CN110961960A

CN110961960A - A CNC lathe fixture for processing a slender shaft with a flange

Info

Publication number: CN110961960A
Application number: CN201911114154.2A
Authority: CN
Inventors: 王勇; 智静娟; 佟玮; 范晓雷; 杜峻松; 王鑫; 何世林; 戚保凯; 徐青山; 边涛; 史金玉; 刘建秋; 刘全
Original assignee: China Academy of Launch Vehicle Technology CALT; Capital Aerospace Machinery Co Ltd
Current assignee: China Academy of Launch Vehicle Technology CALT; Capital Aerospace Machinery Co Ltd
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-04-07
Anticipated expiration: 2039-11-14
Also published as: CN110961960B

Abstract

A CNC lathe fixture for machining a slender shaft with a flange, comprising: a support ring, etc.; the support ring is installed in an annular groove on the end face of the flange of the part to be processed to form a combination; The circle is matched with the inner hole of the fastening clamp, and the fastening clamp is locked by the fastening structure, so that the inner hole of the fastening clamp shrinks and the outer circle of the flange plate of the part to be processed is tightly held; the fixing ring is connected with the positioning mandrel , and fixed on the positioning mandrel, one end of the positioning mandrel is connected with the main shaft of the machine tool, and the taper surface of the other end is matched with the taper hole of the part to be processed to realize positioning; the limit screw penetrates the limit screw connection hole of the fastening clamp, And stuck in the limit groove on the edge of the fixed ring to realize the synchronous rotation of the part to be processed and the main shaft. The invention improves the one-time pass rate of the flanged slender shaft parts and shortens the product production cycle.

Description

Numerical control lathe clamp for machining slender shaft with flange plate

Technical Field

The invention relates to a numerical control lathe fixture.

Background

The valve is an important executive component in a carrier rocket system, and the reliability of the valve is related to the safety of personnel and equipment and even directly influences the success of a rocket launching task. In order to meet the functional requirements and adapt to the severe working environment, the structural complexity and precision of the valve product of the novel carrier rocket are continuously improved. The slender shaft type part with the flange (see figure 1) is an important component in the valve and plays roles of guiding, connecting and sealing in the valve, so the structural form of the part is more complex, and the requirement on dimensional accuracy is more severe.

The slender shaft parts with the flange plates in the space valve are characterized as follows: (1) the material is a difficult-to-machine material (stainless steel, high-temperature alloy and the like), the material is serious in machining hardening, large in cutting resistance and difficult to control in machining precision; (2) the part has a complex structure and is a multi-step structure consisting of a plurality of excircle shaft sections and thread shaft sections; (3) the length-diameter ratio of the parts is more than 5, and the rigidity is poor; (4) the size precision of the guide surface is high (can reach IT6), the surface roughness is Ra0.4, and the coaxiality requirement of each shaft section is phi 0.02. The structural form of the high-precision slender shaft brings great challenges to the part machining process.

The general processing method of the slender shaft part comprises two methods: (1) the parts are finished by rough machining and finish machining on a numerical control lathe, the machining method has low one-time qualification rate of the guide size, poor rigidity of the parts, easy out-of-tolerance of form and position, and strict requirements on the performance of the lathe; (2) the numerical control lathe finishes semi-finish machining (one end clamps the excircle and one end jacks up) of the slender shaft, and the grinding machine finishes guide surface finish machining (double-tip positioning), and the rough and finish machining positioning of the machining method is inconsistent, and the form and position tolerance of parts is easy to be out of tolerance.

In order to meet the drawing precision requirement and improve the processing efficiency of products, the processing process of the high-precision slender shaft with the flange plate adopts a guide surface for finish grinding, each shaft section is turned, and the clamping and positioning mode of the turned slender rod is consistent with the positioning mode of double centers during grinding. Therefore, the numerical control lathe needs to design a special fixture to realize the double-tip positioning and clamping of the part.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the invention overcomes the defects of the prior art, provides the numerical control lathe fixture for processing the slender shaft with the flange plate, improves the one-time qualification rate of the slender shaft parts with the flange plate, and shortens the production period of products.

The technical scheme adopted by the invention is as follows: a numerical control lathe clamp for machining slender shafts with flanges comprises: the device comprises a support ring, a fastening hoop, a fixing ring, a limiting screw, a positioning core shaft and a fastening mechanism; the support ring is arranged in an annular groove on the end face of the flange of the part to be processed to form a combined body; the outer circle of the flange plate of the part to be machined is matched with the inner hole of the fastening clamp, and the fastening clamp is locked through the fastening structure, so that the inner hole of the fastening clamp is contracted to hold the outer circle of the flange plate of the part to be machined tightly; the fixing ring is connected with the positioning mandrel and fixed on the positioning mandrel, one end of the positioning mandrel is connected with a machine tool spindle, and the conical surface of the other end of the positioning mandrel is matched with the conical hole of the part to be processed to realize positioning; the limiting screw penetrates through a limiting screw connecting hole of the fastening clamp and is clamped in a limiting groove at the edge of the fixing ring, and the part to be processed and the main shaft synchronously rotate.

The positioning mandrel comprises a threaded shaft section, a positioning shaft shoulder, a conical shaft and an optical shaft section; the two sides of the positioning shaft shoulder are respectively provided with a threaded shaft section and a smooth shaft section, the smooth shaft section is connected with a machine tool spindle, the other side of the threaded shaft section is provided with a conical shaft, and the conical surface of the conical shaft is matched and positioned with the conical surface of the part to be processed.

The center of the fixing ring is a threaded hole matched with the threaded shaft section, and limit grooves are uniformly distributed along the circumferential direction of the fixing ring.

The fastening hoop is of an annular structure, an opening is formed along one radius, a lug piece structure with a screw connecting hole is arranged at the opening, and a lug structure which extends outwards and is provided with a limiting screw connecting hole is arranged at the symmetrical position of the lug piece; the central hole of the annular structure is provided with an axial limiting step; and a plurality of unloading grooves are distributed along the circumferential direction of the fastening hoop.

The circumferential unloading grooves are unevenly distributed, and the distribution density of the unloading grooves close to the opening part is reduced.

The fastening mechanism comprises a connecting screw and a locking nut, and the connecting screw penetrates through a screw connecting hole in the fastening hoop and is screwed by the locking nut.

Compared with the prior art, the invention has the advantages that:

(1) the special fixture for the numerical control lathe enables the numerical control lathe to realize double-tip positioning and clamping, realizes the consistency of positioning reference when the semi-finish machining and the finish machining of the numerical control lathe for the slender shaft parts with the flange plates are carried out, and meets the form and position tolerance requirement of design drawings on the premise of ensuring the size precision of the parts.

(2) By using the clamp disclosed by the invention, the one-time qualification rate of high-precision slender shaft parts in batch production can reach 95%; the production process capacity of the product is greatly improved, the product production quality stability is good, the consistency of all sizes of the part product is good, the interchangeability is strong, the part state is good, the reliability of the whole valve operation is improved, the waste of manpower, material resources, financial resources and resources caused by a series of decomposition, repacking, tests and the like due to unqualified product performance is avoided, and the production period of the product is shortened.

Drawings

FIG. 1 is a schematic view of a flanged slender shaft component.

FIG. 2 is a view showing the structure of the numerical control lathe fixture according to the present invention.

Fig. 3 is a block diagram of a positioning mandrel.

Fig. 4 is a structural view of the fixing ring.

Fig. 5 is a structural view of the fastening clip.

Detailed Description

The invention is described with reference to the accompanying drawings.

A numerical control lathe clamp for processing a slender shaft with a flange plate realizes double-center positioning of parts on a numerical control lathe, the structural form of the clamp is shown in figure 2, the clamp is composed of 6 components and comprises: support ring 1, fastening clamp 3, solid fixed ring 4, stop screw 5, positioning core axle 6, connecting screw 7, lock nut 8.

The positioning mandrel 6 is structurally shown in fig. 3 and is an integral structure and comprises a threaded shaft section 61, a positioning shaft shoulder 62, a conical shaft 63 and an optical axis section 64; the two sides of the positioning shaft shoulder 62 are respectively provided with a threaded shaft section 61 and an optical axis section 64, the optical axis section 64 is connected with a main shaft of a machine tool, the other side of the threaded shaft section 61 is provided with a conical shaft 63, and a 60-degree conical surface of the conical shaft 63, namely a positioning surface 65, is matched with the 60-degree conical surface of the part 2 to be processed for positioning;

as shown in fig. 4, the center of the fixing ring 4 is a threaded hole matched with the threaded

shaft section

61, and 2 limiting grooves 41 are uniformly distributed along the circumferential direction of the fixing ring 4. The function of the clamp is to realize the connection between a positioning core shaft 6 and a fastening hoop 3 in a lathe clamp;

as shown in fig. 5, the fastening clamp 3 clamps the outer circle of the part 2 to be processed, the part 2 to be processed is connected with the spindle of the machine tool, the fastening clamp 3 is of a semi-open clamp structure and is of an annular structure, an opening is formed along a radius, a lug structure with a screw connecting hole 31 is arranged at the opening, and a lug structure extending outwards and having a limit screw connecting hole 32 is arranged at the symmetrical position of the lug. An axial limiting step 33 is arranged in the central hole of the annular structure; the circle center of the limiting threaded connecting hole 32 and the circle center of the fastening hoop 3 are on the same straight line; the two screw connecting holes 31 are coaxial, a connecting line of the circle centers of the screw connecting holes 32 and the circle center of the fastening hoop 3 is perpendicular to the central lines of the two screw connecting holes 31, and a plurality of unloading grooves 34 are distributed along the circumferential direction of the fastening hoop 3. The circumferential unloading grooves 34 are unevenly distributed, and the distribution density of the unloading grooves 34 near the opening part is reduced.

The support ring 1 is matched with a thin-wall groove of the part 2 to be processed, so that when the fastening clamp 3 clamps an excircle, the thin wall is prevented from deforming to damage the processed surface.

The slender shaft with the groove on the end surface of the flange plate is a part 2 to be processed, and the support ring 1 is arranged in the annular groove of the slender shaft to form a combination body; the excircle of the flange plate is matched with the inner hole of the fastening hoop 3, the connecting screw 7 passes through a screw connecting hole 32 on the fastening hoop 3 and is screwed by the locking nut 8, and the inner hole of the fastening hoop 3 shrinks to hold the excircle of the workpiece 2 tightly; the fixing ring 4 is connected with the positioning mandrel 6 through threads and is fixed on the positioning mandrel 6, one end of the positioning mandrel 6 is connected with a machine tool spindle, and the conical surface of the other end of the positioning mandrel 6 is matched with the conical hole of the part 2 to realize positioning; the limit screw 5 penetrates through the limit screw connecting hole 32 of the fastening hoop 3 and is clamped in the limit groove 41 of the fixing ring 4, so that the workpiece 2 and the main shaft synchronously rotate to finish cutting.

The present invention has not been described in detail, partly as is known to the person skilled in the art.

Claims

1. A CNC lathe fixture for processing a slender shaft with a flange, characterized in that it comprises: a support ring (1), a fastening clamp (3), a fixing ring (4), a limit screw (5), The positioning mandrel (6) and the fastening mechanism; the support ring (1) is installed in the annular groove on the end face of the flange plate of the part to be processed (2) to form a combined body; the outer circle of the flange plate of the part to be processed (2) It is matched with the inner hole of the fastening clamp (3), and the fastening clamp (3) is locked by the fastening structure, so that the inner hole of the fastening clamp (3) shrinks and the flange of the part to be processed (2) is outside. The circle is tightly held; the fixing ring (4) is connected with the positioning mandrel (6) and fixed on the positioning mandrel (6). 2), to achieve positioning; the limit screw (5) penetrates the limit screw connection hole (32) of the fastening clamp (3), and is stuck in the limit groove (41) on the edge of the fixing ring (4). ) to realize the synchronous rotation of the part to be processed (2) and the main shaft.

2. A CNC lathe fixture for processing a flanged slender shaft according to claim 1, wherein the positioning mandrel (6) comprises a threaded shaft segment (61), a positioning shoulder (62), a taper The shaft (63) and the optical shaft segment (64); the two sides of the positioning shoulder (62) are respectively the threaded shaft segment (61) and the optical shaft segment (64). 61) The other side is a tapered shaft (63), and the tapered surface of the tapered shaft (63) is positioned in coordination with the tapered surface of the part (2) to be processed.

3. A CNC lathe fixture for processing a flanged slender shaft according to claim 1 or 2, wherein the center of the fixing ring (4) is a threaded hole matched with a threaded shaft segment (61), Two limiting grooves (41) are evenly distributed along the circumferential direction of the fixing ring (4).

4. A CNC lathe fixture for processing a flanged slender shaft according to claim 3, characterized in that: the fastening clamp (3) is an annular structure with an opening along a radius, and the opening is provided with a belt The lug structure with screw connection holes (31) is provided with a lug structure with a limit screw connection hole (32) extending outward at the symmetrical position of the lug; the central hole of the annular structure is provided with an axial limit step (33). ); a plurality of relief grooves (34) are distributed along the circumferential direction of the fastening clamp (3).

5. A CNC lathe fixture for processing a flanged slender shaft according to claim 4, characterized in that: the circumferential relief grooves (34) are unevenly distributed, and the relief grooves (34) near the opening are The distribution density decreases.

6. A CNC lathe fixture for processing a flanged slender shaft according to claim 5, wherein the fastening mechanism comprises a connecting screw (7) and a locking nut (8), and the connecting screw (7) Pass through the screw connection hole(32) on the fastening clamp(3) and tighten with the lock nut(8).