JPH0640339U - Vaporizer pilot screw adjuster - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] Regarding the pilot screw device for adjusting the low-speed fuel system of the carburetor, the workability is improved and the adjustment is possible within a certain range, and certain restrictions are placed on the removal. [Structure] The screw support boss 6 has an outlet hole 4,
The female screw 7 and the first and second storage holes 8 and 9 are concentrically provided in series.
The screw 10 has a taper needle valve portion 1 from its tip.
1, the male screw 12, the first collar portion 13, and the half-moon-shaped collar portion are concentrically formed. The regulating member has a flat plate annular shape, and a locking portion is partially provided in the regulating hole. With the male thread of the screw screwed onto the female thread and screwed to adjust the effective opening area of the outlet hole with the taper needle valve section, place the 1st collar part in the 1st storage hole and attach the half-moon shaped collar part. The crescent-shaped collar portion of the screw is inserted into the second accommodation hole 9 and fixed by inserting the regulation member 15 onto the locking step portion 9A in the second accommodation hole 9 to fix the half-moon shaped flange portion of the screw in the regulation hole of the regulation member. And the side surface of the half-moon-shaped brim portion is opposed to the locking portion with a gap.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a carburetor that adjusts and controls the amount and concentration of an air-fuel mixture supplied to an engine, and particularly to a pilot screw adjusting device that adjusts the effective opening area of a pilot outlet hole of a low-speed fuel system by screwing. .

[0002]

[Prior art]

 The low speed mixture supplied from the low speed fuel system of the carburetor to the engine is adjusted by screwing the pilot screw to control the effective opening area of the pilot outlet hole. On the other hand, the pilot screw once adjusted in this way must be adjusted within a certain range. That is, if there is no restriction on the adjustment of the pilot screw, the concentration of the low-speed air-fuel mixture will change significantly, which will adversely affect the emission of harmful exhaust gas or the operability of the engine. From the above, in the past, after adjusting the pilot screw once, an adjusting device (limiter cap) is provided so that the pilot screw can be adjusted only within a certain adjustment range. This adjusting device screwed the pilot screw to adjust the effective opening area of the pilot outlet hole, and then integrated the limiter cap made of synthetic resin with the protrusion toward the outside on the outer periphery of the head of the pilot screw. The rotation of the pilot screw is restricted by the projection of the limiter cap contacting the locking part of the carburetor body. (An example of such a conventional technique is disclosed in Japanese Patent Laid-Open No. 52-40234.)

[0003]

[Problems to be solved by the device]

 According to such a conventional adjusting device, the limiter cap is fitted in the longitudinal axis direction of the pilot screw after the position of the pilot screw is set. According to this, the pilot screw moves in the direction of the longitudinal axis by the gap in the threaded portion between the male screw and the female screw, which may change the effective opening area of the pilot outlet hole. However, the work of fitting the limiter cap to the pilot screw must be done carefully, and its workability was extremely poor. Also, the limiter cap is easy to remove because it projects from the end of the pilot screw (because it is in a fitted state). However, if restrictions are placed on this removal, the limiter cap may be blocked. A limiting member is required.

The pilot screw adjusting device according to the present invention has been made in view of the above-mentioned problems. Therefore, the fitting workability of the adjusting device after adjusting the pilot screw is improved to improve the production efficiency of the carburetor and to make the adjustment. It is an object of the present invention to provide the adjusting device which can easily adjust the pilot screw within a certain range after the device is fitted and can put a certain limit on the removal of the adjusting device.

[0005]

[Means for Solving the Problems]

 According to the present invention, in order to achieve the above object, a pilot outlet hole for a low-speed fuel system is opened in an intake passage passing through the carburetor body, and the opening of the pilot outlet hole is screwed to a pilot screw support boss. In the pilot screw adjusting device of the carburetor adjusted by screwing the pilot screw, the pilot screw supporting boss has a female screw for screwing the pilot screw through the pilot outlet hole opening in the intake passage to the end of the pilot screw supporting boss. The first accommodation hole having a diameter φB larger than the diameter φA of the female thread from the end of the female thread, and further locked toward the end of the first accommodation hole. The second storage hole having a diameter φC larger than the diameter φB of the first storage hole is piloted through the step portion. It is opened at the end of the Liu support boss, and on the one hand, the taper needle valve part that controls the effective opening area of the pilot outlet hole, the male screw screwed to the female screw, and the first screw are arranged in the first storage hole. At the same time, the first flange portion having a minus groove with a groove width D formed at the center of the upper surface thereof and one side of the minus groove of the first flange portion extends upward along the groove surface and has a diameter φF of 1 The diameter of the storage hole φB is provided, and the half-moon-shaped collar portion is provided, and the restriction member formed of a flat plate member is formed into an annular shape, and its outer diameter φG is made substantially the same as the diameter of the second storage hole. The diameter φH of the regulation hole bored inward of the regulation hole is larger than the diameter φF of the half-moon-shaped collar portion, and the regulation hole goes toward the center of the regulation hole and its end on the center side is Partial locking part that is more than D / 2 outward from the center When the male thread of the pilot screw is screwed onto the female thread and screwed to adjust the effective opening area of the pilot outlet hole by the taper needle valve section, the first collar section of the pilot screw is first stored. By placing the half-moon-shaped collar part projecting into the second storage hole and arranging it in the hole, and inserting and fixing the regulating member on the locking step part in the second storage hole, the half-moon shape of the pilot screw is obtained. It is characterized in that the shaped collar portion is arranged in the regulation hole of the regulation member and the side surface of the half-moon shaped collar portion is arranged so as to face the locking portion with a gap.

[0006]

[Action]

 The effective opening area of the pilot outlet hole is properly controlled by screwing the male thread of the pilot screw into the female thread of the pilot screw support boss and screwing the pilot screw. By inserting the adjustment tool into the minus groove of the pilot screw through the regulation hole of the regulation member and rotating the adjustment tool, the pilot screw rotates through the minus groove. The effective opening area of the pilot outlet hole is variably adjusted by the rotation of the pilot screw, so the rotation of the pilot screw is within a certain adjustment range by the side surface of the half-moon collar contacting the locking part of the regulating member. Limited to.

[0007]

【Example】

 An embodiment of the carburetor pilot screw adjusting device according to the present invention will be described below. The vaporizer main body 1 will be described with reference to FIG. An intake passage 2 penetrates laterally in the carburetor body 1, and a bypass hole 3 and a pilot outlet hole 4 serving as a low-speed fuel system are opened in the intake passage, and the bypass hole 3 and the pilot outlet hole are opened. 4 are connected by a low speed mixture passage 5. The air-fuel mixture supplied to the low-speed air-fuel mixture passage 5 is formed by controlling fuel and air by a low-speed fuel jet and a low-speed air jet (not shown). A female screw 7 having a diameter φA is screwed from the pilot outlet hole 4 toward the end 6A of the pilot screw support boss 6. A first storage hole 8 having a diameter φB larger than the diameter φA of the female screw 7 from the end 7A of the female screw 7 is bored toward the end 6A of the pilot screw support boss 6. The second storage hole 9 having a diameter φC larger than the diameter φB of the first storage hole 8 is inserted from the end portion 8A of the first storage hole 8 through the locking step 9A to form the end portion 6A of the pilot screw support boss 6. Open to. That is, in the pilot screw support boss 6, the pilot outlet hole 4, the female screw 7, the first storage hole 8, and the second storage hole 9 are concentric with each other from the intake passage 2 side toward the end 6A of the pilot screw support boss 6. It is lined up.

The pilot screw 10 is composed of the following and is shown in FIGS. 2 and 3. Reference numeral 11 denotes a tapered needle valve portion formed at the tip portion thereof, which is inserted into the pilot outlet hole 4 to control the effective opening area of the pilot outlet hole 4. A male thread 12 is formed above the taper needle valve portion 11, and the male thread 12 is screwed to the female thread 7. The first flange 13 is formed on the upper part of the male screw 12, and the diameter φE of the first flange 13 is smaller than the diameter φB of the first storage hole 8, while the upper surface 13A of the first flange 13 is formed. A minus groove 13B having a groove width D is bored at the center of the crossing the upper surface 13A. Furthermore, the upper surface 13A of the first flange portion 13 is formed with a half-moon-shaped flange portion 14 protruding from it, and the outer diameter φF of the flange portion forming the arc surface is the diameter φB of the first storage hole 8. The side surface 14A having a smaller diameter and forming the cutout portion extends upward along the one side groove surface 13C of the minus groove 13B. That is, in the pilot screw 10, the tapered needle valve portion 11, the male screw 12, the first collar portion 13, and the half-moon-shaped collar portion 14 are concentrically connected from below in FIG.

The restriction member 15 is shown in FIGS. 4 and 5. The regulating member 15 is formed of a flat plate-shaped member and has an annular shape. The outer diameter φG is approximately the same as the diameter φC of the second storage hole 9 so that it can be press-fitted or inserted into the second storage hole 9, and the diameter φH of the control hole 15A that is bored inward is The diameter is larger than the outer diameter φF of the half-moon-shaped collar portion 14. In this example, φH is the same as the diameter φB of the first storage hole 8. Further, a locking portion 15B partially protruding toward the center 15D of the regulation hole 15A is formed on a part of the inner circumference of the regulation hole 15A so as to project. The end portion 15C on the center side of the engaging portion 15B is separated from the center 15D of the restriction hole 15A by at least D / 2 or more outwardly (where D / 2 is the groove width D of the minus groove 13B of the pilot screw 10). Half) A first side surface 15E and a second side surface 15F facing the inside of the regulation hole 15A are formed between the center side end portion 15C and the regulation hole 15A.

The pilot screw adjusting device is assembled and formed as follows and is shown in FIGS. 6 and 7. First, the pilot screw 10 is inserted into the second accommodation hole 9, the first accommodation hole 8 and the female screw 7 from the end portion 6A of the pilot screw support boss 6, and the male screw 12 of the pilot screw 10 is screwed to the female screw 7. An adjustment tool such as a flat-blade screwdriver S is inserted into the minor groove 13B and rotated, and the effective opening area of the pilot outlet hole 4 is properly adjusted by the tapered needle valve portion 11. With the above, the setting of the opening of the pilot screw 10 in the initial state is completed. In this state, the first collar portion 13 of the pilot screw 10 is in the first storage hole 8, the lower half-moon shaped collar portion 14 of the pilot screw 10 is arranged in the first storage hole 8, and the upper one is the second storage hole 8. It is arranged so as to project into the hole 9. Next, the regulating member 15 is inserted or press-fitted on the locking step portion 9A of the second storage hole 9. At this time, the position is set so that the locking portion 15B of the regulating member 15 does not come into contact with the half-moon shaped flange portion 14 of the pilot screw 10. In this example, the center side end 15C of the locking portion 15B of the regulating member 15 is made to face the side surface 14A of the half-moon shaped flange portion 14. The upper side of the half-moon shaped flange portion 14 is the regulation hole 15A of the regulating member 15. Placed inside. According to the above, the first gap P is formed between the first side surface 15E of the locking portion 15B of the regulating member 15 and the side surface 14A of the half-moon collar portion 14, and the second side surface 15F and the half-moon collar portion 14 are formed. The second gap R is formed between the side surface 14A and the side surface 14A. The first gap P and the second gap R are shown in FIG. Then, in such a state, the restricting member 15 does not rotate inside the second housing hole 9, and the pilot screw support boss 6 outside the second housing hole 9 is compressed and deformed inward, or the restricting member 15 is formed. Is fixed to the second storage hole 9 with an adhesive or the like. With the above, the work of the pilot screw adjusting device is completed. In this state, the minus groove 13B of the pilot screw 10 is arranged in the vertical direction in FIG. 7, and is located between the side surface 14A of the half-moon collar portion 14 and the first side surface 15E and the second side surface 15F of the locking portion 15B, respectively. A gap P and a second gap R are formed.

Next, the adjustment of the pilot screw from the above state will be described. First, the effective opening area of the pilot outlet hole 4 is reduced as follows. (A case where the screw is a right-hand screw will be described.) From the opening of the second storage hole 9 through the regulation hole 15A of the regulation member 15, insert the minus driver S as an adjustment tool into the minus groove 13B of the pilot screw 10. Then, rotate the flat-blade screwdriver S clockwise. According to this, the minus driver S can rotate clockwise in the first gap P, and the minus driver S rotates clockwise when the minus driver S abuts the first side surface 15E of the locking portion 15B. In this state (the position of the minus driver S in this state is shown by the dotted line in FIG. 7), the rotation is stopped further clockwise. Therefore, the clockwise rotation of the pilot screw 10 is also performed in synchronization with the rotation of the minus driver S, and the effective opening area of the pilot outlet hole 4 can be reduced according to the clockwise rotation. Moreover, the rotation of the minus driver S is blocked by the first side surface 15E of the locking portion 15B, and the clockwise rotation of the pilot screw 10 is also blocked, so that the effective opening area of the pilot outlet hole 4 is reduced. Can be suppressed within a certain range.

Next, when increasing the effective opening area of the pilot outlet hole 4, it is performed as follows. From the opening of the second storage hole 9, insert the minus driver S as an adjustment tool into the minus groove 13B of the pilot screw 10 through the regulation hole 15A of the regulation member 15, and then rotate the minus driver S counterclockwise. To do. According to this, the minus driver S can rotate counterclockwise in the second gap R, and the minus driver S rotates counterclockwise when the minus driver S 2 rotates on the second side surface of the locking portion 15B. It stops in the state of contact with 15F, and further rotation in the counterclockwise direction is prevented. Therefore, the counterclockwise rotation of the pilot screw 10 is also performed in synchronization with the rotation of the minus driver S, and the effective opening area of the pilot outlet hole 4 is increased according to the rotation in the counterclockwise direction. In addition, the rotation of the minus driver S is blocked by the second side surface 15F of the locking portion 15B, and the counterclockwise rotation of the pilot screw 10 is also blocked, so that the effective opening area of the pilot outlet hole 4 is reduced. Can be suppressed within a certain range.

[0013]

[Effect of device]

 As described above, according to the carburetor pilot screw adjusting device of the present invention, the following effects can be achieved. That is, the restriction member that restricts the adjustment of the pilot screw within a certain range does not apply any force to the longitudinal direction of the pilot screw. Therefore, there is no need to consider the pilot screw during the work of fixing the regulating member in the second storage hole after adjusting the pilot screw, and the production efficiency of the carburetor can be greatly improved. It is a thing. Further, since the regulation member is formed in a flat plate shape and is inserted and fixed in the second storage hole, there is a restriction on the removal of the regulation member. (The limitation on removal means that it can be removed when it is necessary and cannot be removed carelessly.) Even if the pilot screw is the conventional one, the collar ( It is provided with a minus groove (corresponding to the first flange portion). To obtain the pilot screw according to the present invention, the flange portion is extended to form the second flange portion, and the upper surface of the first flange portion is formed when the minus groove is formed. The cost of materials and processing is extremely low, and the increase in parts cost can be minimized. Furthermore, the regulating member can also be obtained by press punching a simple flat plate or by injection molding with a die that is easy to divide into upper and lower halves, which can also suppress an increase in component cost.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of a carburetor main body used in a carburetor pilot screw adjusting device according to the present invention.

FIG. 2 is a perspective view of a pilot screw used in the carburetor pilot screw adjusting device according to the present invention.

3 is a top plan view of the pilot screw of FIG. 2. FIG.

FIG. 4 is a perspective view of a regulating member used in the pilot screw adjusting device of the carburetor according to the present invention.

5 is a top plan view of the restriction member of FIG. 4. FIG.

FIG. 6 is a vertical sectional view showing an embodiment of a carburetor pilot screw adjusting device according to the present invention.

FIG. 7 is a top plan view of the pilot screw portion of FIG.

[Explanation of symbols]

 4 Pilot Outlet Hole 6 Pilot Screw Support Boss 6A End 7 Female Thread 7A Female Thread End 8 First Storage Hole 8A First Storage Hole End 9 Second Storage Hole 9A Second Storage Hole End 10 Pilot Screw 11 Taper Needle valve part 12 Male screw 13 First flange part 13A Center of upper surface 13B Minus groove 13C One side groove surface 14 Half moon shaped flange part 15 Restricting member 15A Restricting hole 15B Locking part 15D Center of restricting hole

Claims (1)

[Scope of utility model registration request] 1. A pilot outlet hole for a low-speed fuel system is opened in an intake passage passing through a carburetor body, and the opening of the pilot outlet hole is adjusted by screwing a pilot screw screwed to a pilot screw support boss. In the pilot screw adjusting device of the carburetor, the intake passage 2 is attached to the pilot screw support boss 6.
A female screw 7 for screwing the pilot screw 10 through the pilot outlet hole 4 is continuously provided toward the end 6A of the pilot screw support boss 6 and a diameter φB larger than the diameter φA of the female screw 7 from the end 7A of the female screw 7. The first storage hole 8 having the above is continuously provided toward the end portion 6A, and further, from the end portion 8A of the first storage hole 8 to the locking step portion 9A.
The second storage hole 9 having a diameter φC larger than the diameter φB of the first storage hole 8 through the pilot screw support boss 6.
On the end 6A of the pilot screw 10
The taper needle valve portion 11 for controlling the effective opening area of the pilot outlet hole 4, the male screw 12 screwed to the female screw 7, and the groove width at the center of the upper surface 13A which is arranged in the first storage hole 8. A first flange portion 13 having a minus groove 13B of D and a minus groove 13B of the first flange portion 13
And a half-moon shaped flange portion 14 extending upward along the one side groove surface 13C and having a diameter φF smaller than the diameter φB of the first storage hole 8, and a regulation formed by a flat plate member. The member 15 is formed in an annular shape, the outer diameter φG of which is substantially the same as that of the second storage hole 9, and the restriction hole 15 bored inward of the second storage hole 9.
The diameter φH of A is made larger than the diameter φF of the half-moon-shaped collar portion 14, and the regulation hole is directed toward the center 15D of the regulation hole 15A and its center side end portion 15C is D / 2 from the center 15D of the regulation hole 15A. The locking portion 15B separated outwardly
Is partially provided, and the male screw 7 of the pilot screw 10 is screwed onto the female screw 7 and screwed to adjust the effective opening area of the pilot outlet hole 4 by the tapered needle valve portion 11, and the pilot screw 10 The first brim 13 is arranged in the first storage hole 8 and the half-moon-shaped brim 14 is arranged so as to project into the second storage hole 9 and is regulated on the locking step 9A in the second storage hole 9. By inserting and fixing the member 15, the half-moon shaped flange portion 14 of the pilot screw 10 is arranged in the regulation hole 15A of the regulation member 15 and the side surface 14A of the half-moon shaped collar portion 14 is separated from the locking portion 15B. A carburetor pilot screw adjusting device that is placed opposite to each other.