A clamping method for machining large thin-walled parts

Abstract

The present application relates to the field of thin-walled part processing, and discloses a clamping method for processing large thin-walled parts, which comprises the following steps: step one, placing the tooling on the surface of the machine tool after pressing it tightly with the positioning block, and aligning the flatness of the tooling; step two, placing the large-end flange of the workpiece horizontally on the upper surface of the positioning block, pressing the upper end surface of the large-end flange of the workpiece with the lever dial gauge, observing the stable value of the needle and recording it, and verifying the flatness of the upper end surface of the large-end flange of the workpiece; step three, arranging the pressing plates on both sides of the reinforcing block above the large-end flange of the workpiece, and pressing the workpiece downward with the pressing plates, and observing the needle indication of the lever dial gauge during the pressing process; step four, when the change amplitude of the value of the lever dial gauge is greater than 0.05 mm after the pressing plates press the workpiece, filling the gap between the workpiece and the tooling with the shims, and observing the needle of the lever dial gauge and recording it during the filling process. The present application solves the problem of deformation of the workpiece during the clamping process of the large thin-walled part.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of thin-walled part processing, and more particularly to a clamping method for processing large thin-walled parts. BACKGROUND

[0002] In the machining process, the following two machining methods are generally used for machining large parts. Vise clamping: generally suitable for machining small and medium-sized parts, this clamping method belongs to general clamping, and the clamping height is positively correlated with the size of the workpiece, that is, the larger the workpiece, the larger the vise opening and the clamping height. Press plate clamping: this clamping method is suitable for machining large parts, and the clamping force is large. The workpiece is locked on the press plate by screws to fix the workpiece. The above two machining methods are suitable for parts with stable structure and poor deformation. The machining center processes the workpiece through the press plate clamping method, but the hole roundness of the workpiece after machining is 0.10 out of tolerance, and the end face hole position degree is 0.1 out of tolerance.

[0003] Since the large thin-walled workpiece is large (diameter 2.5m) and thin-walled (wall thickness 4.5mm), the strength of the workpiece is poor, and deformation is easy to occur during clamping. After the lower flange is machined by numerical control turning, the flatness is greater than 0.1. At present, the press plate is directly used for clamping. During the process of pressing the lower flange of the press plate, the workpiece will be deformed due to the poor flatness of the lower flange after pressing, resulting in deformation of the hole and out-of-tolerance of the hole position tolerance. This method is not suitable for high-precision workpieces. SUMMARY

[0004] To solve the above technical problems, the present application provides a clamping method for machining large thin-walled parts.

[0005] The specific scheme adopted by the present application is as follows: a clamping method for machining large thin-walled parts, the method comprising the following steps:

[0006] Step one, place the workpiece on the surface of the machine tool after the positioning block is pressed tightly, and find the flatness of the workpiece;

[0007] Step two, place the large end flange of the workpiece horizontally on the upper surface of the positioning block, press the upper end surface of the large end flange of the workpiece with a lever dial gauge, observe the stable value of the needle and record it, and verify the flatness of the upper end surface of the large end flange of the workpiece;

[0008] Step three, set a press plate on both sides of the reinforcing block above the large end flange of the workpiece, the press plate presses the workpiece downward, and the needle reading of the lever dial gauge is observed during the pressing process;

[0009] Step four, when the press plate is pressed against the workpiece, the change range of the lever dial gauge value is greater than 0.05mm, the tool is used to detect the gap between the workpiece and the tool, the spacer is used to pad into the gap between the workpiece and the tool, and the process of padding is observed and recorded.

[0010] The number of the lever dial gauges is four, and the four lever dial gauges are uniformly distributed around the large-end flange of the workpiece.

[0011] The number of the positioning blocks is four, and the four positioning blocks are arranged directly below the reinforcing block of the workpiece.

[0012] In step one, the flatness of the four bosses of the tool is less than 0.01mm.

[0013] In step two, when the lower end surface flatness of the large-end flange of the workpiece is poor, the position where the lower end surface flatness of the large-end flange is less than 0.1mm can be found by rotating the workpiece around the Z-axis.

[0014] In step three, the needle indication of the four lever dial gauges is observed during the pressing process, and the change amount of the needle indication of the lever dial gauges is required to be less than 0.05mm.

[0015] The positioning blocks are uniformly distributed between the workpiece and the tool.

[0016] The tool is a feeler gauge.

[0017] The present application has the following beneficial effects relative to the prior art:

[0018] The present application adopts the positioning block to press the tool against the machine tool surface, finds the flatness of the tool, places the large-end flange of the workpiece downward on the upper surface of the positioning block, uses the lever dial gauge to press the upper end surface of the large-end flange of the workpiece, observes the stable needle value, sets the pressing plate on both sides of the reinforcing block above the large-end flange of the workpiece, presses the workpiece downward, observes the needle indication of the lever dial gauge during the pressing process, uses the tool to detect the gap between the workpiece and the tool when the change range of the lever dial gauge value is greater than 0.05mm after the pressing, pads the gap between the workpiece and the tool with the spacer, and observes the needle of the lever dial gauge during the padding process. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The figure is a structural schematic diagram of the present application.

[0020] Among them, the reference signs are respectively:

[0021] 1, positioning block, 2, big end flange, 3, lever dial gauge, 4, tooling, 5, workpiece, 6, reinforcing block. DETAILED DESCRIPTION

[0022] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described below by specific embodiments shown in the drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0023] The present application provides a clamping method for machining large thin-walled parts, the method comprising the following steps: step one, placing the tooling 4 on the machine tool surface after pressing it tightly with the positioning block 1, and aligning the flatness of the tooling 4; step two, placing the big end flange 2 of the workpiece 5 horizontally on the upper surface of the positioning block 1, pressing the upper end surface of the big end flange 2 of the workpiece 5 with the lever dial gauge 3, observing the stable needle value and recording, and verifying the flatness of the upper end surface of the big end flange 2 of the workpiece 5; step three, setting pressure plates on both sides of the reinforcing block 6 above the big end flange 2 of the workpiece 5, the pressure plates pressing the workpiece 5 downward, and observing the needle reading of the lever dial gauge 3 during the pressing process; step four, when the needle value of the lever dial gauge 3 changes by more than 0.05mm after the pressure plates press the workpiece 5, detecting the gap between the workpiece 5 and the tooling 4 with a tool, and filling the gap between the workpiece 5 and the tooling 4 with a spacer, and observing the needle of the lever dial gauge 3 during the filling process and recording. The number of the lever dial gauges 3 is four, and the four lever dial gauges 3 are evenly distributed around the big end flange 2 of the workpiece 5. The number of the positioning blocks 1 is four, and the four positioning blocks 1 are arranged directly below the reinforcing block 6 of the workpiece 5. The flatness of the four bosses of the tooling 4 in step one is less than 0.01mm. In step two, when the lower end surface flatness of the big end flange 2 of the workpiece 5 is poor, the position where the lower end surface flatness of the big end flange 2 is less than 0.1mm can be found by rotating the workpiece 5 around the Z-axis. In step three, the needle readings of the four lever dial gauges 3 are observed during the pressing process, and the change in the needle reading of the lever dial gauge 3 should be less than 0.05mm. The positioning blocks 1 are evenly distributed between the workpiece 5 and the tooling 4. The tool is a feeler gauge.

[0024] Example 1

[0025] The application provides a clamping method for processing large thin-walled parts: the positioning block (rectangular block) is pressed against the tooling and the tooling is placed on the machine tool surface, and the four protrusions of the tooling are aligned to be less than 0.01mm in flatness. The large end flange of the workpiece is placed horizontally on the surface of the tooling with the large end flange facing down, and the spindle uses a lever dial gauge to verify the flatness of the upper end surface of the large end flange of the workpiece. When the lower end surface of the large end flange (lower flange) is poor in flatness, the relative flatness of the lower end surface can be found by rotating the workpiece around the Z-axis, and the flatness is less than 0.1mm. The ball head of the four lever dial gauges is pressed against the upper end surface of the lower flange of the workpiece, and the needle value is observed and recorded when the needle value is stable. Eight pressing plates are used to press the workpiece from both ends of the four reinforcing blocks, and the needle value of the four lever gauges is observed during the pressing process. The change in the needle value of the four lever gauges should be less than 0.05mm. If the change in the needle value of the pressing plate at a certain position is too large (more than 0.05mm), it indicates that the gap between the lower end surface of the lower flange of the workpiece and the protrusion of the tooling is too large. In this case, a feeler gauge is used to detect the gap between the workpiece and the tooling, and a copper sheet slightly thinner than the feeler gauge is used to pad into the gap between the workpiece and the tooling. The four lever dial gauges are observed during the padding process to ensure that the needle of the lever dial gauge does not move. After padding, the pressing plate is used to press and observe the change in the needle value of the four lever dial gauges.

[0026] The above drawings and explanations are only one specific embodiment of the application, but the specific protection scope of the application is not limited to the above explanations. Any technical idea within the scope of the application disclosed herein, and any simple replacement or change according to the technical solution of the application, should be within the protection scope of the application.

Claims

1. A clamping method for machining large thin-walled parts, characterized in that, The method comprises the following steps: Step one, the tooling (4) is placed on the machine tool surface after being pressed by the positioning block (1), and the flatness of the tooling (4) is aligned; Step two, the large end flange of the workpiece (5) is placed horizontally on the upper surface of the positioning block (1), the upper end surface of the large end flange of the workpiece (5) is pressed by using the lever dial gauge (3), the stable needle value is observed and recorded, and the flatness of the upper end surface of the large end flange of the workpiece (5) is verified; Step three, the pressing plate is arranged on both sides of the reinforcing block (6) above the large end flange of the workpiece (5), the pressing plate presses the workpiece (5) downward, and the needle indication of the lever dial gauge (3) is observed during the pressing process; Step four, when the needle value of the lever dial gauge (3) changes by more than 0.05mm after the pressing plate presses the workpiece (5), the gap between the workpiece (5) and the tooling (4) is detected by using a tool, and the gap between the workpiece (5) and the tooling (4) is padded by using a pad, and the needle of the lever dial gauge (3) is observed and recorded during the padding process; In step three, the needle indications of the four lever dial gauges (3) are observed during the pressing process, and the change amounts of the needle indications of the four lever dial gauges (3) are all less than 0.05mm; The diameter of the workpiece (5) is 2.5m, and the wall thickness is 4.5mm.

2. The method of claim 1, wherein The number of the lever dial gauges (3) is four, and the four lever dial gauges (3) are uniformly distributed around the large end flange of the workpiece (5).

3. The method of claim 2, wherein The number of the positioning blocks (1) is four, and the four positioning blocks (1) are arranged directly below the reinforcing block (6) of the workpiece (5).

4. The method of claim 3, wherein In step one, the flatness of the four bosses of the tooling (4) is less than 0.01mm.

5. The method of claim 4, wherein In step two, when the lower end surface of the large end flange of the workpiece (5) has poor flatness, the position where the flatness of the lower end surface of the large end flange is less than 0.1 is found by rotating the workpiece (5) around the Z axis.

6. The method of claim 1-5, wherein The positioning blocks (1) are uniformly distributed between the workpiece (5) and the tooling (4).

7. The method of claim 6, wherein The tool is a feeler gauge.

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