Expansion clamping device

Abstract

The utility model belongs to the technical field of tools, and particularly relates to an expansion clamping device which comprises a core shaft, an expansion sleeve, a positioning key, an expansion block, a locking nut, a power-assisted rod, a positioning pin and a fixing sleeve, and the core shaft is a main body part of the expansion clamping device and is in a stepped long shaft shape; the expansion sleeve is installed from the small-diameter end of the mandrel and installed on the mandrel, one end of the positioning key is installed in a groove in the small-diameter end of the mandrel, and the other end of the positioning key is matched with a long groove in the inner diameter of the expansion block. The expansion block is installed from the small-diameter end of the mandrel and installed on the mandrel, the locking nut is installed from the small end of the mandrel, and the assistance rod is installed in a small radial hole of the locking nut. The fixing sleeve is mounted at the small-diameter end of the mandrel, and the positioning pin is mounted in the radial through holes of the fixing sleeve and the mandrel, so that the fixing sleeve and the mandrel are connected together. The tool is simple in structure, low in cost and easy to operate, all needed sizes and form and location tolerances can be machined under the condition of one-time positioning, and the problems of deformation, tool vibration and the like in the part machining process are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of tools and fixtures, and particularly relates to an expansion and clamping device. Background Art

[0002] Thin-walled cylindrical parts are prone to tool vibration during machining due to their wall thickness ranging from 0.8mm to 2mm, resulting in the roughness of the part's outer surface failing to meet the drawing requirements. During machining, the parts are deformed due to the thin walls, making it difficult to guarantee the size and form tolerances of the parts. The current machining method uses an internal nylon mandrel, which is clamped by a three-jaw chuck at one end and axially positioned by a tail top at the tail. During machining, tool vibration is significant, the feed rate and speed are limited, the machining efficiency is low, and the part quality is unstable. To address this issue, there is an urgent need for an expansion clamping device to solve the problems of deformation and tool vibration that occur during part machining. Utility Model Content

[0003] The purpose of the utility model is to solve the above problems and provide an expansion clamping device.

[0004] The purpose of this utility model is achieved through the following technical solutions.

[0005] A clamping device includes a core shaft, a clamping sleeve, a positioning key, a clamping block, a locking nut, a power rod, a positioning pin, and a fixing sleeve. The core shaft is the main part of the clamping device and is in the shape of a stepped long axis. The clamping sleeve is installed from the small diameter end of the core shaft and installed on the core shaft. One end of the positioning key is installed in the groove at the small diameter end of the core shaft, and the other end is matched with the long groove of the inner diameter of the clamping block. The clamping block is installed from the small diameter end of the core shaft and installed on the core shaft. The clamping block is cylindrical, with one end of the outer diameter being an external thread connected to the locking nut and the other end being connected to the outer diameter of the clamping block. The outer shape is conical and matches the inner cone of the expansion sleeve. The locking nut is installed from the small end of the core shaft, and the internal thread of the locking nut is screwed with the external thread of the expansion block. Holes are evenly distributed on the outer diameter of the locking nut for installing the power rod when the locking nut is screwed together; the power rod is installed in the radial small hole of the locking nut; the fixed sleeve is installed on the small diameter end of the core shaft, and the outer diameter of the locating pin matches the hole in the radial center position of the fixed sleeve. The locating pin is installed in the radial through hole of the fixing sleeve and the core shaft to connect the fixing sleeve and the core shaft together.

[0006] Furthermore, the expansion sleeve is a cylindrical structure with inner cone shapes at both ends of the inner diameter of the cylinder. Six long grooves are milled symmetrically on the outer diameter axis of the expansion sleeve. The expansion sleeve is installed on the outer cone of the core shaft, and the tail end is expanded by the expansion block to achieve the effect of supporting the inner diameter of the processed part.

[0007] Furthermore, the positioning key is a rectangular parallelepiped with arc-shaped ends. One end of the positioning key is installed in the groove of the core shaft, which plays a radial positioning role to prevent the positioning key from rotating on the core shaft; the other end cooperates with the long groove on the inner diameter of the expansion block to enable it to move freely in the axial direction.

[0008] Furthermore, through the axial movement of the expansion block, the two conical surfaces generate an extrusion force, causing the expansion sleeve to expand, thereby achieving the purpose of supporting the processed part.

[0009] Furthermore, the locking nut is cylindrical in shape, with an internal thread designed at one end of the inner diameter to connect with the external thread of the expansion block, and four holes evenly distributed on the outer diameter of the locking nut for installing the power rod when the locking nut is screwed in.

[0010] Furthermore, the power-assisting rod is a slender cylindrical rod with two parts. One half of the power-assisting rod has a smooth surface, and the outer diameter of the other half is designed to be knurled, which is convenient for increasing friction when used by hand. The power-assisting rod is installed in the radial hole of the locking nut for tightening and loosening the locking nut.

[0011] Furthermore, the positioning pin is a slender cylindrical shape, and the outer diameter of the positioning pin matches the hole at the radial center position of the fixing sleeve. After the fixing sleeve is installed on the small diameter end of the core shaft, the positioning pin passes through the radial center hole of the fixing sleeve and the radial hole at the small diameter end of the core shaft to connect the fixing sleeve and the core shaft.

[0012] Beneficial effects of the utility model

[0013] Compared with existing processing methods, the expansion clamping device of the utility model has a simple structure, low cost, and is easy to operate. It can process all required dimensions and form and position tolerances in one positioning, solving the problems of deformation and tool vibration that occur during part processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of the utility model;

[0015] Figure 2 It is a top view of the utility model;

[0016] Figure 3 for Figure 2 Left view of;

[0017] In the figure, 1- mandrel, 2- expansion sleeve, 3- positioning key, 4- expansion block, 5- locking nut, 6- power rod, 7- positioning pin, 8- fixing sleeve; DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] Example 1

[0020] An expansion clamping device, comprising: a core shaft 1, an expansion sleeve 2, a positioning key 3, an expansion block 4, a locking nut 5, a power rod 6, a positioning pin 7, and a fixing sleeve 8

[0021] The core shaft 1 is in the shape of a stepped long axis. The large diameter end of the core shaft is used for chuck clamping and alignment, and the remaining diameters are used to install the expansion sleeve 2, positioning key 3, expansion block 4, locking nut 5, positioning pin 6 and fixing sleeve 7.

[0022] The expansion sleeve 2 is a cylindrical structure with inner cone shapes at both ends of the inner diameter of the cylinder. Six long grooves are milled symmetrically on the outer diameter axis of the expansion sleeve 2. The expansion sleeve 2 is installed on the outer cone of the core shaft 1, and the tail end is expanded by the expansion block 4 to achieve the effect of supporting the inner diameter of the processed part.

[0023] The positioning key 3 is a rectangular parallelepiped with arc-shaped ends. One end of the positioning key 3 is installed in the groove of the core shaft 1, which plays a radial positioning role to prevent the positioning key 3 from rotating on the core shaft 1; the other end cooperates with the long groove on the inner diameter of the expansion block 4, allowing it to move freely in the axial direction.

[0024] The expansion block 4 is cylindrical, with one end of the outer diameter being an external thread connected to the locking nut 5, and the other end being conical in shape and matching the inner cone of the expansion sleeve 2. Through the axial movement of the expansion block 4, the two conical surfaces generate extrusion pressure, causing the expansion sleeve 2 to expand, thereby achieving the purpose of supporting the processed parts.

[0025] The locking nut 5 is cylindrical in shape, with an internal thread at one end of the inner diameter connected to the external thread of the expansion block 4. The outer diameter of the locking nut 5 is evenly distributed with 4 holes for installing the power rod 6 when the locking nut 5 is screwed in.

[0026] The booster rod 6 is a slender cylindrical rod with two parts. One half of the rod is smooth, while the other half has a knurled outer diameter to increase friction when held in hand. The booster rod 6 is installed in the radial hole of the lock nut 5 for tightening and loosening the lock nut 5.

[0027] The locating pin 7 is a slender cylindrical shape. The outer diameter of the locating pin 7 matches the hole at the radial center position of the fixing sleeve 8. After the fixing sleeve 8 is installed to the small diameter end of the core shaft 1, the locating pin 7 passes through the radial center hole of the fixing sleeve 8 and the radial hole at the small diameter end of the core shaft 1 to connect the fixing sleeve 8 and the core shaft 1.

[0028] The fixing sleeve 8 is in the shape of a circular ring, and the inner diameter of the fixing sleeve 8 matches the outer diameter of the small end of the core shaft 1. A through hole is designed at the radial center position of the fixing sleeve 8 for installing the positioning pin 7.

[0029] Connection relationship: The core shaft 1 is the main part of the expansion and clamping device. The expansion sleeve 2 is installed from the small end of the core shaft 1 and installed on the core shaft 1. The positioning key 3 is installed in the groove at the small diameter end of the core shaft 1. The expansion block 4 is installed from the small end of the core shaft 1 and installed on the core shaft 1. The inner groove of the expansion block 4 is aligned with the positioning key 3 and can move freely axially after installation. The locking nut 5 is installed from the small end of the core shaft 1. The internal thread of the locking nut 5 is screwed into the external thread of the expansion block 4. The fixing sleeve 8 is installed on the small diameter end of the core shaft 1. The positioning pin 7 is installed in the radial through hole of the fixing sleeve 8 and the core shaft 1 to connect the fixing sleeve 8 and the core shaft 1 together.

[0030] The utility model provides a method for using an expansion clamping device as follows: the expansion sleeve 2 is installed from the small end of the core shaft 1 and installed on the core shaft 1, the positioning key 3 is installed in the groove at the small diameter end of the core shaft 1, the expansion block 4 is installed from the small end of the core shaft 1 and installed on the core shaft 1, the inner groove of the expansion block 4 and the positioning key 3 are installed to align with each other, and after installation, it is ensured that the expansion block 4 can move freely axially, the locking nut 5 is installed from the small end of the core shaft 1, two power rods 6 are installed in the radial small holes of the locking nut 5, the locking nut 5 is screwed together with the expansion block 4, and the expansion block 4 is caused to move axially through the threaded screwing, and the outer cone surface of the expansion block 4 applies axial extrusion force to the inner cone surface of the expansion sleeve 2, thereby expanding the expansion sleeve 2. After expansion, the outer diameter of the expansion sleeve 2 is fitted with the inner diameter of the processed part, and the axial screwing of the locking nut 5 is stopped at this time. When the parts are processed, the locking nut 5 is screwed in the reverse direction through the two assist rods 6. The fixed sleeve 8 limits the axial position of the locking nut 5. When the locking nut 5 is screwed in the reverse direction, the expansion block 4 is pulled to move axially in the reverse direction on the core shaft 1. The extrusion force is released, the expansion sleeve 2 returns to its initial state, and the parts can be removed from the expansion clamp.

Claims

1. A clamping device, comprising a core shaft (1), an expansion sleeve (2), a positioning key (3), an expansion block (4), a locking nut (5), a power rod (6), a positioning pin (7), and a fixing sleeve (8), characterized in that: The core shaft (1) is the main part of the expansion clamping device and is in the shape of a stepped long axis; the expansion sleeve (2) is installed from the small diameter end of the core shaft (1) and installed on the core shaft (1); one end of the positioning key (3) is installed in the groove of the small diameter end of the core shaft (1), and the other end is matched with the long groove of the inner diameter of the expansion block (4); the expansion block (4) is installed from the small diameter end of the core shaft (1) and installed on the core shaft (1); the expansion block (4) is cylindrical, one end of the outer diameter is an external thread connected to the lock nut (5), and the other end is conical and matched with the inner cone of the expansion sleeve (2). The lock nut (5) is installed from the core shaft (1). The small end is installed, the internal thread of the locking nut (5) is screwed together with the external thread of the expansion block (4), and the outer diameter of the locking nut (5) is evenly designed with holes for installing the power rod (6) when the locking nut (5) is screwed together; the power rod (6) is installed in the radial small hole of the locking nut (5); the fixing sleeve (8) is installed on the small diameter end of the core shaft (1), the outer diameter of the positioning pin (7) is matched with the hole at the radial center position of the fixing sleeve (8), and the positioning pin (7) is installed in the radial through hole of the fixing sleeve (8) and the core shaft (1), so that the fixing sleeve (8) and the core shaft (1) are connected together.

2. The clamping device according to claim 1, characterized in that: The expansion sleeve (2) is a cylindrical structure, and the inner diameter ends of the cylinder are in the shape of inner cones. The expansion sleeve (2) is symmetrically milled with six long grooves in the axial direction of the outer diameter. The expansion sleeve (2) is installed on the outer cone of the core shaft (1), and the tail end is expanded by the expansion block (4) to achieve the effect of supporting the inner diameter of the processed part.

3. The clamping device according to claim 1, characterized in that: The positioning key (3) is a rectangular parallelepiped with arc-shaped ends. One end of the positioning key (3) is installed in the groove of the core shaft (1) to play a radial positioning role and prevent the positioning key (3) from rotating on the core shaft (1); the other end cooperates with the long groove on the inner diameter of the expansion block (4) to enable it to move freely in the axial direction.

4. The clamping device according to claim 1, characterized in that: Through the axial movement of the expansion block (4), the two conical surfaces generate extrusion force, causing the expansion sleeve (2) to expand, thereby achieving the purpose of supporting the processed parts.

5. The clamping device according to claim 1, characterized in that: The locking nut (5) is cylindrical in shape, and one end of the inner diameter is designed with an internal thread to connect with the external thread of the expansion block (4). The outer diameter of the locking nut (5) is evenly designed with four holes for installing the auxiliary rod (6) when the locking nut (5) is screwed in.

6. The clamping device according to claim 1, characterized in that: The booster rod (6) is in the shape of an elongated cylinder and has two parts. One half of the booster rod (6) has a smooth surface, and the other half has a knurled outer diameter. The booster rod (6) is installed in the radial hole of the locking nut (5) for tightening and loosening the locking nut (5).

7. The clamping device according to claim 1, characterized in that: The positioning pin (7) is in the shape of an elongated cylinder. The outer diameter of the positioning pin (7) matches the hole at the radial center position of the fixing sleeve (8). After the fixing sleeve (8) is installed on the small-diameter end of the core shaft (1), the positioning pin (7) passes through the radial center hole of the fixing sleeve (8) and the radial hole at the small-diameter end of the core shaft (1), thereby connecting the fixing sleeve (8) and the core shaft (1).

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