Pneumatic impact tool with improved damping structure

Abstract

The present invention relates to a pneumatic impact tool with an improved damping structure. The tool has a handle with a recessed chamber, in which a cylinder and a flow reversing valve are arranged. The cylinder is connected to an inner tube, which has a ring wall with at least one exhaust hole and a chamber. Inside the ring wall, a flow passage is arranged, which connects the flow reversing valve and the chamber. The flow passage forms a first inlet and a second inlet in the chamber. The flow reversing valve can switch the flow to enter the chamber through either inlet. A hammer is arranged in the chamber and tightly contacts the ring wall. A cylindrical gap is formed between the middle part of the hammer and the ring wall. The hammer has an exhaust passage, which connects the chamber and the cylindrical gap. When high-pressure gas is injected into the chamber through the first inlet, the hammer is pushed backward. The high-pressure gas is sequentially discharged through the exhaust passage, the cylindrical gap and the exhaust hole, thereby reducing the force with which the hammer is pushed.

Description

Technical Field

[0001] This invention relates to hand tools, and more particularly to a pneumatic impact tool with an improved vibration damping structure. Background Technology

[0002] Pneumatic impact tools vibrate during use due to the reciprocating movement of the hammer. Prolonged use can have adverse effects on the user's hand, especially for pneumatic impact tools with stronger striking force, which can cause greater vibration and injury to the user. Therefore, improvements are necessary.

[0003] Taiwan Invention Patent Publications I235700 and I729809 disclose a pneumatic tool with an air chamber at the rear of its barrel. This air chamber is compressed by the hammer as it moves backward, creating a cushioning effect and reducing vibrations caused by the hammer on the barrel. Figure 4 of I729809 discloses another pneumatic tool with a spring or rubber block at the rear of its barrel. When the hammer moves backward, it pushes the spring or rubber block, causing deformation that creates a cushioning effect and reduces vibrations caused by the hammer on the barrel.

[0004] Both of the above-mentioned existing structures involve adding other components (changing the spatial configuration to form an air chamber, adding springs or rubber blocks, etc.) to the existing structure of pneumatic tools. After the pneumatic tool generates large vibrations, the vibration is reduced by buffering. In addition to the disadvantage of increased cost, the most important thing is that the vibration reduction effect is not ideal, and users will still feel hand discomfort during operation.

[0005] The aforementioned patent No. I235700 Figure 5 The revealed structure includes an air inlet pipe connected to the front of the barrel, which allows the hammer, already moved to the front of the barrel, to be moved backward by high-pressure gas. An exhaust port is located approximately in the middle of the barrel for depressurization. However, during the hammer's forward impact with the tool head and subsequent rebound, the high-pressure gas in the barrel can only escape after the hammer passes through the exhaust port in the middle. Before the gas escapes, the high-pressure gas has already driven the hammer backward to the rear of the barrel, resulting in a significant impact on the rear of the barrel. This is the root cause of the vibration in the pneumatic tool. Summary of the Invention

[0006] The main objective of this invention is to provide a pneumatic impact tool with an improved vibration-damping structure. By incorporating vent holes in the tubing, the impact force of the hammer's backward movement is directly reduced through air release, thereby decreasing vibration. This invention achieves vibration reduction without adding additional components.

[0007] To achieve the aforementioned objectives, the present invention provides a pneumatic impact tool with an improved vibration reduction structure, comprising:

[0008] A handle with a recess inside, the handle having an air intake channel connected to the recess, wherein an airflow switch is provided in the air intake channel;

[0009] A cylindrical component is housed in the recessed chamber. An airflow reversing valve is provided in the cylindrical component. A through hole communicating with the air inlet channel is provided on one side wall of the cylindrical component, so that high-pressure gas is introduced into the airflow reversing valve.

[0010] An inner tube includes an annular wall fixed to the tube and a chamber surrounded by the annular wall. The front end of the annular wall is provided with a tool head. The annular wall is provided with at least one exhaust hole that connects the chamber to the outside. The interior of the annular wall is provided with an airflow passage that connects the airflow reversing valve and the chamber. The airflow passage forms a first air inlet at the front end of the chamber. The rear end of the chamber is provided with a second air inlet that connects to the airflow reversing valve. The airflow reversing valve can switch the airflow to enter the chamber from either the first air inlet or the second air inlet.

[0011] A hammer body disposed within the chamber has a head and a body, wherein the head is closer to the first air inlet than the body. The body includes a front section, a middle section, and a rear section, wherein the front section and the rear section are closely connected to the annular wall, and a cylindrical gap exists between the middle section and the annular wall. The head is provided with an exhaust channel connecting the chamber and the cylindrical gap. When the airflow reversing valve injects high-pressure gas into the chamber from the second air inlet, the hammer body is pushed by the high-pressure gas and moves toward the tool head. When the airflow reversing valve injects high-pressure gas into the chamber from the first air inlet, the hammer body is pushed away from the tool head by the high-pressure gas. During this process, when the cylindrical gap connects to the exhaust hole, the high-pressure gas in the chamber is released sequentially through the exhaust channel, the cylindrical gap, and the exhaust hole, thereby reducing the force of the hammer body being pushed.

[0012] When the hammer body is in contact with the tool head, the cylindrical gap is connected to the vent hole.

[0013] The ring wall has three vent holes, each at a different distance from the tool head.

[0014] When the hammer body is in contact with the tool head, the cylindrical gap is connected to the two vent holes closest to the tool head.

[0015] The exhaust passage includes an axial section and a radial section connected in a T-shape.

[0016] The axial section is located in the center of the hammer head.

[0017] The beneficial effects of the present invention are as follows: The present invention directly weakens the impact force of the hammer body 4 backward by venting air at the source of vibration of the pneumatic tool (i.e., the impact force of the hammer body 4 backward), thus achieving the purpose of fundamental solution. This can produce a better vibration reduction effect than the existing structure, while not affecting the force of the high-pressure gas driving the hammer body forward to impact the tool head. Therefore, it can produce a vibration reduction effect while taking into account the output power of the pneumatic tool. Attached Figure Description

[0018] Figure 1 This is a three-dimensional exploded view of the present invention;

[0019] Figure 2 This is a cross-sectional schematic diagram of the entire invention;

[0020] Figure 3 This is a cross-sectional schematic diagram of the hammer body of the present invention;

[0021] Figures 4 to 6 This is a schematic diagram of the operating state of the present invention. Detailed Implementation

[0022] Please see section [number] Figure 1 , Figure 2 The image shows a pneumatic impact tool with an improved vibration reduction structure provided by the present invention, comprising a handle 1, a cylindrical part 2, an inner tube 3, and a hammer body 4. The handle 1 can be pistol-shaped or cylindrical; in this embodiment, the handle 1 is pistol-shaped. A recess 11 is provided at the top of the handle 1. An air intake channel 12 extending upwards and communicating with the recess 11 is provided at the bottom of the handle 1 for connecting to an external high-pressure gas supply source. An air intake switch 13 for controlling airflow is provided in the air intake channel 12, and a button 14 is connected to the air intake switch 13 on one side of the handle 1 for operation.

[0023] In this embodiment, the cylindrical component 2 is housed in the recess 11, and a spring 15 is provided at the bottom end of the recess 11 to buffer the cylindrical component 2. The side wall of the cylindrical component 2 is provided with a through hole 21 communicating with the air intake channel 12, and an existing airflow reversing valve 22 is provided in the cylindrical component 2. After the high-pressure gas is introduced into the air intake channel 12, it will enter the airflow reversing valve 22 through the through hole 21. The airflow reversing valve 22 is used to output the high-pressure gas through two different paths.

[0024] The inner tube 3 is a circular tube structure with an annular wall 31 and a chamber 32 surrounded by the annular wall 31. The annular wall 31 extends into the cylindrical component 2 and is threadedly fastened to the cylindrical component 2. The inner tube 3 extends beyond the cylindrical component 2, and its front end is provided with a tool head 5, which can be replaced according to actual usage requirements. An airflow channel 33, which connects to the airflow reversing valve 22, is provided in the annular wall 31, separate from the interior of the chamber 32. A first air inlet 34 is formed at the front end of the chamber 32; and a second air inlet 35, which connects to the airflow reversing valve 22, is provided at the rear end of the chamber 32. Accordingly, the airflow reversing valve 22 can selectively output high-pressure gas to the airflow channel 33 at appropriate times, and then inject it into the chamber 32 through the first air inlet 34; or inject high-pressure gas into the chamber 32 through the second air inlet 35.

[0025] Furthermore, the annular wall 31 is provided with at least one exhaust port 36 connecting the chamber 32 to the outside; in this embodiment, there are three exhaust ports 36, which are arranged in a straight line along the axial direction of the inner tube 3, and the distance between each exhaust port 36 and the tool head 5 is different. Further, the three exhaust ports 36 are located between the first air inlet 34 and the second air inlet 35.

[0026] like Figure 2 , Figure 3 As shown, the hammer body 4 is disposed in the chamber 32 and includes an integrally connected head 41 and a body 42, wherein the head 41 is closer to the first air inlet 34 than the body 42. In this embodiment, the head 41 is conical and has a planar end face 411. The body 42 is cylindrical and includes a front section 421, a middle section 422, and a rear section 423, wherein the outer diameters of the front section 421 and the rear section 423 are equal to the inner diameter of the chamber 32, and thus are in close contact with the annular wall 31; while the outer diameter of the middle section 422 is slightly smaller than the outer diameters of the front section 421 and the rear section 423, and similarly slightly smaller than the inner diameter of the chamber 32, thus forming a cylindrical gap 43 between the middle section 422 and the annular wall 31.

[0027] The hammer body 4 has an exhaust channel 44 inside, which connects the chamber 32 and the cylindrical gap 43. In this embodiment, the exhaust channel 44 includes an axial section 441 formed by drilling along the central position of the end face 411 of the head 41, and a radial section 442 formed by drilling along the radial direction from the middle section 422. The two sections meet to form a T-shaped connection.

[0028] In this embodiment, the relative positional relationship between the cylindrical gap 43 and the exhaust port 36 is shown in Figure 4. Specifically, when the hammer 4 moves to the foremost position of the chamber 32 and contacts the tool head 5, the extension range of the cylindrical gap 43 extends to the two exhaust ports 36 closest to the tool head 5, and the connection port between the radial section 442 of the exhaust channel 44 and the cylindrical gap 43 is located near the front section 421.

[0029] With the above structure, when button 14 is pressed to control the airflow switch 13, causing high-pressure gas to be introduced into the airflow reversing valve 22 through the air intake channel 12, the airflow reversing valve 22 first injects high-pressure gas into the chamber 32 through the second air intake 35. At this time, the high-pressure gas pushes the hammer 4 forward at high speed and strikes the tool head 5 to produce a working effect. Then, the airflow reversing valve 22 switches the air supply path, stopping the injection of high-pressure gas into the chamber 32 through the second air intake 35, and instead introducing high-pressure gas into the airflow channel 33, and then injecting it into the chamber 32 through the first air intake 34. The technology of the airflow reversing valve 22 switching the air supply path is a common existing technology and will not be described in detail here.

[0030] At this point, the high-pressure gas begins to push the hammer 4 backward. For example... Figure 5 , Figure 6 As shown, when the hammer 4 begins to leave the tool head 5, the high-pressure gas in the chamber 32 can begin to leak to the outside through the axial section 441 and radial section 442 of the exhaust channel 44, along with the cylindrical gap 43 and the exhaust hole 36, thereby reducing the pressure in the chamber 32 and weakening the force that pushes the hammer 4. Accordingly, when the hammer 4 moves to the rear end of the chamber 32, the amplitude of the vibration will be reduced.

[0031] Furthermore, during the vibration reduction process, when the hammer 4 is located at the front end of the chamber 32 as shown in Figure 4, air can be released through the cylindrical gap 43 connected to the exhaust port 36. Compared to existing structures, the air release timing of this invention is earlier, thus significantly reducing the force pushing the hammer 4. Moreover, during the retraction of the hammer 4, as shown in Figure 5, air can be continuously released through the cylindrical gap 43 connected to different exhaust ports 36, thereby continuously weakening the force pushing the hammer 4 backward, and thus significantly reducing vibration.

[0032] The unique feature of this invention is that it directly weakens the impact force of the hammer 4 retracting at the source of vibration in the pneumatic tool (i.e., the impact force of the hammer 4 retracting), thereby achieving a fundamental solution. This results in a better vibration reduction effect than existing structures, while not affecting the force of the high-pressure gas driving the hammer to advance and impact the tool head. Therefore, it can produce a vibration reduction effect while taking into account the output power of the pneumatic tool.

Claims

1. A pneumatic impact tool with an improved vibration reduction structure, characterized in that, It includes: A handle with a recess inside, the handle having an air intake channel connected to the recess, wherein an airflow switch is provided in the air intake channel; A cylindrical component is housed in the recessed chamber. An airflow reversing valve is provided in the cylindrical component. A through hole communicating with the air inlet channel is provided on one side wall of the cylindrical component, so that high-pressure gas is introduced into the airflow reversing valve. An inner tube includes an annular wall fixed to the tube and a chamber surrounded by the annular wall. The front end of the annular wall is provided with a tool head. The annular wall is provided with at least one exhaust hole that connects the chamber to the outside. The interior of the annular wall is provided with an airflow passage that connects the airflow reversing valve and the chamber. The airflow passage forms a first air inlet at the front end of the chamber. The rear end of the chamber is provided with a second air inlet that connects to the airflow reversing valve. The airflow reversing valve can switch the airflow to enter the chamber from either the first air inlet or the second air inlet. A hammer body disposed within the chamber has a head and a body, wherein the head is closer to the first air inlet than the body. The body includes a front section, a middle section, and a rear section, wherein the front section and the rear section are closely connected to the annular wall, and a cylindrical gap exists between the middle section and the annular wall. The head is provided with an exhaust channel connecting the chamber and the cylindrical gap. When the airflow reversing valve injects high-pressure gas into the chamber from the second air inlet, the hammer body is pushed by the high-pressure gas and moves toward the tool head. When the airflow reversing valve injects high-pressure gas into the chamber from the first air inlet, the hammer body is pushed away from the tool head by the high-pressure gas. During this process, when the cylindrical gap connects to the exhaust hole, the high-pressure gas in the chamber is released sequentially through the exhaust channel, the cylindrical gap, and the exhaust hole, thereby reducing the force of the hammer body being pushed.

2. The pneumatic impact tool with an improved vibration reduction structure as described in claim 1, characterized in that: When the hammer body is in contact with the tool head, the cylindrical gap is connected to the vent hole.

3. The pneumatic impact tool with an improved vibration reduction structure as described in claim 1, characterized in that: The ring wall has three vent holes, each at a different distance from the tool head.

4. The pneumatic impact tool with an improved vibration reduction structure as described in claim 3, characterized in that: When the hammer body is in contact with the tool head, the cylindrical gap is connected to the two vent holes closest to the tool head.

5. The pneumatic impact tool with an improved vibration reduction structure as described in claim 1, characterized in that: The exhaust passage includes an axial section and a radial section connected in a T-shape.

6. The pneumatic impact tool with an improved vibration reduction structure as described in claim 5, characterized in that: The axial section is located in the center of the hammer head.

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