Electric hammer drill bit quick clamping device

Abstract

The invention discloses a quick clamping device for an electric hammer drill, comprising a front cover, a cylinder body, and a clamping mechanism. The clamping mechanism comprises a drill sleeve, a clamping sleeve, a replacement sleeve, and a drill. The drill sleeve is provided with first and second steel ball grooves and a cylindrical pin positioning groove respectively. The clamping sleeve is provided on the drill sleeve. An elastic clamping ring for pressing the steel ball is installed on the clamping ring slot. A cylindrical pin is installed on the cylindrical pin positioning groove. The outer side of the cylindrical pin cooperates with the involute groove, and the inner side cooperates with the clamping groove of the drill. The steel cylindrical pin is in a loose fit in the initial state. When the drill is installed and the replacement sleeve is rotated, the replacement sleeve drives the steel ball to slide from the second steel ball groove to the first steel ball groove through the clamping sleeve. The cylindrical pin slides from the distal end to the proximal end relative to the involute groove of the clamping sleeve and pushes the cylindrical pin to cooperate with the clamping groove to clamp the drill. After adopting this structure, it has the advantages of reasonable structural design, stable and reliable clamping, good durability, and long product service life.

Description

Technical Field

[0001] The invention relates to the technical field of drill bit clamping, in particular to an electric hammer drill bit quick clamping device used in conjunction with an electric hammer for quickly installing and disassembling the drill bit. Background Art

[0002] The electric hammer is an electric drilling tool that can both drive the drill bit to rotate and reciprocate to hammer the drill bit. When the electric hammer is working, the transmission mechanism drives the drill bit to rotate. At the same time, there is a reciprocating hammering motion driven by the crankshaft connecting rod piston in the vertical direction. The compressed air in the cylinder reciprocates to make the air pressure in the cylinder change periodically. The changing air pressure drives the hammer in the cylinder to reciprocate and hit the drill bit. It is mainly used to drill holes in concrete, floor slabs, brick walls and stones. During the use of the electric hammer, the drill bit of the electric hammer needs to be replaced frequently. At present, the market generally uses a clamping device that drives the steel ball to clamp the drill bit through a spring to drive the clamping sleeve. The clamping device has the following problems during use: First, the contact area between the steel ball and the drill bit is small, and the friction is more serious. During the replacement of the drill bit, the patent has the problem that the steel ball is seriously worn, which easily causes the electric hammer drill bit to be unable to be firmly clamped. Second, the steel ball is worn more than the drill sleeve, and the drill sleeve cannot position the steel ball, and it directly falls out of the positioning hole of the drill sleeve, causing the cylinder body to be damaged and scrapped. In view of the above problems, many manufacturers and knowledgeable people have carried out development and research, but no ideal product has been launched so far. Summary of the invention

[0003] In order to overcome the above-mentioned defects in the prior art, the purpose of the present invention is to provide a quick clamping device for an electric hammer drill bit with reasonable structural design, convenient operation and use, stable and reliable clamping, good durability and long product service life.

[0004] The present invention creates a technical solution adopted to solve the above technical problems, which includes a front cover fixed on the machine body, a cylinder body rotatable relative to the front cover, and a clamping mechanism. The clamping mechanism includes a drill sleeve, a clamping sleeve, a replacement sleeve, and a drill bit which are connected to the cylinder body as a whole. The drill sleeve is provided with a first steel ball groove, a second steel ball groove, and a cylindrical pin positioning groove respectively. The inner wall of the clamping sleeve is provided with an involute groove, and the outer wall is provided with a clamping ring groove and a steel ball hole opened on the clamping ring groove. The clamping sleeve is rotatably sleeved on the drill sleeve, and the steel ball hole thereof is provided with steel balls matching the first steel ball groove and the second steel ball groove. The clamping ring groove is provided with a steel ball. An elastic clamping ring is installed to press the steel ball, and a movable cylindrical pin is installed on the cylindrical pin positioning groove. The outer side of the cylindrical pin cooperates with the involute groove, and the inner side of the cylindrical pin cooperates with the clamping groove of the drill bit. The replacement sleeve fixing sleeve is arranged on the clamping sleeve; in the initial state, the steel ball cooperates with the second steel ball groove, and the cylindrical pin cooperates with the distal end of the involute groove, and the cylindrical pin is in a loose fit at this time; when the drill bit is installed and the replacement sleeve is rotated by a certain angle, the replacement sleeve drives the steel ball to slide from the second steel ball groove to the first steel ball groove through the clamping sleeve, and the cylindrical pin slides from the distal end to the proximal end relative to the involute groove of the clamping sleeve and pushes the cylindrical pin to cooperate with the clamping groove to clamp the drill bit.

[0005] According to a further solution created by the present invention, the angle between the first steel ball groove and the second steel ball groove is controlled to be between 45 and 65 degrees.

[0006] According to a further solution of the present invention, the elastic clamping ring has an opening, and a positioning pin fixedly connected to the clamping sleeve is provided at the opening.

[0007] According to a further solution of the present invention, a protective sleeve positioning groove and a protective sleeve clamping groove are provided on the drill sleeve, and the protective sleeve is fixed on the drill sleeve by cooperating with the protective sleeve positioning groove and the protective sleeve clamping groove.

[0008] According to a further solution of the present invention, the replacement sleeve is provided with a coupling surface or coupling teeth, and the clamping sleeve is sleeved with the coupling surface or coupling teeth through cooperation.

[0009] According to a further solution of the present invention, a clamping arrow is provided on the replacement sleeve, and a release mark and a locking mark cooperating with the clamping arrow are correspondingly provided on the protective sleeve.

[0010] After adopting the above structure, compared with the prior art, there are the following advantages and effects: First, in the initial state, the steel ball cooperates with the second steel ball groove, and the cylindrical pin cooperates with the distal end of the involute groove, and the cylindrical pin is in a loose fit at this time; when the drill bit is installed and the replacement sleeve is rotated to a certain angle, the replacement sleeve drives the steel ball to slide from the second steel ball groove to the first steel ball groove through the clamping sleeve, and the cylindrical pin slides from the distal end to the proximal end relative to the involute groove of the clamping sleeve and pushes the cylindrical pin to cooperate with the clamping groove to clamp the drill bit, which can ensure that the cylindrical pin and the clamping groove of the drill bit cooperate stably and reliably. Second, the elastic clamping ring can ensure that the steel ball is flexible when rotating and reliable when positioning, and will not fall out of the steel ball hole of the clamping sleeve, and the positioning pin can prevent the elastic clamping ring from rotating and shifting. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the three-dimensional structure created by the present invention.

[0012] Figure 2 Schematic diagram of the decomposition structure created by the present invention.

[0013] Figure 3 It is a schematic diagram of the matching structure created by the present invention.

[0014] Figure 4 For the invention, when the drill bit is not installed Figure 3 Schematic diagram of the AA cross-section structure.

[0015] Figure 5 When the drill bit is installed for the invention Figure 3 Schematic diagram of the AA cross-section structure.

[0016] Among them, 1 cylinder body, 11 drill sleeve, 12 first steel ball groove, 13 protective sleeve slot, 14 protective sleeve positioning groove, 15 cylindrical pin, 16 cylindrical pin positioning groove, 17 second steel ball groove, 2 front cover, 3 replacement sleeve, 31 clamping arrow, 4 protective sleeve, 41 release mark, 42 ​​locking mark, 5 drill bit, 51 clamping groove, 6 clamping sleeve, 61 positioning pin, 62 coupling surface or coupling tooth, 63 steel ball, 64 clamping ring slot, 65 involute slot, 7 elastic clamping ring. DETAILED DESCRIPTION

[0017] Figures 1 to 5As shown, the first specific implementation scheme of the electric hammer drill bit quick clamping device created by the present invention comprises a front cover 2 fixed on the machine body, a cylinder body 1 rotatable relative to the front cover, and a clamping mechanism, wherein the clamping mechanism comprises a drill sleeve 11 connected to the cylinder body 1 as a whole, a clamping sleeve 6, a replacement sleeve 3, and a drill bit 5, the drill sleeve 11 is provided with a first steel ball groove 12, a second steel ball groove 17 and a cylindrical pin positioning groove 16, the inner wall of the clamping sleeve 6 is provided with an involute groove 65, the outer wall is provided with a clamping ring groove 64 and a steel ball hole opened on the clamping ring groove 64; the clamping sleeve 6 is rotatably sleeved on the drill sleeve 11, and the steel ball hole thereof is provided with a steel ball 63 matching with the first steel ball groove 12 and the second steel ball groove 17, the clamping ring groove 64 is provided with an elastic clamping ring 7 for pressing the steel ball 63, and the cylindrical pin positioning groove 16 is provided with a movable cylindrical pin 15 A raised portion is provided on the inner side of the cylindrical pin 15 , and the outer side of the cylindrical pin 15 cooperates with the involute groove 65 . The raised portion on the inner side of the cylindrical pin 15 cooperates with the clamping groove 51 of the drill bit 5 . The replacement sleeve 3 is fixedly mounted on the clamping sleeve 6 .

[0018] In the initial state of the invention, the steel ball 63 cooperates with the second steel ball groove 17, and the cylindrical pin 15 cooperates with the distal end of the involute groove 65, and the cylindrical pin 15 is in a loose fit at this time; when the drill bit 5 needs to be installed, the clamping groove 51 of the drill bit 5 is aligned with the release mark 41 and the clamping arrow 31 and inserted into the drill sleeve 11, and then the replacement sleeve 3 is rotated 60 degrees. The replacement sleeve 3 drives the steel ball 63 to slide from the second steel ball groove 17 to the first steel ball groove 12 through the clamping sleeve 6, and the cylindrical pin 15 slides from the distal end to the proximal end relative to the involute groove 65 of the clamping sleeve 6 and pushes the cylindrical pin 15 to cooperate with the clamping groove 51 to clamp the drill bit 5, thereby completing the clamping of the drill bit 5; when rotating, the drill sleeve 11 drives the drill bit 5 to rotate through the cylindrical pin 15, and when the cylinder body 1 drives the hammer to reciprocate and hit the drill bit 5, the cylindrical pin 15 can move axially relative to the clamping groove 51 of the drill bit 5. The procedure for replacing the drill bit 5 is opposite to that for installing the drill bit 5 , which will not be repeated here.

[0019] In order to ensure that the involute groove 65 has a relatively reasonable arc length, the included angle between the first steel ball groove 12 and the second steel ball groove 17 is controlled to be between 45 and 65 degrees, and the included angle given in this embodiment is 60 degrees.

[0020] In order to prevent the elastic clamping ring 7 from rotating and shifting, the elastic clamping ring 7 has an opening, and a positioning pin 61 fixedly connected to the clamping sleeve 6 is provided at the opening.

[0021] In order to provide better protection, the drill sleeve 11 is provided with a protective sleeve positioning groove 14 and a protective sleeve clamping groove 13 , and the protective sleeve 4 is fixed on the drill sleeve 11 by cooperating with the protective sleeve positioning groove 14 and the protective sleeve clamping groove 13 .

[0022] The replacement sleeve 3 is provided with a coupling surface or coupling teeth 62 , and the clamping sleeve 6 is sleeved with the coupling surface or coupling teeth 62 by cooperating with the clamping sleeve 6 .

[0023] In order to facilitate the clamping of the drill bit, a clamping arrow 31 is provided on the replacement sleeve 3, and a release mark 41 and a locking mark 42 that match the clamping arrow 31 are correspondingly provided on the protective sleeve 4.

[0024] The above is only a specific embodiment of the present invention and does not limit the present invention in any form. Simple modifications, equivalent changes or modifications made without departing from the technical solution of the present invention are all within the protection scope of the present invention.

Claims

1. A quick clamping device for an electric hammer drill, comprising a front cover (2) fixed to a machine body, a cylinder body (1) rotatable relative to the front cover (2), and a clamping mechanism, wherein: The clamping mechanism comprises a drill sleeve (11) connected to the cylinder body (1), a clamping sleeve (6), a replacement sleeve (3), and a drill bit (5). The drill sleeve (11) is provided with a first steel ball groove (12), a second steel ball groove (17), and a cylindrical pin positioning groove (16) correspondingly. The inner wall of the clamping sleeve (6) is provided with an involute groove (65), and the outer wall is provided with a clamping ring groove (64) and a steel ball hole opened on the clamping ring groove (64). The clamping sleeve (6) is rotatably sleeved on the drill sleeve (11), and the steel ball hole thereof is provided with a steel ball (63) matched with the first steel ball groove (12) and the second steel ball groove (17). An elastic clamping ring (7) for pressing the steel ball (63) is installed on the clamping ring groove (64), and a movable cylindrical pin (15) is installed on the cylindrical pin positioning groove (16). ), the outer side of the cylindrical pin (15) cooperates with the involute groove (65), the inner side of the cylindrical pin (15) cooperates with the clamping groove (51) of the drill bit (5), and the replacement sleeve (3) is fixedly mounted on the clamping sleeve (6); in the initial state, the steel ball (63) cooperates with the second steel ball groove (17), and the cylindrical pin (15) cooperates with the distal end of the involute groove (65), and the cylindrical pin (15) is in a loose fit at this time; when the drill bit (5) is installed and the replacement sleeve (3) is rotated by a certain angle, the replacement sleeve (3) drives the steel ball (63) to slide from the second steel ball groove (17) to the first steel ball groove (12) through the clamping sleeve (6), and the cylindrical pin (15) slides from the distal end to the proximal end relative to the involute groove (65) of the clamping sleeve (6) and pushes the cylindrical pin (15) to cooperate with the clamping groove (51) to clamp the drill bit (5).

2. The electric hammer drill bit quick clamping device according to claim 1 is characterized in that: The included angle between the first steel ball groove (12) and the second steel ball groove (17) is controlled to be between 45 and 65 degrees.

3. The electric hammer drill bit quick clamping device according to claim 1 or 2, characterized in that: The elastic clamping ring (7) has an opening, and a positioning pin (61) fixedly connected to the clamping sleeve (6) is provided at the opening.

4. The electric hammer drill bit quick clamping device according to claim 3 is characterized in that: The drill sleeve (11) is provided with a protective sleeve positioning groove (14) and a protective sleeve clamping groove (13), and the protective sleeve (4) is fixed on the drill sleeve (11) by cooperating with the protective sleeve positioning groove (14) and the protective sleeve clamping groove (13).

5. The electric hammer drill bit quick clamping device according to claim 4 is characterized in that: The replacement sleeve (3) is provided with a coupling surface or coupling teeth (62), and the clamping sleeve (6) is sleeved with the coupling surface or coupling teeth (62) by cooperating with the coupling surface or coupling teeth (62).

6. The electric hammer drill bit quick clamping device according to claim 5 is characterized in that: The replacement sleeve (3) is provided with a clamping arrow (31), and the protective sleeve (4) is correspondingly provided with a release mark (41) and a locking mark (42) that match the clamping arrow (31).

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