JP2579302Y2 - Hair clipper type brush cutter - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clipper-type brush cutter and, more particularly, to a clipper-type cutter which reciprocates a cutting blade by rotating the eccentric cam.

[0002]

2. Description of the Related Art For example, in a hair clipper-type brush cutter for cutting weeds, such as cutting weeds, cutting lawns, cutting hedges, etc. on levee or irrigation canals, it is usually installed at one end of an operation rod. Output from a power source such as an internal combustion engine
The cutting is transmitted to a cutting blade device via a power transmission device, and a pair of upper and lower elongated cutting blades are reciprocated relatively to each other in a longitudinal direction to cut vegetation.

[0003] As shown in Figs. 4 to 6, for example, as shown in Figs. 4 to 6, a device using an eccentric cam as a transmission means for reciprocating a sliding blade type clipper blade is disclosed in Japanese Patent Application No. It is described in JP-A-3-11949. FIG. 4 is a side sectional view of a main part of the bush cutter in the conventional embodiment, FIG. 5 is a view taken in the direction of the arrow VV in FIG. 4, and FIG.

A clipper blade reciprocating device 1 shown in FIGS.
It has a case 3 variably attached to the tip of a gear reduction device 2 connected to the tip of an operation rod of a brush cutter (not shown). The case 3 is composed of upper and lower halves integrally connected by a plurality of bolts 4. Consists of bodies 6 and 7. Case 3 is:
A main shaft 8 driven by a transmission shaft (not shown) of the operation rod is vertically supported rotatably via bearings 9 and 10, and the main shaft 8 is connected to an output end 11 of the gear reduction device 2. Have been. The main shaft 8 is integrally formed with a pair of circular eccentric cams 12 and 13 that are vertically separated from each other in the axial direction. These eccentric cams 12 and 13 are arranged with an angular phase shifted by 180 degrees from each other. Has been established.

Further, a pair of upper and lower elongated cutting blades 14 and 15
Are arranged so as to protrude from the inside of the case 3 to the front and outside thereof, and the front portions 31, 32 and the rear portions 33, 34 of the portions of the cutting blades 14, 15 housed in the case 3 It is supported by a bearing 17 provided at a front end 16 and a bearing 19 provided at a rear end 18, respectively, and is configured to be slidable in the front-rear direction.
The lower receiving plate constituting the bearing 17 of the front end 16 has an integral fixed blade 20 protruding forward from the lower half 7 of the case 3. The part is formed so that grass and the like can be cut.

Since the main shaft 8 and the eccentric cams 12 and 13 are integrally formed, the eccentric cams 12 and 13 are formed integrally.
Lateral curved portions 21 and 22 are formed at an intermediate portion in the case 3 in which the cutting blades 14 and 15 are disposed so as to sandwich the cutting blades 14 and 15 therebetween. In this manner, the laterally curved portions 21 and 22 of the cutting blades 14 and 15 can be arranged so as to bypass and cross the side of the intermediate portion 5 of the main shaft 8 and to cross the upper and lower portions. It can be held between the eccentric cams 12 and 13.

The upper and lower cutting blades 14, 15 superimposed on each other
On the respective planes including the eccentric cams 12 and 13 in contact with the upper and lower surfaces of the cutting blades, driven members 41 and 42 as followers of the cam motion are provided in the front-rear direction (longitudinal direction) of the cutting blades 14 and 15. It is provided along. The upper driven member 41 is a plate-like member in which connecting rod portions 23 and large and small circular rings 25 and 27 are integrally formed at both ends thereof.
Similarly, the lower driven member 42 is a plate-like member in which the connecting rod portion 24 and the large and small circular rings 26 and 28 are integrally formed.

The eccentric cams 12 and 13 are pivotally fitted to the large ends 25 and 26 of the driven members 41 and 42, respectively. The small ends 27 of the driven members 41 and 42
And 28 have pins 29 on the cutting blades 14 and 15, respectively.
And 30. With such a configuration, when the main shaft 8 is driven and rotated by the reduced rotational force from the gear reduction device 2, the cutting blades 14 and 15 have opposite phases through the eccentric cams 12 and 13 and the driven members 41 and 42, respectively. Reciprocating to cut plants and the like.

[0009]

As described above, in the conventional clipper-type brush cutter, since both the upper and lower cutting blades have the laterally curved portions formed on the same side, the mass is ubiquitous on one side. Therefore, the balance during the reciprocating motion is deteriorated, and there is a possibility that the operating performance and the durability of the cutting blade may be affected. Also, in terms of manufacturing technology, when quenching a metal blade whose mass is ubiquitous on one side like the cutting blade,
There is a problem that the possibility of occurrence of distortion increases, and therefore the wall thickness must be increased, resulting in an increase in weight as a whole.

Furthermore, since the eccentric cam and the main shaft are integrally connected and integrally formed, there is a problem that the processing is not easy and the production cost is increased. Moreover, there is a problem that the end face of the eccentric cam comes into contact with the laterally curved portions (portions A and B in FIG. 6) of the cutting blade during the rotational movement of the eccentric cam, and the eccentric cam and the cutting blade member are worn. Was.

The present invention has been made in view of such a problem, and has as its object to prevent deformation during machining, such as hardening of a cutting blade, and to balance movement during reciprocation. Good, and the manufacturing process of the eccentric cam can be easily performed, maintenance work such as replacement of members can be easily performed, and the whole can be made inexpensive and lightweight, and Another object of the present invention is to provide a hair clipper-type brush cutter designed to improve the durability of a movable member.

[0012]

In order to achieve the above-mentioned object, a clipper-type brush cutter according to the present invention basically comprises:
A main shaft rotatably supported by the case, a cutting blade protruding forward from the case and slidably supported in the front-rear direction by bearings disposed at front and rear ends of the case, and a cutting blade disposed on the main shaft. Driven member integrally formed with an eccentric cam, an annular large end pivotally fitted to the eccentric cam at both ends of the connecting rod portion, and an annular small end pivotally attached to the cutting blade. In the clipper-type brush cutter having the above, the eccentric cam is provided with a shaft hole through which the main shaft penetrates and is prevented from rotating, so that the eccentric cam and the main shaft can be freely disengaged, and the cutting blade has It is characterized in that a long hole is formed along the longitudinal direction for penetrating the main shaft.

As a more specific example of the eccentric cam, there is a eccentric cam characterized by having a hollow portion formed in the eccentric cam.

[0014]

The eccentric cam rotates when the main shaft rotates in the clipper-type brush cutter according to the present invention constructed as described above. As a result, the driven member is reciprocated in the front-rear direction, and the cutting blade is also reciprocated in the front-rear direction in synchronization with the reciprocation. If the lubricant (grease) is stored in the lightening portion formed on the eccentric cam, the cutting blade can be exuded little by little during the reciprocating motion of the cutting blade, and the lubrication of the sliding member can be maintained. Become.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is an exploded perspective view of a cutting blade drive unit of the clipper-type brush cutter according to the present invention, FIG. 2 is an enlarged plan view of the eccentric cam, and FIG. 3 corresponds to the conventional VV arrow view of FIG. It is a III view. It will be apparent from the following description that the sectional side view of the brush cutter shown in FIG. 4 is the same in the present invention. In the following description, FIGS.
The parts corresponding to the respective parts of the prior art shown in FIG.
The differences from the above-described conventional technology will be mainly described.

As shown in FIG. 1, the main shaft 80 and the eccentric cams 120 and 130 having a circular outer shape are formed separately from each other, which is different from the conventional one in which these are integrally formed. The main shaft 80 is formed of a solid round bar, and the eccentric cams 120 and 130 are vertically separated from each other in the lower half thereof in the axial direction, and are fitted with a non-rotating fit with an angular phase shifted by 180 degrees. It has become. And
In the lower half of the axis 80, the eccentric cams 120, 13
A notch 50 having an arcuate cross section for preventing rotation of 0 is provided. On the other hand, as shown in FIGS. 2 (a) and 2 (b), the eccentric cams 120 and 130 are formed of disk-shaped plate members, and have substantially crescent-shaped lightening portions 53 and 54 which can be used as grease reservoirs inside. , And shaft holes 51 and 52 through which the main shaft 80 passes. As apparent from FIGS. 1 and 2, the eccentric cams 120 and 130 correspond to the notches 50 for preventing rotation of the main shaft 80 in the shaft holes 51 and 52 because the eccentric cams 120 and 130 are attached with an angular phase shifted by 180 degrees from each other. The engagement positions are also shifted from each other by 180 degrees. The eccentric cams 120 and 130 having such a shape are easily manufactured by press working.

A pair of upper and lower elongated cutting blades 140, 150
Although the shape of the blade portion formed at the front position is substantially the same as that of the related art, the shape of a portion accommodated in the case 3 is different. That is, in the prior art, the laterally curved portions are formed only on one side along the length direction of the cutting blade, whereas in the illustrated example of the present invention, the laterally curved portions 210 and 220 are formed on both sides. A long hole 21 is formed in the center of the cutting blade along its longitudinal direction.
1, 221 are drilled. Thus, the cutting blade 1
Since the blades 40 and 150 are formed in a uniform shape, the blade material can be made thinner, and the weight can be reduced and the durability can be improved. In addition, deformation during processing such as quenching can be prevented, and the motion balance during reciprocating motion can be improved by equalizing the mass balance.

In order to assemble the components thus formed, the upper and lower two cutting blades 14 overlapped with each other.
The driven members 41, 4
2 and the small ends 27 and 28 are pivotally connected to the pins 29 and 30, and the large ends 25 and 26 are connected to the cutting blade 1.
They are arranged so as to overlap each other with 40 and 150 therebetween. The eccentric cams 120 and 130 are fitted in the circular rings of the large ends 25 and 26, respectively, and the main shafts 80 are inserted into the shaft holes 51 and 52, so that the eccentric cams 120 and 130 and the main shafts 80 are inserted. Are integrated. In this way, the main shaft 80 is connected to the cutting blade 14.
The cutting blades 140 and 150 are inserted between the eccentric cams 120 and 130 provided apart from each other in the axial direction of the main shaft 80 while passing through the elongated holes 211 and 221 of the main shaft 80.

On the other hand, for example, when disassembling the device when exchanging the eccentric cam, the case 3 is detached from the gear reduction device 2 and then the main shaft 80 is pulled out, so that only the upper and lower cutting blades 140 and 150 are used. And the driven member 4
The eccentric cam 1 can be easily formed without removing the
Exchange of 20, 130 can be performed. With this configuration, when the main shaft 80 is driven and rotated by the reduced rotational force from the gear reduction device 2, the eccentric cam 120
And 130 rotate out of phase with each other. Accordingly, the upper and lower driven members 41 and 42 are reciprocated in the front-rear direction in opposite phases to each other, and the cutting blades 140 and 150 are also reciprocated in the front-rear direction in synchronization with this.

The lightening portions 51 and 52 formed on the eccentric cams 120 and 130 are adapted to supply and store a lubricant such as grease. During the reciprocating movement of 150, the liquid is exuded little by little, and the lubrication of the sliding member can be maintained. The present invention is not limited to the so-called double-action type in which the pair of upper and lower cutting blades reciprocates in the illustrated example, but also the so-called single-action type in which only one of the cutting blades reciprocates. What can be applied is
It will be easily understood.

[0021]

As will be understood from the above description, according to the present invention, it is possible to easily manufacture a cutting blade, a spindle, an eccentric cam, and the like, and to perform maintenance work such as replacement of members. It can be easily performed, and also prevents deformation of the cutting blade during quenching, and improves the durability of the cutting blade.
Excellent effects can be obtained such that the exercise balance during the reciprocating motion can be improved, and the whole can be made inexpensive and lightweight.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a cutting blade drive unit of a clipper-type brush cutter according to the present invention.

FIG. 2 is an enlarged plan view of an eccentric cam.

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 4;

FIG. 4 is a side sectional view of a main part of the brush cutter according to the related art and the embodiment of the present invention.

FIG. 5 is a view taken in the direction of arrows VV of the conventional example in FIG. 4;

FIG. 6 is an exploded perspective view of a cutting blade drive unit according to the related art.

[Explanation of symbols]

53, 54 ... lightening portion, 80 ... spindle, 120, 130 ...
Eccentric cam, 140, 150 ... cutting blade, 211, 221 ... long hole

Claims (2)

(57) [Scope of request for utility model registration] 1. A main shaft (80) rotatably supported by a case (3), and disposed at front and rear ends (16, 18) of the case (3) projecting forward from the case (3). A cutting blade (140, 150) slidably supported in the front-rear direction by bearings (17, 19), an eccentric cam (120, 130) disposed on the main shaft (80),
The eccentric cams (12) are provided at both ends of the connecting rods (23, 24).
0, 130) to be fitted to the large end (2
5, 26) and a driven member (41, 42) integrally formed with an annular small end (27, 28) pivotally attached to the cutting blade (140, 150). , The main shaft (8) to the eccentric cams (120, 130).
0) are provided through which the eccentric cams (120, 130) and the main shaft (8,
0) and the cutting blades (140, 15).
A clipper type brush cutter characterized in that 0) is formed with long holes (211 and 221) for penetrating the main shaft (80) along its longitudinal direction. 2. A clipper-type brush cutter according to claim 1, wherein the eccentric cams (120, 130) are provided with lightening portions (53, 54).