An outer embracing fixing device for polishing a cylindrical workpiece

Abstract

The utility model provides a kind of external embracing type fixing device for polishing cylindrical workpiece, it is related to mechanical clamp technical field, including hollow spindle, embrace mechanism and adjusting mechanism, the hollow spindle is rotatably installed on bearing seat, the hollow spindle front end fixed installation has the limiting sleeve of inner taper surface and is formed with limiting sleeve and a cavity;The embrace mechanism is movably arranged in cavity along the axis of cavity, the front end of the embrace mechanism is equipped with elastic embrace head, the elastic embrace head is equipped with the outer taper surface matched with inner taper surface;The rear end of the hollow spindle is equipped with adjusting mechanism for driving embrace mechanism to move along axis in cavity, the adjusting mechanism is drivingly connected with embrace mechanism;The hollow spindle is synchronously rotated with embrace head in embracing state by limiting sleeve. Realize synchronous efficient, non-destructive polishing of the inner and outer surface of cylindrical workpiece, and give consideration to clamping reliability and machining accessibility.

Description

Technical Field

[0001] This utility model relates to the field of mechanical clamping technology, specifically to an external clamping fixing device for polishing cylindrical workpieces. Background Technology

[0002] When polishing cylindrical workpieces, reliable workpiece fixation and surface protection are core requirements. Currently, mainstream fixation methods all have inherent defects that are difficult to overcome:

[0003] Firstly, the three-jaw chuck external clamping method. Although this method provides a secure clamping, the rigid jaws directly exert force on the outer wall of the workpiece. The strong concentrated stress can easily leave permanent damage such as indentations and clamping marks on the smooth surface, leading to product scrap and low yield.

[0004] Secondly, the internal mandrel clamping method. Although this method can avoid damage to the outer surface, its mandrel rod penetrates through the inner cavity of the workpiece, seriously encroaching on the working space of the polishing tool, hindering the entry and movement of the abrasive (such as cloth wheel, sanding belt), resulting in the inner wall of the workpiece not being effectively polished, forming a new processing blind spot.

[0005] In summary, existing fixture structures, due to their inherent design limitations, cannot simultaneously meet the dual requirements of "damage-free clamping" and "interference-free machining." They either damage the outer surface or hinder the machining of the inner wall, making it difficult to meet the production needs of efficient, high-quality full-surface polishing of cylindrical workpieces. Therefore, this utility model proposes an external clamping and fixing device for polishing cylindrical workpieces. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model proposes an external clamping and fixing device for polishing cylindrical workpieces, which enables simultaneous, efficient, and non-destructive polishing of the inner and outer surfaces of cylindrical workpieces, while taking into account both clamping reliability and machining accessibility.

[0007] The technical solution of this utility model is implemented as follows:

[0008] An external clamping and fixing device for polishing cylindrical workpieces includes a hollow spindle, a clamping mechanism and an adjusting mechanism. The hollow spindle is rotatably mounted on a bearing seat. A limiting sleeve with an inner conical surface is fixedly mounted at the front end of the hollow spindle and together with the limiting sleeve forms a cavity.

[0009] The clamping mechanism is movably disposed in the cavity along the axis of the cavity, and the front end of the clamping mechanism is provided with an elastic clamping head, and the elastic clamping head is provided with an outer conical surface that cooperates with the inner conical surface.

[0010] The rear end of the hollow spindle is provided with an adjustment mechanism for driving the clamping mechanism to move along the axis in the cavity, and the adjustment mechanism is connected to the clamping mechanism in a transmission manner.

[0011] The hollow spindle rotates synchronously with the clamping head, which is in a clamping state, through a limiting sleeve.

[0012] Preferably, the adjusting mechanism includes an adjusting nut, and the rear end of the clamping mechanism is provided with an external thread adapted to the adjusting nut and forms a threaded transmission pair with the adjusting nut.

[0013] Preferably, the adjusting mechanism includes a rigid screw, one end of which is connected to an adjusting nut, and the other end is connected to an elastic clamping head.

[0014] Preferably, the external thread path at the tail of the screw has at least two axial gaps, and the adjusting nut has a pin that penetrates radially and engages with the gaps.

[0015] Preferably, a first washer is provided between the adjusting nut and the rear end of the hollow spindle.

[0016] Preferably, the elastic clamping head is a trumpet-shaped structure with an opening at the rear end.

[0017] Preferably, the elastic clamping head has several strip-shaped slits extending to the front end along the axial direction and is divided by the strip-shaped slits to form multiple independent clamping petals, and the outer wall of the clamping petals is provided with an outer conical surface.

[0018] Preferably, at least two seals are provided between the hollow spindle and the bearing housing, and the seals are respectively located on both axial sides of the bearing housing.

[0019] Preferably, a driven wheel is fixedly connected to the outer wall of the hollow spindle.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] By adjusting the mechanism to drive the clamping mechanism axially, and controlling the radial expansion and contraction of the elastic clamping head, rapid and non-destructive clamping of cylindrical workpieces is achieved. After the workpiece is placed in, the clamping head retracts and contracts, using its large-area flexible contact surface to evenly clamp the outer wall of the workpiece, completely avoiding the indentations and damage caused by point contact in traditional three-jaw chucks. The clamping head ensures that the polishing tool can enter the workpiece without obstruction, completely eliminating the processing blind spots caused by the internal mandrel method. At the same time, the clamping head achieves locking and fixation through the tight fit between its outer conical surface and the inner conical surface of the limiting sleeve, ensuring the reliability of power transmission. When the hollow spindle rotates, the workpiece rotates synchronously and coaxially through this conical surface fit, thereby achieving synchronous, efficient, and non-destructive polishing of the inner and outer surfaces of the cylindrical workpiece, taking into account both clamping reliability and processing accessibility. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a three-dimensional structural diagram of an external clamping and fixing device for polishing cylindrical workpieces according to the present invention;

[0024] Figure 2 This is an axial half-sectional view of an external clamping fixing device for polishing cylindrical workpieces according to this utility model;

[0025] Figure labels: 1-Hollow spindle; 11-Seal; 12-Driven wheel; 2-Clamping mechanism; 3-Adjusting mechanism; 31-Adjusting nut; 32-Screw; 33-Gap; 34-Pin; 35-First washer; 4-Bearing seat; 5-Limiting sleeve; 51-Inner conical surface; 6-Cavity; 7-Clamping head; 71-Gap; 72-Clamping flap; 73-Outer conical surface. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] This embodiment proposes an external clamping and fixing device for polishing cylindrical workpieces, such as... Figure 1 and Figure 2 As shown, the device includes a hollow spindle 1, a clamping mechanism 2, and an adjusting mechanism 3. The hollow spindle 1 is rotatably mounted on a bearing seat 4 via precision bearings, ensuring stability and coaxiality during spindle rotation. A limiting sleeve 5 with a precision inner conical surface 51 is fixedly mounted at the front end of the hollow spindle 1 via a flange or thread. The hollow spindle 1 and the limiting sleeve 5 together form a smooth cavity 6, which provides guidance for the clamping mechanism.

[0030] The clamping mechanism 2 is movably disposed within the cavity 6 along its axis, employing a clearance fit to ensure smooth movement while preventing wobbling. The front end of the clamping mechanism 2 is equipped with an elastic clamping head 7 made of 65Mn spring steel. This elastic clamping head 7 undergoes heat treatment to achieve excellent elasticity and wear resistance. Its outer surface is provided with a precision outer conical surface 73 that mates with the inner conical surface 51. The conical surface angle is preferably 15-30 degrees to ensure good self-locking and force transmission efficiency.

[0031] The rear end of the hollow spindle 1 is provided with an adjustment mechanism 3 for driving the clamping mechanism 2 to move along the axis in the cavity 6. The adjustment mechanism 3 is connected to the clamping mechanism 2 by a threaded drive, and the precise axial displacement control of the clamping mechanism 2 can be achieved by rotating the adjustment mechanism 3.

[0032] The hollow spindle 1 rotates synchronously with the clamping head in a clamping state through the limiting sleeve 5. Its dynamic balance level is not lower than G6.3, ensuring smooth operation and low vibration at high speed (up to 1500 rpm).

[0033] In this embodiment, the adjusting mechanism 3 includes an adjusting nut 31, and the rear end of the clamping mechanism 2 is machined with a precision external thread that matches the adjusting nut 31. The thread accuracy reaches 6g level, forming a reliable threaded transmission pair with the adjusting nut 31, which has the characteristics of good self-locking and high transmission efficiency.

[0034] In this embodiment, the clamping mechanism 2 includes a rigid screw 32, which is made of 45# steel with heat treatment to ensure sufficient strength and rigidity. One end of the screw 32 is connected to the adjusting nut 31, and the other end is fixed to the elastic clamping head 7 through an interference fit or threaded connection. A pin is provided at the connection point for anti-rotation protection.

[0035] In this embodiment, at least two axial gaps 33 are provided on the external thread path at the tail of the screw 32, and the gap depth is 1.2-1.5 times the thread depth. A pin 34 is provided radially through the adjusting nut 31 to engage with the gaps 33. The pin 34 is made of hardened steel. When the adjusting nut 31 is rotated to the predetermined position, inserting the pin 34 can effectively prevent the nut from loosening and ensure stable and reliable clamping force.

[0036] In this embodiment, a first washer 35 is provided between the adjusting nut 31 and the rear end of the hollow spindle 1. The washer is made of copper-based alloy material, which not only reduces friction but also effectively prevents the threaded pair from seizing and extends the service life.

[0037] In this embodiment, the elastic clamping head 7 is a trumpet-shaped structure with an opening at the rear end, and its opening angle is 60-90 degrees, ensuring that it can provide a sufficient clamping range when expanding to adapt to workpieces of different diameters.

[0038] In this embodiment, the elastic clamping head 7 has at least two evenly distributed strip-shaped slits 71 along its axial direction. The slit width is 0.5-1mm, and the depth extends to the front end of the clamping head. Each strip-shaped slit 71 divides the elastic clamping head 7 into multiple independent clamping petals 72. The outer wall of each clamping petal 72 is machined with a precise outer conical surface 73, and the surface roughness Ra ≤ 1.6μm of the conical surface ensures a good fit with the inner conical surface 51 of the limiting sleeve.

[0039] At least two seals 11 are provided between the hollow spindle 1 and the bearing housing 4. The seals 11 are made of fluororubber material, which is wear-resistant and high-temperature resistant. The two seals 11 are located on both sides of the bearing housing 4 along the axial direction, forming an effective labyrinth seal structure, which effectively prevents polishing dust and coolant from entering the bearing and extends the service life of the bearing.

[0040] In this embodiment, a driven wheel 12 is fixedly connected to the outer wall of the hollow spindle 1 via a keyway. The keyway is precision machined to ensure reliable power transmission. The driven wheel 12 can be selected as a pulley, gear, or sprocket depending on the driving method, making it widely applicable and easy to install.

[0041] Working Principle: During operation, firstly, the adjusting nut 31 of the adjusting mechanism 3 is rotated, driving the clamping mechanism 2 to move forward, causing the elastic clamping head 7 to expand outward. The cylindrical workpiece to be polished is placed inside the expanded clamping head, and the adjusting nut 31 is rotated in the opposite direction, causing the clamping mechanism 2 to move backward. At this time, the elastic clamping head 7 radially contracts under the constraint of the conical surface 51 inside the limiting sleeve 5, uniformly clamping the outer wall of the workpiece with its large-area flexible contact surface. At this time, the clamping head 7 is in a clamping state. When polishing is required, external power drives the hollow spindle 1 to rotate through the driven wheel 12. The torque is reliably transmitted to the workpiece through the cooperation between the limiting sleeve 5 and the conical surface of the clamping head 7, achieving high coaxiality and synchronous rotation of the workpiece. After polishing is completed, the adjusting nut 31 is rotated again to expand the clamping head, and the workpiece can be easily removed. Throughout the process, the outer surface of the workpiece is flexibly clamped and protected, while the internal space is completely open, achieving efficient and non-destructive full-surface polishing operations.

[0042] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An external clamping and fixing device for polishing cylindrical workpieces, characterized in that: It includes a hollow spindle (1), a clamping mechanism (2) and an adjusting mechanism (3). The hollow spindle (1) is rotatably mounted on a bearing seat (4). A limiting sleeve (5) with an inner conical surface (51) is fixedly mounted at the front end of the hollow spindle (1) and together with the limiting sleeve (5) forms a cavity (6). The clamping mechanism (2) is movably disposed in the cavity (6) along the axis of the cavity (6). The front end of the clamping mechanism (2) is provided with an elastic clamping head (7). The elastic clamping head (7) is provided with an outer conical surface that cooperates with the inner conical surface (51). The hollow main shaft (1) is provided with an adjustment mechanism (3) for driving the clamping mechanism (2) to move along the axis in the cavity (6), and the adjustment mechanism (3) is connected to the clamping mechanism (2) in a transmission. The hollow spindle (1) rotates synchronously with the clamping head (7) which is in a clamping state through the limiting sleeve (5).

2. The external clamping and fixing device for polishing cylindrical workpieces according to claim 1, characterized in that: The adjustment mechanism (3) includes an adjustment nut (31), and the rear end of the clamping mechanism (2) is provided with an external thread that is compatible with the adjustment nut (31) and forms a threaded transmission pair with the adjustment nut (31).

3. The external clamping and fixing device for polishing cylindrical workpieces according to claim 2, characterized in that: The adjustment mechanism (3) includes a rigid screw (32), one end of which is connected to an adjusting nut (31), and the other end is connected to an elastic clamping head (7).

4. The external clamping and fixing device for polishing cylindrical workpieces according to claim 3, characterized in that: At least two axial gaps (33) are provided on the external thread path at the tail of the screw (32), and a pin (34) is provided on the adjusting nut (31) radially to engage with the gaps (33).

5. The external clamping and fixing device for polishing cylindrical workpieces according to claim 2, characterized in that: A first washer (35) is provided between the adjusting nut (31) and the rear end of the hollow spindle (1).

6. An external clamping and fixing device for polishing cylindrical workpieces according to claim 1 or 3, characterized in that: The elastic clamping head (7) is a trumpet-shaped structure with an open rear end.

7. The external clamping and fixing device for polishing cylindrical workpieces according to claim 6, characterized in that: The elastic clamping head (7) has several strip-shaped slits (71) extending to the front end in the axial direction and is divided by the strip-shaped slits (71) to form multiple independent clamping petals (72). The outer wall of the clamping petals (72) is provided with an outer conical surface (73).

8. The external clamping and fixing device for polishing cylindrical workpieces according to claim 1, characterized in that: At least two seals (11) are provided between the hollow spindle (1) and the bearing housing (4), and the seals (11) are located on both sides of the axial direction of the bearing housing (4).

9. The external clamping and fixing device for polishing cylindrical workpieces according to claim 1, characterized in that: A driven wheel (12) is fixedly connected to the outer wall of the hollow main shaft (1).

10. The external clamping and fixing device for polishing cylindrical workpieces according to claim 9, characterized in that: The driven wheel (12) is a pulley, gear or sprocket.

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