A precision milling device for mass production of small frames

Abstract

A precision milling device for mass production of small frames includes a panel and a support plate respectively installed on the left and right sides of the small frame. An extension seat is provided on one side of the support plate. The panel is connected to the support plate via a double-ended screw. A groove through-hole is provided on the left end face of the panel. A support plate screw hole corresponding to the groove through-hole is provided on the left end face of the support plate. One end of the double-ended screw is connected to the support plate screw hole, and the other end of the double-ended screw passes through the groove through-hole and is connected to the panel via a clamping nut and a washer. A support plate fixing hole is also provided on the left end face of the support plate, and a circular boss is provided on the right end face of the support plate. A countersunk groove mates with the circular boss is provided on the left end face of the extension seat, and a screw hole mates with the support plate fixing hole is provided on the inner end face of the countersunk groove. An annular groove is provided on the side wall of the extension seat. This invention improves the precision milling efficiency of small frames, ensures machining positioning stability and repeatability, and effectively reduces clamping deformation problems.

Description

Technical Field

[0001] This invention relates to a precision milling device for mass production of small frames. Background Technology

[0002] Finish milling is a crucial process in frame machining, playing a decisive role in machining accuracy. Small frames are typically finished using precision horizontal machining centers; however, horizontal machining centers have high unit costs and are mostly used for single-piece machining, resulting in high time costs. Therefore, for batch production of small frames, finish machining should utilize CNC milling, which has a lower unit cost.

[0003] However, using conventional CNC milling methods to precision mill small frames in batches is inefficient and often fails to meet the required machining accuracy.

[0004] The clamping method in precision milling is a crucial factor affecting machining efficiency and accuracy. The conventional clamping method for precision milling the various sides of a small frame in CNC milling involves using several equal-height blocks to support the machining positioning surface at one end of the frame side, clamping it with several pressure plates, aligning it, and then milling the end face, holes, bosses, countersunk grooves, and other structures on the opposite side of the frame. This process is repeated, changing the machining positioning surface, adding pressure plates, aligning, and milling the relevant structures on the other end until all sides of the frame are machined. This conventional clamping method not only has long auxiliary time for clamping and alignment, resulting in low efficiency, but also requires changing the machining positioning surface at least three times for precision milling of each side of the small frame. The machining datum for each end face is not uniform, requiring additional auxiliary datums. Combined with factors such as clamping deformation, it is difficult to guarantee machining accuracy and dimensional consistency of batch-produced parts, seriously affecting the machining quality of the small frame. Summary of the Invention

[0005] The purpose of this invention is to provide a precision milling device for mass production of small frames, so as to solve the problems in the background art mentioned above.

[0006] The technical solution adopted to achieve the above objectives is a precision milling device for mass production of small frames, comprising a panel and a support plate respectively installed on the left and right sides of the small frame. An extension seat is provided on one side of the support plate. The panel is connected to the support plate via a double-ended screw. A groove through hole is provided on the left end face of the panel. A support plate screw hole corresponding to the groove through hole is provided on the left end face of the support plate. One end of the double-ended screw is connected to the support plate screw hole, and the other end of the double-ended screw passes through the groove through hole and is connected to the panel via a clamping nut and a washer. A support plate fixing hole is also provided on the left end face of the support plate, and a round boss is provided on the right end face of the support plate. A countersunk groove that mates with the round boss is provided on the left end face of the extension seat. A screw hole that mates with the support plate fixing hole is provided on the inner end face of the countersunk groove. An annular groove is provided on the side wall of the extension seat.

[0007] Furthermore, the center positions of the upper, lower, front and rear sides of the panel are provided with panel grooves for cooperating with the left frame boss on the left side of the small frame, and the center positions of the upper, lower, front and rear sides of the tray are provided with tray grooves for cooperating with the right frame boss on the right side of the small frame.

[0008] Furthermore, the right end face of the panel is provided with a panel step for clamping the small frame. The panel step includes a panel step end face and a panel step side face. The panel step end face presses against the left machining positioning surface of the left end of the small frame, and the panel step side face mates with the left end of the inner cavity of the small frame. The left end face of the tray is provided with a tray step for clamping the small frame. The tray step includes a tray step end face and a tray step side face. The tray step end face supports the right machining positioning surface of the right end of the small frame, and the tray step side face mates with the right end of the inner cavity of the small frame.

[0009] Furthermore, the left end face of the tray is provided with a reference hole for calibration, and the right end face of the extended seat is provided with a positioning round boss for positioning in conjunction with the center hole of the four-axis indexing plate.

[0010] Beneficial effects

[0011] Compared with the prior art, the present invention has the following advantages.

[0012] 1. The present invention uses the same machining positioning surface and the same machining datum for all sides of the precision milling of the small frame, and completes the process in one clamping, which improves machining efficiency and machining accuracy;

[0013] 2. In this invention, the stepped sides of the panel and the tray cooperate with the inner cavity of the small frame to ensure the stability of the processing and positioning. The stepped end faces of the panel and the tray symmetrically clamp the small frame. The small frame is only subjected to the clamping force perpendicular to the processing and positioning surface and the force is balanced, which can prevent the deformation caused by the clamping force of the pressure plate on the side of the frame in conventional clamping methods.

[0014] 3. The clamping and positioning of the present invention has high repeatability, and the structure is simple, economical and feasible. Practice has proven that the machining accuracy of the small frame after four-axis precision milling is qualified by the coordinate measuring machine, which can guarantee the clamping requirements of the small frame precision milling and the consistency requirements of the batch production parts. Attached Figure Description

[0015] The present invention will be further described in detail below with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the structure of the present invention;

[0017] Figure 2 This is a front view of the panel structure in this invention;

[0018] Figure 3This is a right view of the panel structure in this invention;

[0019] Figure 4 This is a front view of the structure of the small frame in this invention;

[0020] Figure 5 This is a front view of the structure of the tray in this invention;

[0021] Figure 6 This is a left view of the structure of the tray in this invention;

[0022] Figure 7 This is a front view of the extended seat structure in this invention;

[0023] Figure 8 This is a schematic diagram of the structure of the small frame in this invention. Detailed Implementation

[0024] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0025] like Figures 1-8 As shown, a precision milling device for mass production of small frames includes a panel 1 and a support plate 3 respectively installed on the left and right sides of a small frame 2. An extension seat 4 is provided on one side of the support plate 3. The panel 1 is connected to the support plate 3 by a double-ended screw 5. A waist groove through hole 13 is provided on the left end face of the panel 1. A support plate screw hole 33 corresponding to the waist groove through hole 13 is provided on the left end face of the support plate 3. One end of the double-ended screw 5 is connected to the support plate screw hole 33, and the other end of the double-ended screw 5 passes through the waist groove through hole 13 and is connected to the panel 1 by a clamping nut 51 and a washer 52. A support plate fixing hole 34 is also provided on the left end face of the support plate 3. A round boss 36 is provided on the right end face of the support plate 3. A countersunk groove 41 that mates with the round boss 36 is provided on the left end face of the extension seat 4. A screw hole 42 that mates with the support plate fixing hole 34 is provided on the inner end face of the countersunk groove 41. An annular groove 43 is provided on the side wall of the extension seat 4.

[0026] The top, bottom, front, and back sides of the panel 1 are provided with panel grooves 12 at their center positions for engaging with the left frame boss 24 on the left side of the small frame 2. The top, bottom, front, and back sides of the tray 3 are provided with tray grooves 32 at their center positions for engaging with the right frame boss 25 on the right side of the small frame 2.

[0027] The right end face of the panel 1 is provided with a panel step 11 for clamping the small frame 2. The panel step 11 includes a panel step end face 111 and a panel step side face 112. The panel step end face 111 presses against the left machining positioning surface 21 at the left end of the small frame 2. The panel step side face 112 cooperates with the left end of the inner cavity 22 of the small frame 2. The left end face of the tray 3 is provided with a tray step 31 for clamping the small frame 2. The tray step 31 includes a tray step end face 311 and a tray step side face 312. The tray step end face 311 supports the right machining positioning surface 23 at the right end of the small frame 2. The tray step side face 312 cooperates with the right end of the inner cavity 22 of the small frame 2.

[0028] The left end face of the support plate 3 is also provided with a reference hole 35 for calibration, and the right end face of the extended seat 4 is provided with a positioning round boss 44 for positioning in conjunction with the center hole of the four-axis indexing plate.

[0029] In this invention, the right end face of the panel 1 is provided with a panel step 11 for clamping the small frame 2. The upper, lower, and front and rear end faces of the panel 1 are provided with panel grooves 12. The end face of the panel 1 is also provided with a through-hole 13. The panel 1 is connected to the support plate 3 via a double-ended screw 5. The left end of the double-ended screw 5 is fixed to the through-hole 13 via a clamping nut 51 and a washer 52, and the right end of the double-ended screw 5 is fixed in the support plate screw hole 33 on the support plate 3. The small frame 2 has a support plate 3 on its right side. The support plate 3 has a support plate fixing hole 34 and a support plate screw hole 33 on its left end face. The support plate 3 also has a support plate step 31 for clamping the small frame 2 on its left end face. The support plate 3 has a support plate groove 32 in the middle part of the upper, lower and front and rear end faces. The support plate 3 has a round boss 36 on its right end face. The extension seat 4 has a groove 41 on its left end face. The groove 41 has a screw hole 42 on its inner end face. The extension seat 4 has an annular groove 43 on its outer circumference.

[0030] The right end face of the panel 1 is provided with a panel step 11. The end face 111 of the panel step presses against multiple left machining positioning surfaces 21 on the left end of the small frame 2. The side face 112 of the panel step cooperates with the left end of the inner cavity 22 of the small frame 2. The left end face of the tray 3 is provided with a tray step 31. The end face 311 of the tray step supports multiple right machining positioning surfaces 23 on the right end of the small frame 2. The side face 312 of the tray step cooperates with the right end of the inner cavity 22 of the small frame 2.

[0031] The inner end face of the groove 41 of the extended base 4 is provided with a screw hole 42 for fixing the support plate 3 to the extended base 4 with screws. The panel step 11 at the right end of the panel 1 presses against the left machining positioning surface 21 at the left end of the small frame 2. The support plate step 31 at the left end of the support plate 3 supports the right machining positioning surface 23 at the right end of the small frame 2. The panel groove 12 and support plate groove 32 on the panel 1 and the support plate 3 are used to avoid the left frame boss 24 and the right frame boss 25 on both sides of the small frame 2. The panel 1, the support plate 3 and the small frame 2 are assembled into one piece by the double-ended screw 5, the clamping nut 51 and the washer 52, thereby clamping and fixing them for four-axis precision milling.

[0032] In the specific implementation of this invention, CNC milling is first used to mill the left and right end faces, bosses and other structures of the small frame 2 in vertical milling mode. The four left machining positioning surfaces 21 on the left end are coplanar and the four right machining positioning surfaces 23 on the right end are coplanar. The left and right ends of the inner cavity 22 are then precision milled.

[0033] The machining process of the extended seat 4 is as follows: CNC lathe finishes the positioning round boss 44 and the outer step end face on the right end face of the extended seat 4, leaving a margin; the rest of the structure is machined to the required dimensions; the groove 41 on the left end face of the extended seat 4 is cut into the outer circle in one cut; the outer circle of the extended seat 4 is corrected; CNC milling finishes the positioning round boss 44 on the right end face of the extended seat 4 with a clearance of 0.02-0.03mm from the center hole of the four-axis indexing plate, and the outer step end face is polished; and the screw hole 42 is drilled and tapped.

[0034] The processing steps for the pallet 3 are as follows: CNC milling of the pallet 3's shape, the four pallet grooves 32 on the side of the pallet 3, and the round boss 36 on the right end face to the required dimensions; drilling of the pallet fixing holes 34 and drilling and tapping of the pallet screw holes 33; inserting the round boss 36 on the right end face of the pallet 3 into the countersunk groove 41 on the left end face of the extension seat 4 and fastening it with corresponding screws; positioning with the positioning round boss 44 on the right end face of the extension seat 4 and inserting it into the center hole of the four-axis indexing plate; positioning with the outer step end face of the positioning round boss 44 on the right end of the extension seat 4, correcting the outer circle of the extension seat 4, precision milling of the pallet step 31 on the left end face of the pallet 3, with a clearance of 0.01~0.02mm between the side 312 of the pallet step and the right end of the inner cavity 22 of the small frame 2, and precision milling of the reference hole 35 on the left end face of the pallet 3.

[0035] The processing steps of panel 1 are as follows: CNC milling of the outer shape of panel 1, four panel grooves 12 on the side of panel 1, milling of waist groove through holes 13, precision milling of panel step 11 on the right end face of panel 1, and the gap between the side face of panel step 112 and the left end of the inner cavity 22 of small frame 2 is 0.04-0.05mm.

[0036] Milling device calibration: Place the pressure plate inside the annular groove 43 on the outer circumference of the upper four axes and the extended seat 4. Mount the support plate 3 and the extended seat 4 together on the four-axis indexing plate. Use a dial indicator to calibrate the reference hole 35 on the left end face of the support plate 3. After adjusting it to the correct position, tighten the fastening screws on the pressure plate that are connected to the T-shaped nut in the T-shaped groove of the indexing plate.

[0037] Clamping: Position the small frame 2 on the tray 3 using the tray step 31 on the left end face of the tray 3. The tray step end face 311 supports the multiple right machining positioning surfaces 23 on the right end of the small frame 2 for axial positioning. The tray step side face 312 mates with the right end of the inner cavity 22 of the small frame 2 for radial positioning. Then, position the panel 1 on the small frame 2 using the panel step 11 on the right end face of the panel 1. The panel step end face 111 presses against the multiple left machining positioning surfaces 21 on the left end of the small frame 2 for axial positioning. The panel step side face 112 mates with the left end of the inner cavity 22 of the small frame 2 for radial positioning. Screw the double-ended screw 5 through the waist groove through hole 13 of the panel 1 into the tray screw hole 33 on the left end face of the tray 3, and tighten it with the clamping nut 51 and washer 52.

[0038] Calibration: Calibrate one end hole and end face of the side of the small frame 2 to align the center of the part; for parts to be replaced in the same batch, only the panel 1 needs to be removed and reinstalled, without removing the support plate 3 and the extension seat 4, and without needing to calibrate the precision milling device again; after removing the support plate 3 and the extension seat 4 to process parts from different batches, the reference hole 35 on the left end face of the support plate 3 can be calibrated and adjusted according to the above precision milling device calibration steps to ensure the consistency of batch production processing dimensions.

Claims

1. A precision milling device for mass production of small frames, comprising a panel (1) and a support plate (3) respectively installed on the left and right sides of a small frame (2), characterized in that, An extension seat (4) is provided on one side of the tray (3). The panel (1) is connected to the tray (3) by a double-headed screw (5). A groove through hole (13) is provided on the left end face of the panel (1). A tray screw hole (33) corresponding to the groove through hole (13) is provided on the left end face of the tray (3). One end of the double-headed screw (5) is connected to the tray screw hole (33). The other end of the double-headed screw (5) passes through the groove through hole (13) and is pressed. Nut (51) and washer (52) are connected to panel (1). The left end face of the support plate (3) is also provided with support plate fixing hole (34). The right end face of the support plate (3) is provided with round boss (36). The left end face of the extension seat (4) is provided with countersunk groove (41) that matches the round boss (36). The inner end face of the countersunk groove (41) is provided with screw hole (42) that matches the support plate fixing hole (34). The side wall of the extension seat (4) is provided with annular groove (43). The panel (1) has a panel groove (12) at the center of the upper, lower and front and rear sides for cooperating with the left frame boss (24) on the left side of the small frame (2), and the tray (3) has a tray groove (32) at the center of the upper, lower and front and rear sides for cooperating with the right frame boss (25) on the right side of the small frame (2). The right end face of the panel (1) is provided with a panel step (11) for clamping the small frame (2). The panel step (11) includes a panel step end face (111) and a panel step side face (112). The panel step end face (111) presses against the left machining positioning surface (21) of the left end of the small frame (2). The panel step side face (112) cooperates with the left end of the inner cavity (22) of the small frame (2). The left end face of the tray (3) is provided with a tray step (31) for clamping the small frame (2). The tray step (31) includes a tray step end face (311) and a tray step side face (312). The tray step end face (311) supports the right machining positioning surface (23) of the right end of the small frame (2). The tray step side face (312) cooperates with the right end of the inner cavity (22) of the small frame (2).

2. The precision milling device for mass production of small frames according to claim 1, characterized in that, The left end face of the tray (3) is provided with a reference hole (35) for calibration, and the right end face of the extension seat (4) is provided with a positioning round boss (44) for positioning in conjunction with the center hole of the four-axis indexing plate.

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