Drill chuck and drill chuck jaw

Abstract

The present application provides a drill chuck, comprising a drill body, a nut and a chuck jaw, three jaw holes are equidistantly arranged on the drill body around a center line and are inclined to the center line, the outer side surface of the chuck jaw and the engagement structure of the nut are circular arc teeth, a plurality of the circular arc teeth are arranged along the length direction of the chuck jaw on the outer side surface of the chuck jaw, the circular arc sizes of the plurality of the circular arc teeth are consistent, the radius of the chuck jaw circular arc tooth is less than or equal to the minimum thread radius of the nut, and the extension arc line of the same chuck jaw tooth circular arc is not connected with the extension lines of the two tooth circular arcs adjacent to it above and below. In the clamping range of the present application, the difference of the clamping force for the large-diameter drill and the small-diameter drill is reduced, the assembly of the drill chuck is more convenient, the efficiency is higher, and the production cost is also reduced.

Description

Technical Field

[0001] This invention relates to a drill chuck and the jaws of the drill chuck. Background Technology

[0002] The drill chuck includes a drill body with three jaw holes equidistant from the center line. A nut is installed on the drill body, and the outer surfaces of the three jaws are provided with external threads that mesh with the internal threads of the conical holes of the nut.

[0003] The external threads of the three jaws of the same drill chuck are all based on conical helices; the machining method is described in [link to documentation]. Figure 6 The process involves using a clamping fixture to fix three jaws of the same drill chuck in a conical shape. The outer arc surface of the jaws is machined using a hob along a conical helical curve. This maintains the helical continuity of the same set of jaws, ensuring equal pitch on each jaw. However, due to the characteristics of the conical helix, the radius of the arc closer to the apex of the cone is smaller, resulting in a larger helix angle. Since the jaws move different distances back and forth during operation for drill bits of different diameters, and the engagement position between the jaws and the nut varies, the clamping force (corresponding to a large difference in maximum output torque) differs significantly between large-diameter and small-diameter drill bits. For the same drill chuck, it is possible that the clamping force (maximum output torque) meets the standard for large-diameter drill bits, but may not meet the requirements for small-diameter drill bits. Summary of the Invention

[0004] The purpose of this invention is to provide a drill chuck that reduces the difference in clamping force between large-diameter and small-diameter drill bits within its clamping range. To this end, the invention adopts the following technical solution:

[0005] A drill chuck includes a drill body, a nut, and jaws. Three jaw holes, inclined at an angle to the center line, are equidistantly arranged on the drill body. The jaws are characterized by having a multi-arc toothed engagement structure with the nut, where the multi-arc teeth are arranged along the length of the jaws. The arc size of each arc tooth is uniform; the radius of the arc teeth is less than or equal to the minimum thread radius of the nut; and the extended arc of a single jaw tooth is not connected to the extended arcs of its two adjacent teeth.

[0006] Furthermore, the radii of all the arc-shaped teeth are the same.

[0007] Furthermore,

[0008] Furthermore, the arc-shaped teeth of each jaw are independent entities, and the extended arc of the tooth arc is discontinuous with the arc of the teeth of the other two jaws of the drill chuck.

[0009] Furthermore, the radius of the teeth on the arc of the gripper is smaller than the minimum thread radius of the nut, and the gripper always contacts the nut thread at the apex of the arc during operation.

[0010] Furthermore, the three jaws used in the drill chuck are identical.

[0011] The present invention also provides a drill chuck jaw, which reduces the difference in clamping force for large-diameter drill bits and small-diameter drill bits when the drill chuck uses the jaw. To this end, the present invention adopts the following technical solution: the meshing structure provided on the outer side of the jaw is an arc-shaped tooth, and multiple arc-shaped teeth are provided on the outer side of the jaw along the length direction of the jaw, and the helix angle of the multiple arc-shaped teeth is the same.

[0012] Furthermore, the radii of all the arc-shaped teeth are the same.

[0013] By employing the technical solution of this invention, the meshing part of the jaws is changed, ensuring the consistency of each tooth and reducing the difference in clamping force for large-diameter and small-diameter drill bits. Furthermore, the radius of the arc-shaped teeth of the jaws is less than or equal to the minimum thread radius of the nut, ensuring that the jaws always contact the nut thread at the arc apex during operation, further reducing the aforementioned differences. Moreover, with this invention, the three jaws used in the drill chuck are identical. This eliminates the need for binding in groups of three, as in the past, because the external threads of the three jaws were different. This prevented situations where a defective jaw could render the entire group of three unusable. In comparison, the assembly of the drill chuck is more convenient and efficient, while production costs are reduced. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the gripper at the usage angle in the embodiment provided by the present invention.

[0015] Figure 2 for Figure 1 The right-hand view.

[0016] Figure 3 for Figure 1 AA sectional view.

[0017] Figure 4 This is a view of the drill chuck from direction B.

[0018] Figure 5 This is a cross-sectional view of the drill chuck.

[0019] Figure 6 This is a schematic diagram of the meshing connection between the nut and the clamp.

[0020] Figure 7 This is a schematic diagram of the machining of an existing gripper.

[0021] Figure 8 For Figure 1 A schematic diagram of the existing gripper viewed from the B-direction perspective.

[0022] Figure 9 For existing grippers, according to Figure 1 Enlarged cross-sectional view of line AA.

[0023] Figure 10 A line graph comparing the clamping forces of the drill chuck using the jaws provided by this invention and jaws using existing technology for drill bits of different diameters.

[0024] Figure 11 Histogram comparing the clamping forces of the drill chuck using the jaws provided by this invention and jaws using existing technology for drill bits of different diameters. Detailed Implementation

[0025] Referring to the accompanying drawings, the present invention provides a drill chuck comprising a drill body 1, a nut 2, and jaws 3. The drill body 1 has three jaw holes 11 equidistantly arranged around a center line, inclined to the center line. The outer surface of the jaws 3 engages with the nut 2 via multiple arc-shaped teeth 30. The nut 2 has a central conical hole 20, the wall of which is provided with an internal thread 21. The internal thread 21 is also a conical helix, with a smaller radius and a larger helix angle closer to the apex of the cone. The multiple arc-shaped teeth 30 engage with the internal thread 21.

[0026] Multiple arc-shaped teeth 30 are arranged on the outer side of the gripper 3 along its length. These arc-shaped teeth 30 are inclined at a line 3010 connecting the arc apexes 301 of the multiple arc-shaped teeth 30, as shown in the figure. This inclination causes the outline of the arc-shaped teeth 30 to be a convex arc shape, and the height of the arc apex 301 is higher than the left and right ends 302 of the arc-shaped teeth (or, in other words, the arc apex 301 is farther from the head 302 of the gripper). Preferably, the inclination angles of the multiple arc-shaped teeth 30 towards the connecting line 3010 are the same, such as... Figure 2As shown, the inclination angle a1 of the lower arc is the same as the inclination angle b1 of the upper arc. The radius of the arc teeth 30 of the jaw is less than or equal to (preferably less than) the minimum thread radius of the nut (i.e., the thread radius of the minimum point 210 of the central conical hole 20), so that the jaw always contacts the nut thread at the arc apex 301 during operation. Each arc tooth of the jaw has the same arc size and the same arc radius, which maximizes the consistency of the meshing effect with the nut thread at various positions and improves the consistency of the clamping force of the drill chuck for various diameter drill bits. In this way, when applied to the drill chuck, the three jaws used are identical, which facilitates parts management. Unlike in the past, where the external threads of the three jaws were different, requiring them to be bound in groups of three, and thus potentially leading to the scrapping of all three jaws if one jaw was defective.

[0027] like Figure 6 As shown, the existing method for machining jaws involves using a fixture to fix three jaws C, which are applied to the same drill chuck, in a conical shape. The outer arc surface of the jaws is machined using a hob D along a conical spiral curve path. Figure 7 As shown, the helix angle 'a' at the lower end is different from the helix angle 'b' at the upper end. The helix angle 'a' at the lower end is smaller than the helix angle 'b' at the upper end. The helix angle is the angle between the tangent to the arc and the straight line perpendicular to the center line of the drill chuck. Figure 8 As shown, in the AA section view, the outlines E0 of each thread segment E above it can be seen. The present invention uses arc-shaped teeth, and each arc-shaped tooth has the same radius. Figure 3 As shown in the attached diagram, reference numeral 300 represents the outline of the arc-shaped tooth 30, which does not exist. Figure 8 The situation is shown.

[0028] Table 1 shows the difference in output torque between drill chucks of the same structure when using the jaws provided by this invention (three identical jaws) and when using jaws from existing technology. The table shows that, after adopting the technical solution of this invention, the difference in clamping force between large-diameter drill bits (13mm diameter) and small-diameter drill bits (9mm diameter) is reduced within the clamping range. Figure 10 , 11 The comparison chart generated from this experiment shows that the new process represents a drill chuck using the jaws of this invention, while the old process represents a drill chuck using existing jaws. Table 1:

[0029]

[0030] 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 those skilled in the art within the scope of the present invention are covered by the protection scope of the present invention.

Claims

1. A drill chuck, comprising a drill body, a nut, and jaws, wherein the drill body has three jaw holes equidistantly arranged around a center line and inclined to the center line, characterized in that, The engagement structure between the outer surface of the jaws and the nut consists of multiple arc-shaped teeth. These multiple arc-shaped teeth are arranged along the length of the jaws on the outer surface of the jaws, and the arc size of the multiple arc-shaped teeth is consistent. The radius of the arc-shaped teeth of the jaws is less than or equal to the minimum thread radius of the nut. The extended arc of the same gripper tooth is not connected to the extended arcs of its two adjacent teeth.

2. A drill chuck as described in claim 1, characterized in that, The radii of all the arc-shaped teeth are the same.

3. A drill chuck as described in claim 1, with the jaws viewed from the front, characterized in that, The outline of the arc-shaped teeth is an upward-convex arc.

4. A drill chuck as described in claim 1, characterized in that, Each jaw's arc-shaped tooth is an independent entity, and the extended arc of the tooth's arc is discontinuous with the arcs of the teeth of the other two jaws of the drill chuck.

5. A drill chuck as described in claim 1, characterized in that, The radius of the teeth on the arc of the gripper is smaller than the minimum thread radius of the nut, and the gripper is always in contact with the nut thread at the apex of the arc during operation.

6. A drill chuck as described in claim 1, 2, 3, 4 or 5, characterized in that, The drill chuck uses three identical jaws.

7. A drill chuck jaw, characterized in that, The outer surface of the gripper is provided with a circular arc tooth structure for meshing. Multiple circular arc teeth are provided on the outer surface of the gripper along the length of the gripper, and the multiple circular arc teeth have the same helix angle.

8. A drill chuck jaw as described in claim 7, characterized in that, The radii of all the arc-shaped teeth are the same.

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