JPH0356322Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a brake device for a chain saw that is used to stop the rotation of a saw chain by operating the brake lever in an emergency during operation of the chain saw. It is.

(b) Prior art and problems to be solved Conventionally, in the brake system of this type of chain saw, the brake drum is linked to the sprocket that rotationally drives the saw chain, and the brake drum is pivotably pivoted to the case by a support shaft. A brake lever is provided, and a swinging body is installed in parallel with the brake lever and pivotably pivoted to the case by the support shaft, and the swinging body is linked to the brake lever and is connected to the brake drum. One end of a brake band provided along the outer periphery is pivotally connected to either the case or the rocking body, and the rocker is biased in one direction by the bomb. A movable piece is provided, and the other side is provided with a first locking part for holding the brake band in a brake release position by locking with a second locking part provided on the swinging piece, and the brake lever is actuated in the braking direction. A lock release means for swinging the swinging piece in the lock release direction is provided. Conventionally, as shown in FIG. 5, the brake lever 49 and the swing piece 33 are pivotally attached to the case 1 by stepped bolts 69 and 71, and a side plate 59 covering the side surface of the swing body 27 is attached. was separately fixed to the case 1 with screws to prevent chips from the chain saw from entering. In this configuration, the brake lever 49,
Attachment of the rocking body 27 and attachment of the side plate 59 are separate and require two steps, which is not desirable in terms of assembly efficiency.

(c) Means and operation for solving the problem In the present invention, a support shaft for pivotally connecting the brake lever and the swinging body is buried in the case, and the brake lever is fitted onto the tip of the support shaft. A side plate is provided that covers and locks the sides of the lever and rocking body, and by screwing the side plate to the case,
At the same time, it locks the brake lever and the swinging body, thereby improving the efficiency of the assembly work.

(d) Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In Figures 1 to 4, reference numeral 1 denotes a synthetic resin case of a chain saw, in which an engine (not shown) is installed, and is slidable along the outer periphery of a guide bar 3 protruding forward. The provided saw chain 5 is rotationally driven. The case 1 is divided into a case body 7 and a lid part 9, and a saw chain 5 is inserted between the case body 7 and the lid part 9.
is provided. 11 is a support supported on the upper part of the case body 7; 13 is a rear handle whose one end is fixed to the support 11 and whose lower end is supported at the rear of the case body 7; and 15 is a rear handle whose one end is fixed to the support 11. , a front handle whose other end is supported by the case body 7. 17 is a brake band provided along the outer periphery of a brake drum 21 fixed to a sprocket 19 that suspends and drives a saw chain 5 of an engine (not shown); The other end is connected by a shaft 29 to a swinging body 27 which is pivotally mounted to the lid portion 9 by a support shaft 25 . Reference numerals 31 and 31 designate support pieces fixed to the lid portion 9 in order to hold the brake band 17 at an appropriate distance from the brake drum 21. One end of the support shaft 25 is embedded integrally when the lid portion 9 is molded. 33 is the shaft 3 attached to the lid part 9.
A swinging piece 37 pivotably mounted by a shaft 39 is a first locking portion provided on the swinging body 27, and in this embodiment, it is composed of a roller 41 rotatably supported by a shaft 39. One end of the shaft 35 is embedded integrally when the lid portion 9 is molded. Reference numeral 43 denotes a second locking portion provided on the swinging piece 33, which in this embodiment is composed of a concave cam portion 45 that locks the roller 41. 47 is the swing piece 33
This is a bullet device that urges in the direction of locking (direction of arrow A in Figure 2). The cam portion 45 engages with the roller 41 to hold the brake band 17 in a brake-released state,
Further, the swinging body 27 is configured to swing in the direction of arrow B. Reference numeral 49 denotes a brake lever pivotally attached to the lid portion 9 via a support shaft 25, and is arranged in parallel with the swinging body 27. The swinging body 27 is interlocked with the brake lever 49 within a predetermined swing range. That is, the brake lever 49 is
It reciprocates freely between a shaft 29 and a roller 41 provided on the shaft, and contacts the shaft 29 and the roller 41, thereby interlocking the rocking body 27. Reference numeral 53 designates an engagement hole provided in the brake lever 49. When one end of the bullet 47 is engaged and the tips of the bullet 47 are located at both ends of the engagement hole 53, the brake lever 49 is moved to that position. The surface on which the bullet 47 presses in the middle thereof is inclined with respect to the biasing direction of the bullet 47, and the support shaft 25 is held by a component of the biasing force. The brake lever 49 is shaped so as to rotate in the direction of arrow C in FIG. 2 at the center. 55 is a recess provided at one end of the engagement hole 53, and 57 is a protection plate fixed to the tip of the brake lever 49. Reference numeral 59 denotes a side plate provided with fitting holes 61 and 63 that fit into the ends of the support shaft 25 and the shaft 35, which is fixed to the lid part 9 by screws 65 and 67 and the screw 23, and which is connected to the swinging body 27 and the brake lever 49. covers the sides of the rocking body 2 to prevent chips from entering.
7. The brake lever 49, the swinging piece 33, and the side surface of the brake band 21 are abutted and locked.

In the embodiments described above, the operator holds the front handle 15 and the rear handle 13 and cuts wood or the like using the saw chain 5 which is rotated by the engine. In an emergency such as when the saw chain 5 bites into wood, when the protection plate 57 is pressed and rotated in the direction of arrow C in FIG. 2, the front edge of the brake lever 49 contacts and presses the roller 41, causing is released from the second locking part 43 of the swinging piece 33, that is, the cam part 45, and the swinging body 27 moves in the direction of arrow B.
direction, the brake band 17 is pulled,
It comes into contact with the outer periphery of the brake drum 21 to perform braking.
Further, the roller 41 is pressed by the swinging piece 33 which is urged in the direction of arrow A by the bullet 47, and the brake band 17 maintains the braking state. At this time, the other end of the bullet 47 obliquely presses the contact surface of the engagement hole 53, so the brake lever 49 is urged in the direction of arrow C to press the roller 41, and the swinging body 2
7 in the direction of arrow B, the braking force of the brake band 17 is further urged. Next, when the brake lever 49 is operated in the opposite direction to the arrow C, the shaft 2
9 is pressed, the rocking body 27 rotates in the opposite direction to the arrow B, releasing the braking of the brake band 17, and when the rollers 41 reach the position of the cam portion 45, they engage with each other and the rocking body 27 is maintained in its state. Next, when the brake lever 49 is rotated in the direction of arrow C to a position where it contacts the roller 41, it returns to its original position in the operating state shown in FIG. In addition, when assembling the brake lever 49, the swinging body 27, and the swinging piece 33, the brake lever 49, the swinging body 27, and the
is fitted to the support shaft 25, the swinging piece 33 is fitted to the shaft 35, and the side plate 59 is fixed with the screws 65, 67, 23, then the brake lever 49, the swinging body 27,
The swing piece 33 can be easily locked at the same time.

(e) Effect of the invention Since the invention has the configuration as described in the claims, the brake lever and the swinging body can be assembled together by fixing the side plate with screws and locking them at the same time. Work efficiency can be improved, and the support shaft and shaft can be used only once when molding the lid.
Since the end is buried as one piece, the strength of the support shaft, shaft, and lid is improved compared to the screw-in type.
The lid part can be manufactured from synthetic resin with high strength and safety, and the number of parts can be reduced to reduce manufacturing costs.

FIG. 5 shows a conventional example, in which the brake lever 49 and the swinging body 27 are pivotally connected and locked by a stepped bolt 69, and the swinging piece 33 is connected to a stepped bolt 71.
Further, the roller 41 and the brake band 17 are locked by snap springs 73 and 75 at the tips of the shafts 39 and 29, respectively.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented in other embodiments as well. Further, the symbols shown in the claims do not limit the technical scope of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a perspective explanatory view of one embodiment of the present invention;
The figure is a side sectional view of the main part, Figure 3 is a plane sectional view of the main part,
FIG. 4 is a side view of other main parts, and FIG. 5 is a plan cross-sectional view of the main parts of the conventional example. 1...Case, 5...Saw chain, 17...Brake band, 19...Sprocket, 21...
Brake drum, 25... Support shaft, 33... Swing piece, 37... First locking part, 43... Second locking part,
47... Bullet, 49... Brake lever, 59...
...Side plate.

Claims (1)

[Scope of utility model registration request] Sprocket 19 that rotationally drives the saw chain 5
A brake drum 21 that interlocks with the brake drum 21 and a brake lever 49 that is swingably pivotally connected to the case 1 by the support shaft 25 are provided. A rocking body 27 is provided which is pivotally connected to the rocking body 2.
7 is interlocked with the brake lever 49 and pivotally connected to one end of the brake band 17 provided along the outer periphery of the brake drum 21, so that either one of the case 1 and the rocking body 27
It is pivotably mounted on the side, and the projectile 47
A swinging piece 33 biased in the direction is provided, and a first locking portion 43 provided on the swinging piece 33 is provided to hold the brake band 17 in the brake release position. A locking portion 37 is provided, and when the brake lever 49 is operated in the braking direction, the swinging piece 33 is
In the brake device for a chain saw, which is provided with a lock release means for swinging in the lock release direction, the support shaft 25 is embedded integrally in the case 1, and the support shaft 25 is fitted to the tip of the support shaft 25. A brake device for a chain saw, characterized in that a side plate 59 is provided that covers and locks the side surfaces of the swinging body 27 and the brake lever 49.