JPH0335525Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an improvement in the drive mechanism of a chain saw suitable for cutting relatively hard synthetic resins, metals, etc.

(Prior art and its problems) Conventionally, chain saws have been improved mainly for cutting wood (for example, U.S. Pat. No. 392,904), so the chain saw structure is suitable for cutting relatively hard synthetic resins, metals, etc. As a result, the present inventors conducted extensive research and found that the teeth of the chain sprocket were easily attached to the base of the cutting link. The structure is simplified by providing a recessed part in which the parts can freely engage, omitting the drive link required in conventional chain saws, and reducing the pitch of the cutting edge (Japanese Patent Application No. 59-255643). The cutting link with cutting edge is located in the center of the side link to reduce vibration when cutting the material to be processed (Patent Application No. 59-255644), and the base of the cutting link in the saw chain is The guide groove provided around the guide bar guides the guide bar, and the side link connecting the cutting link slides around the guide bar to suppress the vibration of the chain saw (Japanese Patent Application No. 59-255645). We have proposed a chain saw suitable for cutting relatively hard synthetic resins, metals, etc.

Since the saw chain C of such a chain saw has a unique configuration, a conventional chain saw drive mechanism cannot be directly adopted.

In other words, in the case of a woodworking chain saw as disclosed in JP-A No. 58-14702, in which a single blade is connected by a pair of opposing side links, a configuration is adopted in which the drive tongue piece enters between the teeth of the sprocket. can be done, but
For the central cutting link that has multiple cutting edges, it is necessary to form a recess in the base part and drive the tip of the sprocket tooth by engaging with the recess (see Japanese Patent Laid-Open No. 50-6000). Therefore, the above type cannot be used as is, and it is necessary to devise ways to mesh with the sprocket.

(Purpose of the invention) The present invention consists of a cutting center link 1 having an appropriate number of cutting edges, pivotally connected by a pair of side links 2, 2, and a saw chain C that is endlessly stretched on a guide bar 3. In this new chain saw, the teeth of the chain sprocket 4 are engaged with a recess formed in the base of the cutting center link 1 to rotate the chain saw.
Furthermore, it is an object of the present invention to provide a chain saw suitable for cutting relatively hard synthetic resins, metals, and the like.

(Summary of the invention) The present invention provides the above-mentioned chainsaw with a pair of guide plates attached to both sides of the chain sprocket, and guides the vicinity of the recess of the cutting center link that meshes with the teeth of the chain sprocket with both guide plates. The chain saw drive mechanism is characterized in that the saw chain C is rotated while the saw chain C is rotated.

In this invention, in terms of drive function, the shape of the valley between the adjacent teeth of the chain sprocket corresponds to the bending angle of the base of the cutting center link that meshes with the adjacent chain sprocket. It is preferable that both links mesh with each other as a whole, and the outer peripheral shape of the guide plate corresponds to the bending angle of the side link of saw chain C, which is fed by meshing with the chain sprocket, and is positioned in contact with the lower surface of the side link. It may be polygonal or disc-shaped to allow regulation;
Preferably, it rotates synchronously with the chain sprocket.

(Structure of the invention) Hereinafter, the structure of the invention will be explained in detail based on the attached drawings showing specific examples thereof.

Figure 1 is a front view of the chain saw with some parts omitted.
2 is a sectional view taken along the line 1 in FIG. 1, FIG. 3 is a top view of the cutting center link, and FIG. 4 is a front view showing a modified example of the guide plate and chain sprocket of the chain saw drive mechanism.

In the drawing, M is a chain saw, and a saw chain C consisting of a cutting center link 1 having an appropriate number of cutting edges pivotally connected by a pair of side links 2, 2 is stretched endlessly on a guide bar 3. The teeth of the chain sprocket 4 are engaged with a recess formed in the base of the cutting link 1 to rotate the chain sprocket.

Specifically, the tip of the guide bar 3 is formed in an arc shape like a general chain saw,
A guide groove 31 for guiding the saw chain C is formed around the guide bar 3. On the other hand, on the base side of the guide bar 3, a handle 32 that is bent and stretched as appropriate is fixed, and the chain sprocket 4 is disposed on the base side of the guide bar 3, and is attached to the handle 32. It is attached to a drive shaft 43 that is operatively connected to a rotational drive device such as a motor (not shown).

The sorting chain C displaces a plurality of cutting center links 1... and a plurality of side links 2, which are extremely thin compared to the cutting links 1, above the height center position of the cutting links 1. They are pivotally connected to each other and have an endless configuration as a whole. This cutting link 1 has two pairs of cutting edges 11R, 11R', which form an appropriate number (five in the drawing) of left and right set teeth.
11L and 11L' are formed sandwiching the center edge 11C, and the entire saw chain C forms equally spaced edge pitches, while the base side has a recess 12 in which the teeth 41 of the chain sprocket 4 engage.
is formed.

Therefore, the saw chain C engages with the teeth 41 of the chain sprocket 4 and the base recess 12 of the cutting center link, is rotationally driven in the direction of arrow A, and travels in the direction of arrow B. At this time, since the cutting link 1 is configured to be pivotally connected by a plurality of side links 2 which are extremely thin compared to the cutting link 1, the saw chain C does not have sufficient strength in the torsional direction. Although it tends to swing left and right, it travels while being held and guided by the guide groove 31 of the guide bar 3, with the swinging left and right being suppressed. On the other hand, when cutting the material to be cut, the cutting edge 11R of the cutting ring 1 is
cuts into the material to be cut, cutting ring 1
tends to cause a pivot action in the direction of arrow C in Fig. 1, but cutting link 1
The base portion of the cutting link 1 is clamped and guided by the guide groove 31, and the pivoting connection portion with the side link 2 is displaced toward the cutting edge, so that the pivot action of the cutting link 1 is suppressed.

However, it is not enough to suppress the left and right swinging and pivot action of saw chain C during running and cutting.
Even when the saw chain sprocket 4 is being rotated by the saw chain sprocket 4, if it is not prevented from swinging to the left and right, not only will the driving force not be transmitted accurately, but the chain sprocket 4
A smooth transition from the chain sprocket 4 to the guide bar 3 cannot be performed.

Therefore, in the present invention, guide plates 5, 5 are provided on the drive shaft 43 on both sides of the chain sprocket 4 so as to rotate in synchronization with the chain sprocket 4.
The saw chain C is rotated while being guided by both guide plates 5, 5 in the vicinity of the base recess 12 of the cutting link 1 which meshes with the teeth of the chain sprocket 4.

The outer peripheral shape of the guide plate 5 may be a shape capable of guiding the vicinity of the base recess 12 of the cutting link 1 that meshes with the teeth of the chain sprocket 4, for example, a simple circular shape 5. As shown in the imaginary line and in FIG. 4, the side links 2, 2... of the saw chain C, which is meshed with the chain sprocket 4 and fed, are polygonal in shape so as to be able to regulate their position by coming into contact with the lower surface of the saw chain C. In consideration of the meshing pitch between the joint 4 and the side link 2, that is, the bending angle at the meshing position of the side link 2, the shape is a regular octagon 5' in FIG. 1 and a regular hexagon 5'' in FIG.

Furthermore, the shape of the trough 42 between the teeth 41, 41 of the chain sprocket 4 corresponds to the bending angle of the base of the cutting link 1 that meshes with the chain sprocket 4, and the shape of the trough 42 corresponds to the bending angle of the base of the cutting link 1 that meshes with the chain sprocket 4, and the trough 42 has a bulge toward the center of the trough. By forming the chevron shape, the saw chain C is maintained in a meshing posture vertically and horizontally, and the recess 1 of the cutting link 1 is inserted into the teeth 41 of the chain sprocket 4.
At the same time, the base bottoms before and after the recess of the cutting link 1 also mesh with the troughs 42 of the chain sprocket 4, and the outer periphery of the guide plate 5 and the side link 2 As a result, the rotational driving force of the chain sprocket 4 is reliably transmitted to the saw chain C.

Note that 44 is a keyway for positioning the chain sprocket 4 and the guide plate 5.

(Operations and Effects of the Invention) As is clear from the above explanation, according to the invention, a pair of guide plates are attached to both sides of the chain sprocket, and a pair of guide plates are provided near the recess of the cutting link that meshes with the teeth of the chain sprocket. The chain sprocket 4 is guided by both guide plates and rotated while maintaining the meshing posture of the saw chain C, so that the chain sprocket 4 is Not only is the rotational driving force of the saw chain C reliably transmitted, but the saw chain C is smoothly transferred to the guide bar 3, making it a desirable drive for a chain saw suitable for cutting relatively hard synthetic resins, metals, etc. A mechanism will be provided.

[Brief explanation of the drawing]

Figure 1 is a front view of the chain saw with some parts omitted.
2 is a cross-sectional view taken along the line -- in FIG. 1, FIG. 3 is a top view of the cutting link, and FIG. 4 is a front view of essential parts showing a modification of the guide plate. M...Chain saw, C...Saw chain, W...
... Material to be cut, 1 ... Cutting center link, 2 ... Side link, 3 ... Guide bar, 4
...Chain sprocket, 5...Guide plate.

Claims (1)

[Scope of claim for utility model registration] A cutting center link 1 having an appropriate number of cutting edges, a pair of side links 2,
The saw chain C, which is pivotally connected at 2, is stretched endlessly on the guide bar 3, and the protruding tip teeth of the chain sprocket 4 are engaged with the recess formed in the center of the base of the cutting link 1. In a chainsaw M which is rotationally driven and has guide plates 5, 5 attached to both sides of the sprocket 4 to be driven simultaneously, the shape of the valley between each tooth of the chain sprocket 4 is the same as that of the chain sprocket 4. Corresponding to the bending angle of the base of cutting link 2 that meshes with
A chainsaw drive mechanism is characterized in that it has a mountain shape that bulges toward the trough and guides and drives while regulating the bending angle of the cutting link.