Pneumatic hammer

Abstract

A pneumatic hammer is provided, including: a body, including an air inlet; a cylinder, connected to the body, including a first chamber, a second chamber, a partition radially spaced between the first chamber and the second chamber, and a residual gas discharge pipe, the partition including a through hole, the through hole communicating with the first chamber and the second chamber, the residual gas discharge pipe extending in the cylinder wall of the cylinder and penetrating the partition and communicating with the first chamber and the second chamber; a working piece, arranged at one end of the cylinder; a valve group, accommodated in the second chamber, including a seat and a valve member movably arranged on the seat, the outer peripheral surface of the valve member is provided with a concave groove, the valve member can movably close or not close the through hole, the concave groove corresponds to and communicates with the residual gas discharge pipe, or is offset and not communicated with the residual gas discharge pipe as the valve member moves; and a piston, movably accommodated in the first chamber.

Description

[Technical Field]

[0001] This invention relates to a pneumatic tool, and more particularly to a pneumatic hammer. [Previous Technology]

[0002] A pneumatic hammer is a tool that uses compressed gas as a power source. It drives a hammer (piston) to strike a shaft back and forth rapidly. The shaft then transmits the impact force to the target object, allowing for various operations such as pulling, hammering, digging, or cutting. For example, in the automotive repair field, pneumatic hammers are often used to disassemble automotive components that are difficult to remove manually, such as fuel injectors. In the construction field, pneumatic hammers can be used for impacting or chiseling objects.

[0003] In conventional pneumatic hammers, the striking hammer moves back to its initial position in the cylinder chamber after each striking operation. As the striking hammer gets closer to the end face of the cylinder chamber, it compresses the residual gas in the cylinder chamber, thus encountering greater resistance. Therefore, the striking hammer cannot accurately return to its initial position, which greatly affects the smoothness of the pneumatic hammer's operation and the impact effect.

[0004] Therefore, it is necessary to provide a novel and progressive pneumatic hammer to solve the above-mentioned problems. [Summary of the Invention]

[0005] The main objective of this invention is to provide a pneumatic hammer that can remove residual gas so that the valve can be accurately reset to its initial position without being affected by residual gas pressure.

[0006] To achieve the above objective, the present invention provides a pneumatic hammer, comprising: a body including an air inlet; a cylinder connected to the body, including a first chamber, a second chamber, a spacer radially spaced between the first chamber and the second chamber, and a residual gas discharge pipe, the spacer including a through hole communicating between the first chamber and the second chamber, the residual gas discharge pipe extending in the cylinder wall of the cylinder and penetrating the spacer and communicating between the first chamber and the second chamber; a working member disposed at one end of the cylinder; a valve assembly disposed in the second chamber, including a seat and a valve movably disposed in the seat, the outer peripheral surface of the valve having a groove, the valve movably closing or not closing the through hole, the groove corresponding to and communicating with the residual gas discharge pipe or misaligned and not communicating with it as the valve moves; and a piston movably disposed in the first chamber.

Implementation Method

[0007] The following examples illustrate possible implementations of the present invention, but are not intended to limit the scope of protection of the present invention. The words "a" or "at least one" preceding the terms mentioned herein are not intended to limit the quantity. Depending on the requirements, there may also be "multiple" items. This variation in quantity is also within the scope of protection, as will be stated in advance.

[0008] Please refer to Figures 1 to 13, which show one embodiment of the present invention. The pneumatic hammer 1 of the present invention includes a body 10, a cylinder 20, a working part 30, a valve group 40 and a piston 50.

[0009] The main body 10 includes an air intake 11. The cylinder 20 is connected to the main body 10. The cylinder 20 includes a first chamber 21, a second chamber 22, a spacer 23 radially spaced between the first chamber 21 and the second chamber 22, and a residual gas discharge pipe 28. The spacer 23 includes a through hole 231 that connects the first chamber 21 and the second chamber 22. In this embodiment, the residual gas discharge pipe 28 extends into the cylinder wall of the cylinder 20, passes through the spacer 23, and connects the first chamber 21 and the second chamber 22. The working member 30 is disposed at one end of the cylinder 20. The valve assembly 40 is housed in the second chamber 22. The valve assembly 40 includes a seat 41 and a valve member 42 movably disposed on the seat 41. The seat 41 includes a connecting pipe 411 communicating with the gas in the intake passage 11. The outer peripheral surface of the valve member 42 has a groove 420. The valve member 42 can move to close or not close the through hole 231. The groove 420 moves with the valve member 42 and corresponds to and communicates with the residual gas discharge pipe 28 (Figures 9 and 10), or is misaligned and not communicating (Figure 7). Furthermore, gas from the intake passage 11 flows through the connecting pipe 411 and actuates the valve member 42 to close or not close the through hole 231. The piston 50 is movably housed in the first chamber 21. Furthermore, one end face of the piston 50 is provided with a protrusion 51, which can impact the valve member 42 and move away from the interval 23. More specifically, when the through hole 231 is not closed by the valve member 42, the gas actuates the piston 50 to impact the working member 30. When the gas actuates the piston 50 to move back towards the interval 23, the protrusion 51 impacts the valve member 42 and moves away from the interval 23. This allows residual gas in the first chamber 21 to be expelled, ensuring that the valve 42 can be accurately reset to its initial position without being affected by residual gas pressure. Furthermore, before the piston 50 returns to contact the spacer 23, it can be buffered by the compressed gas between the two, reducing the impact on the piston 50, the spacer 23, and the valve 42, significantly reducing damage to the components. When the protrusion 51 moves against the valve 42, the compressed gas can open the valve 42 through the through hole 231 and gradually release the compressed gas, placing the piston 50 at the next initial impact position, thus enabling reciprocating impact actions.

[0010] The cylinder 20 further includes a first cylinder body 24 and a second cylinder body 25 that are screwed together, which facilitates installation, disassembly, replacement and maintenance. The first chamber 21 is located in the first cylinder body 24, the seat 41 is accommodated in the second cylinder body 25, and the spacer 23 abuts against the first cylinder body 24 and the seat 41.

[0011] The cylinder 20 further includes a first pipe 26 and a first exhaust pipe 27 connecting the first chamber 21. The first pipe 26 is in gas communication with the connecting pipe 411. One end of the first pipe 26 is further away from the spacer 23 than one end of the first exhaust pipe 27. The first exhaust pipe 27 connects to the outside of the cylinder 20. In this embodiment, the piston 50 includes an annular recess 52. When the piston 50 contacts the working piece 30, the annular recess 52 is in gas communication with the connecting pipe 411 via the first pipe 26. As the piston 50 moves from the spacer 23 toward the working piece 30, it compresses gas that is discharged from the cylinder 20 through the first exhaust pipe 27. After the piston 50 impacts the working piece 30, the gas from the intake passage 11 flows through the connecting pipe 411 and the first pipe 26 into the annular recess 52, pushing the piston 50 back toward the spacer 23. Preferably, the annular recess 52 gradually deepens towards the spacer 23, which can provide a larger force-bearing area and increase the force that pushes the piston 50 back.

[0012] The partition 23 further includes a through channel 232, the seat 41 further includes a first connecting pipe 412 extending from the peripheral wall of the seat 41, and a second connecting pipe 413 connecting the groove 420, the residual gas discharge pipe 28 includes the channel 232 and the first connecting pipe 412, and the cylinder 20 further includes a gas discharge pipe 29 connecting the second connecting pipe 413 and the cylinder 20. Preferably, the groove 420 is arranged around the outer peripheral surface of the valve member 42. The groove 420 moves with the valve member 42 and corresponds to the residual gas discharge pipe 28 (Figures 9 and 10), or is misaligned with the residual gas discharge pipe 28 such that one end of the residual gas discharge pipe 28 is closed by the peripheral surface of the valve member 42 (Figure 7). When the piston 50 returns and moves through the first exhaust pipe 27, the compressed air in the first chamber 21 can be discharged to the outside through the residual gas discharge pipe 28, the groove 420, the second connecting pipe 413 and the gas discharge pipe 29 when the piston 50 approaches the spacer 23 (Figures 9, 12 and 13). This allows the residual gas in the first chamber 21 to be removed, so that the valve 42 can be accurately reset to the initial position (the valve 42 contacts the spacer 23 (Figures 7, 8 and 13)) without being affected by the residual gas pressure, thus obtaining the advantage of the longest impact stroke distance originally designed.

[0013] In detail, the valve 42 further includes a base 421 and a side protrusion 422 laterally connected to the base 421. The side protrusion 422 extends into the through hole 231 and is axially opposite to the protrusion 51 of the piston 50. Preferably, the side protrusion 422 is radially spaced from the wall of the through hole 231 to provide a larger gas flow. The side protrusion 422 can move through the through hole 231 and partially extend into the first chamber 21. When the gas actuates the piston 50 to move back towards the spacer 23, the protrusion 51 impacts the side protrusion 422, which can prevent the valve 42 from being directly impacted and reduce damage. In detail, the side protrusion 422 is plate-shaped and includes two opposing arc surfaces 423. The two arc surfaces 423 are matched with the shape of the inner surface of the through hole 231. The side protrusion 422 can move stably along the inner surface of the through hole 231, guiding and maintaining the linear movement of the valve 42 without deflection. Thus, the operation and opening and closing of the valve 42 are more stable and precise and less prone to wear. In this embodiment, the protrusion 51 includes an end plane 511, and the side protrusion 422 includes an end plane 424. When the protrusion 51 impacts the side protrusion 422, the end plane 511 of the protrusion 51 and the end plane 424 of the side protrusion 422 are flat against each other, improving the stable contact between the protrusion 51 and the side protrusion 422 and the stable and precise operation of the valve 42.

[0014] Preferably, the pneumatic hammer 1 further includes a first elastic element 60 and a second elastic element 70, which axially abut against the cylinder 20 and the body 10, respectively. The axial forces exerted by the first elastic element 60 and the second elastic element 70 on the cylinder 20 are in opposite directions. In this embodiment, the first elastic element 60 is a coiled spring sleeved on the first cylinder 24 and abutting against the inner wall of a front shell 12 of the body 10. The second elastic element 70 is a wave-shaped spring sheet abutting against the inner walls of the second cylinder 25 and a rear shell 13 of the body 10. The first elastic element 60 and the second elastic element 70 can respectively buffer the impact force generated by the piston 50's forward impact and backward return. [Simplified Explanation of the Diagram]

[0015] Figure 1 is a perspective view of an embodiment of the present invention. Figure 2 is an exploded view of an embodiment of the present invention. Figure 3 is another exploded view of an embodiment of the present invention. Figure 4 is a perspective view of a piston of an embodiment of the present invention. Figure 5 is a side view of a piston of an embodiment of the present invention. Figure 6 is a perspective view of a valve of an embodiment of the present invention. Figures 7 and 8 are cross-sectional views of a piston of an embodiment of the present invention in an initial position. Figure 9 is a cross-sectional view of a piston of an embodiment of the present invention in an impact position. Figure 10 is a partially enlarged cross-sectional view of an embodiment of the present invention. Figure 11 is another cross-sectional view of a piston of an embodiment of the present invention in an impact position. Figures 12 and 13 are partially enlarged cross-sectional views of a residual gas removal process of an embodiment of the present invention.

Claims

1. A pneumatic hammer, comprising: A body, including an intake manifold; a cylinder connected to the body, including a first chamber, a second chamber, a spacer radially spaced between the first chamber and the second chamber, and a residual gas discharge pipe, the spacer including a through hole communicating between the first chamber and the second chamber, the residual gas discharge pipe extending in the cylinder wall of the cylinder and passing through the spacer and communicating between the first chamber and the second chamber; a working member disposed at one end of the cylinder; a valve assembly disposed in the second chamber, including a seat and a valve movably disposed in the seat, the outer peripheral surface of the valve having a groove, the valve movably closing or not closing the through hole, the groove corresponding to and communicating with the residual gas discharge pipe or misaligned and not communicating with it as the valve moves; and a piston movably disposed in the first chamber.

2. The pneumatic hammer as claimed in claim 1, wherein the cylinder further includes a first cylinder body and a second cylinder body that are screwed together, the first chamber is located in the first cylinder body, the seat is accommodated in the second cylinder body, and the spacer abuts against the first cylinder body and the seat.

3. The pneumatic hammer as claimed in claim 2, wherein the spacer further includes a through channel, the seat further includes a first connecting pipe extending from the peripheral wall of the seat and a second connecting pipe connecting the groove, the residual gas discharge pipe includes the channel and the first connecting pipe, and the cylinder further includes a gas discharge pipe connecting the second connecting pipe and a gas discharge pipe outside the cylinder.

4. The pneumatic hammer as claimed in claim 1, wherein the valve includes a base and a side protrusion laterally connected to the base, a protrusion is provided on one end face of the piston, the side protrusion extends into the through hole and is axially opposite to the protrusion of the piston, and when gas from the air inlet actuates the piston to move back toward the spacer, the protrusion impacts the side protrusion.

5. The pneumatic hammer as claimed in claim 4, wherein the side protrusion is radially spaced from the wall of the through hole.

6. The pneumatic hammer as claimed in claim 4, wherein the lateral protrusion is movable through the through hole and partially extends into the first chamber.

7. The pneumatic hammer as claimed in claim 1, wherein the cylinder further includes a first pipe communicating with the first chamber and a first exhaust pipe, the seat includes a connecting pipe communicating with the gas in the intake manifold, the first pipe communicating with the gas in the connecting pipe, one port of the first pipe being further away from the spacer than one port of the first exhaust pipe, and the first exhaust pipe communicating with the outside of the cylinder.

8. The pneumatic hammer as claimed in claim 3, wherein the valve includes a base and a side protrusion laterally connected to the base, a protrusion is provided on one end face of the piston, the side protrusion extends into the through hole and is axially opposite to the protrusion of the piston, and when gas from the intake passage actuates the piston to move back towards the spacer, the protrusion impacts the side protrusion; the side protrusion is plate-shaped and includes two opposing arc surfaces, the two arc surfaces matching the shape of the inner surface of the through hole; the protrusion includes an end face, the side protrusion includes an end face, and when the protrusion impacts the side protrusion, the end face of the protrusion is flush with the end face of the side protrusion; the side protrusion is radially spaced from the wall of the through hole; the side protrusion is movable through the through hole and partially extends into the first chamber; the cylinder further includes a... The first pipe and the first exhaust pipe are included. The seat includes a connecting pipe that communicates with the gas in the intake manifold. The first pipe communicates with the gas in the connecting pipe. One end of the first pipe is further away from the spacer than one end of the first exhaust pipe. The first exhaust pipe connects to the outside of the cylinder. The pneumatic hammer also includes a first elastic member and a second elastic member. The first elastic member and the second elastic member axially abut against the cylinder and the body, respectively. The axial forces exerted by the first elastic member and the second elastic member on the cylinder are in opposite directions. The groove is provided on the outer peripheral surface of the valve. The groove moves with the valve and corresponds to the residual gas discharge pipe, or is misaligned with the residual gas discharge pipe so that one end of the residual gas discharge pipe is closed by the peripheral surface of the valve.

9. The pneumatic hammer as claimed in any one of claims 7 to 8, wherein the piston includes an annular recess that is in gas communication with the communication conduit when the piston contacts the working element.

10. The pneumatic hammer as claimed in claim 9, wherein the annular recess deepens in the direction of the spacer.

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