Hobbing clamp

Abstract

The utility model relates to the field of modern machinery manufacturing, in particular to a gear hobbing clamp which comprises an installation seat, a gear hobbing clamp body and a gear hobbing clamp body. The installation seat is fixedly installed on a workbench of a machine table, a conical inner cavity is formed in the installation seat, the axis of the conical inner cavity coincides with the rotating center of the workbench, and external threads are arranged on the top of the installation seat. The collet nut is mounted at the top of the mounting seat through an internal thread arranged in the collet nut; and the elastic collet chuck is clamped in the conical inner cavity of the mounting seat. The collet nut and the elastic collet are assembled together, the installation base is screwed through the collet nut, the central spindle is inserted into the elastic collet, and when the collet nut is screwed down, the conical surface of the elastic collet is evenly and elastically contracted in the radial direction, so that the central spindle is accurately locked with high precision and repeated positioning precision. And finally, the workpiece is installed on the mandrel, and the center is matched with the center to abut against the center hole in the mandrel, so that the purpose that the workpiece installed in the mandrel can be accurately machined is achieved.

Description

Technical Field

[0001] The utility model relates to the field of modern mechanical manufacturing, in particular to a hobbing fixture. Background Technique

[0002] Hobbing is a common gear processing method used to produce various types of gears such as spur gears, helical gears, and herringbone gears. The fixture is a key component for fixing and positioning the gear blank in hobbing, and its performance directly affects the processing quality and production efficiency. A commonly used hobbing fixture is positioned by a round table and driven by a key block. According to the characteristics of each part of the gear, that is, inner ring positioning and keyway driving, it is ensured that the gear will not be affected after machining and will not affect the subsequent use of the gear. At the same time, since the side surface of the round table is an inclined surface and can deflect a certain angle with the dial rod, gears with different inner diameters and thicknesses can be adapted.

[0003] The patent with the publication number CN114769743A discloses a flange hobbing fixture with high stability, including a hollow base. A transmission cylinder is rotatably connected to the base, and the transmission cylinder is driven by a power device. A support device is arranged on the transmission cylinder, and the support device is used to support the flat gear blank, and the support device contacts the end surface of the gear blank. It is characterized in that: a positioning device is arranged above the transmission cylinder, and the positioning device is used to position the gear blank so that there is no relative displacement between the gear blank and the transmission cylinder. At the same time, a key block is arranged at the position corresponding to the keyway on the gear blank on the transmission cylinder, and the key block and the keyway cooperate with each other, wherein the key block is connected to the transmission cylinder through a connecting device, and the connecting device is used to provide power to drive the gear blank to rotate.

[0004] The following defects exist in the above related technologies: Using a flange for positioning and realizing the positioning of the mandrel through the mutual cooperation between the key block and the keyway easily leads to poor clamping accuracy of the mandrel. The positioning accuracy is not high, and it may be necessary to additionally correct the position of the mandrel by dial indicator. This will not only affect the machining accuracy and surface quality of the gear, but also may lead to adverse consequences such as low production efficiency and increased scrap rate. Therefore, it is necessary to design a high-precision hobbing fixture to solve the above problems. Summary of the Utility Model

[0005] In order to overcome the disadvantages that the clamping accuracy of the mandrel of the existing hobbing fixture is poor and additional operations such as dial indicator are required to correct the accuracy of the mandrel, the technical problem is: to provide a high-precision hobbing fixture.

[0006] The technical solution is as follows: A hobbing fixture includes: a mounting base fixedly installed on the working table of the machine tool. The mounting base has a conical inner cavity, and the axis of the conical inner cavity coincides with the rotation center of the working table. The top of the mounting base has an external thread; a collet nut installed on the top of the mounting base through an internal thread provided therein; a collet clamped in the conical inner cavity of the mounting base; a mandrel, the lower end of the mandrel is self-centering and clamped by the collet, the upper end of the mandrel is matched with the center hole on it and the center hole of the machine tool and the center hole of the machine tool's center hole, and the mandrel is used for positioning the workpiece; a lower washer arranged at the lower shaft body of the mandrel where the workpiece is installed; an upper washer arranged at the upper shaft body of the mandrel where the workpiece is installed; a locking nut arranged at the top of the mandrel, and the mandrel is used to cooperate with the center hole of the machine tool's center hole.

[0007] Further, the collet nut has an inner conical surface arranged at the inner wall of the top of the collet nut; an eccentric ring arranged at the structure where the inner side of the collet nut ejects, and the inner hole of the eccentric ring is offset relative to the axis of the collet nut.

[0008] Further, both the lower washer and the upper washer are replaceably arranged on the mandrel, and the lower washer and the upper washer can be replaced with corresponding specifications according to the actual size of the clamped workpiece.

[0009] Further, a notch for increasing the turning friction is circumferentially opened on the outer side surface of the collet nut.

[0010] Further, the collet has a lower conical surface arranged at the lower end of the main body of the collet, and the lower conical surface is matched with the conical inner cavity of the mounting base; an upper conical surface arranged at the top end of the main body of the collet, and the upper conical surface is matched with the inner conical surface of the collet nut.

[0011] Further, the collet is also provided with a ring groove arranged between the lower conical surface and the upper conical surface, and the ring groove is slidably clamped and matched with the eccentric ring.

[0012] Further, the mandrel has a clamping position at the lower end of the main body of the mandrel. The clamping position is the loading position where the collet clamps, and the loading position is at the middle and upper end of the main body of the mandrel, and the loading position is where the workpiece is loaded.

[0013] Further, the mandrel includes a shoulder arranged between the clamping position and the loading position, and the shoulder is a raised portion of the shaft body of the mandrel.

[0014] Further, the upper end of the mandrel is also provided with a thread arranged on the outer side wall of the upper end of the mandrel, and the thread is used to adapt to the locking nut to turn the workpiece.

[0015] Further, a central hole is provided at the top end of the mandrel, and the central hole is used to fit the center of the machine tool, so that the mandrel can rotate synchronously under the clamping of the center of the machine tool and the mounting seat.

[0016] The beneficial effects are as follows: In the present utility model, the collet nut and the elastic collet are assembled together, then the collet nut is screwed onto the mounting seat, and the mandrel is inserted into the elastic collet. While tightening the collet nut, the conical surface of the elastic collet uniformly radially elastically contracts, so as to achieve precise locking of the mandrel with high precision and repeated positioning accuracy. Finally, a workpiece is loaded onto the mandrel, and the center hole on the mandrel is topped with a center, so as to achieve the purpose of precise machining of the workpiece loaded on the mandrel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a three-dimensional structural schematic diagram of the present utility model.

[0018] Figure 2 is a sectional view of the overall structure of the present utility model.

[0019] Figure 3 is a three-dimensional structural schematic diagram of the elastic collet of the present utility model.

[0020] Figure 4 is a three-dimensional structural schematic diagram of the collet nut of the present utility model.

[0021] Figure 5 is a sectional view of the mandrel structure of the present utility model.

[0022] Names and serial numbers of components in the figure: 01 - mounting seat, 02 - collet nut, 0201 - inner conical surface, 0202 - eccentric ring, 03 - elastic collet, 0301 - lower conical surface, 0302 - upper conical surface, 0303 - annular groove, 04 - lower washer, 05 - workpiece, 06 - upper washer, 07 - locking nut, 08 - mandrel, 0801 - clamping position, 0802 - shoulder, 0803 - loading position, 0804 - thread, 0805 - central hole, 09 - center. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The preferred technical solutions of the present utility model will be described in detail below with reference to the accompanying drawings.

[0024] Example 1: A hobbing fixture, as Figure 1 and Figure 2As shown in the figure, it includes: a mounting base 01, which is fixedly installed on the workbench of the machine tool. The mounting base 01 is internally provided with a conical inner cavity, and the axis of the conical inner cavity coincides with the rotation center of the workbench. The top of the mounting base 01 is provided with an external thread 0804; a collet nut 02, which is installed on the top of the mounting base 01 through an internal thread 0804 provided inside; an elastic collet 03, which is clamped in the conical inner cavity of the mounting base 01; a mandrel 08, the lower end of the mandrel 08 is self-centered and clamped by the elastic collet 03, and the upper end of the mandrel 08 is matched with the center hole 0805 on it and the center hole 09 of the machine tool. The mandrel 08 is used for positioning the workpiece 05; a lower washer 04, which is arranged at the lower shaft body of the mandrel 08 where the workpiece 05 is installed; an upper washer 06, which is arranged at the upper shaft body of the mandrel 08 where the workpiece 05 is installed; a locking nut 07, which is arranged at the top of the mandrel 08. The mandrel 08 is used to cooperate with the center hole 09 to stably press the workpiece 05 on the mandrel 08. The lower washer 04 and the upper washer 06 are both replaceably arranged on the mandrel 08, and the lower washer 04 and the upper washer 06 can be replaced with corresponding specifications according to the actual size of the clamped workpiece 05.

[0025] As Figure 1 and Figure 4 shown in the figure, the collet nut 02 is internally provided with an inner conical surface 0201, and the inner conical surface 0201 is arranged at the inner wall of the top of the collet nut 02; an eccentric ring 0202, the eccentric ring 0202 is arranged at the structure ejected from the inner side of the collet nut 02. The inner hole of the eccentric ring 0202 is offset relative to the axis of the collet nut 02. A notch for increasing the screwing friction is circumferentially opened on the outer side surface of the collet nut 02.

[0026] As Figure 2 and Figure 3 shown in the figure, the elastic collet 03 is provided with a lower conical surface 0301, and the lower conical surface 0301 is set at the lower end of the main body of the elastic collet 03. The lower conical surface 0301 is matched with the conical inner cavity of the mounting base 01; an upper conical surface 0302, the upper conical surface 0302 is set at the top of the main body of the elastic collet 03. The upper conical surface 0302 is matched with the inner conical surface 0201 of the collet nut 02. The elastic collet 03 is also provided with a ring groove 0303, and the ring groove 0303 is arranged between the lower conical surface 0301 and the upper conical surface 0302. The ring groove 0303 is slidably clamped and matched with the eccentric ring 0202.

[0027] As Figure 2 and Figure 5As shown, a clamping position 0801 is provided on the mandrel 08. The clamping position 0801 is at the lower end of the main body of the mandrel 08. The clamping position 0801 is the loading position 0803 where the elastic collet 03 clamps. The loading position 0803 is at the upper middle part of the main body of the mandrel 08. The loading position 0803 is where the workpiece 05 is loaded. The mandrel 08 includes a shoulder 0802. The shoulder 0802 is provided between the clamping position 0801 and the loading position 0803. The shoulder 0802 is a raised part of the shaft body of the mandrel 08. A thread 0804 is also provided at the upper end of the mandrel 08. The thread 0804 is provided on the outer side wall at the upper end of the mandrel 08. The thread 0804 is used to cooperate with the locking nut 07 to twist the workpiece 05. A central hole 0805 is opened at the top end of the mandrel 08. The central hole 0805 is used to cooperate with the center point 09 of the machine tool, so that the mandrel 08 can rotate synchronously under the clamping of the center point 09 of the machine tool and the mounting seat 01.

[0028] Before using this fixture to process gear hobbing, the operator first fixedly installs the mounting seat 01 onto the workbench for gear hobbing processing, then takes out a collet nut 02, squeezes and snaps it into the elastic collet 03. At this time, the eccentric ring 0202 of the collet nut 02 will be caught in the ring groove 0303 of the elastic collet 03, and the inner conical surface 0201 of the collet nut 02 faces the upper conical surface 0302 of the elastic collet 03. After installing the collet nut 02 with the elastic collet 03, screw the collet nut 02 with the elastic collet 03 onto the mounting seat 01. At this time, the collet nut 02 is not completely tightened on the thread 0804 of the mounting seat 01. Then insert the mandrel 08 into the elastic collet 03 from top to bottom. At this time, the clamping position 0801 of the mandrel 08 will enter the inner hole of the elastic collet 03, and the lower edge surface of the shoulder 0802 of the mandrel 08 will be in contact with the top surface of the elastic collet 03. Then completely tighten the untightened collet nut 02 on the mounting seat 01, so that the internal elastic collet 03 uniformly contracts radially under the force extrusion of the two end conical surfaces until the mandrel 08 is completely locked. Similarly, when it is necessary to disassemble or replace the fixture parts, first unscrew the collet nut 02 in the reverse direction, so that the elastic collet 03 no longer clamps. Under the action of the eccentric ejection structure of the collet nut 02, the mandrel 08 can be pulled out from the elastic collet 03. Finally, unscrew the collet nut 02, and unhook the collet nut 02 from the elastic collet 03 to complete the rapid disassembly of the fixture.

[0029] After the elastic collet 03 stably and completely locks and installs the mandrel 08, first, the lower washer 04, the workpiece 05, and the upper washer 06 are successively sleeved on the mandrel 08 on the mounting base 01. At this time, the lower end of the lower washer 04 will be in close contact with the upper edge surface of the shoulder 0802 of the mandrel 08, and the workpiece 05 will be stably clamped between the lower washer 04 and the upper washer 06. Thus, the vibration effect during the machining of the workpiece 05 is reduced through the lower washer 04 and the upper washer 06. Then, the locking nut 07 is screwed onto the upper end of the mandrel 08 through the thread 0804 but not tightened. Finally, the lower pressing center point 09 of the machine tool is pressed against the center hole 0805 on the mandrel 08, and at the same time, the locking nut 07 is tightened in cooperation to press the workpiece 05 under the action of the lower washer 04 and the upper washer 06. Then, the machine tool equipment is started to perform hobbing machining on the workpiece 05. When the machining of the workpiece 05 is completed, similarly, the center point 09 is moved upward and the locking nut 07 is loosened, and then the upper washer 06, the workpiece 05, and the lower washer 04 are successively removed, and the convenient removal of the workpiece 05 can be completed.

[0030] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A hobbing machining fixture, comprising: Mounting base, the mounting base is fixedly installed on the machine table workbench, a conical inner cavity is provided inside the mounting base, the axis of the conical inner cavity coincides with the rotation center of the workbench, and an external thread is provided at the top of the mounting base; characterized in that, a collet nut is installed on the top of the mounting base through an internally provided internal thread; an elastic collet is clamped in the conical inner cavity of the mounting base; a mandrel, the lower end of the mandrel is self-centering and clamped by the elastic collet, the upper end of the mandrel is matched with the center hole on it and the center hole of the machine tool and the center hole of the machine tool is used for workpiece positioning; a lower washer is arranged at the lower shaft body of the mandrel where the workpiece is installed; an upper washer is arranged at the upper shaft body of the mandrel where the workpiece is installed; a locking nut is arranged at the top of the mandrel, and the mandrel is used to cooperate with the center hole of the machine tool and the center hole of the machine tool is used for workpiece positioning.

2. The hobbing fixture according to claim 1, wherein An inner conical surface is provided inside the collet nut, and the inner conical surface is arranged at the inner wall of the top of the collet nut; an eccentric ring, the eccentric ring is arranged at the structure where the inner side of the collet nut ejects, and the inner hole of the eccentric ring is offset relative to the axis of the collet nut.

3. The hobbing fixture according to claim 2, characterized in that, Both the lower washer and the upper washer are replaceably arranged on the mandrel, and the lower washer and the upper washer can be replaced with corresponding specifications according to the actual size of the clamped workpiece.

4. A hobbing machining fixture according to claim 3, characterized in that, A notch for increasing the screwing friction is circumferentially opened on the outer side surface of the collet nut.

5. A hobbing machining fixture according to claim 4, characterized in that, A lower conical surface is provided on the elastic collet, and the lower conical surface is arranged at the lower end of the main body of the elastic collet, and the lower conical surface is matched with the conical inner cavity of the mounting base; an upper conical surface, the upper conical surface is arranged at the top end of the main body of the elastic collet, and the upper conical surface is matched with the inner conical surface of the collet nut.

6. The hobbing fixture according to claim 5, characterized in that, A ring groove is further provided on the elastic collet, and the ring groove is arranged between the lower conical surface and the upper conical surface, and the ring groove is slidably clamped and matched with the eccentric ring.

7. The hobbing fixture according to claim 6, characterized in that, A clamping position is provided on the mandrel, and the clamping position is the lower end of the main body of the mandrel, and the clamping position is the loading position clamped by the elastic collet, and the loading position is the middle upper end of the main body of the mandrel.

8. A hobbing fixture according to claim 7, characterized in that, A shoulder is included on the mandrel, and the shoulder is arranged between the clamping position and the loading position, and the shoulder is the protruding part of the shaft body of the mandrel.

9. A hobbing fixture according to claim 8, characterized in that, A thread is further provided at the upper end of the mandrel, and the thread is arranged on the outer side wall of the upper end of the mandrel.

10. A hobbing fixture according to claim 9, characterized in that, A center hole is opened at the top end of the mandrel, and the center hole is used to adapt to the center hole of the machine tool and the center hole of the machine tool is used for workpiece positioning.

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