Novel integrated weldless high-temperature and high-pressure gate valve and valve body machining process thereof

Abstract

The invention discloses a novel integrated weldless high-temperature and high-pressure gate valve and a valve body machining process thereof.The high-temperature and high-pressure gate valve comprises a valve body which comprises a valve body internally provided with a fluid channel, a valve seat integrally formed in the valve body, a valve deck arranged on the valve body and a valve plate used for blocking the fluid channel; the transmission mechanism comprises a ball screw and a valve rod check block, wherein one end of the ball screw penetrates through the valve deck to be connected with the valve plate, and the valve rod check block is arranged on the ball screw. The position indicator is obliquely arranged on the valve cover, the position indicator is perpendicular to the valve rod check block, impurities can be effectively prevented from entering the valve cover, the position indicator is perpendicular to the valve rod check block, stress of a ball head in the position indicator is always in the movement direction, guiding stress is more uniform, abrasion is even, and the service life of the valve cover is prolonged. Serious faults such as overstress deformation and breakage of the ball head in the prior art are solved.

Description

Technical Field

[0001] The invention relates to the technical field of gate valves, and in particular to a novel integrated weld-free high-temperature and high-pressure gate valve and a valve body processing technology thereof. Background Art

[0002] For the "position indicator thrust rod stuck" fault, the macroscopic appearance is that the valve moves too far, and the position indicator signal feedback is obviously delayed. The reasons for the fault are: 1) There are impurities / wear between the graphite sleeve and the thrust rod, and the spring thrust is insufficient, which leads to slow rebound of the thrust rod, which in turn manifests as a delayed response; 2) The thrust rod and the valve stem stopper are misaligned, that is, the slope of the stopper is large (usually 15-20°), and the sensitivity of the position indicator is too high at the end of the valve action. After multiple actions, the thrust rod and the valve stem stopper are worn, resulting in structural interference, and then the thrust rod is deformed, resulting in the thrust rod being stuck, and even the valve is over-closed / over-opened, resulting in serious faults such as overstress deformation and breakage of the ball head. Summary of the invention

[0003] The purpose of the present invention is to solve the above-mentioned deficiencies and provide a novel integrated weld-free high-temperature and high-pressure gate valve and a valve body processing technology thereof.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solution: a new integrated weld-free high-temperature and high-pressure gate valve, comprising: The valve body comprises a valve body with a fluid passage arranged inside, a valve seat integrally formed and arranged in the valve body, a valve cover arranged on the valve body and a valve plate for blocking the fluid passage; The transmission mechanism comprises a ball screw having one end passing through the valve cover and connected to the valve plate, and a valve stem stopper arranged on the ball screw; A fully enclosed electric mechanism, which is arranged on the valve cover and connected to the other end of the ball screw to drive the ball screw to move; The position indicator is obliquely arranged on both sides of the valve cover, perpendicular to the valve stem stopper and matched with the valve stem stopper.

[0005] Furthermore, the position indicator includes a pressure-bearing shell arranged on the valve cover, a push rod with a ball head at one end and cooperating with the valve stem stopper, the pressure-bearing shell includes a first shell for arranging a ceramic piezoelectric sheet and a second shell with an inner cavity larger than the first shell, the other end of the push rod passes through the second shell and extends into the first shell, and a ceramic piezoelectric sheet is arranged on the outside of the side wall of the first shell away from the second shell and a temperature measuring point is arranged on the first shell.

[0006] Furthermore, a ball guide sleeve mounted on the push rod is provided in a tongue-and-groove connection on the second shell and fixed by screws.

[0007] Furthermore, a baffle is provided on a section of the push rod located inside the second shell, and a spring is provided between the baffle and a connection between the first shell and the second shell.

[0008] Furthermore, the position indicator is measured in the following manner: Displacement = k / v × (1 + αΔT); Where: displacement is the measured displacement; v is the peak voltage of the third echo generated by the ceramic piezoelectric patch; k is the piezoelectric coefficient, which expresses the relationship between displacement and voltage; α is the temperature coefficient, which indicates the effect of temperature change on displacement; ΔT is the temperature change.

[0009] Furthermore, the exterior of the valve stem stopper is configured as a first inclined surface and a second inclined surface which are symmetrical in vertical direction, and a connection between the first inclined surface and the second inclined surface is configured as a spherical chamfer.

[0010] Furthermore, the push rods on both sides are respectively perpendicular to the first inclined surface and the second inclined surface.

[0011] Furthermore, the angle between the first inclined surface and the vertical direction is A, and the angle A is calculated as follows: ; Where: r1 is half of the inner diameter of the valve cover minus 3mm; r2 is the radius of the valve stem; d is the theoretical maximum straight-line running distance of a gate valve with a diameter of d; d 误差 The error of the theoretical maximum straight-line running distance of the gate valve is ±0.5mm; 1 is half the length of the arc chord of the spherical chamfered surface.

[0012] A valve body processing technology, used for processing the above-mentioned novel integrated weld-free high-temperature and high-pressure gate valve, comprises the following steps: S1. Subtractive processing: Process the valve body shape and internal structure. Based on the design drawings, reduce the thickness of the sealing surface by 5±0.1mm, increase the thickness of the fluid channel by 1.2mm, and process the basic structure of the valve body and valve seat; S2. Additive processing: Cobalt-based alloy is used for laser cladding of the sealing surface. The sealing surface includes the inlet sealing surface and the outlet sealing surface. The outlet sealing surface is processed first, and then the inlet sealing surface is processed. The two processing processes are the same; S3, finishing: Finish the valve body after laser cladding according to the standard size of the design drawing; S4. Surface inspection and cleaning: Inspect the surface of the valve body after fine machining, treat the cracked parts and re-clad them until no cracks appear. Use an ultrasonic cleaning machine to clean the valve body to ensure that there are no impurities, oil stains, or particles on the surface. S5. Electric spark surface processing: Process the valve seat sealing surface to ensure that the sealing surface roughness meets the sealing requirements; S6, water-tight test: install the valve plate in the valve body, simulate the motor through the push rod, ensure that the sealing force between the valve plate and the valve seat meets the design requirements, pressurize the valve inlet water to 1.2 times the valve design pressure, check the valve outlet leakage, if there is leakage, repeat S5.

[0013] Furthermore, in step S2, the steps of processing the sealing surface are specifically as follows: S21. Place the valve body to be processed into the workpiece heater, place the inlet end on a 5° inclined plane, and adjust the angle of the outlet sealing surface by a feeler gauge to make the outlet sealing surface horizontal by ±0.05°; S22, set the heating temperature of the workpiece heater to 180°C, and set the insulation range to ±10°C, take five temperature points on the inner wall of the valve body, and the temperature difference between the highest and lowest temperatures is less than 5°C; S23. Since the heating process may cause the position to shift, check whether the angles of the outlet sealing surface and the inlet sealing surface meet the requirements; S24. Push the laser head of the two-axis powder spraying laser cladding machine downward from the middle flange of the valve body, use a square spot with a size of 0.5*0.5mm, set the cladding thickness to 3mm, and process from inside to outside and from left to right. When processing near the edge of the fluid channel, adjust the cladding power until it is away from the edge of the fluid channel; S25. After the cladding is completed, keep the valve body temperature of the workpiece heater at 180±10℃, wait for 4 hours, and ensure that the workpiece is not cracked before cooling down to room temperature; S26, remove welding thermal stress, set the temperature of the workpiece heater to 700±30℃ for annealing, keep warm for 5h, then linearly cool down to 200℃, and the cooling time shall not be less than 24h; S27, remove the outermost layer in the cladding process, check whether the cladding layer has cracks, and if there are cracks, remove them together; S28. Repeat S21-S27 twice to ensure that the actual thickness of the cladding layer is greater than 5 mm.

[0014] Furthermore, in the step S24, the cladding power is adjusted in the following manner: When the center of the light spot is processed to a distance of less than 1mm from the edge of the fluid channel, reduce the power by 20%; when the center of the light spot is 0.5mm away from the edge of the flow channel, stop cladding, and the laser head will make an empty stroke until the center of the light spot is 0.5mm away from the edge of the fluid channel, then start the laser head again with a starting power of 80% of the set power; when the center of the light spot is 1mm away from the edge of the fluid channel, adjust the feed to the set power.

[0015] Furthermore, the specific operations of step S5 are as follows: S51. Design and manufacture of EDM electrodes: The electrode is a discharge body for processing the valve seat sealing surface. It is made of copper. The tooling structure is the same as the valve plate, but the contact surface is consistent with the valve seat surface. The thickness is 0.1mm less than the valve plate. The surface treatment of the valve seat and the guide rail on the valve seat can be performed at the same time. S52, install the valve body: install the valve body horizontally on the EDM machining center, and use the center axis of the upper flange of the valve body as the center line to install the valve body and the EDM motor; S53. Set roughness reference lines: Set 10 reference lines as roughness reference lines on the flange section of the upper part of the valve body, including 5 reference lines on the inlet sealing surface and 5 reference lines on the outlet sealing surface. Set up a roughness detection instrument and measure the average roughness of the 10 reference lines. The roughness is measured from the upper flange of the valve body downward until the sealing surface contacts the valve body. S54, set the parameters of the EDM machining center: set the discharge voltage to 80V, the discharge current to 2A, the pulse width to 10μs, the pulse interval to 50μs, the working gap to 20μm, and the discharge frequency to 500kHz; S55, Adaptive processing parameter optimization: Since the stress material on the cladding surface is not completely consistent during the cladding process, fixed parameters cannot be used for processing, but dynamic adjustments must be made based on the roughness measurement results.

[0016] Furthermore, in S55, the dynamic adjustment method is as follows: After every 15 minutes of processing, the roughness is tested and compared with the previous roughness. If the roughness does not change, the discharge current is reduced by 0.1A and the roughness Ra (i) is recorded. i represents the i-th time after the roughness does not change.

[0017] Furthermore, during the dynamic adjustment process, if the roughness still cannot meet the requirements after three times, the adjustment is performed according to the following formula: ln(Ra(i) / K)=M·ln(I(i))-N·ln(d(i)); Where: Ra(i) is the average roughness recorded for the i-th time; I(i) is the discharge current corresponding to the i-th recording; d(i) is the working interval set at the i-th recording; K is the roughness reference coefficient; M is the current influence coefficient; N is the gap influence coefficient; By substituting the above formula into 3 groups (Ra(i), I(i), d(i)) and the above data groups, the predicted values ​​of the three parameters K, M, and N can be obtained; then the roughness Ra(i+1) corresponding to the i+1th record, the working gap d(i+1) set at the i+1th record, and the predicted values ​​of K, M, and N are substituted into the following formula to obtain the recommended discharge current; ; Process for 1 hour according to the recommended discharge current I (i+1). If the requirements are still not met after 1 hour, repeat the above process.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention can effectively prevent impurities from entering by obliquely setting the position indicator on the valve cover, and the position indicator is perpendicular to the valve stem stopper. In addition, because the position indicator and the valve stem stopper are arranged vertically, the force on the ball head in the position indicator is always along the direction of movement, the guiding force is more uniform, and the wear is also uniform, thus solving the serious faults of the ball head in the prior art such as overstress deformation and breakage; 2. The present invention sets the valve stem stopper as a first inclined plane and a second inclined plane that are symmetrical in the upper and lower directions, and sets the angle between the first inclined plane and the vertical direction to be A, thereby ensuring that the ball head in the position indicator is in full contact with the valve stem stopper. In addition, by setting a spherical chamfer between the first inclined plane and the second inclined plane, it is ensured that once the ball head enters the reverse direction, the ball head will not be stuck in the middle of the valve stem stopper; 3. The present invention integrates the valve body and the valve seat into an integrated design. Firstly, the valve body has no pressure-bearing weld structure, which avoids the stress concentration and potential leakage risk caused by traditional welds, and significantly improves the safety and reliability of the valve under high-pressure conditions; secondly, the valve plates between gate plates of the same caliber are interchangeable without grinding, which reduces the processing and maintenance costs; finally, through optimized subtractive and additive processing technology, combined with the electric spark precision processing method, the multiple processing and adjustment steps in the traditional process are reduced, and the processing efficiency is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 FIG. 1 is a schematic diagram of an embodiment of the present invention.

[0020] Figure 21 is a three-view diagram of a valve body according to an embodiment of the present invention.

[0021] Figure 3 FIG. 4 is a schematic diagram of a position indicator according to an embodiment of the present invention.

[0022] Figure 4 It is a partial schematic diagram of a valve stem stopper according to an embodiment of the present invention.

[0023] In the figure: 1. valve body; 11. valve body; 12. valve seat; 13. valve cover; 14. valve plate; 15. fluid channel; 2. transmission mechanism; 21. ball screw; 22. valve stem stopper; 3. fully enclosed electric mechanism; 4. position indicator; 41. pressure-bearing shell; 42. ball head; 43. push rod; 44. ceramic piezoelectric sheet; 411. first shell; 412. second shell; 413. temperature measuring point; 414. ball guide sleeve; 46. baffle; 45. spring; 221. first inclined surface; 222. second inclined surface. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0025] See also Figure 1-4 .

[0026] The novel integrated weld-free high-temperature and high-pressure gate valve of the present invention comprises: The valve body 1 comprises a valve body 11 with a fluid passage 15 disposed therein, a valve seat 12 integrally formed and disposed in the valve body 11, a valve cover 13 disposed on the valve body 11, and a valve plate 14 for blocking the fluid passage 15; The transmission mechanism 2 includes a ball screw 21 with one end passing through the valve cover 13 and connected to the valve plate 14, and a valve stem stopper 22 arranged on the ball screw 21; A fully enclosed electric mechanism 3, which is disposed on the valve cover 13 and connected to the other end of the ball screw 21 to drive the ball screw 21 to move; The position indicator 4 is obliquely arranged on both sides of the valve cover 13 , perpendicular to the valve stem stopper 22 and matched with the valve stem stopper 22 .

[0027] By setting the position indicator 4 to be inclined and perpendicular to the valve stem stopper 22 and cooperate with the valve stem stopper 22, since the main impurities fall from the upper side, the oblique guide is less likely to introduce impurities, and by designing the position indicator 4 to be perpendicular to the valve stem stopper 22, the ball head 42 is perpendicular to the valve stem stopper 22, and the force on the ball head 42 is always along the direction of movement, so that the guiding force will be more uniform, making the wear more uniform.

[0028] Preferably, the position indicator 4 is a high-temperature and high-pressure linear position indicator 4. The high-temperature and high-pressure linear position indicator 4 adopts the method of ultrasonic micrometer and has its own temperature compensation, which is less affected by temperature. At the same time, the ultrasonic displacement measurement method has a fault self-detection function. When the self-detection finds that the position indicator 4 is faulty, it will limit the valve action, basically eliminating the occurrence of breakage failure.

[0029] In one embodiment, the position indicator 4 includes a pressure-bearing shell 41 disposed on the valve cover 13, a push rod 43 having a ball head 42 at one end and cooperating with the valve stem stopper 22, the pressure-bearing shell 41 includes a first shell 411 for arranging a ceramic piezoelectric sheet 44 and a second shell 412 whose inner cavity is larger than the first shell 411, the other end of the push rod 43 passes through the second shell 412 and extends into the first shell 411, the ceramic piezoelectric sheet 44 is disposed on the outside of the side wall of the first shell 411 away from the second shell 412, and a temperature measuring point 413 is disposed on the first shell 411. In this design, by improving the structure of the position indicator 4, and the push rod 43 and the ball head 42 on the position indicator 4 are perpendicular to the valve stopper, it is ensured that they are not separated during the entire valve action process, collision and extrusion are avoided, and all-round measurement of the opening of the electric gate valve is realized.

[0030] In one embodiment, the second housing 412 is provided with a ball guide sleeve 414 sleeved on the push rod 43 and fixed by screws. In this design, the ball guide sleeve 414 replaces the sliding guide sleeve, which greatly reduces the friction during the action process, reduces the amount of wear, and avoids jamming caused by wear.

[0031] In one embodiment, a baffle 46 is provided on a section of the push rod 43 located inside the second housing 412, and a spring 45 is provided between the baffle 46 and the connection between the first housing 411 and the second housing 412. This design can facilitate the movement and reset of the push rod 43 and the ball head 42.

[0032] In one embodiment, the position indicator 4 is measured as follows: Displacement = k / v × (1 + αΔT); Where: displacement is the measured displacement; v is the peak voltage of the third echo generated by the ceramic piezoelectric piece 44; k is the piezoelectric coefficient, which expresses the relationship between displacement and voltage; α is the temperature coefficient, which indicates the effect of temperature change on displacement; ΔT is the temperature change. This design adopts a temperature-compensated non-contact displacement measurement method, and measures the strength of the third peak echo signal through the ceramic piezoelectric piece 44 on the outer wall of the high-temperature and high-pressure pipe, thereby realizing the measurement of the valve opening under high-temperature and high-pressure conditions. At the same time, the temperature measurement point 413 signal is used to compensate for the nonlinear change of displacement measurement under high-temperature, medium-temperature and normal-temperature conditions, thereby improving the measurement progress to the 0.01mm level.

[0033] Preferably, the self-check formula of the position indicator 4 is as follows: ; Where: Displacement 测 is the displacement obtained by measurement; Displacement 预期 is the expected displacement; frequency 实际 is the actual ultrasound excitation frequency; frequency 预期 This design realizes the fault self-check of the position indicator 4 through the change of the frequency of the transmitted and received signals of the ceramic piezoelectric piece 44, and solves the problem that the traditional position indicator 4 cannot identify faults.

[0034] In one embodiment, the outer portion of the valve stem stopper 22 is configured with a first inclined surface 221 and a second inclined surface 222 that are symmetrical in the upper and lower directions, and the connection between the first inclined surface 221 and the second inclined surface 222 is configured as a spherical chamfer. In this design, in order to allow the ball head 42 to fully contact the valve stopper, and to ensure that once the ball head 42 enters the reverse direction, the ball head 42 will not be stuck in the middle of the valve stopper, the connection between the first inclined surface 221 and the second inclined surface 222 is configured as a spherical chamfer.

[0035] Preferably, the spherical chamfer is generally R25. The best width is 2mm. It is difficult to make a spherical surface if it is less than 2mm, and the block size is too large if it is greater than 2mm.

[0036] In one embodiment, the push rods 43 on both sides are respectively perpendicular to the first inclined surface 221 and the second inclined surface 222. In this design, by arranging the push rods 43 on both sides, and the push rods 43 are respectively perpendicular to the first inclined surface 221 and the second inclined surface 222, the accuracy of the detection of the position indicator 4 can be guaranteed, and the detection can be performed during the use of the valve.

[0037] In one embodiment, the angle between the first inclined surface 221 and the vertical direction is A, and the angle A is calculated as follows: ; Wherein: r1 is half of the inner diameter of the valve cover 13 minus 3mm; by subtracting 3mm from the inner diameter of the valve cover 13, the valve stem stopper 22 can move normally in the valve cover 13, and there will be no large gap between the valve stem stopper 22 and the valve cover 13; r2 is the radius of the valve stem; d is the theoretical maximum straight-line running distance of a gate valve with a diameter of d; d 误差 The error of the theoretical maximum straight-line running distance of the gate valve is ±0.5mm; 1 is half the length of the arc chord of the chamfered section of the spherical surface. In this design, the angle A can be calculated according to valves of different calibers through the above formula, thereby facilitating the design of the valve stopper.

[0038] Taking the DN70 gate valve as an example, the theoretical maximum running distance is 70mm, r1 is 25mm, r2 is 15mm, d 误差 is 1 mm, at this time, the angle A is 8.2°.

[0039] A valve body processing technology, used for processing the above-mentioned novel integrated weld-free high-temperature and high-pressure gate valve, comprises the following steps: S1. Subtractive machining: The shape and internal structure of the valve body 11 are machined using a 5-axis CNC machine tool. Based on the design drawings, the thickness of the sealing surface is reduced by 5±0.1mm, and the thickness of the fluid channel 15 is increased by 1.2mm, so as to machine the basic structure of the valve body 11 and the valve seat 12; S2. Additive processing: Cobalt-based alloy is used for laser cladding of the sealing surface. The outlet sealing surface is processed first, and then the inlet sealing surface. The two processing processes are the same. During cladding, slight deformation of other parts is inevitable. Slight deformation only affects the sealing surface, because the outlet sealing surface plays the main sealing role. Therefore, the inlet sealing surface is processed first, and then the outlet sealing surface. In this way, even if deformation occurs, it will only affect the inlet sealing surface, and the impact on the outlet sealing surface is small. S21, place the valve body 11 to be processed into the workpiece heater, place the inlet end on a 5° inclined plane, and adjust the angle of the outlet sealing surface by a feeler gauge to make the outlet sealing surface horizontal ±0.05°; S22, setting the heating temperature of the workpiece heater to 180°C, and setting the insulation range to ±10°C, taking five temperature points on the inner wall of the valve body 11, and the temperature difference between the highest and lowest temperatures is less than 5°C; S23. Since the heating process may cause the position to shift, check whether the angles of the outlet sealing surface and the inlet sealing surface meet the requirements; S24. Push the laser head of the two-axis powder spraying laser cladding machine downward from the middle flange of the valve body 11, use a square spot with a size of 0.5*0.5mm, set the cladding thickness to 3mm, and perform the cladding from the inside to the outside and from left to right. When processing near the edge of the fluid channel 15, adjust the cladding power until it is away from the edge of the fluid channel 15; when the center of the spot is processed to a distance of less than 1mm from the edge of the fluid channel 15, reduce the power by 20%; when the center of the spot is 0.5mm away from the edge of the flow channel, stop cladding, and at this time, the laser head performs an empty stroke until the center of the spot is 0.5mm away from the edge of the fluid channel 15, and then start the laser head again, and the starting power is 80% of the set power; when the center of the spot is 1mm away from the edge of the fluid channel 15, adjust the feed to the set power; S25. After the cladding is completed, the temperature of the valve body 11 of the workpiece heater is maintained at 180±10°C, and the temperature is cooled to room temperature after waiting for 4 hours to ensure that the workpiece has no cracks; S26, remove welding thermal stress, set the temperature of the workpiece heater to 700±30℃ for annealing, keep warm for 5h, then linearly cool down to 200℃, and the cooling time shall not be less than 24h; S27, remove the outermost layer in the cladding process, check whether the cladding layer has cracks, and if there are cracks, remove them together; S28, repeat S21-S27 twice to ensure that the actual thickness of the cladding layer is greater than 5 mm; S3, finishing: using a 5-axis CNC machine tool, the valve body 11 after laser cladding is finished according to the standard size of the design drawing; S4. Surface inspection and cleaning: Inspect the surface of the cladding valve body 11 after fine machining, treat the cracked part and re-clad it until no cracks appear, and clean the valve body 11 with an ultrasonic cleaning machine to ensure that there are no impurities, oil stains, or particles on the surface; S5. Electric spark surface machining: The sealing surface of the valve seat 12 is machined to ensure that the roughness of the sealing surface meets the sealing requirements.

[0040] S51. Design and manufacture of electric spark electrodes: The electrode is a discharge body for machining the sealing surface of the valve seat 12. It is made of copper. The tooling structure is the same as that of the valve plate 14, but the contact surface is consistent with the surface of the valve seat 12. The thickness is 0.1mm less than that of the valve plate 14. The surface of the valve seat 12 and the guide rail on the valve seat 12 can be processed at the same time. S52, installing the valve body 11: horizontally installing the valve body 11 on the electric spark machining center, using the central axis of the upper flange of the valve body 11 as the center line to install the valve body 11 and the electric spark motor; S53, setting roughness reference lines: setting 10 reference lines as roughness reference lines on the flange section of the upper part of the valve body 11, including 5 reference lines on the inlet sealing surface and 5 reference lines on the outlet sealing surface, setting a roughness detection instrument, and measuring the average roughness of the 10 reference lines. The roughness is measured from the upper flange of the valve body 11 downward until the sealing surface contacts the valve body 11; S54, set the parameters of the EDM machining center: set the discharge voltage to 80V, the discharge current to 2A, the pulse width to 10μs, the pulse interval to 50μs, the working gap to 20μm, and the discharge frequency to 500kHz; S55, Adaptive processing parameter optimization: Since the stress material of the cladding surface is not completely consistent during the cladding process, fixed parameters cannot be used for processing, but dynamic adjustment must be made in combination with the roughness measurement results; after every 15 minutes of processing, the roughness is tested and compared with the last roughness. If the roughness does not change, the discharge current is reduced by 0.1A, and the roughness Ra (i) at this time is recorded, where i represents the i-th time after the roughness does not change; S6, water-tightness test: install the valve plate 14 in the valve body 11, simulate the motor through the push rod, ensure that the sealing force between the valve plate 14 and the valve seat 12 meets the design requirements, pressurize the valve inlet with water to 1.2 times the valve design pressure, check the valve outlet leakage, if there is leakage, repeat S5.

[0041] In one embodiment, during the dynamic adjustment process, if the roughness still cannot meet the requirement after three times, the adjustment is performed according to the following formula: ln(Ra(i) / K)=M·ln(I(i))-N·ln(d(i)); Where: Ra(i) is the average roughness recorded for the i-th time; I(i) is the discharge current corresponding to the i-th recording; d(i) is the working interval set at the i-th recording; K is the roughness reference coefficient, which is used to reflect the influence of discharge current I(i) on roughness. The larger the value, the more sensitive the change of discharge current is to the final roughness during the machining process. M is the current influence coefficient, which is used to reflect the influence of discharge current I(i) on roughness. The larger the value, the more sensitive the change of discharge current is to the final roughness during the machining process. N is the gap influence coefficient, which is used to measure the influence of the working gap d (i) on the roughness. The larger the value, the more significant the influence of the gap on the roughness. By substituting the above formula into 3 groups (Ra(i), I(i), d(i)) and the above data groups, the predicted values ​​of the three parameters K, M, and N can be obtained; then the roughness Ra(i+1) corresponding to the i+1th record, the working gap d(i+1) set at the i+1th record, and the predicted values ​​of K, M, and N are substituted into the following formula to obtain the recommended discharge current; ; Process for 1 hour according to the recommended discharge current I (i+1). If the requirements are still not met after 1 hour, repeat the above process.

[0042] The integrated machining process of the present invention combines subtractive machining, additive machining, fine machining and electrospark machining into an overall process. By designing the valve body 11 and the valve seat 12 as an integrated whole, the problem of pressure-bearing welds is avoided. In the field of valves in high-pressure environments, the sealing and structural stability are greatly improved. Through high-precision machining methods, a valve plate 14 can be adapted to a plurality of different valve bodies 11, which solves the complexity of maintenance and use in the valve field. The interchangeable design of the valve plate 14 and the valve body 11 has great use value in the valve industry. The present invention optimizes and adjusts by combining roughness detection to achieve dynamic adjustment of electrospark machining parameters, thereby ensuring the accuracy of the gate valve after machining.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A new type of integrated weld-free high-temperature and high-pressure gate valve, characterized by: include: A valve body (1) comprises a valve body (11) provided with a fluid channel (15) inside, a valve seat (12) integrally formed and provided inside the valve body (11), a valve cover (13) provided on the valve body (11), and a valve plate (14) for blocking the fluid channel (15); A transmission mechanism (2) comprising a ball screw (21) having one end passing through the valve cover (13) and connected to the valve plate (14), and a valve stem stopper (22) arranged on the ball screw (21); A fully enclosed electric mechanism (3), which is arranged on the valve cover (13) and connected to the other end of the ball screw (21) for driving the ball screw (21) to move; The position indicator (4) is obliquely arranged on both sides of the valve cover (13), perpendicular to the valve stem stopper (22) and matched with the valve stem stopper (22).

2. The novel integrated weld-free high-temperature and high-pressure gate valve according to claim 1 is characterized in that: The position indicator (4) comprises a pressure-bearing shell (41) arranged on the valve cover (13), a push rod (43) having a ball head (42) at one end and cooperating with the valve stem stopper (22), the pressure-bearing shell (41) comprising a first shell (411) for arranging a ceramic piezoelectric sheet (44) and a second shell (412) having an inner cavity larger than that of the first shell (411), the other end of the push rod (43) passes through the second shell (412) and extends into the first shell (411), the ceramic piezoelectric sheet (44) is arranged on the outside of the side wall of the first shell (411) away from the second shell (412), and a temperature measuring point (413) is arranged on the first shell (411).

3. The novel integrated weld-free high-temperature and high-pressure gate valve according to claim 2 is characterized in that: A ball guide sleeve (414) sleeved on the push rod (43) is provided on the second shell (412) in a tongue-and-groove connection and fixed by screws.

4. The novel integrated weld-free high-temperature and high-pressure gate valve according to claim 3 is characterized in that: A baffle (46) is provided on a section of the push rod (43) located inside the second shell (412), and a spring (45) is provided between the baffle (46) and the connection between the first shell (411) and the second shell (412).

5. The novel integrated weld-free high-temperature and high-pressure gate valve according to claim 4 is characterized in that: The measuring method of the position indicator (4) is as follows: Displacement = k / v × (1 + αΔT); Where: displacement is the measured displacement; v is the peak voltage of the third echo generated by the ceramic piezoelectric piece (44); k is the piezoelectric coefficient, which expresses the relationship between displacement and voltage; α is the temperature coefficient, which indicates the effect of temperature change on displacement; ΔT is the temperature change.

6. The novel integrated weld-free high-temperature and high-pressure gate valve according to any one of claims 2 to 5, characterized in that: The exterior of the valve stem stopper (22) is configured as a first inclined surface (221) and a second inclined surface (222) which are symmetrical in vertical direction, and the connection between the first inclined surface (221) and the second inclined surface (222) is configured as a spherical chamfer.

7. The novel integrated weld-free high-temperature and high-pressure gate valve according to claim 6 is characterized in that: The pushing rods (43) on both sides are respectively perpendicular to the first inclined surface (221) and the second inclined surface (222).

8. The novel integrated weld-free high-temperature and high-pressure gate valve according to claim 6 is characterized in that: The angle between the first inclined surface (221) and the vertical direction is A, and the angle A is calculated as follows: ； Where: r1 is half of the inner diameter of the valve cover (13) minus 3 mm; r2 is the radius of the valve stem; d is the theoretical maximum straight-line running distance of a gate valve with a diameter of d; d 误差 The error of the theoretical maximum straight-line running distance of the gate valve is ±0.5mm; 1 is half the length of the arc chord of the spherical chamfered surface.

9. A gate valve processing technology, characterized in that: The method for processing the novel integrated weld-free high-temperature and high-pressure gate valve according to any one of claims 1 to 8 comprises the following steps: S1. Subtractive processing: The outer shape and internal structure of the valve body (11) are processed. Based on the design drawings, the thickness of the sealing surface is reduced by 5±0.1 mm, and the thickness of the fluid channel (15) is increased by 1.2 mm, so as to obtain the basic structure of the valve body (11) and the valve seat (12); S2. Additive processing: The sealing surface is laser clad with cobalt-based alloy. The outlet sealing surface is processed first, and then the inlet sealing surface is processed. The two processing processes are the same; S3, finishing: finishing the valve body (11) after laser cladding according to the standard size of the design drawing; S4. Surface inspection and cleaning: Inspect the surface of the valve body (11) after fine machining, treat the cracked part and re-clad it until no cracks appear, and clean the valve body (11) with an ultrasonic cleaning machine to ensure that there are no impurities, oil stains, or foreign particles on the surface; S5, electric spark surface processing: processing the sealing surface of the valve seat (12) to ensure that the roughness of the sealing surface meets the sealing requirements; S6, water-tightness test: install the valve plate (14) in the valve body (11), simulate the motor by the push rod, ensure that the sealing force between the valve plate (14) and the valve seat (12) meets the design requirements, pressurize the valve inlet with water to 1.2 times the valve design pressure, check the valve outlet for leakage, and repeat S5 if there is leakage.

10. The gate valve processing process according to claim 9, characterized in that: In step S2, the steps for processing the sealing surface are specifically as follows: S21, place the valve body (11) to be processed into a workpiece heater, place the inlet end on a 5° inclined plane, and adjust the angle of the outlet sealing surface by a feeler gauge so that the outlet sealing surface is horizontal ±0.05°; S22, setting the heating temperature of the workpiece heater to 180°C, and setting the insulation range to ±10°C, taking five temperature points on the inner wall of the valve body (11), and the temperature difference between the highest and lowest temperatures is less than 5°C; S23. Since the heating process may cause the position to shift, check whether the angles of the outlet sealing surface and the inlet sealing surface meet the requirements; S24, push the laser head of the two-axis powder spraying laser cladding machine downward from the middle flange of the valve body (11), use a square spot with a size of 0.5*0.5 mm, set the cladding thickness to 3 mm, and process from the inside to the outside and from the left to the right. When processing near the edge of the fluid channel (15), adjust the cladding power until it is away from the edge of the fluid channel (15); S25. After the cladding is completed, the temperature of the valve body (11) of the workpiece heater is maintained at 180±10°C, and the temperature is cooled to room temperature after waiting for 4 hours to ensure that the workpiece has no cracks; S26, remove welding thermal stress, set the temperature of the workpiece heater to 700±30℃ for annealing, keep warm for 5h, then linearly cool down to 200℃, and the cooling time shall not be less than 24h; S27, remove the outermost layer in the cladding process, check whether the cladding layer has cracks, and if there are cracks, remove them together; S28. Repeat S21-S27 twice to ensure that the actual thickness of the cladding layer is greater than 5 mm.

11. The gate valve processing process according to claim 10, characterized in that: In the step S24, the cladding power is adjusted in the following manner: When the center of the light spot is processed to a distance of less than 1 mm from the edge of the fluid channel (15), the power is reduced by 20%; when the distance between the center of the light spot and the edge of the flow channel is 0.5 mm, the cladding is stopped, and the laser head performs an empty stroke until the distance between the center of the light spot and the edge of the fluid channel (15) is 0.5 mm, and then the laser head is started again, and the starting power is 80% of the set power; when the distance between the center of the light spot and the edge of the fluid channel (15) is 1 mm, the feed is adjusted to the set power.

12. The gate valve processing process according to any one of claims 9 to 11, characterized in that: The specific operation of step S5 is as follows: S51. Design and manufacture of electric spark electrodes: The electrode is a discharge body for machining the sealing surface of the valve seat (12). It is made of copper. The tooling structure is the same as that of the valve plate (14), but the contact surface is consistent with the surface of the valve seat (12). The thickness is 0.1 mm less than that of the valve plate (14). The surface of the valve seat (12) and the guide rail on the valve seat (12) can be processed at the same time. S52, installing the valve body (11): installing the valve body (11) horizontally on the electric spark machining center, using the central axis of the upper flange of the valve body (11) as the center line to install the valve body (11) and the electric spark motor; S53, setting roughness reference lines: setting 10 reference lines as roughness reference lines on the upper flange section of the valve body (11), including 5 reference lines on the inlet sealing surface and 5 reference lines on the outlet sealing surface, setting a roughness detection instrument, and measuring the average roughness of the 10 reference lines. The roughness is measured from the upper flange of the valve body (11) downward until the sealing surface contacts the valve body (11); S54, set the parameters of the EDM machining center: set the discharge voltage to 80V, the discharge current to 2A, the pulse width to 10μs, the pulse interval to 50μs, the working gap to 20μm, and the discharge frequency to 500kHz; S55, Adaptive processing parameter optimization: Since the stress material on the cladding surface is not completely consistent during the cladding process, fixed parameters cannot be used for processing, but dynamic adjustments must be made based on the roughness measurement results.

13. The gate valve processing process according to claim 12, characterized in that: In the S55, the dynamic adjustment method is as follows: After every 15 minutes of processing, the roughness is tested and compared with the previous roughness. If the roughness does not change, the discharge current is reduced by 0.1A and the roughness Ra (i) is recorded. i represents the i-th time after the roughness does not change.

14. The gate valve processing process according to claim 13, characterized in that: During the dynamic adjustment process, if the roughness still cannot meet the requirements after 3 times, adjust according to the following formula: ln(Ra(i) / K)=M·ln(I(i))-N·ln(d(i)); Where: Ra(i) is the average roughness recorded for the i-th time; I(i) is the discharge current corresponding to the i-th recording; d(i) is the working interval set at the i-th recording; K is the roughness reference coefficient; M is the current influence coefficient; N is the gap influence coefficient; By substituting the above formula into 3 groups (Ra(i), I(i), d(i)) and the above data groups, the predicted values ​​of the three parameters K, M, and N can be obtained; then the roughness Ra(i+1) corresponding to the i+1th record, the working gap d(i+1) set at the i+1th record, and the predicted values ​​of K, M, and N are substituted into the following formula to obtain the recommended discharge current; ； Process for 1 hour according to the recommended discharge current I (i+1). If the requirements are still not met after 1 hour, repeat the above process.

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