A self-locking drill chuck

Abstract

The present invention provides a self-locking drill chuck, wherein the outer diameter of a circle of teeth of the self-locking structure on the drill body is not greater than the inner diameter of the nut, the spring sheet is connected to the nut through its main body and rotates synchronously, in the axial direction of the drill chuck, the main body of the spring sheet moves backward to the rear of the teeth and does not cover the periphery of the teeth, the spring sheet is provided with an axial protrusion at the part of the spring sheet body close to the locking end, and the spring sheet is provided with an axial protrusion on the basis of the spring sheet body so that the locking end reaches the position matching with the teeth in the axial direction. The structure of the present invention helps the front part of the self-locking drill chuck to reduce the diameter, helps the front part of the self-locking drill chuck to achieve a streamlined shape similar to a bullet head and realizes the miniaturization of the self-locking drill chuck; the present invention can fully guarantee the internal space of the drill chuck on the basis of reducing the diameter of the drill body material, reducing the weight and cost of the drill chuck, and meeting the configuration, installation and positioning of various functional components.

Description

Technical Field

[0001] The invention relates to a drill chuck, in particular to a hand-tight drill chuck. Background Art

[0002] In the prior art, a drill chuck is provided with a drill body, a clamping jaw, a nut, a bearing, a gasket, a rotating sleeve, and a rear sleeve. The drill chuck is clamped or loosened by rotating the nut to drive the clamping jaw to move forward or backward. The self-locking structure in the drill chuck is a structure to prevent the drill chuck from being loosened by the reaction force it receives during work. It is generally matched with a spring sheet and teeth on the drill body. The teeth are generally arranged at the front of the drill body, and the spring sheet is located at a position covering the periphery of the teeth and connected to the nut sleeve. In this way, the radial dimension of the front part of the drill chuck is large, and a streamlined shape similar to a cone of the drill chuck cannot be achieved. At present, there is a trend in the drill chuck, hoping that the drill chuck can be more compact, lightweight, and easier to assemble. Not only can it better adapt to the new situation of the development of power tools and achieve the purpose of energy saving and consumption reduction, but it can also help to reduce production costs. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a self-locking drill chuck, which helps to miniaturize the self-locking drill chuck. To this end, the present invention adopts the following technical solutions:

[0004] A self-locking drill chuck comprises a rotating sleeve, a drill body, a nut, a clamping claw, a self-locking structure and a washer, wherein the washer is supported on a step of the drill body, the self-locking structure comprises a circle of teeth and a spring sheet, the circle of teeth being arranged on the circumference of the front part of the drill body, the spring sheet having a locking end and a locking end protrusion which match the teeth, and the rotating sleeve having a cam structure which matches the locking end protrusion and controls the locking end of the spring sheet; the characteristic is that: the outer diameter of the circle of teeth on the drill body is not greater than the inner hole diameter of the nut, the spring sheet is connected with the nut through its main body and rotates synchronously, in the axial direction of the drill chuck, the main body of the spring sheet moves backward to the rear of the teeth and does not cover the periphery of the teeth, the spring sheet is provided with an axial protrusion at the position of the spring sheet main body close to the locking end, and the spring sheet, through the axial protrusion on the basis of the spring sheet main body, makes the locking end reach the position matching the teeth in the axial direction.

[0005] On the basis of adopting the above technical solutions, the present invention may also adopt the following further technical solutions, or use these further technical solutions in combination:

[0006] The drill body is not provided with a nut groove, the nut is an integral nut, the rotating sleeve comprises a main sleeve body and a metal shell, and the main sleeve body is provided with the cam structure.

[0007] The main sleeve body of the rotating sleeve does not extend axially to the axial position corresponding to the rear end of the clamping jaw when the clamping jaw retreats to the limit position. The metal shell of the rotating sleeve is radially positioned with the rear end of the drill body through a rear cover fixed at the rear thereof.

[0008] The drill body is not provided with a nut groove, the nut is an integral nut, and the spring sheet is arranged inside the drill chuck by the spring sheet body being positioned and matched with the nut in the radial direction, being connected to the rotating sleeve in the circumferential direction, and being clamped between the rotating sleeve and the nut in the axial direction.

[0009] The rotating sleeve comprises a main sleeve body and a metal shell, and the main sleeve body is provided with the cam structure and a structure connected with the spring sheet.

[0010] The main body of the spring sheet is provided with a radial convex groove, and the groove bottom of the radial convex groove and the non-convex part of the spring sheet main body and the key at the front end of the nut form a radial positioning structure of the spring sheet, the length of the radial convex groove in the circumferential direction is greater than the length of the key on the nut in the radial convex groove, the groove bottom of the radial convex groove further protrudes outward beside the key and is connected to the rotating sleeve, and the groove wall on one side of the radial convex groove and the key on the nut in the radial convex groove serve as a torque input matching structure for clamping operation before entering the locking state, and the rotating sleeve and the nut are arranged in a torque input matching structure when entering the locking state and entering the non-locking state from the tightening state.

[0011] The rotating sleeve comprises a main sleeve body and a metal shell, wherein the main sleeve body is provided with the cam structure and a structure connected with the spring sheet body; the main sleeve body and the nut are provided with a torque input matching structure when the drill chuck enters a locking state and enters a non-locking state from a locking state.

[0012] The front axial positioning of the integral nut is formed by the cooperation between the integral nut and the main sleeve body. The nut is radially positioned and matched with the main sleeve body, and the diameter of the drill body is reduced to have a certain distance from the nut.

[0013] The nut is placed on the washer through the bearing, and the radial positioning of the bearing is not through the drill body, but through the cooperation with one or two of the washer, the main sleeve body, and the nut;

[0014] The washer is provided with a jaw clearance hole for the jaw; the inner periphery of the washer between the two jaw clearance holes forms a radial positioning fit with the drill body; a plurality of teeth are provided on the inner periphery of the washer between the jaw clearance holes, and the tooth tips of the inner periphery teeth of the washer are embedded in the surface of the drill body; the inner periphery of the washer between the jaw clearance holes is integrally embedded in the groove on the surface of the drill body; the drill body has a positioning step at the front of the supporting step, and the circumference of the positioning step radially positions the washer, the positioning step protrudes from the drill body part in front of it, and the tooth tips of the inner periphery teeth of the washer are embedded in the surface of the drill body at the positioning step.

[0015] The circumferential trajectory of the teeth partially overlaps with the contour of the jaw hole on the surface of the drill body.

[0016] The structure of the present invention helps to reduce the diameter of the front part of the self-locking drill chuck, helps to realize the streamlined shape of the front part of the self-locking drill chuck similar to the bullet head and realizes the miniaturization of the self-locking drill chuck; the present invention can fully ensure the internal space of the drill chuck on the basis of reducing the diameter of the drill body material, reducing the weight and cost of the drill chuck, meet the configuration, installation and positioning of various functional components, and improve the holding ability in the self-locking state, so as to prevent the drill chuck from exiting the self-locking state due to inertia when rotating at high speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an exploded view of an embodiment of the present invention.

[0018] Figure 2 It is a half-section schematic diagram of an embodiment of the present invention.

[0019] Figure 3 Schematic diagram of a nut according to an embodiment of the present invention.

[0020] Figure 3a A schematic diagram of another nut implementation method according to an embodiment of the present invention.

[0021] Figure 4 The figure is a schematic diagram of a spring sheet implementation method according to an embodiment of the present invention.

[0022] Figure 5 for Figure 4 Front view of the spring leaf shown.

[0023] Figure 6 This is a front view of another spring sheet implementation method of an embodiment of the present invention when installed on a nut.

[0024] Figure 7 for Figure 6 A perspective view of the illustrated embodiment.

[0025] Figure 7a For the general Figure 6 The nut in the embodiment shown is replaced by Figure 3a A three-dimensional view of an embodiment after the nut is inserted.

[0026] Figure 8 for Figure 6 Schematic diagram of the spring leaf of the illustrated embodiment.

[0027] Fig. 9 This is a schematic diagram of an embodiment of the present invention without the rotating sleeve and the rear cover.

[0028] Fig.10 Schematic diagram of the internal structure of the main sleeve according to an embodiment of the present invention.

[0029] Fig.11 4 is a cross-sectional view of the main sleeve body according to an embodiment of the present invention.

[0030] Fig.12 It is an AA cross-sectional view of the embodiment of the present invention in a non-locked state.

[0031] Fig.13 It is a BB cross-sectional view of the embodiment of the present invention in a non-locked state. DETAILED DESCRIPTION

[0032] Refer to the accompanying drawings. The self-locking drill chuck provided by the present invention includes a rotating sleeve 2, a drill body 1, a nut 3, a washer 4, a bearing 5, a clamping jaw 6, and a self-locking structure. The drill body is provided with an inclined clamping jaw hole 10 for the clamping jaw 6 to slide forward and backward along the clamping jaw hole 10, and the washer 4 is supported on a step 11 in the middle of the drill body 1. The drill body is not provided with a nut groove, and the nut is an integral nut. The rotating sleeve 2 includes a main sleeve body 21 and a metal shell 22. A decorative steel cap 23 is also provided at the front end of the rotating sleeve. The rotating sleeve is rotatably connected to the front of the drill body through the decorative steel cap 23, and is limited at the front in the axial direction, for example, the rotating sleeve 2 is limited at the front by the cooperation of the clamping ring 12 connected to the drill body 1 and the decorative steel cap 23. The main sleeve body 21 can be made of engineering plastics.

[0033] The front end of the main sleeve 21 is in a truncated cone shape, and the decorative steel cap 23 is also in a matching truncated cone shape, and is bent inside to form a central hole wall 231 that is clearance-matched and radially positioned with the front column 13 of the drill body.

[0034] The main sleeve body 21 of the rotating sleeve 2 does not extend axially to the axial position corresponding to the rear end of the clamping jaws 6 when the clamping jaws 6 retreat to the limit position. The rotating sleeve 2 is radially positioned with the rear end of the drill body by a rear cover 8 fixed to the rear part of the metal shell 22, so that the requirements of the clamping jaws 6 for movement space can be met while reducing the overall diameter of the drill chuck.

[0035] The front axial positioning of the integral nut 3 is formed by the cooperation between the integral nut 3 and the main sleeve body 21. A corresponding limiting cooperation step 211 can be provided inside the main sleeve body 21. The nut 3 is radially positioned with the inner side wall 212 of the main sleeve body 21. The drill body 1 does not directly radially position the nut. The diameter of the drill body 1 is reduced to have a certain interval 15 with the nut 3. The radial positioning of the bearing 5 is also not through the drill body 1. The bearing frame of the bearing 5 has a folded edge 51, which is radially positioned by cooperating with the inner wall of the main sleeve body and / or the washer 4 through the folded edge 51.

[0036] The washer 4 is provided with a jaw clearance hole 41 for the jaws to allow the jaws 6 to move forward and backward after the diameter of the drill body 1 is reduced; the inner periphery 42 of the washer between the two jaw clearance holes 41 forms a radial positioning fit with the drill body; a plurality of teeth 43 are provided on the inner periphery of the washer between the two jaw clearance holes, and the tooth tips of the teeth 43 are embedded in the surface of the drill body, thereby facilitating the installation of the washer 4 and having a circumferential anti-rotation effect.

[0037] The inner periphery of the gasket between the two jaws' clearance holes can be integrally embedded in the groove on the surface of the drill body for easy installation.

[0038] The drill body has a positioning step 16 at the front of the supporting step. The circumference of the positioning step 16 is radially positioned with respect to the washer 4. The positioning step 16 protrudes from the drill body portion in front of it. The tooth tips of the teeth 43 are embedded in the drill body surface at the positioning step.

[0039] The self-locking structure comprises a circle of teeth 14 and a spring sheet 8, wherein the circle of teeth 14 is arranged on the circumferential surface of the front part of the drill body. According to the structure of the present invention, the position of the teeth 14 can be further back in the axial direction than the teeth of the previous self-locking structure, and the circumferential trajectory of the circle of teeth 14 can partially overlap with the contour 101 of the clamping jaw hole 10 on the surface of the drill body in the axial direction, that is, the length of the teeth 141 corresponding to the front end of the clamping jaw hole in the axial direction is shorter than the length of the teeth 142 beside the clamping jaw hole.

[0040] The spring sheet 8 has a locking end 81 and a locking end protrusion 82 that cooperate with the tooth 14, and the main sleeve 21 has a cam structure 216 that controls the locking end of the spring sheet and cooperates with the locking end protrusion 82; the spring sheet 8 is connected to the nut 3 through its main body 80 and rotates synchronously; in the axial direction of the drill chuck, the main body 80 of the spring sheet moves backward to the rear of the tooth 14 and does not cover the periphery of the tooth 14. The spring sheet 8 is provided with an axial protrusion 810 at the position of the spring sheet main body 80 close to the locking end. On the basis of the spring sheet main body 80, the spring sheet 8 uses the axial protrusion 810 to make the locking end 81 reach the position that cooperates with the tooth 14 in the axial direction.

[0041] Reference Figure 3 , 4 5. The spring sheet can be made of material according to its axial height (the axial dimension between the bottom of the spring sheet body 80 and the front end of the axial protrusion 810), and the axial protrusion 810 is formed at the end of the spring sheet body 80.

[0042] Reference Figure 6 , 7 8. The spring sheet can be made only according to the axial height of the spring sheet body 80 and be axially bent forward at the end to form the axial protrusion 810 at the end of the spring sheet body 80.

[0043] The spring sheet 8 is arranged inside the drill chuck by positioning the spring sheet body 80 with the nut 3 in the radial direction, connecting with the main sleeve body 21 in the circumferential direction, and being clamped between the main sleeve body 21 and the nut 3 in the axial direction, which can help reduce the size of the drill chuck and help improve the holding ability in the self-locking state.

[0044] The main body 80 of the spring sheet is provided with a radial convex groove 83, and the radial convex groove 83 is located near the tail of the spring sheet. The groove bottom 831 of the radial convex groove 83 and the non-convex part 84 on the main body of the spring sheet form a radial positioning structure of the spring sheet 8 with the keys 31 and 32 at the front end of the nut 3. The length of the radial convex groove 83 in the circumferential direction is greater than the length of the key 31. The groove bottom of the radial convex groove 83 further protrudes outward 832 at the side part of the key 31 and is connected to the main sleeve 21. A side groove wall 833 of the radial convex groove and the key 31 serve as a torque input matching structure for clamping operation before entering the locking state. The main sleeve 21 is provided with a key 213, and the key 213 cooperates with the groove 33 on the nut 3 to form a torque input matching structure when the drill chuck enters the locking state and enters the non-locking state from the locking state.

[0045] The structure provided on the main sleeve body and connected to the outward protrusion 832 on the spring sheet body is a connecting groove 214 in a locked state and a connecting groove 215 in a non-locked state.

[0046] like Figure 3a , 7a As shown, a third key 34 can be further provided at the front end of the nut 3, with the key 31 centered, the key 32 located on one side of the key 31 and corresponding to the tail end of the spring sheet, the third key 34 located on the other side of the key 31, the radial convex groove 83 located near the tail of the spring sheet, the tail of the spring sheet as a non-convex portion 84 radially matched with the inner side of the key 32, and the non-convex portion 841 of the spring sheet body 80 on the other side of the radial convex groove 83 is positioned and matched with the inner side of the key 32.

[0047] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by any technician in the field of the present invention are included in the protection scope of the present invention.

Claims

1. A self-locking drill chuck, comprising a rotating sleeve, a drill body, a nut, a clamping claw, a self-locking structure, and a washer, wherein the washer is supported on a step of the drill body, the self-locking structure comprises a circle of teeth and a spring sheet, the circle of teeth is arranged on the front circumference of the drill body, the spring sheet has a locking end and a locking end protrusion, and the rotating sleeve has a cam structure that cooperates with the locking end protrusion to control the locking end of the spring sheet; characterized in that: The outer diameter of a circle of teeth on the drill body is not greater than the inner diameter of the nut. The spring sheet is connected to the nut through its main body and rotates synchronously. In the axial direction of the drill chuck, the main body of the spring sheet moves backward to the rear of the teeth and does not cover the periphery of the teeth. The spring sheet is provided with an axial protrusion at a position close to the locking end of the spring sheet main body. The spring sheet is provided with an axial protrusion on the basis of the spring sheet main body so that the locking end reaches a position matching with the teeth in the axial direction. The drill body is not provided with a nut groove, the nut is an integral nut, the rotating sleeve comprises a main sleeve body and a metal shell, and the main sleeve body is provided with the cam structure; The spring sheet is arranged inside the drill chuck by the spring sheet body being positioned and matched with the nut in the radial direction, being connected with the rotating sleeve in the circumferential direction, and being clamped between the rotating sleeve and the nut in the axial direction; The main body of the spring sheet is provided with a radial convex groove, and the groove bottom of the radial convex groove and the non-convex part of the spring sheet main body and the key at the front end of the nut form a radial positioning structure of the spring sheet, the length of the radial convex groove in the circumferential direction is greater than the length of the key on the nut in the radial convex groove, the groove bottom of the radial convex groove further protrudes outward beside the key and is connected to the rotating sleeve, and the groove wall on one side of the radial convex groove and the key on the nut in the radial convex groove serve as a torque input matching structure for clamping operation before entering the locking state, and the rotating sleeve and the nut are arranged in a torque input matching structure when entering the locking state and entering the non-locking state from the locking state.

2. A self-locking drill chuck as claimed in claim 1, characterized in that The main sleeve body of the rotating sleeve does not extend axially to the axial position corresponding to the rear end of the clamping jaw when the clamping jaw retreats to the limit position. The metal shell of the rotating sleeve is radially positioned with the rear end of the drill body through a rear cover fixed at the rear thereof.

3. A self-locking drill chuck as claimed in claim 1, characterized in that The rotating sleeve comprises a main sleeve body and a metal shell, and the main sleeve body is provided with the cam structure and a structure connected with the spring sheet.

4. A self-locking drill chuck as claimed in claim 1, characterized in that The rotating sleeve comprises a main sleeve body and a metal shell, wherein the main sleeve body is provided with the cam structure and a structure connected with the spring sheet body; the main sleeve body and the nut are provided with a torque input matching structure when the drill chuck enters a locking state and enters a non-locking state from a locking state.

5. A self-locking drill chuck as claimed in claim 1, characterized in that The front axial positioning of the integral nut is formed by the cooperation between the integral nut and the main sleeve body. The nut is radially positioned and matched with the main sleeve body, and the diameter of the drill body is reduced to have a certain distance from the nut. The nut is placed on the washer through the bearing, and the radial positioning of the bearing is not through the drill body, but is radially positioned by cooperating with one or two of the washer, the main sleeve body, and the nut.

6. A self-locking drill chuck as claimed in claim 1, characterized in that The washer is provided with a jaw clearance hole for the jaw; the inner periphery of the washer between the two jaw clearance holes forms a radial positioning fit with the drill body; a plurality of teeth are provided on the inner periphery of the washer between the jaw clearance holes, and the tooth tips of the teeth on the inner periphery of the washer are embedded in the surface of the drill body; The inner periphery of the gasket between the jaw clearance holes is integrally embedded in a groove on the surface of the drill body; The drill body has a positioning step in front of the supporting step, the circumference of the positioning step radially positions the washer, the positioning step protrudes from the drill body part in front of it, and the tooth tips of the peripheral teeth in the washer are embedded in the drill body surface at the positioning step.

7. A self-locking drill chuck as claimed in claim 1, characterized in that In the axial direction, the circumferential trajectory of the teeth partially overlaps with the contour of the jaw hole on the drill body surface.

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