CN116551630A - Pneumatic impact tool with vibration damping structure - Google Patents

Abstract

The invention discloses a pneumatic impact tool with a vibration reduction structure, which is related to manual operation. The pneumatic impact tool with the vibration reduction structure comprises a grab handle, wherein a cylinder and an airflow reversing valve are arranged in the grab handle. The cylinder is connected with an inner pipe fitting and comprises a ring wall and a cavity, a hammer body is arranged in the cavity and is divided into a front cavity and a rear cavity, the ring wall is provided with at least one exhaust hole, and an air flow reversing valve can switch air flow input into the front cavity and the rear cavity. The outer peripheral surface of the hammer body is provided with an exhaust passage which is communicated with the front cavity and is not communicated with the rear cavity. When high-pressure gas is input into the front cavity, the hammer body is pushed backwards, and the high-pressure gas is discharged through the exhaust channel and the exhaust hole, so that the pushing force of the hammer body is reduced.

Description

Pneumatic impact tool with vibration damping structure

Technical Field

The invention relates to a manual pneumatic impact tool, in particular to a pneumatic impact tool with a vibration reduction structure.

Background

The pneumatic impact tool can vibrate due to the reciprocating displacement of the hammer body in the use process, has adverse effects on the palm held by a user after long-term use, and particularly has the advantages that the stronger the impact force is, the larger the vibration caused by the pneumatic impact tool is, and the larger the damage to the user is, so the pneumatic impact tool needs to be improved.

Taiwan patent publication nos. I235700 and I729809 respectively disclose a pneumatic tool, in which a pneumatic chamber is disposed at the rear of the barrel structure for compressing air in the pneumatic chamber when the hammer moves backward, thereby generating a buffering effect and reducing vibration of the barrel caused by the hammer. Another pneumatic tool is disclosed in fig. 4 of I729809, wherein a spring or a rubber block is disposed behind the barrel for pushing the spring or the rubber block when the hammer moves backward, thereby deforming the spring or the rubber block to generate a buffering effect and reducing the vibration of the hammer on the barrel.

In both of the above-mentioned known structures, other members (such as an air chamber formed by changing the space arrangement, a spring or a rubber block) are additionally provided in addition to the existing structure of the pneumatic tool, and after the pneumatic tool generates a large vibration, the vibration is reduced by buffering, and besides the disadvantage of increased cost, most importantly, the vibration reduction effect is not ideal, and the user still feels uncomfortable on the hand during operation.

In the structure disclosed in fig. 5 of the above-mentioned I235700 patent, an air inlet pipe is provided which is connected to the front end of the gun barrel for allowing the hammer body which has moved to the front end of the gun barrel to move backward through the high pressure air, and an air outlet hole is provided at the middle position of the gun barrel for releasing pressure. However, in the process that the hammer body rebounds backwards when striking the tool head forwards, the high-pressure gas in the gun barrel must be discharged after the hammer body passes through the vent hole in the middle position, but the gas drives the hammer body to retreat to the rear end of the gun barrel at high pressure before discharging, so that the hammer body strikes the rear end of the gun barrel with larger force, which is the root cause of the vibration of the pneumatic tool.

In view of the above, how to improve the above problems is a primary problem to be solved by the present invention.

Disclosure of Invention

The main object of the present invention is to provide a pneumatic impact tool with a vibration damping structure, which is provided with an exhaust passage communicating with a front chamber of an inner pipe fitting on a hammer body, and continuously exhausts air at the beginning of the back-up process of the hammer body, thereby directly weakening the impact force of the back-up of the hammer body and further reducing vibration. The invention can generate vibration damping effect without adding extra components.

In order to achieve the above object, the present invention provides a pneumatic impact tool having a vibration damping structure, comprising:

a grab handle, the interior of which is provided with a concave chamber, the grab handle is provided with an air inlet channel connected with the concave chamber, wherein an air flow switch is arranged in the air inlet channel;

a cylinder part accommodated in the concave chamber, wherein an airflow reversing valve is arranged in the cylinder part, and a through hole communicated with the air inlet channel is arranged on one side wall of the cylinder part, so that high-pressure gas is led into the airflow reversing valve;

the inner pipe fitting comprises a ring wall fixed on the barrel and a cavity surrounded by the ring wall, a hammer closely connected with the ring wall is arranged in the cavity to divide the cavity into a front cavity and a rear cavity, a tool head is arranged at the front end of the ring wall, the ring wall is provided with at least one exhaust hole for communicating the cavity to the outside, an air flow channel for communicating the air flow reversing valve and the front cavity is arranged in the ring wall, the air flow channel forms a first air inlet in the front cavity, the rear cavity is provided with a second air inlet connected with the air flow reversing valve, and the air flow reversing valve can alternatively input the air flow into the front cavity from the first air inlet or the rear cavity from the second air inlet;

the hammer body is provided with a head end close to the first air inlet and a tail end close to the second air inlet, and an exhaust channel is arranged on the peripheral surface of the hammer body, wherein the exhaust channel extends to the head end and is communicated with the front cavity, and the exhaust channel is not connected with the tail end and is not communicated with the rear cavity; when high-pressure gas is injected into the front chamber from the first air inlet, the hammer body is pushed by the high-pressure gas to be far away from the tool head, and in the process, when the exhaust channel of the hammer body is communicated with the exhaust hole, the high-pressure gas in the front chamber is discharged through the exhaust channel and the exhaust hole, so that the pushing force of the hammer body is reduced.

In one embodiment, the exhaust passage is formed by a spiral groove recessed on the outer peripheral surface of the hammer.

Preferably, the groove communicates with the vent hole when the hammer is in contact with the tool bit. Further, the annular wall is provided with three exhaust holes, and the distances between each exhaust hole and the tool head are respectively different; when the hammer body is positioned at a position contacted with the tool head, the groove is communicated with the two exhaust holes closest to the tool head.

In another embodiment, the exhaust channel includes a groove portion and a cylindrical gap, the groove portion extends linearly along the moving direction of the hammer body to the head end and is communicated with the front chamber, and the cylindrical gap is a space between a strip-shaped concave portion concavely arranged on the outer peripheral surface of the hammer body and the annular wall.

Preferably, the cylindrical gap communicates with the vent hole when the hammer is in contact with the tool bit. Further, the annular wall is provided with three exhaust holes, and the distances between each exhaust hole and the tool head are respectively different; when the hammer body is positioned at a position contacted with the tool head, the cylindrical gap is communicated with the two exhaust holes closest to the tool head.

Preferably, the distance between the vent and the tool head is no greater than half of the total length of the chamber.

The above objects and advantages of the present invention will be readily apparent from the following detailed description of the selected embodiments and the accompanying drawings.

Drawings

FIG. 1 is an exploded perspective view of a first embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of the whole first embodiment of the present invention;

FIG. 3 is a perspective view of a hammer of a first embodiment of the present invention;

fig. 4 to 6 are schematic views illustrating an operation state of the first embodiment of the present invention;

FIG. 7 is an exploded perspective view of a second embodiment of the present invention;

FIG. 8 is a schematic cross-sectional view of the second embodiment of the present invention;

FIG. 9 is a perspective view of a ram according to a second embodiment of the invention;

fig. 10 to 12 are schematic views illustrating an operation state of the second embodiment of the present invention.

The main reference numerals illustrate:

rear cavity 322 of grab handle 1

Air flow passage 33 of recess 11

First intake port 34 of intake passage 12

Second air inlet 35 of air flow switch 13

Exhaust hole 36 of button 14

Spring 15 hammer 4

Head end 41 of cartridge 2

Tail end 42 of through hole 21

Outer peripheral surface 43 of air flow reversing valve 22

Groove 44 of inner tube 3

Tool head 5 of annular wall 31

Chamber 32 hammer 9

Front chamber 321 headend 91

Tail end 92 barrel gap 96

Band-shaped concave portion 97 of outer peripheral surface 93

Groove portion 95

Detailed Description

Referring to fig. 1 to 2, a first embodiment of a pneumatic impact tool with vibration damping structure according to the present invention includes a handle 1, a barrel 2, an inner tube 3 and a hammer 4. The grip 1 may be formed in a pistol shape or a straight barrel shape, and in this embodiment, the grip 1 is pistol-shaped. The top of the handle 1 is provided with a recess 11. The bottom of the handle 1 is provided with an air inlet channel 12 extending upwards and communicating with the recess 11 for connection to an external high pressure gas supply. An air flow switch 13 for controlling the air flow is arranged in the air inlet channel 12, and a button 14 is connected with the air flow switch 13 at one side of the grab handle 1 for operation.

The barrel 2 of the embodiment is accommodated in the recess 11, and a spring 15 for buffering the barrel 2 is disposed at the bottom end of the recess 11. The sidewall of the cylinder 2 is provided with a through hole 21 communicating with the air inlet channel 12, and a well-known air flow reversing valve 22 is arranged in the cylinder 2, and after the high pressure air is introduced into the air inlet channel 12, the high pressure air enters the air flow reversing valve 22 through the through hole 21, and the air flow reversing valve 22 is used for outputting the high pressure air in two different paths.

The inner pipe 3 is a circular pipe structure and is provided with a ring wall 31 and a cavity 32 surrounded by the ring wall 31, wherein the ring wall 31 extends into the barrel 2 and is locked on the barrel 2 by threads; the chamber 32 is provided with a hammer 4 closely attached to the annular wall 31, so that the chamber 32 is partitioned into a front chamber 321 and a rear chamber 322. The inner tube 3 extends out of the barrel 2, and a tool head 5 is arranged at the front end of the inner tube, and the tool head 5 can be replaced according to actual use requirements. The annular wall 31 is provided with an air flow channel 33 which is communicated with the air flow reversing valve 22 and is different from the chamber 32, and a first air inlet 34 is formed in the front chamber 321; the rear chamber 322 is further provided with a second air inlet 35 connected to the air flow reversing valve 22. Accordingly, the air flow reversing valve 22 can alternatively output high-pressure air to the air flow channel 33 at a proper time, and then the high-pressure air is injected into the front chamber 321 through the first air inlet 34; or high pressure gas is injected into the rear chamber 322 through the second gas inlet 35.

Furthermore, the annular wall 31 is provided with at least one vent 36 for communicating the chamber 32 to the outside; in the present embodiment, the number of the exhaust holes 36 is three, which are arranged in a straight line along the axial direction of the inner pipe 3, and the distances between the exhaust holes 36 and the tool bit 5 are different. Further, the three exhaust holes 36 are disposed between the first air inlet 34 and the second air inlet 35, and the distance between the exhaust holes 36 and the tool head 5 is not greater than half of the total length of the chamber 32.

As shown in fig. 2 to 3, the hammer 4 includes a head end 41 adjacent to the first air inlet 34 and a tail end 42 adjacent to the second air inlet 35, and has an outer peripheral surface 43 therebetween, and the outer diameter of the hammer 4 is equal to the inner diameter of the chamber 32, so that the outer peripheral surface 43 is closely adhered to the annular wall 31. The outer peripheral surface 43 is provided with an exhaust channel, wherein the exhaust channel extends to the head end 41 and is communicated with the front chamber 321, and the exhaust channel is not connected to the tail end 42, so that the exhaust channel is not communicated with the rear chamber 322. In the present embodiment, the exhaust channel is formed by grooves 44 concavely formed on the outer peripheral surface 43, wherein the grooves 44 extend in a spiral shape, and the number and pitch of the grooves 44 can be changed according to design requirements.

In this embodiment, the relative position of the groove 44 and the vent hole 36 is shown in fig. 4. Specifically, the groove 44 communicates with the two exhaust holes 36 closest to the tool head 5 when the hammer 4 moves to a position contacting the tool head 5.

With the above structure, when the button 14 is pressed to control the air flow switch 13 so that the high pressure air is introduced into the air flow reversing valve 22 through the air inlet channel 12, the air flow reversing valve 22 first injects the high pressure air into the rear chamber 322 from the second air inlet 35, and at this time, the high pressure air pushes the hammer 4 to move forward at a high speed and impact the tool head 5 to generate a working effect. Next, the gas flow switching valve 22 switches the gas supply path to stop the injection of the high pressure gas from the second gas inlet 35 into the rear chamber 322, but instead directs the high pressure gas into the gas flow passage 33 and then into the front chamber 321 through the first gas inlet 34. As for the technology of switching the air supply path by the air flow reversing valve 22, the technology is generally known and will not be described herein.

At this time, the high-pressure gas starts to push the hammer 4 to move backward. As shown in fig. 4, when the hammer 4 starts to leave the tool bit 5, the high pressure gas in the front chamber 321 can start to leak to the outside through the channel formed by the communicating groove 44 and the vent hole 36, so as to reduce the pressure in the front chamber 321 and further reduce the pushing force of the hammer 4, and accordingly, when the hammer 4 moves to the end of the stroke as shown in fig. 6, the amplitude of the vibration will be reduced.

In the vibration damping process of the present invention, when the hammer 4 is at the start of the stroke as shown in fig. 4, the air vent 36 is communicated by the groove 44, so that air release can be started at this time, in other words, the air release timing of the present invention is greatly earlier than that of the conventional structure, so that the force for pushing the hammer 4 can be greatly weakened.

Moreover, during the retraction of the ram 4, as shown in fig. 5, different vent holes 36 may be communicated through the grooves 44 to continue venting, so that the force pushing the ram 4 to retract is continuously attenuated, and the vibration is greatly attenuated.

The invention has the characteristics that the impact force of the backward movement of the hammer body 4 is directly weakened by adopting a mode of releasing air at the source of vibration generated by the pneumatic tool (namely the impact force of the backward movement of the hammer body 4), so that the aim of treating the root cause is fulfilled, better vibration reduction effect can be generated compared with the well-known structure, and the force of the high-pressure air driving the hammer body to move forward to impact the tool head is not influenced, so that the vibration reduction effect can be generated on the premise of considering the output power of the pneumatic tool.

Fig. 7 to 9 are second embodiments of the present invention, which are pneumatic impact tools having the same structure as the above embodiments, except for the construction of the hammer 9, so that the following description will be added to the structure of the above embodiments.

The hammer 9 also has a head end 91 and a tail end 92 with an outer peripheral surface 93 therebetween, and an exhaust channel is disposed on the outer peripheral surface 93, wherein the exhaust channel extends to the head end 91 and communicates with the front chamber 321, and the exhaust channel is not connected to the tail end 92, as in the previous embodiment, and accordingly the exhaust channel does not communicate with the rear chamber 322. In this embodiment, the exhaust passage includes a groove 95 and a cylindrical gap 96. The groove 95 extends linearly along the moving direction of the hammer 9, and has one end connected to the head end 91 and communicating with the front chamber 321, and the other end connected to the cylindrical gap 96. The cylindrical gap 96 is a space between the annular wall 31 and the band-shaped recess 97 recessed from the outer peripheral surface 93.

The relative positional relationship of the exhaust passage and the exhaust hole 36 is thus formed as shown in fig. 10. Specifically, in the present embodiment, when the hammer 9 moves to a position contacting the tool bit 5, the cylindrical gap 96 communicates with the two exhaust holes 36 closest to the tool bit 5.

As in the first embodiment, in the present embodiment, when the hammer 9 is at the start of the stroke as shown in fig. 10, the vent hole 36 is connected through the cylindrical gap 96, and then venting can be started, in other words, the venting timing is greatly earlier than in the conventional structure. During the retraction of the ram 9, different vent holes 36 may be connected through the cylindrical gap 96 as shown in fig. 11 to continuously vent, and further as in the first embodiment, continuously attenuate the force with which the ram 9 is pushed to retract, so that the vibration is greatly attenuated when the ram 9 reaches the end of the stroke shown in fig. 12.

The above examples are provided for illustration only and are not intended to limit the invention, but equivalent component substitutions are contemplated.

In view of the above, it will be apparent to those skilled in the art that the present invention can achieve the above objects, and the present invention meets the requirements of the patent laws.

Claims (10)

1. A pneumatic impact tool having a vibration-damping structure, comprising:

a grab handle, the interior of which is provided with a concave chamber, the grab handle is provided with an air inlet channel connected with the concave chamber, wherein an air flow switch is arranged in the air inlet channel;

a cylinder part accommodated in the concave chamber, wherein an airflow reversing valve is arranged in the cylinder part, and a through hole communicated with the air inlet channel is arranged on one side wall of the cylinder part, so that high-pressure gas is led into the airflow reversing valve;

the inner pipe fitting comprises a ring wall fixed on the barrel and a cavity surrounded by the ring wall, a hammer closely connected with the ring wall is arranged in the cavity to divide the cavity into a front cavity and a rear cavity, a tool head is arranged at the front end of the ring wall, the ring wall is provided with at least one exhaust hole for communicating the cavity to the outside, an air flow channel for communicating the air flow reversing valve and the front cavity is arranged in the ring wall, the air flow channel forms a first air inlet in the front cavity, the rear cavity is provided with a second air inlet connected with the air flow reversing valve, and air flow can be input into the front cavity from the first air inlet or the rear cavity from the second air inlet;

the hammer body is provided with a head end close to the first air inlet and a tail end close to the second air inlet, and an exhaust channel is arranged on the peripheral surface of the hammer body, wherein the exhaust channel extends to the head end and is communicated with the front cavity, and the exhaust channel is not connected with the tail end and is not communicated with the rear cavity; when high-pressure gas is injected into the front cavity from the first air inlet, the hammer body is pushed by the high-pressure gas to be far away from the tool head, and in the process, when the exhaust channel is communicated with the exhaust hole, the high-pressure gas in the front cavity is discharged through the exhaust channel and the exhaust hole, so that the pushing force of the hammer body is reduced.

2. The pneumatic impact tool with vibration reduction structure according to claim 1, wherein the exhaust passage is constituted by a spiral groove concavely provided on the outer peripheral surface of the hammer body.

3. The pneumatic impact tool having a vibration reduction structure according to claim 2, wherein the groove communicates with the vent hole when the hammer is located in contact with the tool bit.

4. A pneumatic impact tool with vibration reduction structure as claimed in claim 2, wherein the annular wall is provided with three exhaust holes, each of which is different in distance from the tool head.

5. The pneumatic impact tool having a vibration reduction structure of claim 4, wherein the groove communicates with the two vent holes closest to the tool bit when the hammer is positioned in contact with the tool bit.

6. The pneumatic impact tool with vibration damping structure according to claim 1, wherein the exhaust passage includes a groove portion and a cylindrical gap, the groove portion extends linearly along the moving direction of the hammer body to the head end and communicates with the front chamber, the cylindrical gap being a space between a band-shaped recess concavely provided on the outer peripheral surface of the hammer body and the annular wall.

7. The pneumatic impact tool with vibration reduction structure according to claim 6, wherein the cylindrical gap communicates with the exhaust hole when the hammer body is located at a position in contact with the tool bit.

8. The pneumatic impact tool with vibration reduction structure according to claim 6, wherein the annular wall is provided with three exhaust holes, and distances between the exhaust holes and the tool head are different.

9. The pneumatic impact tool with vibration reduction structure according to claim 8, wherein the cylindrical gap communicates with the two exhaust holes closest to the tool bit when the hammer body is located in contact with the tool bit.

10. The pneumatic impact tool with vibration reduction structure of claim 1, wherein the distance between the vent hole and the tool head is not more than half of the total length of the chamber.