Nylon cutter unit for brush cutters

Abstract

This invention provides a nylon cutter unit for brush cutters that can improve the durability of nylon cords. [Solution] The nylon cutter unit for the brush cutter comprises a first disc portion, a second disc portion, a cylindrical wall provided between the first disc portion and the second disc portion, a spool provided in the center of the cylindrical wall for winding and housing the nylon cord, and a holding member provided on a part of the cylindrical wall for holding the nylon cord pulled out from the spool. The holding member has a guide path for guiding the nylon cord from the spool to the outside of the cylindrical wall, an eyelet for causing the nylon cord to protrude to the outside of the cylindrical wall, a first curved surface portion connected to the cylindrical wall on the rotational side of the eyelet and having a first curvature greater than the breaking curvature of the nylon cord, and a second curved surface portion connected to the cylindrical wall on the opposite side of the rotational direction of the eyelet and having a second curvature greater than the first curvature.

Description

Technical Field

[0001] This specification discloses a technology related to a nylon cutter unit for a lawn mower.

Background Art

[0002] A lawn mower is a handheld machine for mowing weeds and small shrubs. A nylon cutter unit for a lawn mower is used by being attached to a rotating shaft provided at the tip of the lawn mower. From the side surface of the nylon cutter unit for a lawn mower, a nylon cord, which is a nylon-made cord, protrudes. When this nylon cord rotates at high speed, weeds and small shrubs are cut. Patent Document 1 describes a nylon cutter unit for a lawn mower that pulls out and protrudes a nylon cord wound around a spool to the outside through a through-hole from the inside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The nylon cutter unit for a lawn mower in Patent Document 1 has a problem that when the nylon cord contacts an obstacle, it bends at a sharp angle starting from the through-hole, and the nylon cord is likely to break early due to stress concentration.

Means for Solving the Problems

[0005] One embodiment of a nylon cutter unit for a brush cutter disclosed herein comprises: a first disc-shaped disc portion; a second disc-shaped disc portion arranged coaxially with the first disc portion and having the same size as the first disc portion; a cylindrical wall provided between the first disc portion and the second disc portion and having a smaller diameter than the first disc portion and the second disc portion; a spool provided in the center of the cylindrical wall for winding and housing a nylon cord; and a retaining member provided in a part of the cylindrical wall for holding the nylon cord pulled out from the spool. The holding member has a guide path extending in the opposite direction to the tangential direction of rotation of the nylon cutter unit for the brush cutter, guiding the nylon cord from the spool to the outside of the cylindrical wall; an eyelet that causes the nylon cord that has passed through the guide path to protrude to the outside of the cylindrical wall; a first curved surface portion connected to the cylindrical wall on the rotational side of the nylon cutter unit for the brush cutter from the eyelet, having a first curvature greater than the breaking curvature of the nylon cord; and a second curved surface portion connected to the cylindrical wall on the opposite side of the rotational direction from the eyelet, having a second curvature greater than the first curvature. With this form of nylon cutter unit for a brush cutter, the nylon cord protrudes from the eyelet sandwiched between the first and second curved surface portions, which have a curvature greater than the breaking curvature of the nylon cord, thereby dispersing stress when the nylon cord comes into contact with an obstacle, and thus improving the durability of the nylon cord. [Brief explanation of the drawing]

[0006] [Figure 1] This is a perspective view showing a nylon cutter unit for a brush cutter. [Figure 2] This is a cross-sectional view showing the internal structure of a nylon cutter unit for a brush cutter. [Modes for carrying out the invention]

[0007] Figure 1 is a perspective view showing a nylon cutter unit 100 for a brush cutter. Figure 2 is a cross-sectional view showing the internal structure of the nylon cutter unit 100 for a brush cutter. The nylon cutter unit 100 for a brush cutter is used by being attached to a rotating shaft 810 provided at the tip of a brush cutter 800. The nylon cutter unit 100 for a brush cutter comprises a shaft connecting portion 105, a first disc portion 110, a second disc portion 120, a cylindrical wall 130, a spool 140, a holding member 150, and a nylon cord 170.

[0008] The shaft connecting portion 105 of the brush cutter nylon cutter unit 100 is provided on the first disc portion 110. The shaft connecting portion 105 is configured to connect the brush cutter nylon cutter unit 100 to the rotating shaft 810 of the brush cutter 800. The shaft connecting portion 105 may be a bolt. The brush cutter nylon cutter unit 100 rotates in the rotational direction DR around the axis AX1 as the rotating shaft 810 rotates.

[0009] The first disc portion 110 of the nylon cutter unit 100 for the brush cutter is a disc-shaped component. An axial connecting portion 105 protrudes from the center of the first disc portion 110.

[0010] The second disc portion 120 of the brush cutter nylon cutter unit 100 is a disc-shaped member. The second disc portion 120 is the same size as the first disc portion 110. The second disc portion 120 is arranged coaxially (axis AX1) with the first disc portion 110.

[0011] The cylindrical wall 130 of the nylon cutter unit 100 for the brush cutter is a member provided between the first disc portion and the second disc portion. The cylindrical wall 130 has a cylindrical shape with a smaller diameter than the first disc portion 110 and the second disc portion 120. The center of the cylinder in the cylindrical wall 130 is located on the axis AX1.

[0012] The spool 140 of the nylon cutter unit 100 for the brush cutter is a component around which the nylon cord 170 is wound. The spool 140 is located in the center of the cylindrical wall 130. The center of the spool 140 is located on the axis AX1. The nylon cutter unit 100 for the brush cutter may have multiple spools 140 stacked vertically.

[0013] The retaining member 150 of the brush cutter nylon cutter unit 100 is a member that holds the nylon cord 170 drawn out from the spool 140. The retaining member 150 is provided on a part of the cylindrical wall 130. In this embodiment, the brush cutter nylon cutter unit 100 is provided with two retaining members 150 in positions that are point-symmetrical with respect to the axis AX1. The brush cutter nylon cutter unit 100 only needs to be provided with one or more retaining members 150.

[0014] The retaining member 150 has a guide path 152, an eyelet 154, a first curved portion 156, and a second curved portion 158.

[0015] The guide path 152 of the holding member 150 is a passage that extends in the opposite direction to the tangential direction of the rotation (rotation direction DR) of the nylon cutter unit 100 for the brush cutter. The guide path 152 guides the nylon cord 170 from the spool 140 to the outside of the cylindrical wall 130. The guide path 152 has a bend 152p along the way. This prevents the nylon cord 170 from loosening in the guide path 152.

[0016] The eyelets 154 of the retaining member 150 are openings that allow the nylon cord 170, which has passed through the guideway 152, to protrude to the outside of the cylindrical wall 130. The retaining member 150 may have multiple eyelets 154 of sizes corresponding to the thickness of the nylon cord 170.

[0017] The first curved portion 156 of the retaining member 150 is a wall surface that connects to the cylindrical wall 130 on the rotational direction DR side of the nylon cutter unit for the brush cutter, rather than to the eyelet 154. The first curved portion 156 has a first curvature R1 that is greater than the breaking curvature of the nylon cord 170.

[0018] The second curved surface portion 158 of the holding member 150 is a wall surface that connects to the cylindrical wall 130 on the side opposite to the rotational direction DR from the eyelet 154. The second curved surface portion 158 has a second curvature R2 that is larger than the first curvature R1.

[0019] According to the nylon cutter unit 100 for a lawn mower described above, by protruding the nylon cord 170 from the eyelet 154 sandwiched between the first curved surface portion 156 and the second curved surface portion 158 having a curvature larger than the breaking curvature of the nylon cord 170, when the nylon cord 170 comes into contact with an obstacle, the stress is dispersed, so that the durability of the nylon cord 170 can be improved.

[0020] The technology disclosed in this specification is not limited to the above-described embodiments, examples, and modifications, and can be realized in various configurations without departing from the spirit thereof. For example, among the technical features in the above-described embodiments, examples, and modifications, those corresponding to the technical features in each form described in the summary of the invention column can be appropriately replaced and combined in order to solve some or all of the above-described problems or to achieve some or all of the above-described effects. Further, the technical features not described as essential in this specification can be appropriately deleted.

Explanation of Signs

[0021] 100…Nylon cutter unit for a lawn mower 105…Shaft connecting portion 110…First disk portion 120…Second disk portion 130…Cylindrical wall 140…Spool 150…Holding member 152…Guide path 152p…Bending portion 154…Eyelet 156…First curved surface portion 158…Second curved surface portion 170…Nylon cord 800…Lawn mower 810... Rotation axis AX1…Axis line DR... Direction of rotation R1...First curvature R2... Second curvature

Claims

[Claim 1] A nylon cutter unit for a brush cutter, A first disc-shaped disc portion, A second disc portion is arranged coaxially with the first disc portion and has the same disc shape as the first disc portion, A cylindrical wall is provided between the first disc portion and the second disc portion, and has a diameter smaller than that of the first disc portion and the second disc portion, A spool is provided in the center of the cylindrical wall for winding and housing a nylon cord, A retaining member provided on a part of the cylindrical wall for holding the nylon cord pulled out from the spool, Equipped with, The aforementioned retaining member is A guide path extending in the opposite direction to the tangential direction of rotation of the nylon cutter unit for the brush cutter, which guides the nylon cord from the spool to the outside of the cylindrical wall, An eyelet that causes the nylon cord that has passed through the guideway to protrude to the outside of the cylindrical wall, A first curved surface portion is connected to the cylindrical wall on the rotational side of the nylon cutter unit for the brush cutter, beyond the eyelet, and has a first curvature greater than the breaking curvature of the nylon cord. A second curved surface portion is connected to the cylindrical wall on the opposite side of the rotational direction from the eyelet, and has a second curvature greater than the first curvature. A nylon cutter unit for a brush cutter, having the following features.

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