A sleeve product processing tool and a processing method

Abstract

The application provides a sleeve product processing tool and processing method, which comprises three parts of a base, a mandrel and a cover. The materials of the three parts are brass, which will not scratch the product. The base plays a connecting and supporting role for the tool mandrel part, and also plays a role of connecting the product. The base has three mounting holes corresponding to the three positioning holes of the product. The center line of the radial step circle of the base and two hole centers is parallel, and the other hole is provided with a positioning pin to limit the axial rotation freedom of the sleeve. The mandrel is composed of a step circle and two threaded ends, and the two threaded ends are used for connecting the tool base and the cover, respectively. The step shafts at the two ends are tightly matched with the inner hole of the sleeve to play a supporting role. The middle section has a smaller diameter and can be used as a weight reduction hole for chip removal. The cover is fixed at the top end by a nut to limit the axial freedom of the sleeve, and the slot is directed to the position of the radial groove of the sleeve to avoid interference between the cover and the tool during processing.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, and specifically relates to a machining tooling and machining method for sleeve-type products. Background Technology

[0002] The sleeve is a key component of a certain type of rocket engine, serving as the connection between the engine body and the thrust chamber. Its structure is as follows: Figure 1 As shown, the material is solution-treated stainless steel 1Cr18N19T1. The existing machining process is as follows: rough machining of the inner and outer surfaces at both ends, finish machining of the inner and outer surfaces at both ends, milling and drilling holes in one flange, milling and drilling holes in the other flange, milling six radial weight-reducing holes, milling axial grooves, with deburring operations performed by fitter in between. The existing machining process has the following five disadvantages:

[0003] 1. The material is solution-treated stainless steel, which is difficult to process, requires a large amount of material removal, and causes rapid tool wear.

[0004] 2. The process involves multiple steps, resulting in a long processing cycle, and repeated clamping introduces errors.

[0005] 3. Stress is released after machining the large notch in the axial groove, causing the part to deform.

[0006] 4. The material removal allowance is large, and the burrs on the flange after processing are large and difficult to remove.

[0007] 5. When milling the upper flange lugs, the lower cylindrical part is only 4mm thick, making clamping difficult. Furthermore, the mounting holes on the upper and lower flange lugs need to be aligned, making positioning difficult during separate machining. Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, the inventors conducted intensive research and provided a machining fixture and method for sleeve-type products. This method utilizes a single fixture to complete the machining of flange lugs, mounting holes, weight-reducing holes, and axial grooves in a single setup. This solves the problems of large repeatability errors and long preparation times. The use of a "saw-instead-of-milling" cutting method for rough machining of the axial grooves overcomes the disadvantages of low cutting efficiency and rapid tool wear; effectively improving production efficiency and ensuring product quality, thus completing this invention.

[0009] The technical solution provided by this invention is as follows:

[0010] Firstly,

[0011] A machining fixture for sleeve-type products, the sleeve-type products including: an upper flange, a lower flange and a sleeve portion; the machining fixture including: a base, a mandrel, a gland and a nut;

[0012] The bottom of the mandrel is fixedly connected to the base;

[0013] The sleeve is fitted onto the outside of the mandrel;

[0014] Lower flange connection base;

[0015] The gland is fitted onto the spindle and inserted into the upper flange;

[0016] The end of the mandrel is threaded with a nut to fix the axial position between the sleeve-type product and the mandrel.

[0017] Preferably, the gland is machined with an opening groove; the opening direction of the opening groove corresponds to the position of the axial groove in the sleeve portion.

[0018] Preferably, the bottom of the mandrel is machined with a threaded shaft, and the mandrel is connected to the fixed base through the threaded shaft.

[0019] Preferably, the mandrel has an outwardly oriented annular flange as a first step and a second step.

[0020] Both the first and second steps are interference-fitted with the inner hole of the sleeve.

[0021] Preferably, the outer diameter of the cylindrical end between the first and second steps is smaller than the inner diameter of the sleeve portion, which is used for chip removal when milling the weight-reducing hole.

[0022] Preferably, the base end face is machined with multiple mounting holes, which are connected to the positioning holes on the lower flange via standard parts.

[0023] Preferably, one of the mounting holes is fitted with a locating pin to restrict the rotational freedom of the sleeve portion along the axial direction.

[0024] Secondly,

[0025] A method for processing sleeve-type products using the machining fixtures described in the first aspect, comprising:

[0026] The base is clamped using a three-jaw chuck;

[0027] Install the mandrel on the base;

[0028] Fit the sleeve part onto the outside of the mandrel and connect the lower flange to the base;

[0029] The gland is fitted onto the mandrel and inserted into the upper flange, so that the opening direction of the slot corresponds to the axial slot position of the sleeve part;

[0030] Install nuts to fix the axial position between the sleeve-type product and the mandrel;

[0031] The upper and lower flanges are machined, and the weight reduction holes and axial grooves on the sleeve section are machined in sequence by turning the machine tool.

[0032] Preferably, the axial groove is machined as follows:

[0033] Pre-drill holes at the end of the axial groove using a drill bit;

[0034] Use an end mill to mill a square groove at the pre-drilled hole location;

[0035] Axial grooves are formed by sawing along boundary line 1 and boundary line 2 respectively, and boundary line 1 and boundary line 2 are connected to the two sides of the square groove-shaped notch.

[0036] After removing the intermediate material from the cutting process, the axial groove is finished by using an end mill.

[0037] Preferably, during sawing, reverse milling is used to turn the burrs outward.

[0038] Compared with the prior art, the advantages of the present invention are mainly reflected in the following aspects:

[0039] 1) This invention features a specially designed fixture that allows for the machining of the flange lugs, mounting holes, weight-reduction holes, and axial grooves of stainless steel sleeve products in a single clamping operation. The fixture restricts axial movement and rotation of the parts, ensuring stable and reliable clamping. It also has a alignment function to guarantee the positional accuracy of the mounting holes on the upper and lower flanges.

[0040] 2) This invention makes full use of the functions of a five-axis machine tool, combining the first three processes into one process, preventing errors caused by repeated clamping and alignment, and reducing preparation and turnaround time, thereby improving production efficiency.

[0041] 3) This invention uniquely involves pre-drilling holes at the root of the axial groove on the product, followed by machining a 13x13XR3 square groove. A "saw-instead-of-milling" cutting method is used for rough machining of the axial groove, similar to wire EDM. The smaller cutting force effectively prevents product deformation. This avoids the disadvantages of traditional layered cutting, such as low efficiency and rapid tool wear, thus improving machining efficiency.

[0042] 4) This invention addresses the machining of thin-walled parts made of 1Cr18Ni9Ti solid solution material. This method has been applied in the processing of a batch of products during the sample stage, and the dimensions and geometric tolerances of the machined parts meet the design requirements. It controls product deformation within 0.08mm, replacing the traditional layer-by-layer milling method, reducing the number of tool replacements from 6 per tool to 50 per tool. It reduces labor intensity and increases processing efficiency by more than 4 times. This method has been formalized into the process specifications, providing a reference for machining similar products. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of similar products;

[0044] Figure 2 This is a schematic diagram of the mandrel;

[0045] Figure 3 This is a schematic diagram of the base;

[0046] Figure 4 This is a schematic diagram of a pressure cap.

[0047] Figure 5 This is an assembly diagram of the present invention;

[0048] Figure 6 This is a schematic diagram of the base;

[0049] Figure 7 This is a sectional view of the base;

[0050] Figure 8 A schematic diagram showing the parts of the product that need to be processed;

[0051] Figure 9 This is a schematic diagram of a saw blade milling cutter;

[0052] Figure 10 This is a schematic diagram of an axial groove;

[0053] Figure 11 This is a schematic diagram of the assembly of the present invention. Detailed Implementation

[0054] This invention provides a machining fixture and method for sleeve-type products. The machining fixture is designed based on the structural characteristics of sleeve-type products, such as... Figure 11 As shown, the machining fixture consists of three parts: a base, a mandrel, and a pressure cap. All three parts are made of brass, which will not scratch the product. The base connects and supports the mandrel part of the fixture, and also connects to the product. The base has three mounting holes, which correspond to the three positioning holes on the product. The radial stepped circle of the base is parallel to the line connecting the centers of two of the holes, and the third hole is fitted with a locating pin to restrict the axial rotational freedom of the sleeve. The mandrel consists of a stepped circle and threads at both ends. The threads at both ends are used to connect to the fixture base and the pressure cap, respectively. The stepped shafts at both ends fit tightly with the inner hole of the sleeve, providing support. The middle section has a smaller diameter and can be used for chip removal when making weight reduction holes. The pressure cap is fixed at the top with a nut, restricting the axial freedom of the sleeve. The slot is oriented towards the radial groove of the sleeve to avoid interference between the pressure cap and the cutting tool during machining.

[0055] When using, first clamp the fixture base with a three-jaw chuck, then install the fixture mandrel. Next, pass the sleeve product through the mandrel, align the three holes on the product flange lugs with the base, and finally install and tighten the pressure cap. After installation, align the radial step circle of the fixture base for machining.

[0056] Specifically, sleeve products such as Figure 1 The diagram shows an upper flange 14-1, a lower flange 14-2, a sleeve portion 15, a weight-reducing hole 16, and an axial groove 17. This invention provides a machining fixture for sleeve-type products, as shown... Figure 5 The machining fixture shown includes: base 1, mandrel 2, pressure cap 3, and nut 4.

[0057] The base 1 is as follows Figure 6 The diagram shows a stepped circular rotating structure. A threaded hole 18 is machined at the axis center. The large end of the base 1 has three mounting holes: a first mounting hole 19, a second mounting hole 20, and a third mounting hole 21, which correspond to the three positioning holes on the product. Figure 7 The axis B of the base 1 shown is parallel to the axis A of the first mounting hole 19 and is also parallel to the axes of the second mounting hole 20 and the third mounting hole 21. The third mounting hole 21 is equipped with a locating pin to restrict the rotational freedom of the sleeve along the axial direction.

[0058] The mandrel is as follows Figure 2 The diagram shows a structure consisting of stepped circles at both ends and external threads, specifically a first external thread 22 and a second external thread 23. The threads at both ends are used for connection to the base 1 and the pressure cap 3, respectively. The stepped circles at both ends are as follows... Figure 2 The first step 24, the second step 25, and the inner hole of the sleeve portion 15 are interference-fitted and serve a supporting function. The diameter between the first step 24 and the second step 25 is smaller than the diameter of the inner hole of the sleeve portion 15, which can be used for chip removal when milling weight-reducing holes.

[0059] The cover 3 is as follows Figure 4 The image shows a disk-like structure with an opening slot 28, as shown. Figure 5 As shown, the cap 3 is fixed to the top of the product by the cooperation of the nut 4 and the spindle 2. The small end 29 of the cap 3 is installed in the product direction and is clearance-fitted with the inner hole of the product, which restricts the axial freedom of the sleeve part 15. The opening direction of the opening groove 28 is towards the axial groove 17 of the sleeve part 15 to avoid interference between the cap and the tool during processing.

[0060] The radius of the large end disc on the base 1 is not less than the radius of the upper flange 14-1 of the product.

[0061] A method for processing sleeve products, including installing a small plane of a leveling fixture base (such as...) Figure 3 (As shown), finally install the gland fasteners to complete the machining. First, machine the rotating sleeve body, then perform milling as follows. Figure 1 The upper flange 14-1, lower flange 14-2, weight reduction hole 16, and axial groove 17 are shown. The specific steps include:

[0062] Step 1: Use a three-jaw chuck to clamp base 1, with the large end of base 1 facing upwards;

[0063] Step 2: Install the spindle 2 on the base 1 via the first external thread 22;

[0064] Step 3: Pass the lower flange 14-2 through the mandrel 2 onto the large end disc of the base 1. The three holes on the lower flange 14-2 correspond one-to-one with the three mounting holes on the base 1. Locate the positioning hole on the bottom end face of the lower flange 14-2 that corresponds to the third mounting hole 21 and install the positioning pin. Since the upper and lower ends of the product have been fixed with tooling, restricting its five degrees of freedom, only one positioning pin is needed to further restrict the product's rotation around the tooling axis.

[0065] Step 4: Install the pressure cap 3, with the small end 29 of the pressure cap 3 facing the product direction and the slot 28 facing the axial slot 17. Install the nut 4 to fasten the pressure cap 3 to the product.

[0066] The machining process is carried out on a Micron 5-axis machining center UCP800. First, the upper flange 14-1 and lower flange 14-2 are machined. Then, the A-axis machine table "cradle" section is rotated and the C-axis is rotated to process the flanges sequentially. Figure 1 The weight reduction hole 16 shown and the other five weight reduction holes 16 and axial groove 17 are machined.

[0067] In the machining of axial groove 17, such as Figure 8 , 10 As shown, a pre-drilling hole is first made at the end of the axial groove 17 using a drill bit. Then, a 13×13, 4-R3 square groove is milled at the pre-drilled hole location using an end mill. This facilitates subsequent milling with a saw blade cutter, etc. Figure 9 As shown, the method of "using saw instead of milling" is adopted along... Figure 10 The saw blades are used to cut along the middle boundary lines 1 and 2, connecting with the left and right sides (R3) of the upper edge of the 13×13 square groove. Because the material is stainless steel with good plasticity, some residual metal remains at the two R3 points on the upper edge of the 13×13 square groove after sawing. Therefore, manual removal of the remaining material is necessary, for example, by using pliers to grasp the excess and pull off the incompletely cut portion. During the saw blade milling process, a reverse milling method is used to turn the burrs outwards, reducing the difficulty of burr removal. Finally, the axial groove 17 is finished using an end mill.

[0068] The invention features a unique technology called "saw instead of milling". Since saw blade milling cutters are generally used to cut bar stock or process groove-shaped parts, this processing method uses wire cutting to cut the product with a linear feed path to remove excess material. The advantages of this method are that it reduces the difficulty of removing burrs from stainless steel materials, reduces tool wear during cutting, and has a smaller cutting force, thus replacing the traditional layered milling method and reducing labor intensity.

[0069] This invention provides a reference approach for the efficient and high-quality machining of similar sleeve-shaped parts, and can be promoted in the production of similar products. The machining data for a single product before and after the application of this invention are as follows:

[0070]

[0071] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0072] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for processing sleeve-type products, characterized in that, Sleeve products include: upper flange (14-1), lower flange (14-2) and sleeve part (15); It uses a sleeve-type product processing fixture, which includes: a base (1), a mandrel (2), a pressure cap (3), and a nut (4); The bottom of the spindle (2) is fixedly connected to the base (1); The sleeve part (15) is fitted onto the outside of the mandrel (2); The lower flange (14-2) connects to the base (1); The gland (3) is fitted onto the spindle (2) and inserted into the upper flange (14-1); The end of the mandrel (2) is threaded with a nut (4) to fix the axial position between the sleeve product and the mandrel (2); The gland (3) is machined with an opening groove (28); the opening direction of the opening groove (28) corresponds to the position of the axial groove (17) of the sleeve part (15); Processing methods include: Clamp the base with a three-jaw chuck (1); Install the spindle (2) on the base (1); The sleeve part (15) is fitted onto the outside of the mandrel (2), and the lower flange (14-2) is connected to the base (1). The gland (3) is fitted onto the spindle (2) and inserted into the upper flange (14-1); so that the opening direction of the opening groove (28) corresponds to the position of the axial groove (17) of the sleeve part (15); Install the nut (4) to fix the axial position between the sleeve product and the mandrel (2); The upper flange (14-1) and lower flange (14-2) are machined, and the turning machine tool is used to machine the weight reduction hole (16) and axial groove (17) on the sleeve part (15) in sequence. The axial groove (17) is machined as follows: Use a drill bit to pre-drill a hole at the end of the axial groove (17); Use an end mill to mill a square groove at the pre-drilled hole location; A axial groove (17) is formed by sawing along boundary line 1 and boundary line 2 respectively. Boundary line 1 and boundary line 2 are connected to the two sides of the square groove-shaped notch. After removing the intermediate material from the cutting process, the axial groove (17) is finished by using an end mill.

2. The processing method for a sleeve-type product according to claim 1, characterized in that, When sawing, reverse milling is used to turn the burrs outward.

3. The processing method for a sleeve-type product according to claim 2, characterized in that, The bottom of the mandrel (2) is machined with a threaded shaft, and the mandrel (2) is fixedly connected to the base (1) through the threaded shaft.

4. The processing method for a sleeve-type product according to claim 2, characterized in that, The spindle (2) has an outwardly circumferential flange as the first step (24) and the second step (25); The first step (24) and the second step (25) are both interference fit with the inner hole of the sleeve part (15).

5. The processing method for a sleeve-type product according to claim 4, characterized in that, The outer diameter of the cylindrical section between the first step (24) and the second step (25) is smaller than the inner hole of the sleeve part (15), and is used for chip removal when milling the weight reduction hole (16).

6. The processing method for a sleeve-type product according to claim 4, characterized in that, The base (1) end face is machined with multiple mounting holes, which are connected to the positioning holes on the lower flange (14-2) through standard parts.

7. The processing method for a sleeve-type product according to claim 6, characterized in that, One of the mounting holes is fitted with a locating pin to limit the rotational freedom of the sleeve portion (15) along the axial direction.

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