Air type impact tool

Abstract

To provide an air type impact tool which achieves further tip tool popping prevention effect, vibration absorption effect, and silencing effect.SOLUTION: An air type impact tool 1 includes a cap member 40 formed by a tapered coil spring shape. In the cap member 40, a tip tool recovery coil spring 50 which is placed in contact with an inner peripheral surface of a tapered portion of the cap member 40 and a vibration absorption coil spring 70 are disposed. The tip tool recovery coil spring 50 is disposed in a hollow part of the vibration absorption coil spring 70.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pneumatic impact tool that applies an impact to a workpiece by the action of a mechanism in which a tip tool reciprocates. [Background technology]

[0002] Conventionally, as an impact tool that applies an impact to a workpiece to excavate or cut the workpiece, there has been known one that has a cylinder inside the tool body and a tip tool that reciprocates within the cylinder (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 59-176683 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned impact tool, the tip tool violently reciprocates inside the cylinder, so that strong vibrations are transmitted to the hands of the worker, making it difficult to work for long periods of time. In addition, the violent collision between the parts can cause loud noise, so there is room for improvement in these problems.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an impact tool which has even greater vibration absorbing and noise reducing effects. [Means for solving the problem]

[0006] The present invention relates to a pneumatic impact tool comprising: a tool body into which compressed air is introduced; a long tip tool having a tip portion that is protruded forward with respect to the tool body in a state in which the long tip tool is attached to the tool body so as to be slidable in the front-rear direction; and a cap member attached to the front end of the tool body and composed of a tapered coil spring that covers a root end of the protruded portion of the tip tool, the tip tool being inserted into the cap member so that a tip portion of the tip tool is protruded forward from the cap member, and the tip tool is reciprocated using compressed air introduced into the tool body to apply an impact to a workpiece from the tip portion of the tip tool, a tip side spring receiving surface portion and a root end side spring receiving surface portion arranged on the root end side of the tip side spring receiving surface portion are configured by an inner circumferential surface of the tapered portion of the cap member, a tip tool return coil spring which is expandable and contractible within an elastically deformable range and urges the tip tool in a direction to retract the tip tool is arranged between the front end of the flange portion and the tip side spring receiving surface portion, a vibration absorbing coil spring which is elastically compressed within an elastically deformable range is arranged between the front end of the tool body and the root end side spring receiving surface portion, and the tip tool return coil spring is arranged in an inner hollow portion of the vibration absorbing coil spring.

[0007] In this configuration, the cap member has a function of preventing the tip tool from jumping out from the tip side of the cap member. Furthermore, the cap member covers the root end of the portion where the tip tool is inserted, thereby reducing sound leakage and improving the silencing effect. In addition, since the cap member itself is configured to support a vibration absorbing coil spring in a tapered coil spring shape, the vibration propagating from the tool body to the cap member is also propagated to the vibration absorbing coil spring, and the vibration and noise transmitted to the operator can be dramatically reduced by converting them into thermal energy. In addition, the tip tool return coil spring is disposed in the inner hollow portion of the vibration absorbing coil spring, making it possible to make the entire device compact. Note that the tip tool return coil spring plays a role of pressing the tip tool against the tool body, for example, in a state where compressed air is not introduced, so that the tip tool can immediately start reciprocating by introducing compressed air in this state. If the tip tool is not pressed against the tool body in a state where compressed air is not introduced, compressed air leaks from the tip tool mounting portion, causing so-called empty striking, and the tip tool cannot immediately start reciprocating.

[0008] In addition, a configuration is proposed in which a circular washer member, through which the tip tool is slidably inserted, is disposed on the inner peripheral side of the tapered portion of the cap member, and the tip side spring receiving surface portion is formed by an end face on the root end side of the washer member.

[0009] With this configuration, the front end of the tip tool return coil spring, which comes into contact with the inner circumferential surface of the tapered portion of the cap member, can be received by the washer member, and it is possible to prevent the coil spring wire constituting the front end of the tip tool return coil spring and the coil spring wire constituting the inner circumferential surface of the cap member from becoming caught between each other. Effect of the Invention

[0010] The impact tool of the present invention has an effect of preventing the tip tool from jumping out, and also has an effect of reducing vibration transmitted to the hand of the operator and an effect of silencing noise. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a side sectional view of the pneumatic impact tool in which the tip tool according to Example 1 is in an initial state. [Diagram 2] FIG. 2 is a partially enlarged cross-sectional side view of FIG. [Diagram 3] FIG. 2 is a partially enlarged cross-sectional side view of the pneumatic impact tool according to the first embodiment, in which the tip tool is in an advanced state. [Figure 4] FIG. 11 is a side sectional view of the pneumatic impact tool according to the second embodiment, in which the tip tool is in an initial state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The embodiment of the present invention will be described according to the examples. Note that the present invention is not limited to the examples shown below, and design changes are possible as appropriate. For convenience, the examples are described by specifying the beginning and end, but the present invention is not limited thereto.

[0013] Example 1 As shown in Figs. 1 to 3, the pneumatic impact tool 1 is driven by compressed air, for example, and includes a tool body 10. A cylinder section 20 that is long in the front-rear direction is provided inside the tool body 10. A long tip tool 30 that reciprocates slidably in the front-rear direction inside the cylinder section 20 by the action of the introduced compressed air is attached to the cylinder section 20. Specifically, the tip tool 30 is composed of a portion in which a large-diameter flange section 31 is formed and a portion that is located on the front end side of the flange section 31 and has a smaller diameter than the flange section 31. The small-diameter portion projects forward from the front end of the tool body 10, and the tip contacts the workpiece W.

[0014] In addition, a cap member 40 is fitted onto the outer peripheral surface of the front end of the tool body 10. The cap member 40 is composed of a tapered coil spring, and the front end of the tip tool 30 is protruded forward from the front end by inserting the tip tool 30 into the cap member 40. In other words, the root end of the portion of the tip tool 30 that is protruded forward is covered by the cap member 40.

[0015] An annular washer member 45, through which the tip tool 30 is slidably inserted, is disposed inside the tapered portion of the cap member 40. The end face on the base end side of this washer member 45 constitutes a tip side spring receiving surface portion 46. The end face on the tip side of the washer member 45 abuts against the inner peripheral surface of the tapered portion of the cap member 40.

[0016] Further, a root end side spring receiving surface portion 48 is formed by the inner circumferential surface of the tapered portion of the cap member 40 on the root end side relative to the washer member 45 .

[0017] Inside the cap member 40, a tip tool return coil spring 50 is disposed on the front end side of the flange portion 31 of the tip tool 30. Specifically, the tip tool return coil spring 50 has the tip tool 30 inserted into its inner hollow portion, and is arranged with the front-rear direction as the expansion / contraction direction, elastically compressed within a range that allows elastic deformation, between a front wall portion 31a formed by the front wall portion of the flange portion 31 and a tip side spring receiving surface portion 46 of the washer member 45. In the initial state A where the tip tool 30 is rearwardly retracted as shown in FIG. 1, the front end portion of the tip tool return coil spring 50 abuts against the tip side spring receiving surface portion 46, and the rear end portion of the tip tool return coil spring 50 abuts against the front wall portion 31a of the tip tool 30.

[0018] Furthermore, inside the cap member 40, a vibration absorbing coil spring 70 that is elastically compressed within an elastically deformable range is disposed between the front wall portion 11a of the front end of the tool body 10 and the root end side spring receiving surface portion 48 of the cap member 40. Specifically, the vibration absorbing coil spring 70 has the tip tool 30 and the tip tool return coil spring 50 inserted into its inner hollow portion, and the front-rear direction is the direction of expansion and contraction, with the front end of the vibration absorbing coil spring 70 abutting against the root end side spring receiving surface portion 48 of the cap member 40, and the rear end of the vibration absorbing coil spring 70 abutting against the front wall portion 11a of the tool body 10.

[0019] In the pneumatic impact tool 1, compressed air is sent to the space behind the tip tool 30 in the cylinder portion 20, so that the tip tool 30 starts to move forward.

[0020] 3, when the tip tool 30 reaches its most advanced state, compressed air is discharged from the cylinder portion 20 to the outside, and the tip tool 30 retreats due to the biasing force of the tip tool return coil spring 50, returning to the state shown in FIGS. 1 and 2. Then, compressed air is again sent to the space behind the tip tool 30 in the cylinder portion 20, and the tip tool 30 begins to advance. This is repeated to apply an impact to the workpiece W from the tip of the tip tool 30.

[0021] Here, while the tip tool 30 moves back and forth, the vibration absorbing coil spring 70 absorbs the vibration propagating from the tool body 10 to the cap member 40 to suppress the generation of noise. In addition, the vibration absorbing coil spring 70 absorbs the vibration of the entire impact tool, thereby reducing the burden on the operator. The vibration absorbing coil spring 70 does not move with the movement of the tip tool 30, and remains in a state of elastic contraction within a range that allows elastic deformation between the front wall portion 11a of the front end of the tool body 10 and the root end side spring receiving surface portion 48 of the cap member 40. The tip tool return coil spring 50 is disposed in the inner hollow portion of the vibration absorbing coil spring 70, thereby making the pneumatic impact tool 1 compact.

[0022] Example 2 The pneumatic impact tool according to the second embodiment will be described in detail below, but the description of the same configuration as that of the first embodiment will be omitted or simplified.

[0023] 4, the pneumatic impact tool 2 does not include the washer member 45 as compared with the pneumatic impact tool 1. As a result, the front end of the tip tool return coil spring 50 abuts against the tip side spring receiving surface portion 81 formed by the inner circumferential surface of the tapered portion of the cap member 40.

[0024] In the pneumatic impact tool 2, like the pneumatic impact tool 1 of the first embodiment, while the tip tool 30 moves back and forth, the vibration absorbing coil spring 70 absorbs the vibration propagating from the tool body 10 to the cap member 40, thereby suppressing the generation of noise. In addition, the vibration absorbing coil spring 70 absorbs the vibration of the entire impact tool, thereby reducing the burden on the operator.

[0025] In the above embodiment, the dimensions and shapes of each part can be freely selected as appropriate. A plurality of tip tool return coil springs 50 and a plurality of vibration absorbing coil springs 70 may be provided. The pneumatic impact tool of the present invention can also be applied to an air hammer tool used underwater, for example. [Explanation of symbols]

[0026] 1 Air impact tool 10 Tool body 11a Front wall of tool body 20 Cylinder section 30 Tip Tool 31 Flange 31a Front wall of flange 40 Cap member 45 Washer material 46,81 Tip side spring receiving surface 48 Root end side spring receiving surface 50 Tip tool return coil spring 70 Vibration absorbing coil spring

Claims

1. a tool body into which compressed air is introduced; a long tip tool having a tip portion that is extended forward with respect to the tool body in a state where the tip tool is slidably attached to the tool body in a front-rear direction; a cap member attached to a front end of the tool body and configured with a tapered coil spring covering a root end of the extended portion of the tip tool, a pneumatic impact tool in which the tip tool is inserted into the cap member and a tip portion of the tip tool protrudes forward from the cap member, and the tip tool is reciprocated by using compressed air introduced into the tool body to apply an impact to a workpiece from the tip portion of the tip tool, a flange portion is provided at a portion of the tip tool located within the cap member, a tip-side spring receiving surface portion and a root-side spring receiving surface portion disposed on the root-side side of the tip-side spring receiving surface portion are formed by an inner peripheral surface of the tapered portion of the cap member, a tip tool return coil spring which is expandable and contractible within an elastically deformable range and which urges the tip tool in a direction to retract the tip tool is disposed between the front part of the flange portion and the tip side spring receiving surface portion, a vibration absorbing coil spring, which is elastically compressed within an elastically deformable range, is disposed between the front end of the tool body and the root end side spring receiving surface portion; The tip tool return coil spring is disposed in the inner hollow portion of the vibration absorbing coil spring. A pneumatic impact tool characterized by:

2. an annular washer member through which the tip tool is slidably inserted is disposed on the inner peripheral side of the tapered portion of the cap member, The tip-side spring receiving surface portion is configured by an end surface on the root end side of the washer member.

2. The pneumatic impact tool according to claim 1.

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