CN105483581B - A rectification method for residual deformation of magnesium alloy thin flat casting - Google Patents

Abstract

The invention relates to a method for rectifying the residual deformation of a magnesium alloy thin flat casting. Aiming at the drawbacks of the residual deformation of the magnesium alloy thin flat casting, the correction method is carried out by combining a correction fixture and a far-infrared tunnel furnace, and the magnesium alloy thin flat casting is installed. In the correction fixture, put it into the far-infrared tunnel furnace, after preheating, constant temperature treatment, cooling and aging treatment, the residual deformation of the magnesium alloy thin flat casting can be corrected, the residual stress can be eliminated, and the shape of the magnesium alloy thin flat casting can be effectively improved. Stability and reliability, after correction, the flatness error of the magnesium alloy thin flat casting is ≦0.05mm, which effectively eliminates the residual deformation of the magnesium alloy thin flat casting. This correction method has advanced technology, accurate and detailed data, advanced and reliable correction fixtures, and a Compact and high precision, it is a very advanced rectification method for residual deformation of magnesium alloy thin flat castings.

Description

A rectification method for residual deformation of magnesium alloy thin flat casting

technical field

The invention relates to a method for rectifying the residual deformation of a magnesium alloy thin flat casting, which belongs to the technical field of magnesium alloy sheet casting processing.

Background technique

Magnesium alloy thin plate castings are widely used in electronic products as shell-shaped structural parts, such as notebook computers, tablet computers, digital cameras, digital cameras, LED displays, and mobile phone parts.

When forming, during the solidification and cooling process of magnesium alloy thin flat castings, due to the different temperatures and cooling rates of various parts, the shrinkage of the castings at the same time is different. Stress is generated due to constraints; when the casting is demoulded and cooled to room temperature, thermal stress is generated due to the resistance of linear shrinkage, which causes residual stress to form inside the casting. When the residual stress exceeds the yield strength of the material, residual deformation will occur; residual deformation will make Magnesium alloy thin flat castings change the original design size, lose the original precision, and also affect the appearance of the product, especially in mass production, castings with residual deformation will form waste products during machining.

At present, the residual deformation of magnesium alloy thin flat castings is mostly corrected by hand, which is labor-intensive, low in production efficiency, and the correction force is not easy to control, which may easily cause castings to be scrapped; some mechanical corrections are also used to put the castings into a heated mold. Relying on the mold to apply anti-deformation to the casting to eliminate residual deformation, this method can only correct the deformation of four sides, and the correction effect on bending deformation, wave deformation, and twisting deformation is not good, and the production efficiency is low; the residual deformation is corrected manually and mechanically. It is only mandatory to temporarily eliminate the residual deformation, and there is still residual stress inside the casting. After the casting is placed for a period of time, or during the subsequent processing, the residual deformation will gradually rebound.

Contents of the invention

purpose of invention

The purpose of the present invention is to address the deficiency and backwardness of the background technology, adopt the method of combining the correction fixture and the far-infrared tunnel furnace to rectify the residual deformation of the magnesium alloy thin flat casting, and place the magnesium alloy thin flat casting on the correction fixture. In the far-infrared tunnel furnace, after preheating, constant temperature treatment, and cooling aging process, the residual deformation of the magnesium alloy thin-walled flat casting is corrected, and the residual stress is eliminated to improve the shape stability of the magnesium alloy thin-walled flat casting.

Technical solutions

The equipment and materials used in the present invention are: far-infrared tunnel furnace, correction fixture, absolute ethanol;

(1) Preparation of correction jigs

The correction jig is divided into two parts, the lower jig and the upper jig;

The main structure of the lower fixture includes: lower base plate, lower reference plate, lower plane adjustment block, positioning pin, guide post support, spring, guide post;

The lower base plate, lower reference plate, and lower plane adjustment block are made of hot work die steel, and after heat treatment and grinding, the surface roughness is Ra0.08-0.16μm; the flatness error of the lower base plate is ≦0.01mm, and the lower reference plate The flatness error of the composed plane is ≦0.01mm, and the flatness error of the composed plane of the lower plane adjustment block is ≦0.01mm;

The main structure of the upper fixture includes: upper pressure plate, upper reference plate, upper plane adjustment block, guide sleeve, locking pin, inner spring;

The upper platen, upper reference plate, and upper plane adjustment block are made of hot work die steel, and after heat treatment and grinding, the surface roughness is Ra0.08-0.16μm; the flatness error of the upper platen is ≦0.01mm, and the upper reference plate The flatness error of the composed plane is ≦0.01mm, and the flatness error of the plane composed of the upper plane adjustment block is ≦0.01mm;

The reference plate and plane adjustment block of the lower fixture and the upper fixture are set symmetrically;

The lower fixture and the upper fixture are connected by the guide post and the guide sleeve, and the thrust spring is installed on each guide post, and the coaxiality error of the guide post and the guide sleeve is ≦Φ0.01mm;

(2) Install magnesium alloy thin flat castings

①Clean the magnesium alloy thin flat casting with absolute ethanol to clean the front and back surfaces, and dry it after cleaning;

② Align the magnesium alloy thin plate casting with the first positioning pin and the second positioning pin on the lower fixture, and install them in parallel on the 9 lower adjustment blocks on the upper part of the lower fixture. The first positioning hole and the second positioning hole of the magnesium alloy thin plate casting The holes are respectively connected with the first positioning pin and the second positioning pin on the lower fixture;

③ Press down the upper fixture, and the first guide bush, the second guide bush, the third guide bush and the fourth guide bush on the upper fixture are respectively aligned with the first guide post, the second guide post and the third guide post on the lower fixture. Column, the fourth guide column, the 9 upper adjustment blocks on the upper fixture evenly press the magnesium alloy thin plate casting in parallel, and are locked by the locking pins on the guide sleeve respectively;

(3) Correction of residual deformation of magnesium alloy thin flat castings

The rectification of the residual deformation of the magnesium alloy thin flat casting is carried out in the far infrared tunnel furnace, and is completed in the process of far infrared heating, constant temperature and cooling aging;

① Clean the furnace cavity to make the furnace clean;

② Turn on the far-infrared tunnel furnace, turn on the first far-infrared heater, the second far-infrared heater, and the cooling fan, set the temperature in the preheating zone to 180°C±2°C, set the temperature in the constant temperature zone to 200°C±2°C, and cool down Zone temperature is set to 15°C±2°C;

③Place the rectifying jig installed with the magnesium alloy thin flat casting in parallel on the conveyor belt of the far-infrared tunnel furnace;

④ Turn on the conveyor belt, and send the rectifying fixture and the magnesium alloy thin flat casting into the far-infrared tunnel furnace;

⑤ The straightening jig and the magnesium alloy thin flat casting in the preheating zone run for 30 minutes, and the running time in the constant temperature zone is 90 minutes. After entering the cooling zone, the conveyor belt is closed, and the first far-infrared heater and the second far-infrared heater are turned off. device, so that it is cooled and aged in the cooling zone for 72h;

⑥The straightening jig is out of the oven, the magnesium alloy thin plate casting is taken out, the plane is placed on a clean stainless steel plate with a thickness of 1mm, and the whole is packaged with soft materials, thus completing the whole process of straightening;

(4) Detection, analysis, characterization

Detect, analyze and characterize the shape, color and flatness of rectified magnesium alloy thin flat castings;

Use a three-coordinate measuring instrument for flatness testing;

Conclusion: The rectified magnesium alloy thin flat casting is silver gray and flat, and the flatness error is ≦0.05mm.

Beneficial effect

Compared with the background technology, the present invention has obvious advances. It aims at the disadvantages of residual deformation of magnesium alloy thin flat castings. It adopts the method of combining the straightening fixture and far-infrared tunnel furnace for correction, and installs the magnesium alloy thin flat castings on the straightening fixture. In the far-infrared tunnel furnace, after preheating, constant temperature treatment and cooling aging treatment, the residual deformation of the magnesium alloy thin flat casting is corrected, the residual stress is eliminated, and the shape stability of the magnesium alloy thin flat casting is effectively improved. and reliability; after rectification, the flatness error of the magnesium alloy thin flat casting is ≦0.05mm, which effectively eliminates the residual deformation of the magnesium alloy thin flat casting. It is a very advanced rectification method for residual deformation of magnesium alloy thin flat castings.

Description of drawings

Figure 1. Front view of magnesium alloy thin flat casting;

Fig. 2, A-A sectional view of Fig. 1;

Fig. 3, B-B sectional view of Fig. 1;

Figure 4. The overall structure of the correction fixture;

Figure 5, the structure diagram of the lower fixture;

Figure 6. The structure diagram of the upper fixture;

Figure 7. Structural diagram of the guide sleeve;

Figure 8. The locking state diagram of the guide sleeve;

Figure 9. The state diagram of the correction fixture after installing the magnesium alloy thin flat casting;

Fig. 10. Rectification state diagram of residual deformation of magnesium alloy thin flat casting;

As shown in the figure, the list of reference signs is as follows:

1. Correction jig, 2. Lower base plate, 3. First lower reference plate, 4. Second lower reference plate, 5. Third lower reference plate, 6. Fourth lower reference plate, 7. Fifth lower reference plate, 8. The sixth lower reference plate, 9. The seventh lower reference plate, 10. The eighth lower reference plate, 11. The ninth lower reference plate, 12. The first lower adjustment block, 13. The second lower adjustment block, 14, The third lower adjustment block, 15, the fourth lower adjustment block, 16, the fifth lower adjustment block, 17, the sixth lower adjustment block, 18, the seventh lower adjustment block, 19, the eighth lower adjustment block, 20, the ninth Lower adjustment block, 21, first positioning pin, 22, second positioning pin, 23, inner spring, 24, upper pressing plate, 25, first upper reference plate, 26, second upper reference plate, 27, third upper reference Plate, 28, the fourth upper reference plate, 29, the fifth upper reference plate, 30, the sixth upper reference plate, 31, the seventh upper reference plate, 32, the eighth upper reference plate, 33, the ninth upper reference plate, 34, the first upper adjustment block, 35, the second upper adjustment block, 36, the third upper adjustment block, 37, the fourth upper adjustment block, 38, the fifth upper adjustment block, 39, the sixth upper adjustment block, 40, The seventh upper adjustment block, 41, the eighth upper adjustment block, 42, the ninth upper adjustment block, 43, the first guide post support, 44, the second guide post support, 45, the third guide post support, 46 , the fourth guide post support, 47, the first guide post, 48, the second guide post, 49, the third guide post, 50, the fourth guide post, 51, the first guide sleeve, 52, the second guide sleeve, 53, the third guide sleeve, 54, the fourth guide sleeve, 55, the first locking pin, 56, the second locking pin, 57, the third locking pin, 58, the fourth locking pin, 59, the first Thrust spring, 60, the second thrust spring, 61, the third thrust spring, 62, the fourth thrust spring, 63, magnesium alloy thin plate casting, 64, the first positioning hole, 65, the second positioning hole, 66, far infrared Tunnel furnace, 67, insulation layer, 68, first exhaust hole, 69, second exhaust hole, 70, cooling fan, 71, furnace seat, 72, conveyor belt, 73, first far-infrared heater, 74, the first Two far-infrared heaters, 75, electric control box, 76, display screen, 77, indicator light, 78, temperature controller, 79, conveyor belt controller, 80, cooling fan controller, 81, furnace chamber.

detailed description

The present invention will be further described below in conjunction with accompanying drawing:

Shown in Figures 1, 2 and 3 are the structural diagrams of the magnesium alloy thin flat casting. The magnesium alloy thin flat casting 63 has a plane size length≦300mm, a width≦200mm, and a flat part thickness≦3mm. The upper part is provided with a first positioning hole 64, The second positioning hole 65 .

As shown in Figures 4, 5, and 6, they are structural diagrams of the correction fixture, and the correction fixture 1 is composed of a lower fixture and an upper fixture;

The main structure of the lower fixture includes: lower base plate, lower reference plate, lower plane adjustment block, positioning pin, guide post support, thrust spring, guide post;

The lower base plate 2 of the lower fixture is a reference frame, and the first lower reference plate 3, the second lower reference plate 4, the third lower reference plate 5, the fourth lower reference plate 6, the fifth lower reference plate 7, The sixth lower reference plate 8, the seventh lower reference plate 9, the eighth lower reference plate 10, and the ninth lower reference plate 11; the four corners of the lower base plate 2 are provided with a first guide post support 43, a second guide post support 44. The third guide post support 45, the fourth guide post support 46; vertically install the first guide post 47 on the first guide post support 43, and vertically install the second guide post on the second guide post support 44 48. Install the third guide post 49 vertically on the third guide post support 45, install the fourth guide post 50 vertically on the fourth guide post support 46; install the first thrust spring 59 on the first guide post 47, The second thrust spring 60 is installed on the second guide post 48, the third thrust spring 61 is installed on the third guide post 49, the fourth thrust spring 62 is installed on the fourth guide post 50; on the first lower reference plate 3 A first lower adjustment block 12 is provided, a second lower adjustment block 13 is provided on the second lower reference plate 4, a third lower adjustment block 14 is provided on the third lower reference plate 5, and a third lower adjustment block 14 is arranged on the fourth lower reference plate 6. The fourth lower adjustment block 15 is arranged on the top, the fifth lower adjustment block 16 is arranged on the fifth lower reference plate 7, the sixth lower adjustment block 17 is arranged on the sixth lower reference plate 8, and the seventh lower reference plate 9 is provided with the seventh lower adjustment block 18, the eighth lower adjustment block 19 is arranged on the eighth lower reference plate 10, the ninth lower adjustment block 20 is arranged on the ninth lower reference plate 11; A first positioning pin 21 is provided on the block 18, and a second positioning pin 22 is provided on the ninth lower adjustment block 20;

The main structure of the upper fixture includes: upper pressure plate, upper reference plate, upper plane adjustment block, guide sleeve, locking pin, inner spring;

The upper pressing plate 24 of the upper clamp is a reference frame, and the first upper reference plate 25, the second upper reference plate 26, the third upper reference plate 27, the fourth upper reference plate 28, and the fifth upper reference plate 29 are arranged on the lower part of the upper pressing plate 24. , the sixth upper reference plate 30, the seventh upper reference plate 31, the eighth upper reference plate 32, the ninth upper reference plate 33; the four corners of the upper pressing plate 24 are provided with the first guide sleeve 51, the second guide sleeve 52, the first guide sleeve Three guide sleeves 53, the fourth guide sleeve 54; the first upper reference plate 25 is provided with the first upper adjustment block 34, the second upper reference plate 26 is provided with the second upper adjustment block 35, and the third upper reference plate 26 is provided with the second upper adjustment block 35; The third upper adjustment block 36 is arranged on the plate 27, the fourth upper adjustment block 37 is arranged on the fourth upper reference plate 28, the fifth upper adjustment block 38 is arranged on the fifth upper reference plate 29, and the sixth upper reference plate 29 is provided with the fifth upper adjustment block 38. The reference plate 30 is provided with the sixth upper adjustment block 39, the seventh upper reference plate 31 is provided with the seventh upper adjustment block 40, the eighth upper reference plate 32 is provided with the eighth upper adjustment block 41, and the ninth upper reference plate 32 is provided with the eighth upper adjustment block 41. A ninth upper adjustment block 42 is provided on the upper reference plate 33;

The lower clamp and the upper clamp are connected by the first guide post 47 and the first guide sleeve 51, the second guide post 48 is connected with the second guide sleeve 52, the third guide post 49 is connected with the third guide sleeve 53, and the fourth The guide post 50 is matched with the fourth guide sleeve 54 .

As shown in Figures 7 and 8, they are the structural diagrams of the guide sleeve. The inner spring 23 is coaxially installed with the first locking pin 55, the second locking pin 56, the third locking pin 57, and the fourth locking pin 58 respectively. Inner spring 23 unclamps when tight.

As shown in Fig. 9, it is the state diagram of the rectification fixture after the magnesium alloy thin flat casting is installed, the first positioning hole 64 of the magnesium alloy thin flat casting 63 is fitted with the first positioning pin 21 on the lower fixture, and the second positioning hole 65 Fitted with the second positioning pin 22 on the lower fixture, the magnesium alloy thin plate casting 63 is placed on the lower fixture, and placed on the first lower adjustment block 12, the second lower adjustment block 13, the third lower adjustment block 14, the third lower adjustment block Four lower adjustment blocks 15, the fifth lower adjustment block 16, the sixth lower adjustment block 17, the seventh lower adjustment block 18, the eighth lower adjustment block 19, the ninth lower adjustment block 20 top;

The upper clamp is pressed down, and the upper clamp and the lower clamp are clamped by the first guide sleeve 51, the second guide sleeve 52, the third guide sleeve 53, and the fourth guide sleeve 54. The first upper adjustment block 34 of the upper clamp, the second Upper adjustment block 35, third upper adjustment block 36, fourth upper adjustment block 37, fifth upper adjustment block 38, sixth upper adjustment block 39, seventh upper adjustment block 40, eighth upper adjustment block 41, ninth upper adjustment block The adjustment block 42 compresses the magnesium alloy thin plate casting 63 in parallel.

Shown in Fig. 10, it is the residual deformation correction state figure of magnesium alloy thin plate casting, the bottom of far-infrared tunnel furnace 66 is furnace seat 71, and the inside of far-infrared tunnel furnace 66 is furnace chamber 81, and inner wall top is provided with insulation layer 67, in heat preservation The inwall of layer 67 is provided with the first far-infrared heater 73, is provided with the first exhaust hole 68, the second exhaust hole 69 in the upper middle part of far-infrared tunnel furnace 66, and in the upper right part of far-infrared tunnel furnace 66 A cooling fan 70 is provided, and a second far-infrared heater 74 is arranged in the furnace base 71. The upper part of the furnace base 71 is a conveyor belt 72, and the correction fixture 1 and the magnesium alloy thin plate casting 63 inside the conveyor belt 72 are placed on the upper part of the furnace base 71. The right part of tunnel furnace 66 is provided with electric control box 75, is provided with display screen 76, pilot lamp 77, temperature controller 78, conveyor belt controller 79, cooling fan controller 80 on electric control box 75.

Claims (2)

1. A rectifying method for residual deformation of a magnesium alloy thin flat casting, characterized in that: The equipment and materials used are: far-infrared tunnel furnace, correction fixture, absolute ethanol; (1) Preparation of correction jigs The correction jig is divided into two parts, the lower jig and the upper jig; The main structure of the lower fixture includes: lower base plate, lower reference plate, lower plane adjustment block, positioning pin, guide post support, spring, guide post; The lower base plate, lower reference plate, and lower plane adjustment block are made of hot work die steel, and after heat treatment and grinding, the surface roughness is Ra0.08-0.16μm; the flatness error of the lower base plate is ≦0.01mm, and the lower reference plate The flatness error of the composed plane is ≦0.01mm, and the flatness error of the composed plane of the lower plane adjustment block is ≦0.01mm; The main structure of the upper fixture includes: upper pressure plate, upper reference plate, upper plane adjustment block, guide sleeve, locking pin, inner spring; The upper platen, upper reference plate, and upper plane adjustment block are made of hot work die steel, and after heat treatment and grinding, the surface roughness is Ra0.08-0.16μm; the flatness error of the upper platen is ≦0.01mm, and the upper reference plate The flatness error of the composed plane is ≦0.01mm, and the flatness error of the plane composed of the upper plane adjustment block is ≦0.01mm; The reference plate and plane adjustment block of the lower fixture and the upper fixture are set symmetrically; The lower fixture and the upper fixture are connected by the guide post and the guide sleeve, and the thrust spring is installed on each guide post, and the coaxiality error of the guide post and the guide sleeve is ≦Φ0.01mm; Installing Magnesium Alloy Thin Flat Castings Clean the magnesium alloy thin plate castings with absolute ethanol to clean the front and back surfaces, and dry them after cleaning; ② Align the magnesium alloy thin plate casting with the first positioning pin and the second positioning pin on the lower fixture, and install them in parallel on the 9 lower adjustment blocks on the upper part of the lower fixture. The first positioning hole and the second positioning hole of the magnesium alloy thin plate casting The holes are respectively connected with the first positioning pin and the second positioning pin on the lower fixture; ③ Press down the upper fixture, the first guide bush, the second guide bush, the third guide bush and the fourth guide bush on the upper fixture are respectively aligned with the first guide post, the second guide post and the third guide post on the lower fixture. Column, the fourth guide column, the 9 upper adjustment blocks on the upper fixture evenly press the magnesium alloy thin plate casting in parallel, and are locked by the locking pins on the guide sleeve respectively; (3) Correction of residual deformation of magnesium alloy thin flat castings The rectification of the residual deformation of the magnesium alloy thin flat casting is carried out in the far infrared tunnel furnace, and is completed in the process of far infrared heating, constant temperature and cooling aging; ① Clean the furnace cavity to make the furnace clean; ② Turn on the far-infrared tunnel furnace, turn on the first far-infrared heater, the second far-infrared heater, and the cooling fan, set the temperature in the preheating zone to 180°C±2°C, set the temperature in the constant temperature zone to 200°C±2°C, and cool Zone temperature is set to 15°C±2°C; ③ Move the rectifying jig installed with the magnesium alloy thin flat casting in parallel on the conveyor belt of the far-infrared tunnel furnace; ④ Turn on the conveyor belt, and send the straightening jig and the magnesium alloy thin flat casting into the far-infrared tunnel furnace; ⑤ The straightening jig and the magnesium alloy thin flat casting in the preheating zone run for 30 minutes, and the running time in the constant temperature zone is 90 minutes. After entering the cooling zone, the conveyor belt is turned off, and the first far-infrared heater and the second far-infrared heater are turned off. device, so that it is cooled and aged in the cooling zone for 72h; ⑥ The correction jig is out of the oven, the magnesium alloy thin plate casting is taken out, the plane is placed on a clean stainless steel plate with a thickness of 1mm, and the whole is packaged with soft materials, thus completing the whole process of correction; (4) Detection, analysis, characterization Detect, analyze and characterize the shape, color and flatness of rectified magnesium alloy thin flat castings; Use a three-coordinate measuring instrument for flatness testing; Conclusion: The rectified magnesium alloy thin flat casting is silver gray and flat, and the flatness error is ≦0.05mm. 2. the correction method of residual deformation of a kind of magnesium alloy thin plate casting according to claim 1, is characterized in that: The correction jig (1) consists of a lower jig and an upper jig; The main structure of the lower fixture includes: lower base plate, lower reference plate, lower plane adjustment block, positioning pin, guide post support, thrust spring, guide post; The lower base plate (2) of the lower fixture is the reference frame, and the first lower reference plate (3), the second lower reference plate (4), the third lower reference plate (5), and the fourth lower reference plate are set on the upper part of the lower base plate (2). Plate (6), fifth lower reference plate (7), sixth lower reference plate (8), seventh lower reference plate (9), eighth lower reference plate (10), ninth lower reference plate (11); The four corners of the lower base plate (2) are provided with a first guide post support (43), a second guide post support (44), a third guide post support (45), and a fourth guide post support (46); Install the first guide post (47) vertically on the first guide post support (43), install the second guide post (48) vertically on the second guide post support (44), and install the second guide post (48) vertically on the third guide post support ( 45) Vertically install the third guide post (49), vertically install the fourth guide post (50) on the fourth guide post support (46); install the first thrust spring (59) on the first guide post (47) ), install the second push spring (60) on the second guide post (48), install the third push spring (61) on the third guide post (49), install the fourth push spring (60) on the fourth guide post (50) Thrust spring (62); the first lower adjustment block (12) is arranged on the first lower reference plate (3), the second lower adjustment block (13) is arranged on the second lower reference plate (4), and the second lower adjustment block (13) is arranged on the second lower reference plate (4). The third lower reference plate (5) is provided with the third lower adjustment block (14), the fourth lower reference plate (6) is provided with the fourth lower adjustment block (15), and the fifth lower reference plate (7) There is a fifth lower adjustment block (16), a sixth lower adjustment block (17) on the sixth lower reference plate (8), and a seventh lower adjustment block ( 18). The eighth lower adjustment block (19) is set on the eighth lower reference plate (10), and the ninth lower adjustment block (20) is set on the ninth lower reference plate (11); The first positioning pin (21) is provided on the block (18), and the second positioning pin (22) is provided on the ninth lower adjustment block (20); The main structure of the upper fixture includes: upper pressure plate, upper reference plate, upper plane adjustment block, guide sleeve, locking pin, inner spring; The upper platen (24) of the upper fixture is the reference frame, and the first upper reference plate (25), the second upper reference plate (26), the third upper reference plate (27), the fourth upper Reference plate (28), fifth upper reference plate (29), sixth upper reference plate (30), seventh upper reference plate (31), eighth upper reference plate (32), ninth upper reference plate (33) ; Set the first guide sleeve (51), the second guide sleeve (52), the third guide sleeve (53), and the fourth guide sleeve (54) at the four corners of the upper platen (24); on the first upper reference plate ( 25) There is a first upper adjustment block (34), a second upper adjustment block (35) on the second upper reference plate (26), and a third upper adjustment block (35) on the third upper reference plate (27). The adjustment block (36), the fourth upper adjustment block (37) is arranged on the fourth upper reference plate (28), the fifth upper adjustment block (38) is arranged on the fifth upper reference plate (29), and the The sixth upper reference plate (30) is provided with the sixth upper adjustment block (39), the seventh upper reference plate (31) is provided with the seventh upper adjustment block (40), and the eighth upper reference plate (32) is An eighth upper adjustment block (41) is provided, and a ninth upper adjustment block (42) is provided on the ninth upper reference plate (33); The lower fixture and the upper fixture are connected by the first guide post (47) and the first guide sleeve (51), the second guide post (48) is connected with the second guide sleeve (52), the third guide post (49) and the The third guide sleeve (53) is mated and connected, and the fourth guide post (50) is mated and connected with the fourth guide bush (54).