Blank clamping device and method for numerical control machining

Abstract

The invention provides a blank clamping device and method for numerical control machining. The clamping device comprises a datum plate 10, a fixed box body 7 and a movable box body 8, and the datum plate 10, the fixed box body 7 and the movable box body 8 are fixed to a machine tool platform through bolts; the reference plate 10 is of a rectangular structure, dovetail grooves 12 are evenly distributed in one side of the reference plate 10, and the reference plate 10 is connected with the fixed box body 7 and the movable box body 8 in a dovetail groove mode; two contact surfaces of the fixed box body 7 and the part blank 1 are perpendicular to the datum plate; a vertical contact surface of the fixed box body 7 and the part blank 1 plays a role in positioning, and a machining original point is positioned on the plane in numerical control machining; a special sliding block 2 is arranged on the movable box body 8 and is connected with the movable box body 8 through a dovetail-shaped sliding groove 13; the contact face of the special sliding block 2 and the part blank 1 is symmetrical to the contact face of the special sliding block 2 and the dovetail-shaped sliding groove 13. The special sliding block 2 is internally provided with a thread which is a self-locking thread, and the axis of the thread is located on the angular bisector of the included angle formed by the two inclined faces in the special sliding block 2 and is perpendicular to the short plane of the special sliding block 2.

Description

Technical Field

[0001] The invention is applied to the field of mechanical processing, and in particular relates to a blank clamping device and a clamping method for numerical control processing. Background Art

[0002] In the field of CNC milling machine processing of aviation parts, the clamping of small and medium-sized parts mostly adopts pressure plate bolt clamping, vise clamping, and special tooling clamping methods, among which pressure plate bolt clamping is a commonly used part clamping method.

[0003] Among these methods, the pressure plate bolt clamping adopts a clamping method that directly fixes the part on a square box or a machine tool platform. This method has low flexibility for large swing angle processing. In addition, due to part structures such as the lower limit and bottom angle, the processing of a part often requires multiple clamping and multiple alignments. To ensure the processing accuracy of the part, the blank needs to be milled into a regular hexagonal shape before the pressure plate bolt clamping, resulting in a long preparation time before processing. In addition, the position for the pressure plate clamping needs to be reserved in the part clamping plan, which often results in borders around or on both sides of the part, resulting in an increase in the size of the blank and waste.

[0004] Compared with clamping with pressure plate bolts, vise clamping is simpler and more flexible for swing angle processing. Often, part processing can be completed with one clamping. However, this solution is only suitable for processing small parts. The size of the clamped parts is limited by the vise's stroke and the size of the clamping plate. Similarly, if a vise with a larger stroke is used, when processing small parts, the vise's screw direction swing angle processing is prone to interfere with the machine tool spindle.

[0005] Special tooling is very convenient for processing specific parts, but its versatility is low. It is suitable for processing large quantities of single parts. There are more scientific research models of aviation parts, and the design of parts is changed frequently, which often leads to the waste of special tooling.

[0006] The existing clamping methods lack a universal, simple and flexible parts clamping solution that can improve the processing efficiency of small and medium-sized machine tools. Summary of the invention

[0007] The present application provides a blank clamping device and a clamping method for CNC machining, which can solve the problem of low machining efficiency of small and medium-sized machine tools.

[0008] In a first aspect, the present application provides a blank clamping device for CNC machining, comprising a reference plate 10, a fixed box 7 and a movable box 8, wherein:

[0009] The reference plate 10, the fixed box 7 and the movable box 8 are fixed to the machine tool platform by bolts;

[0010] The structure of the reference plate 10 is rectangular, and dovetail grooves 12 are evenly distributed on one side. The reference plate 10 is connected to the fixed box 7 and the movable box 8 in the form of dovetail grooves;

[0011] The two contact surfaces of the fixed box 7 and the part blank 1 are perpendicular to the reference plate 10; the vertical contact surface of the fixed box 7 and the part blank 1 plays a positioning role, locating the machining origin in CNC machining;

[0012] There is a special slider 2 on the movable box 8, and the special slider 2 is connected to the movable box 8 by a dovetail sliding groove 13; the contact surface between the special slider 2 and the part blank 1 is symmetrical to the contact surface between the special slider 2 and the dovetail sliding groove 13; the special slider 2 has a built-in thread, the thread is a self-locking thread, the thread axis is perpendicular to the short plane of the special slider 2 and is located on the bisector of the angle between the two inclined surfaces of the special slider 2; the special bolt 4 is connected to the built-in thread of the special slider 2, and through the tightening action of the thread structure, the special slider 2 is driven to move down along the dovetail sliding groove 13, and the axial force of the thread tightening is converted into a clamping force toward the dovetail sliding groove 13 and the part blank 1 through the two inclined surfaces of the special slider 2; the non-threaded part of the special bolt 4 is toward one side of the axis The curved arc surface is in sliding contact with the spring 3, one end of the spring 3 is fixed to the movable box 8, when the special bolt 4 is unscrewed, the spring pushes the special bolt 4, and the special bolt 4 drives the special slider 2 to move upward along the dovetail sliding groove 13, thereby loosening the part blank 1 and completing the fixture restoration; the bolt head of the special bolt 4 is fixedly connected to the universal flexible shaft joint 5, and the universal flexible shaft joint 5 transfers the wrench action point to one side of the movable box 8, the movable box 8 and the machine tool platform are connected by bolts, and the bolt holes on the movable box 8 are in the form of sliding grooves 11. When the movable box 8 needs to be moved due to the size of the part blank 1, the sliding grooves 11 can adapt to the grid-shaped bolt grooves of the machine tool platform to complete the bolt fixation of the movable box 8 and the machine tool platform.

[0013] Specifically, the upper planes of the movable box 8 and the fixed box 7 are at the same height as the contact surface of the bottom surface of the part blank 1 .

[0014] Specifically, the spacing between the dovetail grooves 12 on the reference plate 10 is smaller than the travel of the special sliding block 2 on the movable box 8 along the horizontal direction.

[0015] Specifically, when the stroke of the special slide block 2 is not enough to clamp the part blank 1 , the dovetail groove 12 on the reference plate 10 can move the movable box 8 equidistantly to adapt to the size of the part blank 1 .

[0016] Specifically, the thickness of the vertical contact surface between the fixed box 7 and the part blank 1 is ≤70 mm.

[0017] Specifically, the special slider 2 cooperates with the dovetail sliding groove 13 and the structure of the part blank 1 to ensure that the bolt is subjected to axial force during clamping, thereby avoiding the phenomenon of bolt breakage due to shear force or loose clamping due to unbalanced force during clamping.

[0018] Specifically, the bolt head of the special bolt 4 is larger than the width of the U-shaped groove 6 on the movable box body 8. When the thread structure is tightened, it contacts the movable box body 8 to form an axial force for tightening the thread.

[0019] Specifically, the diameter of the bolt portion of the special bolt 4 is slightly smaller than the diameter of the non-threaded portion, and the diameter of the non-threaded portion and the diameter of the spring 3 are slightly larger than the width of the U-shaped groove 6. The curved surface shape of the U-shaped groove 6 and the non-threaded portion of the special bolt 4 can constrain the position of the spring.

[0020] Specifically, the total width of the special slider 2 is ≤70 mm. When the part blank 1 is not clamped, when the special slider 2 moves to the lowest point, the side A of the movable box 8 does not exceed the left end point of the special slider 2.

[0021] In a second aspect, the present application provides a blank clamping method for CNC machining, the method comprising:

[0022] Step 1. Attach the fixed box 7 and the reference plate 10 Figure 3 Fixed on the machine tool;

[0023] Step 2. Select a suitable dovetail groove 12 according to the size of the part blank 1 and fix the movable box 8 on the machine tool;

[0024] Step 3. Press the part blank 1 Figure 2 The contact surface between the part blank 1 and the clamping device is processed. The processed plane is required to be flat and parallel to the contact surface of the corresponding special slider 2;

[0025] Step 4. When programming the part, the vertical contact surface between the fixed square box 7 and the part blank 1 is the X=0 or Y=0 plane, and the horizontal contact surface between the movable box 8 and the part blank 1 is the Z=0 plane to establish a coordinate system, with a machining allowance of 5mm, and a frame reserved for the clamping part at the bottom of the part blank 1. The frame thickness is ≥ the vertical stroke of the special slide block 2 on the movable box 8;

[0026] Step 5. Place the part blank 1 on the fixture, tighten the universal flexible shaft joint 5, transmit the tightening force to the special bolt 4, complete the tightening action between the special bolt 4 and the special slider 2, drive the special slider 2 to move down along the dovetail sliding groove 13, and convert the axial force of the thread tightening into the clamping force to the dovetail sliding groove 13 and the part blank 1 through the two inclined surfaces of the special slider 2;

[0027] Step 6. Straighten and align, and then process the parts;

[0028] Step 7. After the parts are processed, unscrew the universal flexible shaft joint 5. When the threaded structure of the special bolt 4 and the special slider 2 is unscrewed, the spring 3 pushes the special bolt 4, and the special bolt 4 drives the special slider 2 to move upward along the dovetail sliding groove 13, thereby loosening the part blank 1 and completing the fixture recovery;

[0029] Step 8. Remove the parts and the processing is completed.

[0030] In summary, the present application provides a clamping device for a part blank 1 for CNC machining, which has the following advantages:

[0031] 1. This method is more flexible for large swing angle processing. The tool can complete large swing angle processing around the parts. This means that more than 90% of aviation parts can be processed in one clamping, which greatly saves processing time.

[0032] 2. Compared with clamping with pressure plate bolts, the part blank 1 does not need to be milled hexagonally before clamping. It only needs to process the vertical surface, horizontal bottom surface and inclined surface in contact with the movable box 8 and the fixed box 7, thus shortening the milling process time.

[0033] 3. Compared with the clamping method of the bolt pressure plate, before processing the part blank 1, there is no need to reserve a large amount of process scaffolding around or on both sides of the part for clamping. Only some margin is required at the bottom of the part, which saves production costs.

[0034] 4. The use of the reference plate 10 and the dovetail groove 12 allows the tooling to be adjusted according to the size of the part blank 1. It has a certain versatility for small and medium-sized aerospace parts and avoids the replacement and purchase of the vise due to the stroke when clamping.

[0035] 5. The combination of the special slider 2, the special bolt 4 and the spring 3 converts the horizontal lead screw of the vise into a longitudinal bolt for tightening, shortening the lateral space occupied by the tooling, increasing the swing angle of the tool, and avoiding the situation in which the lead screw is exposed too long during vise clamping, causing the tool swing angle along the lead screw direction to interfere with the machine tool spindle.

[0036] 6. The universal flexible shaft joint 5 is combined with the special bolt 4 to transfer the action position of the wrench so that the tightening operation is not restricted by space. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a blank clamping device for CNC machining provided in the present application;

[0038] Figure 2 This is an AA cross-sectional view of a blank clamping device for CNC machining provided in the present application;

[0039] Figure 3A BB cross-sectional view of a blank clamping device for CNC machining provided in the present application;

[0040] Among them: 1-part blank, 2-special slider, 3-spring, 4-special bolt, 5-universal flexible shaft joint, 6-U-shaped groove, 7-fixed box, 8-movable box, 9-screw, 10-reference plate, 11-sliding groove, 12-dovetail groove, 13-dovetail sliding groove. DETAILED DESCRIPTION

[0041] The present invention provides a clamping device and a clamping method for a part blank 1 used for CNC machining, which is a flexible and convenient clamping device for small and medium-sized part blanks 1, and helps to improve the energy and efficiency of small and medium-sized machine tools.

[0042] Embodiment 1

[0043] like Figure 1-3 As shown, the present application provides a part blank clamping device for CNC machining, comprising a reference plate 10, a fixed box 7 and a movable box 8, wherein:

[0044] The reference plate 10, the fixed box 7 and the movable box 8 are fixed to the machine tool platform by bolts;

[0045] The structure of the reference plate 10 is rectangular, and dovetail grooves 12 are evenly distributed on one side. The reference plate 10 is connected to the fixed box body 7 and the movable box body 8 in the form of dovetail grooves;

[0046] The two contact surfaces of the fixed box 7 and the part blank 1 are perpendicular to the reference plate 10; the vertical contact surface of the fixed box 7 and the part blank 1 (see attached Figure 2 ) plays a positioning role, locating the machining origin in CNC machining;

[0047] There is a special slider 2 on the movable box 8, and the special slider 2 is connected to the movable box 8 by a dovetail sliding groove 13; the contact surface between the special slider 2 and the part blank 1 is symmetrical to the contact surface between the special slider 2 and the dovetail sliding groove, that is, the attached Figure 2 The angles formed by the two oblique lines and the horizontal line in the cross section of the special slider 4 are complementary; the special slider 2 has a built-in thread, the thread is a self-locking thread, the thread axis is perpendicular to the short plane on the special slider 2 and is located on the bisector of the angle between the two inclined surfaces on the special slider 2; the special bolt 4 is connected to the built-in thread of the special slider 2, and through the tightening action of the thread structure, the special slider 2 is driven to move down along the dovetail sliding groove 13, and the axial force of the thread tightening is converted into a clamping force toward the dovetail sliding groove 13 and the part blank 1 through the two inclined surfaces of the special slider 4; the non-threaded part of the special bolt 4 is a circular arc surface bent toward one side of the axis, and the circular arc surface is in sliding contact with the spring 3, and the other end of the spring 3 is fixed on the movable box 8 as shown in the attached Figure 2When the threaded structure of the special bolt 4 and the special slider 2 is unscrewed, the spring 3 pushes the special bolt 4, and the special bolt 4 drives the special slider 2 to move upward along the dovetail sliding groove 13, thereby loosening the part blank 1 and completing the fixture recovery. The bolt head of the special bolt 4 is fixedly connected to the universal flexible shaft joint 5, and the wrench action point is transferred to one side of the movable box 8 through the universal flexible shaft joint 5 as shown in the attached figure. Figure 2 , so that the operator can tighten the clamp conveniently. The movable box 8 is connected to the machine platform by bolts, and the bolt holes on the box are designed in the form of U-shaped grooves 6 as shown in the attached Figure 3 When the movable box 8 needs to be moved due to the size of the part blank 1, the U-shaped groove 6 can adapt to the grid-shaped bolt groove of the machine tool platform to allow the bolts to pass through and fix the movable box 8 on the machine tool.

[0048] Specifically, the spacing between the dovetail grooves 12 on the reference plate 10 is smaller than the travel of the special sliding block 2 on the movable box 8 along the horizontal direction.

[0049] Specifically, when the stroke of the special slide block 2 is not sufficient to meet the clamping requirements, the dovetail groove 12 on the reference plate 10 allows the movable box 8 to move equidistantly to adapt to the size of the part blank 1.

[0050] It should be noted that the dovetail groove 12 on the reference plate 10 can ensure that the fixed box 7 and the movable box 8 are in the same straight line after installation, so as to control the installation accuracy and further ensure the clamping accuracy.

[0051] It should be noted that the vertical contact surface between the part blank 1 and the fixed box 7 (see attached Figure 2 ) is the reference plane. The reference needs to be milled out before processing. After clamping, it can be used for X=0 reference plane or Y=0 reference plane.

[0052] Specifically, the thickness of the vertical contact surface between the fixed box 7 and the part blank 1 is ≤70 mm. During part processing, a conventional tool along one side of the fixed box 7 can be swung at an angle of 90°, making part processing more flexible.

[0053] Specifically, the structure of the special slider 2 cooperates with the dovetail sliding groove 13 to ensure that the bolt is subjected to axial force during clamping, thereby avoiding the breakage of the special bolt 4 due to shear force and the phenomenon of loose clamping due to unbalanced force during clamping.

[0054] It should be noted that the blank 1 should be clamped according to the attached Figure 2 Processing bevel to match the special slider 2 to complete the clamping and fixing

[0055] Specifically, the bolt head of the special bolt 4 is larger than the width of the U-shaped groove 6 on the movable box 8. When the threaded structure is tightened, it contacts the movable box 8 and the part blank 1. Figure 2 , forming an axial force for tightening the thread.

[0056] Specifically, the diameter of the bolt portion of the special bolt 4 is slightly smaller than the diameter of the non-bolt portion, and the diameter of the non-bolt portion and the diameter of the spring 3 are slightly larger than the width of the U-shaped groove 6 (see the main view for details). Figure 1 And attached Figure 2 ), the curved surface shape of the U-shaped groove 6 and the non-threaded part of the special bolt 4 can constrain the spring position.

[0057] Specifically, attached Figure 2 In the embodiment, the contact surface between the movable box body 8 and the bottom surface of the part blank 1 and the contact surface between the fixed box body 7 and the bottom surface of the part blank 1 are at the same height.

[0058] It should be noted that the contact surface between the movable box 8 and the bottom surface of the part blank 1 is the Z=0 plane in the processing coordinate system because of the pressure applied by the special slider.

[0059] It should be noted that the bottom surface of the part blank 1 needs to be milled flat before clamping to match the upper plane of the movable box 8 as a reference surface during processing.

[0060] Specifically, the total width of the special slider 2 is ≤70mm. When the part blank 1 is not clamped, the special slider 2 moves to the lowest point. Figure 2 The side A of the middle movable box 8 shall not exceed the left end point of the special slide block 2. During part processing, most conventional tools along one side of the special slide block 2 can be swung at an angle of 90°, making part processing more flexible.

[0061] In summary, the present application provides a clamping device for a part blank 1 for CNC machining, which has the following advantages:

[0062] 1. This method is more flexible for large swing angle processing. The tool can complete large swing angle processing around the parts. This means that more than 90% of aviation parts can be processed in one clamping, which greatly saves processing time.

[0063] 2. Compared with clamping with pressure plate bolts, the part blank 1 does not need to be milled hexagonally before clamping. It is only necessary to process the vertical surface, horizontal bottom surface and inclined surface where the part blank 1 contacts the movable box 8 and the fixed box 7, thus shortening the milling process time.

[0064] 3. Compared with the clamping method of the bolt pressure plate, before processing the part blank 1, there is no need to reserve a large amount of process scaffolding around or on both sides of the part for clamping. Only some margin is required at the bottom of the part, which saves production costs.

[0065] 4. The use of the reference plate 10 and the dovetail groove 12 allows the tooling to be adjusted according to the size of the part blank 1. It has a certain versatility for small and medium-sized aerospace parts and avoids the replacement and purchase of the vise due to the stroke when clamping.

[0066] 5. The combination of the special slider 2, the special screw 4 and the spring 3 converts the horizontal lead screw of the vise into a longitudinal bolt for tightening, shortening the lateral space occupied by the tooling, increasing the swing angle of the tool, and avoiding the situation in which the lead screw is exposed too long during vise clamping, causing the tool swing angle along the lead screw direction to interfere with the machine tool spindle.

[0067] 6. The universal flexible shaft joint 5 is combined with the special bolt 4 to transfer the action position of the wrench so that the tightening operation is not restricted by space.

[0068] Embodiment 2

[0069] The present application provides a method for clamping a part blank 1 for CNC machining, comprising:

[0070] Step 1. Attach the fixed box 7 and the reference plate 10 Figure 3 Fixed on the machine tool

[0071] Step 2. According to the size of the part blank 1, select a suitable dovetail groove 12 and fix the movable box 8 on the machine tool.

[0072] Step 3. Press Attach Figure 2 The contact surface between the machined part blank 1 and the clamping device should be parallel to the corresponding contact surface of the special slider, and the rest of the contact surface should be exposed to light.

[0073] Step 4. When programming the part, use the positioning reference surface of the fixed square box 7 (attached Figure 2 The vertical plane where the part blank 1 contacts the fixed box 7 is the X=0 or Y=0 plane, and the contact surface between the movable box 8 and the bottom of the part blank 1 is the Z=0 plane to establish a coordinate system. The part machining allowance is 5mm, and a frame is left at the bottom of the part. The frame thickness is ≥ the vertical stroke of the special slider 2 on the movable box 8

[0074] Step 5. Place the part blank 1 on the clamping device, tighten the universal flexible shaft joint 5, transmit the tightening force to the special bolt 4, complete the tightening action of the thread structure between the special bolt 4 and the special slider 2, drive the special slider 2 to move down along the dovetail sliding groove 13, and convert the axial force of the thread tightening into the clamping force to the dovetail sliding groove 13 and the part blank 1 through the two inclined surfaces of the special slider 2

[0075] Step 6. Straighten and align, and then process the parts

[0076] Step 7. After the parts are processed, unscrew the universal flexible shaft joint 5. When the threaded structure of the special bolt 4 and the special slider 2 is unscrewed, the spring 3 pushes the special bolt 4, and the special bolt 4 drives the special slider 2 to move upward along the dovetail sliding groove 13, completing the fixture recovery, and then loosening the part blank 1.

[0077] Step 8. Remove the parts and the processing is completed.

Claims

1. A blank clamping device for CNC machining, characterized in that: It comprises a reference plate (10), a fixed box (7) and a movable box (8), wherein: The reference plate (10), the fixed box (7) and the movable box (8) are fixed on the machine tool platform by bolts; The reference plate (10) has a rectangular structure, with dovetail grooves (12) evenly distributed on one side. The reference plate (10) is connected to the fixed box (7) and the movable box (8) in the form of dovetail grooves. The two contact surfaces of the fixed box (7) and the part blank (1) are perpendicular to the reference plate (10); the vertical contact surface between the fixed box (7) and the part blank (1) plays a positioning role, and the machining origin in numerical control machining is located on this plane; A special slider (2) is disposed on the movable box (8), and the special slider (2) is connected to the movable box (8) via a dovetail type sliding groove (13); the contact surface between the special slider (2) and the part blank (1) is symmetrical to the contact surface between the special slider (2) and the dovetail type sliding groove (13); the special slider (2) has a built-in thread, the thread is a self-locking thread, the thread axis is located on the bisector of the angle formed by two inclined surfaces in the special slider (2), and is perpendicular to the short plane of the special slider (2). The special bolt (4) is connected with the internal thread of the special slider (2). Through the tightening action of the thread structure, the special bolt (4) drives the special slider (2) to move downward along the dovetail sliding groove (13), and converts the axial force of the thread tightening into a pressing force on the dovetail sliding groove (13) and the part blank (1) through the two inclined surfaces of the special slider (2); the non-threaded part of the special bolt (4) is a circular arc bent toward one side of the axis, and the circular arc part is in sliding contact with one end of the spring (3), and the other end of the spring (3) is fixed on the movable box (8). When the thread structure of the special bolt (4) and the special slider (2) is unscrewed, the spring (3) pushes the special bolt (4) to move. 4), the special bolt (4) drives the special slider (2) to move upward along the dovetail sliding groove (13), thereby loosening the part blank (1) and completing the fixture restoration; the bolt head of the special bolt (4) is fixedly connected to the universal flexible shaft joint (5), and the wrench action point is transferred to one side of the movable box (8) through the universal flexible shaft joint (5). The movable box (8) has a sliding groove (11), and the bolt passes through the sliding groove (11) to fix the movable box (8) on the machine tool. When the movable box (8) needs to be moved due to the size of the part blank (1), the sliding groove (11) can adapt to the grid-shaped bolt groove on the machine tool platform, so that the bolt can smoothly fix the movable box (8).

2. The blank clamping device according to claim 1, characterized in that: The horizontal contact surface between the movable box (8) and the part blank (1) is at the same height as the horizontal contact surface between the fixed box (7) and the part blank (1).

3. The blank clamping device according to claim 1, characterized in that: The spacing between the dovetail grooves (12) on the reference plate (10) is smaller than the travel of the special sliding block (2) on the movable box (8) along the horizontal direction.

4. The blank clamping device according to claim 1, characterized in that: When the travel of the special slide block (2) on the movable box (8) in the horizontal direction is not enough to meet the size requirements of the part blank (1), the dovetail groove (12) on the reference plate (10) can make the movable box (8) move equidistantly to adapt to the size of the part blank (1).

5. The blank clamping device according to claim 1, characterized in that: The thickness of the vertical contact surface between the fixed box (7) and the part blank (1) is ≤70 mm.

6. The blank clamping device according to claim 1, characterized in that: The specially made slide block (2) cooperates with the dovetail type slide groove (13) and the part blank (1) to ensure that the bolt is subjected to axial force when the device is clamped, thereby avoiding the phenomenon that the bolt is broken due to shear force or the clamping is not firm due to uneven force.

7. The blank clamping device according to claim 1, characterized in that: The bolt head of the special bolt (4) is larger than the width of the U-shaped groove (6) on the movable box body. When the thread structure is tightened, the bolt head can contact the movable box body, and an axial force is generated when the thread is tightened.

8. The blank clamping device according to claim 1, characterized in that: The diameter of the threaded portion of the special bolt (4) is slightly smaller than the diameter of the non-threaded portion. The diameter of the non-threaded portion and the diameter of the spring (3) are slightly smaller than the width of the U-shaped groove (6). The curved surface shapes of the U-shaped groove (6) and the non-threaded portion of the special bolt (4) can constrain the relative position of the spring.

9. The blank clamping device according to claim 1, characterized in that: The total width of the special slider (2) is ≤70 mm. When the special slider (2) moves to the lowest point, the side A of the movable box (8) does not exceed the left end point of the special slider (2).

10. A blank clamping method for CNC machining, characterized in that the method include: Step 1. Fix the fixed box (7) and the reference plate (10) on the machine tool according to FIG3 ; Step 2. Select a suitable dovetail groove (12) according to the size of the part blank (1) and fix the movable box (8) on the machine tool; Step 3. Process the contact surface between the part blank (1) and the clamping device according to FIG2. The processed plane must be flat and parallel to the contact surface of the clamping device; Step 4. When programming the part, a coordinate system is established with the vertical contact surface between the fixed square box (7) and the part blank (1) as the X=0 or Y=0 plane, and the horizontal contact surface between the movable box (8) and the part blank (1) as the Z=0 plane. The machining allowance is 5 mm, and a frame is reserved at the bottom clamping part of the part blank (1). The thickness of the frame is ≥ the vertical stroke of the special slider (2) on the movable box (8); Step 5. Place the part blank (1) on the tooling, tighten the universal flexible shaft joint (5), transmit the tightening force to the special bolt (4), complete the tightening action of the thread structure between the special bolt (4) and the special slider (2), drive the special slider (2) to move down along the dovetail sliding groove (13), and convert the axial force of the thread tightening into a clamping force toward the dovetail sliding groove (13) and the part blank (1) through the two inclined surfaces of the special slider (2); Step 6. Straighten and align, and then process the parts; Step 7. After the parts are processed, unscrew the universal flexible shaft joint (5). When the threaded structure of the special bolt (4) and the special slider (2) is unscrewed, the spring (3) pushes the special bolt (4), and the special bolt (4) drives the special slider (2) to move upward along the dovetail sliding groove (13), completing the fixture recovery, and then loosening the part blank (1); Step 8. Remove the parts and the processing is completed.

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