JPH075322U - Liner retaining structure for bearings of brush cutters - Google Patents

Abstract

(57) [Summary] [Purpose] A bearing liner for a bush cutter, in which the bearing liner that supports the transmission shaft of the bush cutter is stopped by using the welding projections of the operating rod made of a welded pipe. I will provide a. [Structure] An engine is mounted on the base end of an operating rod that houses a transmission shaft via a bearing to drive the transmission shaft, and power is transmitted to the cutting blade unit provided at the tip of the operating rod via the transmission shaft. A bush cutter in which a cutting blade is driven by means of a bearing portion that supports a transmission shaft, and a plurality of support legs that extend radially from the bearing portion and that are in contact with the inner peripheral surface of the operating rod. And a pipe in which the operating rod is joined by welding, and a bearing liner supporting the transmission shaft is inserted into the pipe while leaving the welding protrusion on the inner surface of the pipe, and the welding protrusion is used as a bearing. It was used as a detent for the liner.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bearing liner detent structure for a bush cutter, in which a bearing liner that supports a transmission shaft of the bush cutter is detented by using a welding protrusion of an operating rod made of a welded pipe.

[0002]

[Prior art]

 Conventionally known brush cutters include those shown in FIGS. 3 and 4. In this conventional brush cutter, a transmission shaft 13 is rotatably supported by a plurality of bearings 1a and is installed in an operating rod 1 having a long length in the front-rear direction, and an engine 2 is attached to a base end portion of the operating rod 1. Then, the transmission shaft 13 is driven via the centrifugal clutch 2a, and power is transmitted to the cutting blade unit 3 provided at the tip of the operating rod 1 via the transmission shaft 13 to drive the cutting blade 3a.

A horn-shaped handle 5 is attached to a portion of the operating rod 1 near the engine 2 via an attachment unit 4. Grips 6 and 7 are attached to both ends of the handle 5, and a throttle lever 8 is attached to the handle 5 on the grip 7 side. When the throttle lever 8 is operated, the throttle wire 9 connected to the engine 2 is pulled to increase the rotation speed of the engine 2. When the number of revolutions of the engine 2 reaches a predetermined value or more, the centrifugal clutch 2a is engaged and the transmission shaft 13 in the operating rod 1 rotates to transmit the driving force to the cutting blade unit 3 side. The operating rod 1 between the handle 5 and the engine 2 is provided with a hanging metal fitting 11 and a grip 12 for mounting the mounting metal fitting 10a of the shoulder strap 10.

In the operating rod 1, the transmission shaft 13 is rotatably supported by 5 to 6 metal bearings 1 a. A rotary shaft 14 is vertically supported inside the cutting blade unit 3. A bevel gear 15 is attached to the rotary shaft 14, and the bevel gear 15 is provided at the tip of the transmission shaft 13. Bevel gear 16 meshes. The driving force from the transmission shaft 13 is transmitted to the rotary shaft 14 by the meshing of the bevel gears 15 and 16, and thereby the cutting shaft is fastened and fixed to the tip of the rotary shaft 14 by the nut 18 via the blade cap 17. The blade 3a is adapted to rotate.

In the conventional brush cutter having such a configuration, when the engine 2 is started, the throttle lever 8 is operated to pull the throttle wire 9, and the rotational speed of the engine 2 is increased to a predetermined value or more, the centrifugal clutch is generated. The transmission shaft 13 rotatably driven by the plurality of bearings 1a is rotated and the driving force is transmitted to the cutting blade unit 3 side via the transmission shaft 13. Then, the cutting blade 3a is rotated to perform the mowing work.

[0006]

[Problems to be solved by the device]

 By the way, an aluminum pipe is used to reduce the weight of the operating rod 1 of the conventional brush cutter, and the aluminum pipe is generally of a circular cross section manufactured by an extrusion or drawing method. It has a smooth peripheral surface. Therefore, when the transmission shaft 13 is supported by the plurality of bearings 1a inside the operating rod 1, it is necessary to prevent each bearing 1a from rotating, which complicates the configuration. In addition, not only skill is required to stably fix the plurality of bearings 1a within the operating rod 1 at predetermined intervals, but also the work is extremely complicated.

The present invention has been made in view of the above circumstances, and has a simple structure, which enables easy and reliable mounting of the bearing on the operating rod, and also prevents the bearing from rotating. It is an object of the present invention to provide a liner detent structure for a bearing of a brush cutter, which enables a detent to be reliably achieved without taking a separate step and also makes it possible to reduce the weight of the bearing itself.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a cutting blade unit provided at the tip of the operating rod by mounting an engine on the base end of the operating rod that houses the transmission shaft through a bearing to drive the transmission shaft. In a brush cutter in which power is transmitted to a knit through a transmission shaft to drive a cutting blade, a bearing portion supporting the transmission shaft and a bearing portion extending radially from the bearing portion are provided on the inner peripheral surface of the operating rod. A bearing liner consisting of a plurality of support legs in contact with the operating rod, and a pipe in which the operating rod is joined by welding, and a bearing liner supporting the transmission shaft while leaving the welding projections on the inner surface of the pipe inside the pipe. It is characterized in that it is inserted and the welding protrusion serves as a detent for the bearing liner.

[0009]

[Action]

 With the above structure, the bearing liner detent structure of the brush cutter of the present invention uses the operating rod as a welded pipe, and the welding projection on the inner surface of the pipe serves as a detent for the bearing liner. The shaft can be mounted easily and securely. Moreover, it is not necessary to separately provide a bearing rotation preventing means, and a reliable bearing rotation prevention is achieved. Furthermore, the weight of the bearing itself can be reduced and the production cost of the entire brush cutter can be reduced.

[0010]

【Example】

 Hereinafter, details of an embodiment of the present invention will be described with reference to FIGS. 1 and 2. The bearing liner detent structure of the present invention is applied to the above-described bush cutter, and a description of the configuration of the bush cutter will be omitted here.

In the present invention, the operating rod 1 shown in FIGS. 1 and 2 is a circular cross-section pipe (electric resistance welded pipe) joined by welding 19. A bearing liner 20 as a bearing, which will be described later, is fitted into the operating rod (pipe) 1. At that time, the transmission shaft is left with the welding projection 19a left on the inner surface of the operating rod (pipe) 1. The bearing liner 20 for supporting the bearing 13 is fitted and the welding projection 19a thereof is used as a detent for the bearing liner 20.

The bearing liner 20 is integrally formed of resin. The bearing liner 20 includes a bearing portion 21 that supports the transmission shaft 13, and five support legs 22 that extend integrally from the bearing portion 21 in the radial direction and contact the inner peripheral surface of the operating rod 1. It is a thing. An oil-containing film is formed on the inner surface of the bearing portion 21 to improve the lubricity of the transmission shaft 13. The clearance between the bearing portion 21 and the transmission shaft 13 when the transmission shaft 13 is inserted and supported inside the bearing portion 21 is 0.5 mm or more. By increasing the clearance to some extent in this way, the rolling friction due to the contact between the bearing portion 21 and the transmission shaft 13 is reduced, so that the friction heat is less generated and the durability of the resin bearing liner 20 due to the friction heat is reduced. The nature is enhanced. The number of support legs 22 is not limited to five, and may be three, four, six, or the like.

The bearing 21 and the support leg 22 have a length that is substantially the same as the length of the operating rod 1. Further, the support legs 22 are preferably provided at substantially equal intervals in the circumferential direction with respect to the outer circumference of the bearing portion 21, and each tip end thereof has a protrusion dimension with which the inner circumferential surface of the operating rod 1 abuts. There is. For this reason, when the bearing liner 20 is molded, the outer diameter of the support leg 22 is set to be the same as or slightly larger than the inner diameter of the operating rod 1.

When the bearing liner 20 having such a configuration is fitted into the operating rod 1 and assembled, the operation is performed as follows.

First, with the tip end of each support leg 22 of the bearing liner 20 aligned with the inner peripheral surface of the opening end of the operating rod 1 and straddling the welding projection 19a left on the inner surface of the operating rod 1. , Push it to a predetermined position in the operating rod 1. Next, by inserting the transmission shaft 13 into the bearing portion 21, connecting the engine 2 and the centrifugal clutch 2a to the base end side, and connecting the cutting blade unit 3 to the tip end side, the operating rod 1 can be assembled. finish. Of course, the bearing shaft 21 may be inserted through the bearing portion 21 and then the bearing liner 20 may be inserted into the operating rod 1.

Then, when the engine 2 is started and the throttle lever 8 is operated to pull the throttle wire 9 to raise the rotational speed of the engine 2 to a predetermined value or more, the centrifugal clutch 2a is brought into a connected state and the bearing liner. The transmission shaft 13 rotatably supported by 20 rotates in the direction of the arrow in FIG. 2, the driving force is transmitted to the cutting blade unit 3 side through this transmission shaft 13, and the cutting blade 3a rotates to mow the brush. Work is done. At this time, due to the rotation of the transmission shaft 13, a force acts to rotate the bearing liner 20 together, but one of the support legs 22 abuts on the welding projection 19a to prevent the bearing liner 20 from rotating together. .

[0017]

[Effect of device]

 As described above, according to the bearing liner detent structure for a bush cutter according to the present invention, the operating rod is a welded pipe, and the welding projection on the inner surface of the pipe serves as a detent for the bearing liner. The bearing liner and the transmission shaft can be easily, easily and surely attached to the bearing. In addition, it is not necessary to separately provide a bearing detent means, and a reliable bearing detent can be achieved. Furthermore, the weight of the bearing itself can be reduced and the production cost of the entire brush cutter can be reduced.

[Brief description of drawings]

1 is a perspective view of an operating rod and a bearing liner according to the present invention;

FIG. 2 is a sectional view of the same.

FIG. 3 is a perspective view of a brush cutter to which the operating rod and the bearing liner of the conventional example and the present invention are applied.

FIG. 4 is a partial side sectional view of a conventional example.

[Explanation of symbols]

 1 Operation Rod 2 Engine 3 Cutting Blade Unit 3a Cutting Blade 13 Transmission Shaft 19 Welding 19a Welding Protrusion 20 Bearing Liner 21 Bearing Part 22 Support Leg

Claims (1)

[Scope of utility model registration request] 1. A drive shaft is driven by mounting an engine on a base end portion of an operating rod having a transmission shaft mounted therein through a bearing, and a power is transmitted to a cutting blade unit provided at a tip end portion of the operating rod via the transmission shaft. In a brush cutter that is configured to transmit and drive a cutting blade, the bearing includes a bearing portion that supports a transmission shaft and a plurality of support legs that extend radially from the bearing portion and are in contact with the inner peripheral surface of the operating rod. And a pipe in which the operating rod is joined by welding,
A bearing liner for bearing a transmission shaft is inserted into the pipe while leaving a welding projection on the inner surface of the pipe, and the welding projection serves as a detent for the bearing liner. Construction.