Fixture for Milling the Groove of the Shear Pin Safety Valve Body

Abstract

The fixture for milling the valve body groove of the shear pin type safety valve of the present invention includes a workbench. A T-shaped groove is provided on the upper surface of the workbench, and a T-shaped nut is arranged in the T-shaped groove. A base is provided on the workbench. A through hole a perpendicular to the upper surface of the base is provided in the middle part of the base. A mandrel is arranged in the through hole a. The mandrel is a cylindrical structure that is thinner at the upper part and thicker at the lower part. Through slots a are provided at both ends of the base. An eccentric wheel perpendicular to the mandrel is connected in the through slots a through a pin shaft. The eccentric wheel slightly protrudes from the bottom surface of the base. A handle is fixedly connected to the side surface of the eccentric wheel. A boss b is arranged on the side surface of the base close to the through hole a. The boss b is connected to an L-shaped limit block through a threaded pin shaft. The fixture for milling the valve body groove of the present invention can realize the milling processing of valve body grooves of various specifications, has a compact structure, is safe and reliable, and is convenient to use, and solves the problems of difficult clamping and alignment during the processing of valve body grooves.

Description

Technical Field

[0001] The present invention belongs to the technical field of fixtures, and particularly relates to a fixture for milling the valve body groove of a shear pin type safety valve. Background Art

[0002] The safety valve is an important part to ensure the normal operation of petrochemical equipment. The most commonly used one is the shear pin type safety valve, which plays an important role in protecting the equipment operation and personal safety in the system. With the rapid development of modern industry, the demand for safety valves has increased rapidly.

[0003] At present, most of the valve bodies of safety valves are precision castings. The conventional processing scheme is complex, with many auxiliary processes, and it is very difficult to ensure the symmetry requirement after the valve body groove is processed, which seriously affects the product quality and production efficiency of the safety valve and restricts the improvement of production capacity. Summary of the Invention

[0004] The purpose of the present invention is to provide a fixture for milling the valve body groove of a shear pin type safety valve. Using this fixture to process the valve body groove can realize the rapid clamping and alignment of the valve body.

[0005] The technical solution adopted by the present invention is that the fixture for milling the valve body groove of a shear pin type safety valve of the present invention includes a workbench. A T-shaped groove is opened on the upper surface of the workbench, and a T-shaped nut is arranged in the T-shaped groove. A base is arranged on the workbench. A through hole a perpendicular to the upper surface of the base is opened in the middle part of the base. A mandrel is arranged in the through hole a. The mandrel is a cylindrical structure that is thinner at the top and thicker at the bottom. Through slots a are opened at both ends of the base. An eccentric wheel perpendicular to the mandrel is connected in the through slot a through a pin shaft. The eccentric wheel slightly protrudes from the bottom surface of the base. A handle is fixedly connected to the side surface of the eccentric wheel. A boss b is arranged on the side surface of the base close to the through hole a. The boss b is connected to an L-shaped limit block through a threaded pin shaft.

[0006] The characteristics of the present invention also lie in that:

[0007] The inner diameter of the bottom of the mandrel is smaller than that of its upper part. A boss a is arranged at the bottom end of the mandrel. The diameter of the boss a is matched with the groove width of the T-shaped groove on the surface of the workbench. A spring is arranged in the mandrel. One end of the spring touches the transition surface of the inner diameter dimension of the mandrel, and the upper part of the spring touches the bolt head of the adjusting bolt. The adjusting bolt passes through the spring and is connected to the T-shaped nut.

[0008] Threads are arranged on the outer cylindrical surface of the thinner part of the mandrel. The diameter of the thicker part of the mandrel is adapted to the inner diameter of the through hole a in the middle part of the base.

[0009] An axial keyway a is arranged on the outer cylindrical surface of the thicker part of the mandrel. An axial keyway b is arranged on the inner side of the through hole a of the base. The guide key is simultaneously in the keyway a and the keyway b, and the guide key is fixedly connected to the keyway a.

[0010] Hole retaining rings are arranged at both ends of the pin shaft.

[0011] The longitudinal section of the L-shaped limit block is L-shaped, and a pair of connecting pairs are arranged on its side, and the two connecting pairs are connected to the boss b through a threaded pin shaft.

[0012] The handle is perpendicular to a line connecting the center point and the rotation point of the eccentric wheel, and the rotation point of the eccentric wheel is located closer to the through hole a of the base.

[0013] A plurality of T-slots are arranged in parallel.

[0014] The beneficial effects of the present invention are:

[0015] (1) The fixture of the present invention can realize the milling processing of the valve body groove on an ordinary vertical milling machine, boring machine or vertical machining center, CNC boring machine, thereby improving the processing efficiency. In addition, the milling fixture has low manufacturing cost, is convenient and quick to use, and reduces the production cost;

[0016] (2) The present invention adopts the form of threaded connection, and limits the rotational freedom of the valve body to be processed by an L-shaped limit block. The rotating eccentric wheel drives the base to rise and tighten the valve body to limit its axial freedom and radial freedom, ensuring that the valve body and the fixture are tightly matched and will not loosen during the milling process. The processing of each part of the valve body groove is completed by setting the machine tool program to ensure its dimensional tolerance and form and position tolerance. It has a simple structure and is easy to clamp and use, which greatly improves the processing accuracy of the product;

[0017] (3) When the clamp of the present invention is used to process the valve body groove, clamping and alignment are simple and easy to operate, and only the tool needs to be aligned for the first time during processing, and subsequent processing can be directly performed according to the procedure, thereby improving processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a fixture for milling a groove of a valve body of a shear pin type safety valve according to the present invention;

[0019] Figure 2 It is a cross-sectional view of a fixture for milling a groove of a shear pin type safety valve body of the present invention;

[0020] Figure 3 It is a top view of a fixture for milling a groove of a valve body of a shear pin type safety valve of the present invention;

[0021] Figure 4 It is a schematic diagram of the structure of the shear pin type safety valve after the valve body is installed with the fixture for milling the valve body groove of the valve body of the present invention;

[0022] Figure 5 It is a cross-sectional view of the shear pin type safety valve after the valve body is installed with the fixture for milling the valve body groove of the valve body of the present invention;

[0023] Figure 6 The invention is a top view of a shear pin type safety valve after the valve body is installed with a fixture for milling the valve body groove.

[0024] In the figure, 1. Workbench, 2. Base, 3. Eccentric wheel, 4. Handle, 5. Valve body, 6. L-shaped limit block, 7. Threaded pin shaft, 8. T-nut, 9. Mandrel, 10. Spring, 11. Adjusting bolt, 12. Guide key, 13. Screw, 14. Hole retaining ring, 15. Pin shaft. Specific implementation manner

[0025] The present invention will be described in detail below with reference to the accompanying drawings and specific implementation manners.

[0026] The structure of the fixture for milling the valve body groove of the shear pin type safety valve of the present invention is as Figure 1 shown, and it includes a workbench 1. A plurality of parallel T-shaped grooves are provided on the upper surface of the workbench 1. A T-nut 8 is provided in the T-shaped groove. A base 2 is provided on the workbench 1. A through hole a perpendicular to the upper surface of the base 2 is provided in the middle part of the base 2. A mandrel 9 is arranged in the through hole a.

[0027] The mandrel 9 is a cylindrical structure that is thinner at the top and thicker at the bottom. The inner diameter of the bottom of the mandrel 9 is smaller than the inner diameter of its upper part. A boss a is provided at the bottom end of the mandrel 9. The diameter of the boss a matches the groove width of the T-shaped groove on the surface of the workbench 1. The cooperation between the boss a and the T-shaped groove of the workbench 1 plays a limiting role. A spring 10 is installed in the mandrel 9. One end of the spring 10 touches the transition surface of the inner diameter dimension of the mandrel 9, and the upper part of the spring 10 touches the bolt head of the adjusting bolt 11. The adjusting bolt 11 passes through the spring 10 and is connected to the T-nut 8.

[0028] Through slots a are provided at both ends of the base 2. An eccentric wheel 3 perpendicular to the mandrel 9 is connected in the through slot a through a pin shaft 15. The eccentric wheel 3 slightly protrudes from the bottom surface of the base 2. A handle 4 is fixedly connected to the side surface of the eccentric wheel 3. The handle 4 is perpendicular to the connection line between the center point and the rotation point of the eccentric wheel 3, and the rotation point of the eccentric wheel 3 is located closer to the through hole a of the base 2. Hole retaining rings 14 are provided at both ends of the pin shaft 15.

[0029] A boss b is provided on the side surface of the base 2 close to the through hole a. The boss b is connected to the L-shaped limit block 6 through a threaded pin shaft 7 for cooperation with the base 2 for limiting. The longitudinal section of the L-shaped limit block 6 is L-shaped, and a pair of connecting pairs are provided on its side surface. The two connecting pairs are connected to the boss b through the threaded pin shaft 7.

[0030] The diameter of the thinner part at the upper part of the mandrel 9 is adapted to the inner diameter of the vertical threaded hole of the valve body 5 to be machined. Threads are provided on the outer circular surface of the thinner part of the mandrel 9. The diameter of the thicker part of the mandrel 9 is adapted to the inner diameter of the through hole a in the middle part of the base 2. An axial keyway a is provided on the outer circular surface of the thicker part of the mandrel 9. An axial keyway b is provided on the inner side of the through hole a of the base 2. The guide key 12 is simultaneously in the keyway a and the keyway b, and the guide key 12 is fixedly connected to the keyway a.

[0031] The method for machining the valve body groove using the fixture for milling the valve body groove of the present invention is as follows, specifically including the following steps:

[0032] Step 1, machine the vertical threaded holes, horizontal threaded holes and end faces on the valve body 5;

[0033] Step 2, fix the mandrel 9 on the workbench 1, align its axis as the coordinate origin, install the base 2 assembly on the mandrel 9, perform tool setting on the A reference plane on the base 2, which is the upper surface of the base 2, and compile the machining program;

[0034] Step 3, as Figure 4 shown, install the vertical threaded hole of the valve body 5 with the to-be-machined groove machined in Step 1 on the mandrel 9, manually screw the thread to make the lower end face of the vertical threaded hole of the valve body 5 fit with the upper surface of the base 2, that is, fit with the A reference plane. Rotate the L-shaped limit block 6 so that its end face is simultaneously flush with both sides of the circular end face of the horizontal threaded hole of the valve body 5. If one end is not flush, rotate the valve body 5 in the reverse direction until both end faces are flush. At this time, it can be determined that the valve body 5 has been aligned, and the L-shaped limit block 6 restricts the rotation of the valve body 5. Pull the handles 4 on both sides of the base 2 to rotate the eccentric wheel 3 to drive the base 2 to rise and tightly hold the valve body 5;

[0035] Step 4, call the preset machining program to machine the groove;

[0036] Step 5, after machining the groove of the valve body 5, pull the handles 4 on both sides of the base 2 to rotate the eccentric wheel 3 to drive the base 2 to descend, loosen the valve body 5, and rotate to remove the valve body 5.

[0037] The machine tool is an ordinary vertical milling machine, boring machine or vertical machining center, CNC boring machine.

[0038] Set the axis of the mandrel 9 as the machine tool coordinate origin, and the A reference plane of the base 2 is the tool setting reference when the device of the present invention is connected to the machine tool. The B reference plane on the L-shaped limit block 6 is the alignment reference, and the B reference plane is the end face of the L-shaped limit block. Since the distance from the A reference plane to the machining surface at the bottom of the valve body groove is a fixed value, during machining, only the valve body 5 needs to be aligned and tightly held, call the preset program, and perform machining by walking the coordinates.

[0039] The fixture for milling the valve body groove of the present invention can realize the milling machining of valve body grooves of various specifications, has a compact structure, is safe and reliable, and is convenient to use. It solves the problems of difficult clamping and alignment during the machining of valve body grooves, and meets the design requirements of the dimensions, geometric tolerances and surface quality of the valve body grooves. It effectively guarantees the dimensions and geometric tolerances of the valve body grooves, improves the surface quality and machining efficiency, and provides a new idea and method for the machining of valve body grooves.

Claims

1. Fixture for milling the valve body groove of a shear pin type safety valve, characterized in that It includes a workbench (1). A T-shaped groove is formed on the upper surface of the workbench (1). A T-shaped nut (8) is arranged in the T-shaped groove. A base (2) is arranged on the workbench (1). A through hole a perpendicular to the upper surface of the base (2) is formed in the middle part of the base (2). A mandrel (9) is arranged in the through hole a. The mandrel (9) is a cylindrical structure with a thinner upper part and a thicker lower part. Through grooves a are formed at both ends of the base (2). An eccentric wheel (3) perpendicular to the mandrel (9) is connected in the through groove a through a pin shaft (15). The eccentric wheel (3) slightly protrudes from the bottom surface of the base (2). A handle (4) is fixedly connected to the side surface of the eccentric wheel (3). A boss b is arranged on the side surface of the base (2) close to the through hole a. The boss b is connected to an L-shaped limit block (6) through a threaded pin shaft (7). The inner diameter of the bottom of the mandrel (9) is smaller than that of its upper part. A boss a is arranged at the bottom end of the mandrel (9). The diameter of the boss a is matched with the groove width of the T-shaped groove on the surface of the workbench (1). A spring (10) is arranged in the mandrel (9). One end of the spring (10) touches the transition surface of the inner diameter size of the mandrel (9). The upper part of the spring (10) touches the bolt head of an adjusting bolt (11). The adjusting bolt (11) passes through the spring (10) and is connected to the T-shaped nut (8).

2. The fixture for milling the valve body groove of the shear pin type safety valve according to claim 1, wherein Threads are arranged on the outer cylindrical surface of the thinner part of the mandrel (9). The diameter of the thicker part of the mandrel (9) is adapted to the inner diameter of the through hole a in the middle part of the base (2).

3. The fixture for milling the valve body groove of the shear pin type safety valve according to claim 2, characterized in that, An axial key groove a is arranged on the outer cylindrical surface of the thicker part of the mandrel (9). An axial key groove b is arranged on the inner side of the through hole a of the base (2). A guide key (12) is in both the key groove a and the key groove b, and the guide key (12) is fixedly connected to the key groove a.

4. The fixture for milling the valve body groove of the shear pin type safety valve according to claim 1, characterized in that, Circular snap rings for holes (14) are arranged at both ends of the pin shaft (15).

5. The fixture for milling the valve body groove of the shear pin type safety valve according to claim 1, characterized in that, The longitudinal section of the L-shaped limit block (6) is L-shaped. A pair of connecting pairs are arranged on its side surface. The two connecting pairs are connected to the boss b through the threaded pin shaft (7).

6. The fixture for milling the valve body groove of the shear pin type safety valve according to claim 1, wherein, The handle (4) is perpendicular to the connection line between the center point and the rotation point of the eccentric wheel (3), and the rotation point of the eccentric wheel (3) is located closer to the through hole a of the base (2).

7. The fixture for milling the valve body groove of the shear pin type safety valve according to claim 1, wherein, The T-shaped grooves are arranged in parallel in several numbers.

Images