Chisel

Abstract

To provide a chisel capable of transmitting impact force without waste. [Solution] The chisel (1) comprises a long chisel body (20), which comprises a detachment prevention flange (30) that prevents the chisel body (20) from detaching from the tool body (10), a first single diameter section (40) that is formed contiguous with the detachment prevention flange (30) toward the tip and has a smaller diameter than the detachment prevention flange (30) and a constant diameter over a predetermined length, a first reduced diameter section (50) that is formed contiguous with the tip side of the first single diameter section (40) and whose diameter decreases toward the tip over a predetermined length, a second single diameter section (60) that is formed contiguous with the tip side of the first reduced diameter section (50) and has a constant diameter over a predetermined length, and a positioning tip section (70) that is formed contiguous with the tip side of the second single diameter section (60) and whose tip end abuts the workpiece, and has the advantages of easily transmitting impact force to the workpiece (W) by the so-called horn principle and producing low vibration.

Description

[Technical Field]

[0001] The present invention relates to a chisel that is attached to a tool body of an impact tool and transmits an impact force generated from the tool body to a workpiece. [Background technology]

[0002] Conventionally used chisels (tip tools) are generally integrally molded along the front-to-rear direction and have a substantially uniform diameter from the rear end to the front end in order to transmit the impact received from the impact tool body directly to the workpiece (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-142914 Summary of the Invention [Problem to be solved by the invention]

[0004] In the chisels described above, the impact transmitted from the tool body dissipates as sound waves to the outside, leading to increased noise and loss of labor.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a chisel that can transmit impact force efficiently. [Means for solving the problem]

[0006] The present invention provides a chisel that is attached to a tool body and used to apply an impact to a workpiece, the chisel comprising a long chisel body, the chisel body comprising: an anti-detachment flange that engages with a predetermined portion of the tool body to prevent the chisel body from detaching from the tool body; a first single diameter portion that is formed continuous with the anti-detachment flange toward the tip, has a smaller diameter than the anti-detachment flange, and extends along the axial direction of the chisel body for a predetermined length with a single diameter; a first reduced diameter portion that is formed continuous with the tip of the first single diameter portion and extends along the axial direction of the chisel body for a predetermined length with a shape that becomes smaller in diameter toward the tip; a second single diameter portion that is formed continuous with the tip of the first reduced diameter portion and extends along the axial direction of the chisel body for a predetermined length with a single diameter; and a positioning tip portion that is formed continuous with the tip of the second single diameter portion, the most distal end of which abuts against the workpiece.

[0007] In this configuration, by providing the first single-diameter portion adjacent to the detachment prevention flange, the rigidity of the area around the first single-diameter portion relative to the flange is improved, thereby preventing the chisel body from breaking as a whole. Furthermore, by providing the first reduced-diameter portion adjacent to the first single-diameter portion, which has relatively high rigidity, ultrasonic vibrations can be more easily generated and amplified in the first reduced-diameter portion. The first reduced-diameter portion generates lateral vibrations that intersect with the axial direction of the chisel body in addition to the impact force propagating in the axial direction of the chisel body. For example, during excavation work using the chisel, the chisel can laterally expand a hole in the excavation target (e.g., soil or concrete) around the chisel, thereby expanding the hole diameter and gradually reducing frictional resistance between the chisel and the excavation target during the work process. The second single-diameter portion can also be expected to help the chisel body penetrate into the workpiece. Furthermore, the positioning tip can determine the position for excavation. Furthermore, the shapes of the first single diameter portion, the first reduced diameter portion, and the second single diameter portion are expected to have a shock wave concentrating effect using the principle of a so-called horn (ultrasonic welding horn), and it is thought that the impact force can be improved. [Effects of the Invention]

[0008] The chisel of the present invention has an excellent effect of transmitting impact force without waste. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is an explanatory diagram of a chisel according to an embodiment. [Figure 2] 1 is an explanatory diagram showing the process of excavation work using a chisel. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below with reference to the following examples. The present invention is not limited to the following examples, and design changes are possible as appropriate. For convenience, the examples are described with a defined order, but the present invention is not limited to these examples.

[0011] As shown in Figure 1, a chisel 1 is attached to the tip of a tool body 10 of an impact tool when in use. The tool body 10 is driven by compressed air, for example, and an impact force is generated when a hammer 11 arranged inside repeatedly hits the chisel 1.

[0012] The chisel 1 includes a long chisel body 20. The chisel body 20 includes a detachment prevention flange 30 that prevents the chisel body 20 from being detached from the tool body 10.

[0013] The chisel body 20 also has a first single diameter portion 40 formed continuously with the tip end of the anti-detachment flange portion 30, which has a smaller diameter than the anti-detachment flange portion 30 and a single diameter over a predetermined length.

[0014] The chisel body 20 also includes a first reduced diameter portion 50 formed continuously with the tip end of the first single diameter portion 40, the diameter of which decreases over a predetermined length as it approaches the tip end.

[0015] The chisel body 20 also includes a second single diameter portion 60 formed continuously with the tip end of the first reduced diameter portion 50 and having a single diameter over a predetermined length.

[0016] Furthermore, the chisel body 20 is provided with a positioning tip portion 70 formed continuously with the tip side of the second single diameter portion 60, the most distal portion of which comes into contact with the workpiece.

[0017] The chisel 1 is subjected to an impact force when the hammer 11 strikes its rear end. This impact force is generated by surface or point contact between the rear end of the chisel body 10 and the hammer 11. The impact force is concentrated at the tip of the positioning tip 70 due to the horn shape formed by the first single diameter portion 40, the first reduced diameter portion 50, the second single diameter portion 60, and the positioning tip 70, and is transmitted to the workpiece W. This increases the crushing force. Furthermore, since most of the impact force is converted into crushing force, vibration is reduced. The reduced vibration leads to reduced labor and a reduction in vibration disease.

[0018] For example, as shown in Fig. 2, during excavation work using the chisel 1, the excavation target (such as soil or concrete) around the chisel 1 can be pushed apart, thereby expanding the diameter of the excavated hole, and the frictional resistance between the chisel 1 and the excavated target can be gradually reduced during the work process. The second single-diameter portion 60 can be expected to have the effect of causing the chisel body 20 to penetrate into the workpiece. The positioning tip 70 can also be used to determine the position for excavation. Furthermore, the shapes of the first single-diameter portion 40, the first reduced-diameter portion 50, and the second single-diameter portion 60 can be expected to have the effect of concentrating shock waves using the principle of a so-called horn (ultrasonic welding horn), thereby potentially improving impact force.

[0019] Furthermore, since the workpiece W is crushed in a concentrated manner in a localized area, the occurrence of cracks and microcracks is suppressed.

[0020] Furthermore, since the mass is smaller than that of a conventional single-diameter device, the mass ratio with the hammer 11 is advantageous, making it easier to generate a larger impact force.

[0021] In the above embodiment, the dimensions and shapes of each part can be freely selected as appropriate.

[0022] In addition to the first reduced diameter portion, for example, second and third reduced diameter portions may be formed. [Explanation of symbols]

[0023] 1 chisel 10 Tool body 11 Hammer 20 Chisel body 30 Flange for preventing detachment 40 First single diameter section 50 1st reduced diameter section 60 Second single diameter section 70 Positioning tip double work

Claims

1. A chisel that is attached to the tool body and used to apply impact to a workpiece, Equipped with a long chisel body, The chisel body portion is, A flange portion for preventing detachment from the tool body by engaging with a predetermined part of the tool body, A first single-diameter portion is formed continuously with respect to the tip side of the aforementioned anti-detachment flange portion, and is smaller in diameter than the anti-detachment flange portion and extends along the axial direction of the chisel body portion with a single diameter over a predetermined length, A first reduced-diameter portion is formed continuously with respect to the tip of the first single-diameter portion and extends over a predetermined length along the axial direction of the chisel body portion in a shape that becomes smaller in diameter towards the tip, A second single-diameter portion is formed continuously with respect to the tip side of the first reduced-diameter portion and extends along the axial direction of the chisel body portion with a single diameter over a predetermined length, A positioning tip portion is formed continuously with the tip side of the second single-diameter portion, and the tip end of which contacts the workpiece, Equipped with A chisel characterized by the following features.

2. A chisel that is attached to a tool body and used to apply impact to a workpiece, Equipped with a long chisel body, The chisel body portion is, A first single-diameter portion extending along the axial direction of the chisel body over a predetermined length with a single diameter, A first reduced-diameter portion is formed continuously with respect to the tip of the first single-diameter portion and extends over a predetermined length along the axial direction of the chisel body portion in a shape that becomes smaller in diameter towards the tip, A second single-diameter portion is formed continuously with respect to the tip side of the first reduced-diameter portion and extends along the axial direction of the chisel body portion with a single diameter over a predetermined length, A positioning tip portion is formed continuously with the tip side of the second single-diameter portion, and the tip end of which contacts the workpiece, Equipped with A chisel characterized by the following features.

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