Power tool

Abstract

The application provides an electric tool. The electric tool comprises a housing, an impact pin, a retainer sleeved on the impact pin and provided with a retainer limiting portion limited in an axial direction by an inner wall of the housing, a first buffer arranged between the retainer limiting portion and the inner wall of the housing and used for buffering a forward movement of the retainer, a driving assembly used for driving the impact pin to reciprocate, a driving assembly limiting portion arranged at a rear portion of the retainer and used for axially limiting the driving assembly, a second buffer arranged between the driving assembly and the driving assembly limiting portion and used for buffering a forward movement of the driving assembly, and a stopper arranged on the inner wall of the housing and located between the retainer limiting portion and the driving assembly limiting portion. The stopper limits a backward movement end point of the retainer limiting portion and limits a forward movement end point of the driving assembly limiting portion. According to the technical scheme of the application, the stopper is arranged to avoid mutual influence or interference of the first buffer and the second buffer located on both sides of the stopper in the compression and rebound process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric power tools, and more particularly, to an electric power tool with a reciprocating transmission mechanism. BACKGROUND

[0002] In the prior art, for the system with a vibration mechanism such as electric hammer, impact hammer, etc., a piston and cylinder configuration is usually adopted to provide power. In order to avoid providing power in an undesired situation, an unloading hole is usually provided on the hammer tube of such electric power tool, when the unloading hole is closed, the hammer tube can be used as a cylinder; when the unloading hole is opened, the air pressure cannot be formed in the hammer tube. Currently, a ram is usually used to cooperate with the hammer tube to control the opening and closing of the unloading hole. In the working state, when the electric power tool is abutted against the object to be processed, the impact pin will move in the electric power tool towards the hammer tube side and abut against the ram, and then drive the ram to move backward in the hammer tube until the unloading hole is closed to start the impact work. In the non-working state, since the impact pin is not abutted against the object to be processed, it usually returns to its non-working position relatively far away from the ram, and no longer exerts pressure on the ram to force it to close the unloading hole, and the corresponding impact work is also stopped. In order to absorb part of the impact energy in this process, a buffer part is provided to realize the buffering of the forward impact of the impact pin and the ram respectively. However, the buffer parts designed in the past may directly or indirectly contact each other, which makes it difficult to accurately know the required buffering amount and buffering time of the impact pin and the ram respectively through the deformation degree of the buffer part, thereby increasing the design difficulty of the appropriate buffer part. SUMMARY

[0003] Therefore, the present application provides an improved electric power tool, which effectively solves or alleviates one or more of the above problems and other aspects in the prior art.

[0004] To solve one of the above technical problems, according to one aspect of the present application, an electric power tool is provided, comprising: a housing; an impact pin; a retainer sleeved on the impact pin and having a retainer limiting portion limited in an axial direction by an inner wall of the housing; a first buffer arranged between the retainer limiting portion and the inner wall of the housing and used to buffer a forward movement of the retainer; a drive assembly used to drive the impact pin to reciprocate; a drive assembly limiting portion arranged at a rear portion of the retainer and providing an axial limiting of the drive assembly; a second buffer arranged between the drive assembly and the drive assembly limiting portion and used to buffer a forward movement of the drive assembly; and a stopper arranged on the inner wall of the housing and located between the retainer limiting portion and the drive assembly limiting portion; the stopper limits a backward movement end point of the retainer limiting portion and limits a forward movement end point of the drive assembly limiting portion.

[0005] According to the technical solution of the present application, by arranging the stopper on the inner wall of the housing between the retainer limiting portion and the drive assembly limiting portion, the backward movement end point of the retainer limiting portion can be limited, and the forward movement end point of the drive assembly limiting portion can also be limited. In this arrangement, the presence of the stopper avoids the possibility of mutual contact of the retainer limiting portion and the drive assembly limiting portion adjacent to the stopper, thereby also avoiding the possibility of mutual influence or interference of compression and rebound between the first buffer and the second buffer located on the side of the two limiting portions away from the stopper. Therefore, the working state parameters of the two buffers can be more accurately obtained, so as to provide optimized buffer modification and to provide better buffer effect, thereby effectively improving the reliability of the electric power tool. BRIEF DESCRIPTION OF DRAWINGS

[0006] The present application will be more fully understood from the following detailed description taken in connection with the accompanying drawings, in which like references refer to like elements, and in which:

[0007] Figure 1 is a cross-sectional schematic view of one embodiment of the electric power tool, in which the upper half section shows the compressed position of the hammer and the impact pin, and the lower half section shows the uncompressed position of the hammer and the impact pin;

[0008] Figure 2 is a perspective schematic view of one embodiment of the stopper of the electric power tool;

[0009] Figure 3 is a perspective schematic view of another embodiment of the stopper of the electric power tool. DETAILED DESCRIPTION

[0010] The application will be described in greater detail with reference to the exemplary embodiments illustrated in the drawings. It should be understood that the application can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be complete and fully convey the application's concept to those skilled in the art.

[0011] Furthermore, for any individual technical feature described or implied in the embodiments mentioned herein, or any individual technical feature shown or implied in the drawings, the application still allows any combination or deletion to be made between these technical features (or their equivalents) without any technical obstacles, thereby obtaining more other embodiments of the application that can not be directly mentioned herein.

[0012] Referring to Figure 1 , an embodiment of a power tool is shown. The power tool 100 generally includes a housing 110 and a plurality of components arranged in the housing. Specifically, it includes a drill bit 191, a holder 130, an impact pin 120, a drive assembly limiting portion 161, and a drive assembly 150 including a hammer 151, a hammer tube 152, a piston portion 153, etc., arranged in the housing 110 in the order from left to right as shown. The connection relationship or assembly relationship therebetween will be described as follows.

[0013] Continuing to refer to Figure 1 , the front end of the impact pin 120 abuts against the drill bit 191, and the rear end thereof abuts against the hammer 151 of the drive assembly 150 and reciprocates under the drive of the drive assembly 150. The holder 130 is sleeved on the impact pin 120 and has a holder limiting portion 131 limited in the axial direction by the inner wall of the housing 110, thereby limiting the position of the holder 130 relative to the housing 110 in the axial direction. The drive assembly limiting portion 161 is arranged at the rear of the holder 130, thereby limiting the position of the drive assembly 150 in the axial direction.

[0014] As the first set of buffering features of the power tool, a first buffer 141 (e.g., in the form of a buffer ring) is further arranged between the holder limiting portion 131 and the inner wall of the housing 110, which can be used to buffer the forward movement of the holder 130, and the optimization requirement of the buffer here can be understood by the compression amount or the buffer frequency.

[0015] As the second set of buffering features of the power tool, a second buffer 142 (e.g., in the form of a buffer ring) is further arranged between the drive assembly 150 and the drive assembly limiting portion 161, which can be used to buffer the forward movement of the hammer 151 in the drive assembly 150, and the optimization requirement of the buffer here can be understood by the compression amount or the buffer frequency.

[0016] On this basis, in order to realize the accurate evaluation of the compression amount and the buffer time of the two buffer members, so as to provide the basis for subsequent optimization design, the inner wall of the shell 110 between the retainer limiting portion 131 and the drive assembly limiting portion 161 can be provided with a stopper 170. At this time, the stopper 170 can limit the rearward movement endpoint of the retainer limiting portion 131, so that the retainer will not be affected by the buffer rebound caused by the impact of the impact pin 120 on the first buffer member 141; the stopper 170 can also limit the forward movement endpoint of the drive assembly limiting portion 161, so that the drive assembly limiting portion 161 will not be affected by the compression caused by the impact of the drive assembly 120 on the second buffer member 142. In this arrangement, the presence of the stopper avoids the possibility of mutual contact between the retainer limiting portion 131 and the drive assembly limiting portion 161 adjacent to it, thereby avoiding the possibility of mutual influence or interference between the compression and rebound of the first buffer member 141 and the second buffer member 142 located on the side away from the stopper of the two limiting portions. Therefore, the working state parameters of the two buffer members can be more accurately obtained, so as to provide optimized buffer member modification, so as to provide better buffer effect, thereby effectively improving the reliability of the power tool.

[0017] The construction of each component in the power tool and its connection relationship will be further introduced as follows. In addition, for the purpose of further improving reliability, practicality, economy or for other aspects of improvement, additional parts can also be added, which will also be exemplarily illustrated as follows.

[0018] Firstly, the stopper in the foregoing embodiment will be described. Specifically, in order to realize its stop function and at the same time meet the assembly needs of other components in the power tool, the stopper can be provided with a stop protrusion 171 and an inner hole 172. Among them, the stop protrusion 171 should protrude towards the inside of the shell 110, so as to form a barrier to the components on both sides, while the inner hole 172 is formed on the inside of the stop protrusion 171 to facilitate the passage and reciprocating movement of the impact pin and other components. Specifically, in order to achieve this purpose, the components can be provided with the following size relationship: the minimum size of the inner hole 172 is designed to be larger than the maximum axial size of the impact pin 120, so that the impact pin 120 can smoothly perform axial reciprocating movement and perform its impact work, and the minimum size of the inner hole 172 is designed to be smaller than the maximum axial size of the retainer limiting portion 131 and the drive assembly limiting portion 161, so that the stop protrusion 171 surrounding the inner hole 172 can effectively stop the retainer limiting portion 131 and the drive assembly limiting portion 161 in the axial direction, thereby effectively avoiding the compression or rebound of the first buffer member 141 located on the front side of the retainer limiting portion 131 and the second buffer member 142 located on the rear side of the drive assembly limiting portion 161.

[0019] The detailed description will continue with reference to the accompanying drawings Figures 1 to 3 A specific embodiment of the stopper 170 is described hereinafter. In the drawings, the stopper 170 is detachably connected to the housing 110, thereby facilitating the manufacture and enabling timely replacement of the worn parts, ensuring the reliability of the stopper. Specifically, a corresponding mounting groove 111 can be provided in the housing 110, and the detachable stopper 170 is configured as a stopper ring 170 having a mounting notch 173. Thus, such a stopper ring 170 can be telescopically fitted into the mounting groove 111 by extruding the mounting notch 173. Subsequently, the stopper ring 170 is restored to its original shape by releasing the mounting notch 173 and is embedded in the mounting groove 111. It should be noted that in the installed state, the inner edge of the stopper ring 170 at least partially protrudes from the mounting groove 111 to form the aforementioned stopper protrusion 172 to separate the parts on both sides.

[0020] On this basis, in order to facilitate the removal of such a detachable stopper ring 170, a clamping portion 174 can also be provided on the stopper ring 170 near the mounting notch 173. In the state where the stopper ring 170 has been embedded in the mounting groove 111, it is relatively difficult to directly extrude the mounting notch 173 to remove the stopper ring 170. At this time, by providing the clamping portion 174 which is still exposed from the mounting groove 111 in the installed state, and by extruding the mounting notch 173 through the clamping portion 174, the stopper ring 170 can be telescopically removed from the mounting groove 111. It should be noted that the clamping portion 174 should at least have a structure that facilitates manual or mechanical clamping. For example, it can be configured as a hook-shaped feature extending inward from the end of the mounting notch 173, and the hook-shaped feature can also be directed away from the mounting notch 173 to facilitate the formation of a clamping structure. For another example, see Figure 3 The clamping portion 174 can also be configured as a through hole 174 on both ends of the stopper ring 170 forming the mounting notch 173. At this time, the extrusion of the mounting notch 173 can be achieved by inserting a pin-shaped feature in order to clamp and remove the stopper ring 170.

[0021] In addition, although not shown in the drawings, those skilled in the art should know that the stopper 170 can also be integrated with the housing 110. At this time, although it has relatively large manufacturing difficulty, it also avoids the assembly process of the split stopper 170 and the housing, reduces the assembly process, and has higher stability of the stopper position.

[0022] The detailed description will continue with reference to the accompanying drawings Figure 1 to describe the drive assembly mentioned in the power tool.

[0023] The hammer 151 in the driving assembly is arranged on the side of the impact pin 120 away from the drill bit 191 and abuts against the impact pin 120 in the working state. The hammer tube 152 is configured as a hollow tubular structure for accommodating the hammer 151. As shown, the hammer 151 is slidably fitted to the left side of the hammer tube 152, and the piston part 153 is slidably and fitted to the right side of the hammer tube 152. The piston part 153 is driven to reciprocate within the hammer tube 152, thereby controllably forming a high-pressure gas chamber within the hollow tube of the hammer tube 152 and driving the hammer 151 to reciprocate within the hammer tube 152 by compressing the gas within the compression gas chamber 1522 to generate pressure, and driving the impact pin 120 abutting in the working state.

[0024] The illustrated hammer tube 152 is further provided with an unloading hole 1521 on the left side thereof, which communicates the inner wall and the outer wall of the hammer tube 152, to constitute part of the control component of the aforementioned high-pressure gas chamber. When the impact pin 120 abutting against the object to be processed transmits corresponding displacement to the hammer 151, the hammer 151 moves backward along the left side of the hammer tube 152 until the unloading hole 1521 is closed, at which time if the power tool is in the open state, a high-pressure gas chamber can be formed within the hammer tube 152.

[0025] The following also describes the modification of other components in the power tool in combination with Figures 1-3 .

[0026] For example, the power tool can also be provided with an impact pin limiting part 160. At this time, a radially protruding stop wall 112 is further provided on the inner wall of the housing 110, the impact pin limiting part 160 is sleeved on the impact pin 120, and is arranged between the stop wall 112 in the housing 110 and the second buffer 142, thereby achieving the limitation of the rearward movement end point of the impact pin 120. Specifically, a radially protruding shoulder 121 is further provided on the middle section of the impact pin 120, which is located in front of the driving assembly limiting part 161, the second buffer 142 and the impact pin limiting part 162. The axial maximum dimension thereof can be designed to be greater than the minimum dimension of the inner hole 172 of the driving assembly limiting part 161 and the impact pin limiting part 162, and the limitation of the rearward movement end point thereof is specifically realized by constraining the shoulder 121 of the impact pin 120.

[0027] For another example, the power tool may also be provided with a limiting sleeve 180. In this case, the retaining frame 130 is sleeved on the impact pin 120 and the limiting sleeve 180, and limits the two. Specifically, the retaining frame 130 is provided with a radially protruding sleeve limiting portion 132 on the inner wall of the second end away from the hammer 140. The limiting sleeve 180 is disposed within the retaining frame 130 and is axially limited by the sleeve limiting portion 132. In addition, the limiting sleeve 180 is located between the sleeve limiting portion 132 and the impact pin 120, and limits the forward movement end point of the impact pin 120 through the constraining shoulder 121.

[0028] For example, as a specific implementation form of the retainer limiter 131 that constrains the first buffer member 141, it can be configured to protrude radially on the outer wall of the first end of the retainer 130 toward the drive assembly 150; wherein, the retainer limiter 131 abuts the radial inner wall 113 of the housing 110 via the first buffer member 141. Furthermore, in order to facilitate assembly, the housing 110 of the power tool is usually designed as a split structure. For example, it may include a generally tubular main body portion 114 and an end cover flange 115 located at the front end of the main body portion 114. The two can be assembled and fastened by bolts. At this time, the retainer limiter 131 mentioned above will abut the radial inner wall 113 of the end cover flange 115 via the first buffer member 141.

[0029] It should be known that the limiting parts mentioned in the article can be set as metal structures. In this case, the buffer is in contact with the hammer or impact pin through these limiting parts, thereby avoiding direct impact, reducing the material requirements for the buffer, and increasing the life of the buffer.

[0030] The above specific implementation methods are only used to illustrate the present application, and are not intended to limit the present application. In order to illustrate the relative position relationship, relative orientation terms such as left and right, up and down are used in the present application, which are not intended to limit the absolute position. Ordinary technicians in the relevant technical field can also make various changes and modifications to the technical solutions of the present application without departing from the scope of the present application. Therefore, all equivalent technical solutions also fall within the scope of the present application, and the scope of patent protection of the present application should be defined by the claims.

Claims

1. An electric tool, characterized in that: include: Housing (110); Impact pin (120); A retainer (130) sleeved on the impact pin (120) and having a retainer limiting portion (131) limited in the axial direction by the inner wall of the housing (110); a first buffer member (141) disposed between the retaining frame limiting portion (131) and the inner wall of the housing (110) and used to buffer the forward movement of the retaining frame (130); A driving assembly (150) for driving the impact pin (120) to reciprocate; a drive assembly limiting portion (161), which is arranged at the rear of the retaining frame (130) and provides axial limiting for the drive assembly (150); a second buffer member (142), which is disposed between the drive assembly (150) and the drive assembly limiting portion (161) and is used to buffer the forward movement of the drive assembly (150); and A stopper (170) is provided on the inner wall of the housing (110) and is located between the retainer limiting portion (131) and the drive assembly limiting portion (161); the stopper (170) limits the end point of the rearward movement of the retainer limiting portion (131) and limits the end point of the forward movement of the drive assembly limiting portion (161).

2. The electric tool according to claim 1, wherein: The stopper (170) comprises: a stop protrusion (171) protruding toward the inside of the housing (110); and an inner hole (172) formed inside the stop protrusion (171); The minimum size of the inner hole (172) is larger than the maximum axial size of the impact pin (120), and smaller than the maximum axial sizes of the retainer limiting portion (131) and the drive assembly limiting portion (161).

3. The electric tool according to claim 1, wherein: The stopper (170) is integrated with the housing (110); or The stopper (170) is detachably connected to the housing (110).

4. The electric tool according to claim 3, wherein: A mounting groove (111) is provided in the housing (110); and the stopper (170) detachably connected to the housing (110) is configured as a stopper ring having a mounting notch (173); wherein the stopper ring is telescopically installed into the mounting groove (111) by squeezing the mounting notch (173); and in the installed state, the inner edge of the stopper ring at least partially protrudes from the mounting groove (111).

5. The electric tool according to claim 4, characterized in that The stop ring has a clamping portion (174) disposed near the mounting notch (173), and the mounting notch (173) is squeezed by the clamping portion (174) to telescopically remove the stop ring from the mounting groove (111).

6. The electric tool according to claim 5, wherein: The clamping portion (174) is configured as through holes on both ends of the stop ring forming the mounting notch (173).

7. The electric tool according to any one of claims 1 to 6, characterized in that: The drive assembly (150) comprises: A hammer (151) is disposed in the housing (110) and impacts the impact pin (120) in a controlled manner, wherein the hammer (151); A hammer tube (152) is used to accommodate the hammer (151), and is provided with an unloading hole (1521) communicating the inner wall and the outer wall of the hammer tube (152); when the unloading hole (1521) is closed, an air pressure chamber (1522) is formed in the hammer tube (152); and a piston portion (153) which drives the hammer (151) by compressing the gas in the air pressure chamber (1522); The driving assembly limiting portion (161) provides axial limiting for the hammer (151), and the second buffer member (142) is used to buffer the forward movement of the hammer (151).

8. The electric tool according to any one of claims 1 to 6, characterized in that: It also includes an impact pin limiting portion (162) and a stop wall (112) protruding radially inward from the inner wall of the shell (110); wherein the impact pin limiting portion (162) is sleeved on the impact pin (120) and is arranged between the stop wall (112) and the second buffer member (142), and limits the end point of the backward movement of the impact pin (120).

9. The electric tool according to claim 8, wherein: The middle section of the impact pin (120) has a radially protruding shoulder (121), the shoulder (121) is located in front of the drive assembly limiting portion (161), the second buffer member (142) and the impact pin limiting portion (162), and its maximum axial dimension is greater than the minimum dimension of the inner hole (172) of the drive assembly limiting portion (161) and the impact pin limiting portion (162).

10. The electric tool according to any one of claims 1 to 6, characterized in that: It also includes a limiting sleeve (180); the retaining frame (130) further includes a radially protruding sleeve limiting portion (132) provided on the inner wall of the second end away from the driving assembly (150); and the middle section of the impact pin (120) has a radially protruding shoulder (121); wherein the limiting sleeve (180) is provided in the retaining frame (130) and is axially limited by the sleeve limiting portion (132); and the limiting sleeve (180) is located between the sleeve limiting portion (132) and the impact pin (120), and limits the forward movement end point of the impact pin (120) by constraining the shoulder (121).

11. The electric tool according to any one of claims 1 to 6, characterized in that: The retainer limiting portion (131) is arranged to protrude radially on the outer wall of the first end of the retainer (130) toward the drive assembly (150); wherein the retainer limiting portion (131) abuts against the radial inner wall (113) of the housing (110) via a first buffer member (141).

12. The electric tool according to claim 11, wherein: The housing (110) comprises a tubular main body (114) and an end cover flange (115) located at the front end of the main body (114); the retainer limiting portion (131) abuts against the radial inner wall (113) of the end cover flange (115) via a first buffer member (141).

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