the spring 37.
It automatically moves, and the operating rod 34 stops when the groove 34A is engaged with the ball 35 as the intermediate position restricting member N.

It is not possible for the operating rod 34 to stop at the intermediate position by the spring 37.
This can be achieved by appropriately increasing the pressing force of the spring 36 of the ball 44 acting in a direction perpendicular to the pressing force of the operating rod 34 in the longitudinal axis direction Y-Y.

When the operating rod 34 is moved to the intermediate position, the starting fuel pump chamber 21 is compressed and the volume of the chamber is reduced, so that the discharge side check valve 31 opens the discharge valve seat 29 by the decrease in the volume of the chamber. The starting fuel is discharged from the starting fuel discharge passage 28 into the intake passage 2, so that the engine can be ready for the first and complete explosion, and the operating rod 34 can be pulled fully to the left. The cranking operation for starting the engine is started in a state where a returning process of releasing the attractive force to the operating rod 34 in order to move the engine to the intermediate position. Then, since the fuel in the starting fuel pump chamber 21 has already been injected and supplied into the intake pipe from the starting fuel discharge passage 28, a sufficiently rich air-fuel mixture can be supplied to the engine and the initial and complete explosions of the engine can be ensured. Obtainable.

[Problems to be solved by the invention]

The conventional carburetor starting device has the following problems. After pulling the operating rod 34 toward the atmosphere chamber 22 side, return the operating rod 34 to the intermediate position and start the fuel pump chamber 21.
It is difficult to sufficiently increase the amount of fuel injected into the engine by pressurizing the engine. This is because when the operating rod 34 is returned to the intermediate position, the inside of the starting fuel pump chamber 21 is pressurized and the pressurized fuel pressure deforms the diaphragm 20 toward the atmosphere chamber 22 side. Such a state is shown in FIG. 1 because it does not serve to reduce the volume of the chamber 21.

To solve this problem, it is achieved by increasing the stroke of the operating rod 34 and increasing the effective pressure receiving diameter of the diaphragm 20. I hate being hindered.

As described above, the diaphragm 20 is deformed toward the atmosphere chamber 22 side when returning to the intermediate position, and therefore there is a risk of cracking at the deformed portion during long-term use. As a means for solving this, it is conceivable to increase the thickness of the diaphragm 20, but this increases the rigidity of the diaphragm 20 and is not preferable in terms of the operating characteristics of the operating rod 34.

[Means for solving problems]

The carburetor starter according to the present invention has been made in view of the above-mentioned problems, and the device itself can be compactly arranged, and is to obtain the durable starter. It is something like.

That is, the inside is divided into a starting fuel pump chamber 21 and an atmospheric chamber 22 by a diaphragm made of an elastic member, and in the starting fuel pump chamber 21, a suction side check valve 25 is arranged and the float chamber 4 is provided.
The opening of the starting fuel inflow passage 24 communicating below the constant liquid level and the starting fuel discharge passage 28 in which the discharge side check valve 31 is arranged are further opened, and the spring 37 presses the starting fuel pump chamber 21 side. The diaphragm to be provided is integrally provided with an opening / closing valve section 33 capable of controlling opening / closing of the starting fuel discharge passage and an operating rod 34 capable of imparting a pump operating force to the diaphragm, and the operating rod is provided with a diaphragm of the diaphragm. An intermediate position restricting member N is provided which can hold an intermediate position between a first state in which the starting fuel discharge passage 28 is closed by the opening / closing valve portion 33 and a second state in which the diaphragm is pulled to the atmosphere chamber side 22, and the second state. When the attractive force on the operating rod 34 is released from the state, the diaphragm is automatically returned to the substantially intermediate position by the spring force of the spring 37, and the fuel in the starting fuel pump chamber 21 is discharged through the starting fuel discharge passage 28 to be vaporized. In the starter of the The ear diaphragm 50; an inner annular flat portion 50B extending outward of the opening / closing valve portion 50A provided substantially in the center of the diaphragm 50, an outer annular flat portion 50B provided on the outer periphery of the diaphragm 50, and the inner annular flat portion. , The outer annular flat portion, the annular inclined surface portion 50C connecting the
And a cup-shaped retainer 51 for connecting the flat portion 51A along the inner annular flat portion 50B of the diaphragm 50 and the inclined portion 51B along the annular inclined surface portion 50C to each other on the side face of the atmosphere chamber of the diaphragm 50. Then, the spring 37 that contracts the retainer into the atmosphere chamber 22 causes the diaphragm to
It is a carburetor starter that is pressed to 50.

[Action]

When the engine is started, the operating rod is pulled toward the atmosphere chamber to increase the volume of the starting fuel pump chamber to suck the fuel in the float chamber into the starting fuel pump chamber. On the other hand, the attractive force on the operating rod is released to bring the operating rod into a free state. Then, the operating rod is automatically moved to the starting fuel pump chamber side by the spring force of the spring, and the movement of the operating rod to the starting fuel pump chamber side is determined by the intermediate position regulating member.

According to this, the fuel in the starting fuel pump chamber is injected and supplied from the starting fuel discharge passage into the intake passage to prepare for the initial and complete explosions of the engine. In such a state,
On the atmosphere chamber side of the diaphragm, a cup-shaped retainer is provided that connects a flat portion along the inner annular flat portion of the diaphragm and an inclined portion along the annular inclined surface portion. Does not deform to the atmosphere chamber side.

〔Example〕

A second embodiment of the carburetor starter according to the present invention will be described below.
This will be described with reference to FIGS. 3, 3 and 4. The description of the same structure as the conventional one is omitted and the same reference numerals are used.

Reference numeral 50 is a diaphragm that divides the starting fuel pump chamber 21 and the atmosphere chamber 22, and the diaphragm 50 is configured as follows.

That is, 50A is an opening / closing valve portion provided substantially at the center of the diaphragm 50. The opening / closing valve portion 50A is arranged corresponding to the valve seat 32, and by opening / closing the valve seat 32, the starting fuel discharge passage is opened.
Open and close 28.

Further, an inner annular flat portion 50B is provided on the outer side of the on-off valve portion 50A, an annular inclined surface portion 50C extends from the outer side of the inner annular flat portion 50B, and an outer annular surface extends from the outer side of the annular inclined surface portion 50C. The flat portion 50D extends.

A mounting boss 50E is provided on the opposite side of the on-off valve 50A so as to project from the inner annular flat portion 50B toward the atmosphere chamber 22 side. The mounting boss 50E is locked to the protruding end of the mounting boss 50E on the atmosphere chamber 22 side. Tsubabe
A fitting hole 50G having 50F opens.

Further, 51 is a cup-shaped retainer arranged on the surface of the diaphragm 50 on the atmosphere chamber 22 side, and extends from the flat portion 51A along the inner annular flat portion 50B of the diaphragm 50 and the outer side of the flat portion 51A. The flat portion 51A has an inclined portion 51B along the annular inclined surface portion 50C, and an insertion hole 51C to be inserted into the outer periphery of the mounting boss 50E of the diaphragm 50 is formed at the approximate center of the flat portion 51A.

Further, the distal end portion of the operating rod 34 on the diaphragm 50 side is fitted into the fitting hole 50G of the diaphragm 50 and has a locking collar portion.
A locking projection 34C having a locking step 34B that is locked to 50F is formed. The assembly of the diaphragm 50, the retainer 51 and the operating rod 34 will be described below.

First, the opening / closing valve portion 50A of the diaphragm 50 is arranged on the end surface 3A of the float chamber main body 3 in a state corresponding to the valve seat 32.
In this state, the outer annular flat portion 50 of the diaphragm 50 is
D is arranged on the end surface 3A of the float chamber body 3.

Then, the retainer 51 is connected to the opening / closing valve portion 50A of the diaphragm 50.
It is arranged from the opposite side of the.
By inserting into the outer diameter of E, the flat portion 51A of the retainer 51 is arranged on the inner annular flat portion 50B of the diaphragm 50, and the inclined portion 51B is arranged on the annular inclined surface portion 50C of the diaphragm 50.

Next, the spring 37 is placed on the flat portion 51A of the retainer 51, then the cover 23 is placed on the diaphragm 50, and then the cover 23 is fastened to the float chamber main body 3 with screws (not shown). Then, the operating rod 34 is inserted into the operating rod guide hole 23A formed in the cover 23, and the locking projection 34C of the operating rod 34 is fitted into the fitting hole 50G of the diaphragm 50.

Therefore, the starting fuel pump chamber 21 is formed by the diaphragm 50 and the concave portion of the float chamber main body 3, while the diaphragm is
The atmosphere chamber 22 in which the spring 37 for pressing the retainer 51 against the diaphragm 50 is contracted is formed inside by the cover 50 and the cover 23.

Next, the operation will be described.

First, the case where the engine atmosphere temperature and the engine temperature are high will be described. Due to the high temperature, it is not necessary to supply a rich mixture to the engine.

The starting device is therefore kept inactive. This state is shown in Fig. 1. The diaphragm 50 is a spring.
The opening / closing valve section 33, which is pressed by the 37 toward the starting fuel pump chamber 21 side and is integrally provided with the diaphragm 50, is a valve arranged at the opening end of the starting fuel discharge passage 28 toward the starting fuel pump chamber 21 side. The seat 32 is closed, and the starting fuel discharge passage 28
The starting fuel is not supplied into the intake passage 2 from the engine and the fuel at the engine temperature is supplied to the intake pipe from the main nozzle 10 and the constant velocity injection hole (not shown) to satisfy the starting. Is.

Next, regarding the starting in a state where the engine ambient temperature is low, prior to the starting operation of the engine, first, the operating rod 34 is pulled fully to the left in the figure against the spring force of the spring 37. This state is shown in FIG. Specified in. By this operation, the diaphragm 50 and the opening / closing valve section 33 also move to the left in synchronization with the operating rod 34, and the opening / closing valve section 33 opens the valve seat 32 and increases the volume of the starting fuel pump chamber 21. .

According to this, the suction side check valve 25 opens the suction valve seat 26, and the discharge side check valve 31 closes the discharge valve seat 29.

Therefore, by this operation, the fuel stored in the floating chamber 4 is sucked into the starting fuel pump chamber 21.

Next, the pulling operation force to the left with respect to the operating rod 34 is released. According to this, the operating rod 34 is moved toward the starting fuel pump chamber 21 side (to the right side) in the figure by the spring force of the spring 37.
It automatically moves, and the operating rod 34 stops when the groove 34A is engaged with the ball 35 as the intermediate position restricting member N. (This state is shown in FIG. 3.) It is the spring 37 that the operating rod 34 stops at the intermediate position.
This can be achieved by appropriately increasing the pressing force of the spring 36 of the ball 44 acting in a direction perpendicular to the tension in the longitudinal axis Y-Y direction of the operating rod 34.

When the operating rod 34 is moved to the intermediate position, the starting fuel pump chamber 21 is compressed and the volume of the chamber is reduced, so that the discharge side check valve 31 opens the discharge valve seat 29 and starts the fuel discharge passage 28. As a result, the starting fuel is injected and supplied into the intake passage 2, so that it is possible to prepare for the initial and complete explosion of the engine.

When the operating rod 34 automatically returns from the state shown in FIG. 3 to the intermediate position shown in FIG. 4, the diaphragm 50 compresses the starting fuel pump chamber 21, so that the inner annular flat portion 50B of the diaphragm 50 and Annular inclined surface part 50
C is intended to be deformed to the atmosphere chamber 22 side, but in the present invention, the flat portion 51A and the inclined portion 51B are formed in the inner annular flat portion 50B and the annular inclined surface portion 50C which are open to the atmosphere chamber 22 side. A cup-shaped retainer 51, which is connected to the
Since 51 is pressed against the diaphragm 50, the flat portion 51A of the retainer 51 is moved even when the operating rod is moved to the intermediate position.
Also, the diaphragm 50 does not deform toward the atmosphere chamber 22 due to the inclined surface 51B.

If the retainer 51 is made of a synthetic resin material, the shape of the diaphragm 50 can be adjusted very easily, and the surface roughness of the flat portion 51A and the inclined portion 51B that come into contact with the diaphragm 50 during molding can be maintained well. Therefore, even if it is used for a long period of time, there is little risk of tearing due to wear.

When the engine is warmed up after the complete explosion, the operating rod
Since 34 is held in the intermediate position and the valve seat 32 is held in the open state by the opening / closing valve portion 33, the engine negative pressure generated in the intake pipe acts on the discharge side check valve 31 from the starting fuel discharge passage 28. Then, the discharge side check valve 31 is opened from the discharge valve seat 29 against the spring force of the spring 30, and the fuel in the start fuel pump chamber 21 is started.
From 28, it is supplied to the intake passage 2 to satisfy the warm-up operation.

Then, as soon as the warm-up operation of the engine is completed, the operating rod 34 is moved to the fourth position.
The intermediate position shown in FIG. 2 is restored to the original position shown in FIG. According to this, since the opening / closing valve portion 33 closes the valve seat 32, the fuel does not flow out from the inside of the starting fuel pump chamber 21 to the starting fuel discharge passage 28.

[Effect of device]

As described above, the carburetor starter according to the present invention has the following effects.

When the operating rod is pulled to the atmospheric chamber side and the attraction force on the operating rod is released, the diaphragm including the operating rod automatically returns to a certain intermediate position.At this time, a spring is attached to the atmospheric chamber side of the diaphragm. Since the cup-shaped retainer is arranged along the inner annular flat part and the annular inclined surface part of the diaphragm, the diaphragm can be prevented from being deformed toward the atmosphere chamber side when pressurizing the starting fuel pump chamber. Is.

Therefore, the moving amount of the diaphragm is directly converted into the starting fuel discharge amount from the starting fuel pump chamber, so that the desired discharge amount can be obtained without increasing the stroke of the operating rod or the diameter of the diaphragm.

Further, in the case where the starting fuel is discharged by the spring force of the spring, the deformation of the diaphragm may immediately lead to variations in the discharge amount. According to the present invention, the deformation of the diaphragm is prevented, so that the variation in the discharge amount can be suppressed.

When the start-up fuel pump chamber was pressurized, the diaphragm could be prevented from being deformed toward the atmosphere chamber side, so during long-term use, the diaphragm would not deform and fatigue would not cause cracks, resulting in excellent durability. It was possible to provide an improved starting device.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an intermediate position state of a conventional carburetor starter. FIG. 2 is a longitudinal sectional view of a main part showing a closed state of a starting fuel discharge passage of a carburetor starter according to the present invention, and FIG. 3 shows a state in which the operating rod in FIG. FIG. 4 is a longitudinal sectional view of an essential part shown in FIG. 4, and FIG. 4 is a longitudinal sectional view of an essential part showing a state in which the operating rod is returned to an intermediate position from the state of FIG. 1 ... Vaporizer body, 4 ... Float chamber 21 ... Starting fuel pump chamber 22 ... Atmosphere chamber, 24 ... Starting fuel inflow path 25 ... Suction side check valve, 28 ... Starting fuel discharge path 31 ... … Discharge side check valve, 32 …… Valve seat 33 …… Opening / closing valve section, 34 …… Operating rod 37 …… Spring N …… Intermediate position regulating member 50 …… Diaphragm, 50A …… Opening / closing valve section 50B …… Outside Annular flat part 50C …… annular inclined surface part 51 …… retainer, 51A …… flat part 51B …… inclined part

Claims (2)

[Scope of utility model registration request] 1. A starter fuel pump chamber 21 and an atmospheric chamber 22 are divided by a diaphragm made of an elastic member, and a suction side check valve 25 is arranged inside the starter fuel pump chamber 21 and a float chamber is provided. 4, a starting fuel inflow passage 24 communicating below a constant liquid level and a starting fuel discharge passage 28 in which a discharge side check valve 31 is arranged are opened, and a spring 37 is provided to the side of the starting fuel pump chamber 21. The diaphragm to be pressed is integrally provided with an opening / closing valve section 33 capable of controlling opening / closing of the starting fuel discharge passage, and an operating rod 34 capable of imparting a pump operating force to the diaphragm, and the operating rod is provided with a diaphragm. The opening / closing valve portion 33 is provided with an intermediate position restricting member N capable of holding the intermediate position between the first state in which the starting fuel discharge passage 28 is closed and the second state in which the diaphragm is pulled toward the atmosphere chamber side 22, When the attraction force on the operating rod 34 is released from the 2 state, In the carburetor starting device in which the diaphragm is automatically returned to a substantially intermediate position by the spring force of 37 and the fuel in the starting fuel pump chamber 21 is discharged through the starting fuel discharge passage 28, the diaphragm 50 is replaced by the diaphragm 50. An inner annular flat portion 50B extending to the outside of the on-off valve portion 50A provided substantially in the center, an outer annular flat portion 50B provided on the outer periphery of the diaphragm 50, the inner annular flat portion, and an outer annular flat portion, Ring-shaped inclined surface part 50C connecting
And a cup-shaped retainer 51 for connecting the flat portion 51A along the inner annular flat portion 50B of the diaphragm 50 and the inclined portion 51B along the annular inclined surface portion 50C to each other on the side face of the atmosphere chamber of the diaphragm 50. Then, the spring 37 that contracts the retainer into the atmosphere chamber 22 causes the diaphragm to
A carburetor starter that is pressed to 50. 2. The carburetor starter according to claim 1, wherein the retainer is formed of a synthetic resin material.