Tapping guide jig for safety valve seat

Abstract

The tapping guide tool clamp for the safety valve seat, the limiting wheel is inserted into the front end opening of the safety valve seat, and the limiting wheel is detachably connected with the guide tool bottom plate through the axial pull rod; the guide tool bottom plate is provided with a plurality of guide holes penetrating the plate body, the guide holes are arranged in the axial direction and are aligned with the tapping hole positions. The guide holes of the guide tool bottom plate arranged in the valve body can guide the axial movement of the tap, realize the tapping guide of the safety valve seat, and can solve the problems that the tapping cannot be observed, is inconvenient and the tapping precision cannot be controlled when the threaded hole is designed in the one end inside or the inner wall of the valve seat.

Description

Technical Field

[0001] This invention relates to the field of machining special and complex mechanical parts, specifically a tapping guide fixture for a safety valve seat. Background Technology

[0002] A safety valve is an automatic valve that uses the force of the medium itself to discharge a rated amount of fluid to prevent the pressure in the system from exceeding a predetermined safety value. Once the pressure returns to normal, the valve closes again to prevent further flow of the medium. Safety valves are commonly used in pressure vessels, pressure pipelines, and boilers subjected to fire to protect these devices from explosions and damage caused by system overpressure. They play a crucial role in maintaining normal equipment operation and protecting the safety of personnel.

[0003] Some threaded holes in the safety valve seat are located on the inner wall of one end of the seat, requiring a tapping tool (such as a tap) to be inserted from the other end for operation; due to the difficulty of observation during operation, tapping is inconvenient, the accuracy is not high, and the depth control is also poor.

[0004] Meanwhile, safety valves require clamping during tapping; existing safety valve clamps have simple holding structures, mostly using two-sided clamping, which results in poor stability and is not conducive to tapping threaded holes; and some parts of safety valves have high precision requirements, and the above clamping methods cannot guarantee the accuracy during tapping. If these clamps are used too tightly, they can also damage the safety valve, thus affecting its accuracy.

[0005] Therefore, it is necessary to improve the existing technology and design a new tapping guide fixture for safety valve seats to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a tapping guide fixture for a safety valve seat to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the technical solution adopted in this invention includes openings at both the front and rear ends of the safety valve seat, with the inner wall of the front end having a hole to be tapped, comprising a pull rod, a limiting wheel, a guide fixture base plate, and a nut; the limiting wheel is inserted into the front opening of the safety valve seat, and the limiting wheel is detachably connected to the guide fixture base plate via an axial pull rod; the guide fixture base plate has several guide holes penetrating its body, the guide holes being arranged axially and aligned with the hole to be tapped.

[0008] In some embodiments, the pull rod is a three-stage stepped shaft, comprising a small-diameter section, a medium-diameter section, and a large-diameter section in sequence; the limiting wheel and the guide fixture base plate are respectively provided with central through holes corresponding to the medium-diameter section, and the limiting wheel and the guide fixture base plate are respectively fitted into the medium-diameter section of the pull rod through the central through holes, and the front end of the limiting wheel is blocked and limited by the large-diameter section; the small-diameter section of the pull rod is detachably connected to the nut by threads, and the guide fixture base plate is locked.

[0009] In some embodiments, the limiting wheel is frustum-shaped, with its smaller diameter end facing the front end of the safety valve seat. In some embodiments, the guide holes of the guide fixture base plate are evenly distributed along the circumference.

[0010] In some embodiments, there are four guide holes.

[0011] In some embodiments, the front end of the tap passes through a guide hole to perform tapping operations, and the rear end of the tap is detachably connected to the front end of an axially oriented extension rod.

[0012] In some embodiments, the front end of the extension rod is provided with a retractable hole for inserting the rear end of the tap; the wall of the retractable hole is provided with a plurality of axial through grooves, and the hole wall is cut to form a segmented retractable structure.

[0013] In some embodiments, the expandable hole can be a square hole.

[0014] In some embodiments, the rear end of the extension rod is a square head for wrench actuation.

[0015] In some embodiments, the outer wall of the retractable hole is provided with external threads; it also includes a top cap, the front and rear ends of which are through, and the inner wall of which is provided with internal threads that mate with the external threads; a tap is inserted into the retractable hole of the extension rod, and the top cap is screwed in and tightened to complete the fixation.

[0016] In some embodiments, a depth gauge is provided on the rear end face of the guide tool base plate, which is arranged axially.

[0017] In some embodiments, the rear end face of the guide fixture base plate is provided with an arc-shaped guide rail, which is a groove. The two sides of the groove are provided with sliding grooves, and the front end of the depth gauge is provided with a protrusion. The protrusion of the depth gauge is inserted into the sliding groove to move along the arc-shaped guide rail.

[0018] In some embodiments, the guide fixture base plate is further provided with a number of large through holes that penetrate its surface along the axial direction. The large through holes cut the arc guide rail into several segments, and the cross section of the arc guide rail is exposed on each cut surface. Sliding grooves are provided on both sides of the cross section. The protrusions on both sides of the front end of the depth gauge can be inserted into or withdrawn from the corresponding sliding groove from the cross section to achieve sliding along the rail.

[0019] In some embodiments, the depth gauge is provided with a vernier sleeve, which is fixed to the depth gauge by a vernier bolt.

[0020] In some embodiments, a radially arranged circular pointer is also fitted on the extension rod. The circular pointer can slide along the extension rod body, and the edge of the circular pointer points to the scale of the depth gauge. When the circular pointer moves axially with the tap and the extension rod to align with the vernier sleeve, the depth control of tapping is completed.

[0021] In some embodiments, the circular pointer is fixed to the outer wall of the extension rod by the end of a small bolt. In some embodiments, a locating pin is also included, which can pass through a guide hole and be inserted into a hole to be tapped that is not yet tapped, thereby limiting the position of the guide fixture base plate.

[0022] Compared with the prior art, the guide hole of the guide tool base plate set inside the valve body in this invention can guide the axial movement of the tap, realize the tapping guide of the safety valve seat, and solve the problems of not being able to observe, not being convenient to tap, and not being able to control the tapping accuracy when the threaded hole is designed inside one end of the valve seat or on the inner wall.

[0023] The limit wheel blocks one end of the valve body to prevent the guide fixture base plate from coming off; the pull rod can fix the limit wheel and the guide fixture base plate; the large-diameter section of the pull rod that extends outward can be clamped by the processing equipment, which can prevent the safety valve seat from being damaged by the clamping action of ordinary fixtures.

[0024] The extension rod can be used to extend the back end of the tap, overcoming the problem of insufficient tap length and inability to insert a wrench; the retractable hole of the extension rod allows for the replacement of taps of different sizes, increasing the applicability; the depth gauge and the circular pointer work together to make the tapping depth more intuitive and controllable; the invention has a simple structure and low operation difficulty, meeting the requirements of actual operation. Attached Figure Description

[0025] Figure 1 This is a structural diagram of the safety valve seat and its tapping guide fixture (the pull rod and limit wheel are not sectioned);

[0026] Figure 2 This is a structural schematic diagram of the safety valve seat and its tapping guide fixture (only the safety valve seat is cut in half).

[0027] Figure 3 This is a structural diagram of the extension rod;

[0028] Figure 4 This is a schematic diagram of the depth gauge.

[0029] Referring to the attached diagram: 1. Limiting wheel; 2. Pull rod; 3. Guide fixture base plate; 4. Positioning pin; 5. Hexagonal nut; 6. Extension rod; 7. Tap; 8. Safety valve seat; 9. Depth gauge; 3-1. First guide hole; 3-2. Second guide hole; 3-3. Third guide hole; 3-4. Fourth guide hole; 3-5. Arc guide rail; 6-1. Square head; 6-2. Retractable hole; 6-3. Top cap; 6-4. Circular pointer; 6-5. Small bolt; 8-1. Hole to be tapped; 9-1. Vernier sleeve; 9-2. Vernier bolt; 9-3. Raised bar. Detailed Implementation

[0030] The present invention will now be further described with reference to the accompanying drawings.

[0031] See Figure 1 and Figure 2 As shown, this embodiment relates to a tapping guide fixture for a safety valve seat 8, applicable to the manufacturing of special and complex parts. Specifically, the safety valve seat 8 is cylindrical, with through openings at both its front and rear ends. The inner wall of the annular ring at the front opening has four threaded holes distributed circumferentially; this position is the tapping hole 8-1 (initially an unthreaded hole). During tapping, the tool (taper 7) needs to be inserted from the rear end of the safety valve seat 8, making observation difficult and operation inconvenient.

[0032] This embodiment includes a limiting wheel 1, a pull rod 2, a guide fixture base plate 3, a hexagonal nut 5, and a tap 7. The pull rod 2 is a three-tiered stepped shaft, comprising a small-diameter section, a medium-diameter section, and a large-diameter section connected sequentially along the axial direction, all three being coaxial. The limiting wheel 1 and the guide fixture base plate 3 each have a central through hole corresponding to the medium-diameter section. The limiting wheel 1 and the guide fixture base plate 3 are respectively fitted into the medium-diameter section of the pull rod 2 through their central through holes; the front end face of the limiting wheel 1 is blocked and limited by the large-diameter section.

[0033] During assembly, after the limit wheel 1 is fitted onto the pull rod 2, they are inserted together into the front opening of the safety valve seat 8 that needs to be tapped, thus fixing the safety valve seat 8 from one side. The large-diameter section of the pull rod 2 extends forward from the front end of the safety valve seat 8, allowing it to be clamped by the processing equipment, thus preventing damage to the safety valve seat 8 when directly clamped. Its smaller diameter section (partial) and small diameter section are located inside the safety valve seat 8; the outer wall of the small diameter section is threaded, allowing the hexagonal nut 5 to be locked, thereby locking the guide fixture base plate 3. Furthermore, the guide fixture base plate 3 has four holes evenly distributed around its circumference and penetrating its body, namely the first guide hole 3-1, the second guide hole 3-2, the third guide hole 3-3, and the fourth guide hole 3-4. The guide fixture base plate 3 is installed on the pull rod 2 inside the safety valve seat 8. The four holes on the guide fixture base plate 3 should be aligned with the tapping holes 8-1 on the safety valve seat 8. Then, the pull rod 2 and the guide fixture base plate 3 are locked together by the hexagonal nut 5. Subsequently, the tap 7 is passed through the first guide hole 3-1 or the third guide hole 3-3 to tap the holes 8-1.

[0034] Alternatively, two positioning pins 4 can be passed through any two opposite diagonal second guide holes 3-2 and fourth guide holes 3-4, and inserted into two other un-tapping holes 8-1. The positioning pins 4 achieve their positioning function by bearing shear force.

[0035] Preferably, the limiting wheel 1 is frustum-shaped, with its smaller diameter end face (section) facing the front end of the safety valve seat 8, which facilitates its own fixation.

[0036] See Figures 1 to 3 As shown, furthermore, the rear end of the tap 7 can be inserted into the retractable hole 6-2 of the extension rod 6, and the retractable hole 6-2 is preferably a square hole. See also Figure 3 The wall of the retractable hole 6-2 is provided with several axial through grooves, and the hole wall is cut to form a segmented retractable structure.

[0037] The outer wall of the retractable hole 6-2 is provided with external threads; it also includes a top cap 6-3, the front and rear ends of which are through-holes, and the inner wall of the top cap 6-3 is provided with internal threads that mate with the external threads; the tap 7 is inserted into the retractable hole 6-2 of the extension rod, and the top cap 6-3 is screwed in and tightened to fix the tap 7. Furthermore, the square head 6-1 at the rear end of the extension rod 6 can be inserted into and driven to rotate by a wrench. The extension rod 6 overcomes the problem of insufficient length of the tap 7, and the size of the retractable hole 6-2 at its front end is adjustable to accommodate taps of different sizes.

[0038] The extension rod 6 and the tap 7 are inserted together into the first guide hole 3-1 or the third guide hole 3-3 on the guide fixture base plate 3 before the positioning pin 4 is inserted. At this time, in order to control the tapping depth, it is preferable to install the depth gauge 9 on the rear end face of the guide fixture base plate 3. The rear end face of the guide fixture base plate 3 is provided with an arc guide rail 3-5, which is a groove and concentric with the guide fixture base plate 3; the two sides of the groove are provided with radially extending sliding grooves, and the front end of the depth gauge is provided with a corresponding protrusion 9-3; the protrusion 9-3 of the depth gauge 9 is inserted into the sliding groove, which can realize the circumferential movement along the arc guide rail 3-5.

[0039] Further, see Figure 1 The guide fixture base plate 3 is also provided with several large through holes that penetrate its surface axially. These large through holes cut the arc guide rail 3-5 into four segments in the circumferential direction. Each cut surface exposes the cross-section of the arc guide rail 3-5, and sliding grooves are provided on both sides of the cross-section. The protrusions 9-3 on both sides of the front end of the depth gauge 9 can be inserted into or withdrawn from the corresponding sliding grooves through the cross-section, allowing the depth gauge 9 to slide circumferentially along the arc guide rail 3-5.

[0040] The depth gauge 9 is provided with a vernier sleeve 9-1, and the end of the vernier bolt 9-2 can be screwed down to contact the surface of the depth gauge 9, so as to fix the vernier sleeve 9-1 to the depth gauge 9.

[0041] The extension rod 6 is also fitted with a radially arranged circular pointer 6-4. The circular pointer 6-4 can slide axially along the rod body of the extension rod 6 through the inner ring. The edge of the circular pointer 6-4 points to the scale of the depth gauge 9, which can help with observation. The circular pointer 6-4 moves axially with the tap 7 and the extension rod 6. When it is aligned with the vernier sleeve 9-1, the depth control of tapping is completed.

[0042] Preferably, the collar of the circular pointer 6-4 is slidable or fixed by screwing in / out of the end of the radial small bolt 6-5 to the outer wall of the extension rod 6.

[0043] Before tapping, use the small bolt 6-5 to set the position of the circular pointer 6-4 on the extension rod 6, and slide the vernier sleeve 9-1 of the depth gauge 9 close to the lower side of the circular pointer 6-4 on the extension rod 6 to read the scale; then calculate the new scale to be moved down according to the planned tapping depth, and move the upper edge of the vernier sleeve 9-1 to the new scale, and then use the vernier bolt 9-2 to screw down and fix the vernier sleeve 9-1.

[0044] Then tapping can begin. As tapping progresses, the tap 7 and extension rod 6, which extend from the rear end of the safety valve seat 8, move forward axially together. When the edge of the circular pointer 6-4 of the extension rod 6 comes close to the upper edge of the vernier sleeve 9-1, the tapping of one threaded hole is complete. Then, the tapping of the diagonally opposite holes 8-1 is completed in the same way. Then, the two locating pins 4 that have been installed are removed and inserted into the tapped threaded holes, and the tapping of the other two holes 8-1 is completed in the same way.

[0045] The embodiments of the present invention have been described above with reference to the accompanying drawings and examples. The structures given in the embodiments do not constitute a limitation on the present invention. Those skilled in the art can make adjustments as needed, and various modifications or variations within the scope of the appended claims are all within the scope of protection.

Claims

1. A tapping guide fixture for a safety valve seat, wherein the safety valve seat has openings at both the front and rear ends, and the inner wall of the front end has a hole to be tapped, characterized in that: Includes a tie rod, a limit wheel, a guide fixture base plate, and a nut; the limit wheel is inserted into the front opening of the safety valve seat, the limit wheel is frustum-shaped, and its smaller diameter end face faces the front of the safety valve seat; the limit wheel is detachably connected to the guide fixture base plate via an axial tie rod. The guide fixture base plate is provided with several guide holes that penetrate its body. The guide holes are arranged axially and aligned with the holes to be tapped. The tie rod is a three-stage stepped shaft, consisting of a small diameter section, a medium diameter section, and a large diameter section. The limiting wheel and the guide fixture base plate are respectively fitted into the medium diameter section of the tie rod through the central through hole. The front end of the limiting wheel is blocked and limited by the large diameter section. The small diameter section of the tie rod is detachably connected to the nut by threads and locks the guide fixture base plate. The front end of the tap passes through the guide hole for tapping, and the rear end of the tap is detachably connected to the front end of the extension rod set along the axial direction. During assembly, after the limit wheel is fitted onto the pull rod, it is inserted together into the front opening of the safety valve seat that needs to be tapped, thus fixing the safety valve seat from one side; the large-diameter section of the pull rod extends forward from the front end of the safety valve seat, while the small-diameter section is located inside the safety valve seat; during tapping, the tap extends from the rear end of the safety valve seat.

2. The tapping guide fixture for a safety valve seat according to claim 1, characterized in that: The guide holes on the base plate of the guide fixture are evenly distributed along the circumference.

3. The tapping guide fixture for a safety valve seat according to claim 2, characterized in that: There are four guide holes.

4. The tapping guide fixture for a safety valve seat according to claim 1, characterized in that: The front end of the extension rod is provided with a retractable hole for inserting the rear end of the tap; the wall of the retractable hole is provided with several axial through grooves, which cut the hole wall to form a segmented retractable structure.

5. The tapping guide fixture for a safety valve seat according to claim 4, characterized in that: The retractable hole is a square hole.

6. The tapping guide fixture for a safety valve seat according to claim 1, characterized in that: The rear end of the extension rod is a square head for wrench operation.

7. The tapping guide fixture for a safety valve seat according to claim 4 or 5, characterized in that: The outer wall of the retractable hole is provided with external threads; It also includes a top cap, the front and rear ends of which are through, and the inner wall of which is provided with an internal thread that mates with the external thread; Insert the tap into the retractable hole of the extension rod, screw in the top cap and tighten it to complete the fixation.

8. The tapping guide fixture for a safety valve seat according to claim 1, characterized in that: A depth gauge is provided on the rear end face of the guide fixture base plate along the axial direction.

9. The tapping guide fixture for a safety valve seat according to claim 8, characterized in that: The rear end face of the guide fixture base plate is provided with an arc guide rail, which is a groove. The two sides of the groove are provided with sliding grooves, and the front end of the depth gauge is provided with a protrusion. The protrusion of the depth gauge is inserted into the sliding groove to move along the arc guide rail.

10. The tapping guide fixture for a safety valve seat according to claim 9, characterized in that: The guide fixture base plate is also provided with several large through holes that run through its surface along the axis. The large through holes cut the arc guide rail into several segments, and the cross section of the arc guide rail is exposed on each cut surface. Sliding grooves are provided on both sides of the cross section. The protrusions on both sides of the front end of the depth gauge can be inserted into or withdrawn from the corresponding sliding groove from the cross section to achieve sliding along the rail.

11. The tapping guide fixture for a safety valve seat according to claim 8, characterized in that: The depth gauge is equipped with a vernier sleeve, which is fixed to the depth gauge by a vernier bolt.

12. The tapping guide fixture for a safety valve seat according to claim 8, characterized in that: The extension rod is also fitted with a radially arranged circular pointer, which can slide along the extension rod. The edge of the circular pointer points to the scale of the depth gauge. When the circular pointer moves axially with the tap and extension rod and aligns with the vernier sleeve, the depth control of tapping is completed.

13. The tapping guide fixture for a safety valve seat according to claim 12, characterized in that: The circular pointer is fixed to the outer wall of the extension rod by the end of a small bolt.

14. The tapping guide fixture for a safety valve seat according to claim 1, characterized in that: It also includes a positioning pin, which can pass through the guide hole and be inserted into the hole to be tapped, thereby limiting the position of the guide fixture base plate.

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