JP2008077469A - Lever mechanism - Google Patents

Abstract

In a lever mechanism that performs positioning with a sense of moderation in lever operation, the sense of moderation of a sliding contact portion is maintained for a long time.
A cover member 21 is attached to a shaft receiving portion 16B of a lever 16 used for raising and lowering a plunger provided in a starting device 14 of a carburetor 10. The cover member 21 is made of resin, and includes a protrusion 26 having protrusions 26A and 26B and a washer portion 25 that holds the shaft receiving portion 16B. The shaft 17 is inserted through the holes provided in the shaft receiving portion 16B and the washer portion 25, and the lever 16 is fixed to the carburetor body. A bent portion 23 having a mountain shape of a leaf spring 22 fixed to the carburetor body side is pressed against and brought into contact with the protrusion 26A. When the lever 16 is in the first and second positions, the protrusion 26A is brought into contact with the inclined surfaces 23A and 23B of the bent portion 23, respectively.
[Selection] Figure 2

Description

  The present invention relates to a lever mechanism provided with a positioning mechanism having a sense of moderation.

  In the lever mechanism, a mechanism is known in which a protrusion provided on the lever is brought into sliding contact with another member, and the movement of the protrusion accompanying the lever operation is transmitted to the other member. Such a lever mechanism is known in which a protrusion is covered with a cover member made of an elastic body or a low friction material (Patent Document 1).

In particular, in lever operation, in the case of a lever mechanism that positions a rotated lever at a certain position with a sense of moderation, there is a problem that the sense of moderation is impaired when the sliding contact portion wears out. For example, as a carburetor starting device, there is known a plunger type starting device that opens and closes an air-fuel mixture passage by moving a plunger up and down using a lever. In such a starting device, the lever is opened and closed, respectively. Positioned with a sense of moderation.
JP 2005-002632 A

  An object of the present invention is to maintain a feeling of moderation of a sliding contact portion for a long time in a lever mechanism that performs positioning with a feeling of moderation in lever operation. Furthermore, it aims at making the maintenance at the time of abrasion of a sliding contact part easy while reducing the number of parts.

  The lever mechanism of the present invention is a lever mechanism having a lever that is rotated, and a resin cover member that is attached to the lever and rotated integrally with the lever is a plate spring provided on the fixed portion. It is characterized by positioning in the rotation of the lever in cooperation with the bent portion.

  The cover member and the lever include a locking mechanism that fixes the relative position in the rotation direction, the cover member is pivotally supported around the rotation axis of the lever, and the lever and the cover member are rotated integrally. . Further, in fastening the lever to the rotating shaft, it is preferable that the cover member sandwich the lever and function as a washer. Furthermore, the cover member includes, for example, a pair of protrusions that are in sliding contact with the bent portion, and the shape of the cover member is bilaterally symmetrical. It is preferable that the positions of the pair of protrusions are switched by turning the cover member upside down and mounting on the lever.

  The carburetor starting device of the present invention is characterized by including the lever mechanism.

  As described above, according to the present invention, in the lever mechanism that performs positioning with a sense of moderation in lever operation, the moderation sense of the sliding contact portion can be maintained for a long time. In addition, the number of parts can be reduced, and maintenance when the sliding contact portion is worn can be facilitated.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view of a carburetor provided with a plunger type flow control device using a lever mechanism according to an embodiment of the present invention.

  In the present embodiment, the plunger flow control device is used as a carburetor starter. The carburetor 10 of this embodiment is, for example, a piston type carburetor, and a sliding valve is provided in the sliding cylinder 11, and the sliding valve opens and closes the passage in the venturi of the air passage 12 to adjust its width. As is well known, a jet needle inserted into a needle jet is provided at the tip of the sliding valve, and fuel in the float chamber is guided to the venturi in the air passage 12 through the needle jet and atomized.

  The carburetor 10 is provided with a starting device 14, and an air-fuel mixture passage from the starting device 14 is connected to the downstream side of the venturi of the air passage 12. A plunger (not shown) is inserted into the cylinder 15 of the starter 14 as is well known, and the mixture passage and the fuel passage (not shown) are opened and closed by the vertical movement of the plunger. The details of the piston carburetor and the starting device 14 are well known in the art, and a detailed description of the structure is omitted.

  The up and down movement of the plunger in the starter 14 is performed by the turning operation of the lever 16. One end of the lever 16 is pivotally supported around the shaft 17 and an operation portion 18 is provided at the other end. The lever 16 is provided with a connecting lever 16A and is engaged with a plunger shaft 20 integral with the plunger.

  That is, when the lever 16 and the plunger shaft 20 are in the positions depicted by the solid lines in FIG. 1, the plunger is located on the lower side in the cylinder 15, and the mixture passage and the fuel passage are closed. When the user manually operates the operation unit 18 and the lever 16 is rotated upward in the direction A, the connecting lever 16A integrated with the lever 16 is also rotated upward, and the plunger shaft 20 engaged therewith is B Can be lifted upwards. As a result, the lever 16 and the plunger shaft 20 are moved to the positions indicated by the broken lines in FIG. At this time, the plunger moves upward in the cylinder 15 and the mixture passage and the fuel passage are opened.

  Next, the positioning mechanism in the lever mechanism of the present embodiment will be described with reference to FIGS. 2 is a partially enlarged view in FIG. 1 of the end of the lever 16 provided with the positioning mechanism, and FIG. 3 is a partially enlarged perspective view centering on the lever 16 of the carburetor 10.

  As shown in FIG. 2, a cover member 21 (shaded member in the drawing) is mounted around the shaft 17 of the lever 16. The cover member 21 is provided with a pair of protrusions 26A and 26B (note that there may be only one protrusion).

  A leaf spring 22 is fixed to the main body of the carburetor 10 which is a fixing portion. For example, one end (fixed end) of the leaf spring 22 is fastened while being sandwiched between the cap 15 </ b> A of the cylinder 15 and the cylinder 15. On the other hand, the free end side of the leaf spring 22 forms a bent portion 23 bent in a mountain shape. The bent portion 23 is engaged with the protrusion 26 </ b> A and constitutes a positioning mechanism for the lever 16. The protrusion 26B is a spare protrusion, and a method for using the protrusion 26B will be described later.

  That is, when the lever 16 is in the first position indicated by the solid line in FIGS. 1 to 3, that is, when the plunger is in the closed position, the protrusion 26 </ b> A has one inclined surface 23 </ b> A (in this embodiment, on the free end side). A). At this time, the slope 23A of the bent portion 23 is pressed against the protrusion 26A by the spring biasing force.

  When the lever 16 is rotated upward from the first position, the protrusion 26A is rotated while being in sliding contact with the bent portion 23, and gets over the mountain of the bent portion 23 while pushing down the bent portion 23. When the lever 16 reaches the second position indicated by a broken line in FIGS. 1 to 3, that is, the open position of the plunger, one end of the connecting lever 16 </ b> A of the lever 16 comes into contact with and engages with the bracket 24 provided on the main body of the carburetor 10. In addition, the protrusion 26A abuts against the other inclined surface 23B of the bent portion 23 (in this embodiment, the inclined surface on the fixed end side).

  The bracket 24 pivotally supports the lever 16 and restricts its rotation range. In the present embodiment, the position where one end of the connecting lever 16A contacts the bracket 24 is the second position. Further, when the lever 16 is rotated from the second position to the first position, the protrusion 26A is rotated in the opposite direction, moves over the mountain of the bent portion 23, and moves from the inclined surface 23B to the inclined surface 23A.

  Next, the configuration of the lever 16 will be briefly described with reference to FIGS. 4 is a side view of the lever body, and FIG. 5 is a top view.

  As shown in FIGS. 4 and 5, the main body of the lever 16 is formed, for example, by bending a metal plate cut out. One end of the lever 16 is a shaft receiving portion 16B, and a shaft hole 16H for inserting the shaft 17 is provided. The distal end of the connecting lever 16A is split into two along a direction perpendicular to the shaft axis to form a slit 16S, and the plunger shaft 20 is passed between the slits 16S. Further, the distal end of the plunger shaft 20 has a size or a shape that does not pass through the gap of the slit 16S. That is, when the lever 16 is operated and the connecting lever 16A is rotated around the shaft 17, the plunger shaft 20 is moved together with the connecting lever 16A.

  Further, the shaft receiving portion 16B is provided with a locking mechanism that restricts the rotation of the cover member 21 around the shaft axis with respect to the shaft receiving portion 16B. In the present embodiment, the locking mechanism includes, for example, a pair of projecting portions 19A and 19B extending in the radial direction from the peripheral edge portion of the shaft receiving portion 16B. Further, the grip constituting the operation portion 18 described above is attached to the end portion 16C of the lever 16 opposite to the shaft receiving portion 16B.

  6-8 is a figure for demonstrating the structure of the cover member 21 used in this embodiment. 6 and 7 are a front view and a side view of the cover member piece 21, and FIG. 8 is a perspective view of the cover member 21.

  As shown in FIGS. 6 and 7, the cover member piece 21 is bilaterally symmetric when viewed from the front and side, and includes a pair of circular washers 25 and a W-shaped protrusion 26. Each of the washers 25 is formed with a shaft hole 25H through which the shaft 17 having the same diameter as the shaft hole 16H is inserted. In the present embodiment, the center of the shaft hole 25 </ b> H is slightly eccentric from the center of the circular washer portion 25.

  The W-shaped projections 26 are provided on the back side of each washer 25 so that the three upper ends of W overlap the lower peripheral edge of the washer 25, and project to the lower side of W 2. The two ends form the above-described protrusions 26A and 26B. That is, as shown in FIG. 7, the pair of washers 25 are connected to each other by the protrusions 26, face each other at a predetermined interval, and are arranged in parallel. The cover member 21 is integrally molded as a mold.

  Next, a method for attaching the cover member 21 to the lever 16 (shaft receiving portion 16B) will be described with reference to FIGS. FIG. 9 is a diagram schematically showing the procedure for attaching the cover member 21 to the lever 16 and attaching the lever 16 to the carburetor body.

  As shown in FIG. 9, the cover member 21 is attached to the shaft receiving portion 16B of the lever 16, and the shaft hole 16H provided in the washer portion 25 of the cover member 21 and the shaft hole 25H provided in the shaft receiving portion 16B. The shaft 17 is inserted through the shaft. The tip of the shaft 17 is threaded, and is inserted into a shaft receiving hole (not shown) formed in a bracket 24 provided on the main body of the carburetor 10 and screwed. Thereby, the lever 16 is rotatably fixed to the carburetor body.

  In mounting the cover member 21 on the shaft receiving portion 16B, the shaft receiving portion 16B is fitted between a pair of opposed washers 25. That is, the distance between the washer portions 25 facing each other is set to be approximately equal to the thickness of the shaft receiving portion 16B. Thus, when the screw of the shaft 17 is tightened, the two washer portions 25 are sandwiched between the head of the shaft 17 and the carburetor body, and serve as a washer by sandwiching the shaft receiving portion 16B of the lever 16.

  Further, when the cover member 21 is mounted on the shaft receiving portion 16B, the projecting portions 19A and 19B provided on the shaft receiving portion 16B are fitted into the two recessed portions 26R of the protruding portion 26 each having a W shape. . Accordingly, the cover member 21 functions as a locking mechanism so that rotation around the axis of the shaft 17 is restricted with respect to the shaft receiving portion 16 </ b> B, and the cover member 21 is rotated together with the lever 16.

  As described above, according to the present embodiment, the cover member covers the shaft receiving portion of the lever, and provides the replaceable protrusion that slides on the leaf spring and performs positioning with a sense of moderation. Moreover, since the cover member plays a role of a washer in the shaft, the number of parts can be reduced, oversight of missing parts can be reduced, and production efficiency can be improved. In addition, since the cover member is made of a softer resin than the leaf spring member, the feeling of moderation can be maintained for a long time without wearing out the leaf spring.

  In addition, since the cover member of this embodiment is provided with two protrusions and is formed symmetrically on the left and right and front and rear, when one protrusion (for example, 26A) is worn, the cover member is turned over and attached to the shaft receiving portion 16B. Then, the position of the other projection (for example, 26B) used as a reserve and one projection can be exchanged, and the other projection can be used for the positioning mechanism. This facilitates maintenance including replacement of the cover member.

It is a side view of the carburetor provided with the plunger type flow control device using the lever mechanism which is one embodiment of the present invention. It is the elements on larger scale in FIG. 1 of the edge part of the lever provided with the positioning mechanism. It is a partial expansion perspective view centering on the lever of a carburetor. It is a side view of a lever main body. It is a top view of a lever main body. It is a front view of a cover member piece. It is a side view of a cover member. It is a perspective view of a cover member. It is a figure which shows typically the attachment procedure to the lever of a cover member, and the attachment to the carburetor main body of a lever.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Carburator 14 Starter 16 Lever 16A Connection lever 16B Shaft receiving part 17 Shaft 18 Operation part 19A, 19B Protrusion part 20 Plunger shaft 21 Cover member 22 Leaf spring 23 Bending part 24 Bracket 25 Washer part 25H Shaft hole 26 Protrusion part 26A, 26B Protrusion

Claims (6)

A lever mechanism having a lever that is operated to rotate,
A resin cover member mounted on the lever and rotated integrally with the lever performs positioning in rotation of the lever in cooperation with a bent portion of a leaf spring provided on the fixed portion. And lever mechanism.   The lever mechanism according to claim 1, wherein the cover member and the lever include a locking mechanism that fixes a relative position in a rotation direction.   The cover member is pivotally supported around a pivot shaft of the lever, and the lever and the cover member are integrally rotated. The lever mechanism described.   The lever mechanism according to claim 3, wherein the cover member sandwiches the lever and functions as a washer when the lever is fastened to the rotating shaft.   The cover member includes a pair of protrusions that are in sliding contact with the bent portion, the shape of the cover member is bilaterally symmetrical, and the positions of the pair of protrusions are interchanged by turning the cover member over and attaching to the lever. The lever mechanism according to claim 1. A carburetor starting device using the lever mechanism according to any one of claims 1 to 5.

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