Ultra-high pressure reducing valve

Abstract

The invention discloses an ultra-high pressure pressure reducing valve, comprising a valve body, wherein an upper valve sleeve, a middle valve sleeve, a lower valve sleeve, a valve seat, a filter element, a slide valve, a reset spring and a pressure regulating device are arranged in the valve body, and the center lines of the components are on the same axis; since the ultra-high pressure medium enters the annular groove at the matching position of the slide valve and the corresponding hole, the radial unbalanced force on the slide valve is eliminated, and the friction force when the slide valve moves is greatly reduced; the surface of the slide valve is coated with TiN or CrN, and the friction coefficient when the slide valve moves is reduced; the top rod of the upper section of the slide valve and the stainless steel diaphragm are connected in a non-consolidated manner, and the additional friction force caused by improper connection to the slide valve movement is eliminated; the invention structurally ensures the concentricity of the tapered hole and the tapered surface of the valve, and the material hardness of the two is greatly different, so the contact surface is more fitted under ultra-high pressure and the sealing is more reliable; a high-precision filter element is arranged at the inlet to prevent larger particle impurities from entering the valve to affect the movement of the slide valve and the sealing of the valve port.

Description

Technical Field

[0001] The invention relates to the technical field of valves, and in particular to an ultra-high pressure pressure reducing valve. Background Art

[0002] A pressure reducing valve is a valve that reduces the high pressure medium in front of the valve to the required low pressure after the valve, and when the inlet and outlet pressure or flow rate fluctuates, it automatically adjusts itself to ensure that the output pressure remains basically unchanged. Its working principle is that when the pressure or flow rate fluctuates, the valve port size is increased or decreased by the rise or fall of the slide valve, so that the throttling and pressure reduction effect of the valve port increases or decreases, so as to keep the output pressure basically unchanged. For example, when the input pressure increases, the slide valve rises, the valve port size becomes smaller, the throttling and pressure reduction effect increases, and the output pressure is prevented from increasing, thereby ensuring that the output pressure remains basically unchanged. However, there is an important condition for this "basically unchanged", that is, the friction force when the slide valve rises and falls can be ignored relative to the force that pushes it up and down. For ordinary pressure reducing methods of medium and low pressure, since the radial unbalanced force generated by the medium in the gap between the slide valve and the corresponding matching hole on the slide valve is not large, the friction force generated when the slide valve moves can be ignored, especially for pressure reducing valves using lubricating media. However, for ultra-high pressure pressure reducing valves, such as pressure reducing valves for hydrogen fuel cells, the current pressure has reached 70MPa. Due to the large radial unbalanced force on the slide valve, the friction generated when the slide valve moves will hinder the movement of the slide valve, causing slow movement or even stuck, especially for slide valves that use non-lubricating media or have O-rings on the outer diameter. In order to reduce the radial unbalanced force, the commonly used method is to open a number of pressure equalization grooves on the surface of the slide valve, but the effect is not obvious under ultra-high pressure conditions. Moreover, the radial unbalanced force is also related to the shape and position tolerances of the slide valve and the corresponding matching holes (such as taper, non-roundness, non-cylindricity, etc.), matching clearance and installation eccentricity. In addition, the general pressure reducing valve uses soft seals. For ultra-high pressure, the seal must use hard seals. Hard seals are resistant to pressure, wear, scratches, and high temperatures, and have a long service life, but the problem of sealing reliability must be solved. This patent is designed to solve the above-mentioned technical deficiencies of ordinary pressure reducing valves. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that when the radial unbalanced force of the prior art ultra-high pressure pressure reducing valve is very large, the friction force generated when the sliding valve moves will hinder the movement of the sliding valve, causing slow movement or even jamming, as well as the sealing problem of the valve port, and to provide an ultra-high pressure pressure reducing valve that can effectively solve the above problems.

[0004] The specific technical solution adopted by the present invention to solve the above technical problems is an ultra-high pressure pressure reducing valve, including a valve body, an upper valve sleeve, a middle valve sleeve, a lower valve sleeve, a filter element, a sliding valve, a reset spring and an output pressure regulating device are arranged in the valve body, and the center lines of the above parts are on the same axis. The plunger of the lower section of the sliding valve slides in the small hole of the lower sleeve, and the surface is coated with TiN or CrN to reduce the friction coefficient during movement. The cone angle of the middle section cone is the same as the taper of the cone hole below the valve seat, and the two constitute the valve port of the pressure reducing valve. The ball head of the upper section push rod is tightly pressed against the lower end face of the connecting screw under the thrust of the reset spring, and there is a longitudinal blind hole in the center of the lower end face. The upper section of the plunger has four upper radial holes that are evenly distributed and connected to the longitudinal blind hole, and the middle and lower sections of the plunger have four lower radial holes that are evenly distributed and connected to the longitudinal blind hole. The outer mouth of the lower radial hole is provided with an annular groove; the material of the sliding valve is stainless steel, and the material of the valve seat is copper alloy, aluminum alloy or tree with a hardness lower than that of the sliding valve. Grease; Since the ultra-high pressure medium enters the annular groove at the matching place between the slide valve and the corresponding hole, the radial unbalanced force on the slide valve is eliminated, and the friction force when the slide valve moves is greatly reduced; the push rod and the diaphragm of the upper section of the slide valve are connected non-consolidated, which eliminates the additional friction caused by improper connection to the slide valve movement; due to the reasonable structural design, the concentricity of the tapered hole of the valve seat and the tapered surface of the slide valve is guaranteed, and the hardness of the two materials is quite different. In this way, under ultra-high pressure, due to the deformation of the softer material, the contact surface is more fitted and the seal is more reliable; a high-precision filter element is set at the inlet to prevent larger particles from entering the valve and affecting the movement of the slide valve and the sealing of the valve port.

[0005] Preferably, the valve body is a stepped cylinder with a larger diameter at the top and a smaller diameter at the bottom. The bottom of the lower cylinder has a bottom wall, and a circular outer convex ring is provided below the bottom wall. The center of the outer convex ring has an inlet and a through hole 1, and a filter element is provided above the inlet, and a retaining ring is provided for positioning; one side of the upper cylinder has a circular outer convex ring, and the center of the outer convex ring has an outlet and a through hole 2. The upper end of the inner hole of the upper cylinder is provided with an internal thread, and the lower end is provided with a groove for arranging an O-ring 2; the cylinder at the lower part of the lower valve sleeve is transitionally matched with the inner hole of the lower cylinder of the valve body, and the lower end face of the upper cone abuts against the upper end face of the corresponding hole, with a stepped hole with a larger diameter at the top and a smaller diameter at the bottom in the center, and a through hole 3 is provided on the bottom wall; the outer diameter of the middle valve sleeve is slidably matched with the inner hole of the upper cylinder of the valve body, and is provided with upper and lower O-rings 1 and an O-ring Second, there is a pit at the upper end and a tapered hole at the lower end. There is a stepped hole above the tapered hole, and the taper of the tapered hole is the same as the taper of the upper cone of the lower valve sleeve; the large hole of the stepped hole is tightly fitted with a valve seat, and the through hole four in the center of the stepped hole is connected to the upper pit, and an annular channel is formed between the through hole four and the top rod of the upper section of the sliding valve, and four evenly distributed radial through holes are provided on the wall in the center of the through hole four, and an annular groove is provided at the outer mouth of the radial through hole, and the annular groove is connected to the through hole two; the external thread of the middle section of the upper valve sleeve is screwed with the internal thread at the upper end of the inner hole of the cylinder on the valve body, and the cylinder at the lower end is slidably matched with the inner hole of the cylinder on the valve body, and a screw hole is provided in the top cover; the diaphragm is arranged between the upper valve sleeve and the middle valve sleeve, and the upper valve sleeve can be tightened to press the valve body, the lower valve sleeve, the middle valve sleeve, the diaphragm and the upper valve sleeve against each other.

[0006] As a preference, the output pressure regulating mechanism is arranged in the inner cavity of the upper valve sleeve, and is composed of an adjusting screw, a nut 1, an upper spring seat, a spring, a lower spring seat, a diaphragm, a sealing gasket, a connecting screw and a nut 2, and the center lines of the various parts are on the same axis. The adjusting screw is screwed into the screw hole of the upper sleeve top cover, and the output pressure can be adjusted by rotating the adjusting screw to adjust the compression degree of the spring, and the output pressure can be adjusted, and locked with a nut 1 after adjustment.

[0007] The beneficial effects of the present invention are as follows: the ultra-high pressure pressure reducing valve of the present invention eliminates the radial unbalanced force on the slide valve because the ultra-high pressure medium enters the annular groove at the matching position of the slide valve and the corresponding hole, thereby greatly reducing the friction force when the slide valve moves; the slide valve surface is coated with TiN or CrN, which reduces the friction coefficient when the slide valve moves; the top rod and the diaphragm of the upper section of the slide valve are connected by non-consolidation, eliminating the additional friction caused by improper connection to the slide valve movement, and solving the problem that the friction force generated under ultra-high pressure conditions will hinder the movement of the slide valve, causing slow movement or even stuck. In addition, due to the reasonable structural design, the concentricity of the cone hole of the valve seat and the cone surface of the slide valve is guaranteed, and the hardness of the materials of the two is quite different, so that under ultra-high pressure, due to the deformation of the softer material, the contact surface is more fitted, solving the sealing problem of the valve port. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1It is a structural sectional view of the ultra-high pressure pressure reducing valve of the present invention.

[0009] In the figure: 1. adjusting screw, 2. nut 1, 3. upper spring seat, 4. upper valve sleeve, 5. spring, 6. connecting screw, 7. nut 2, 8. lower spring seat, 9. diaphragm, 10. O-ring 1, 11. sealing gasket, 12. O-ring 2, 13. middle valve sleeve, 14. valve seat, 15. filter element, 16. return spring, 17. sliding valve, 18. lower valve sleeve, 19. valve body, A1. inlet, A2. outlet, V. pressure reducing valve port, a. through hole 1, b. through hole 2, c. through hole 3, d. through hole 4, e. radial through hole, f. annular groove, g. annular channel, h. longitudinal blind hole, j. lower radial hole, k. annular groove, m. upper radial hole. DETAILED DESCRIPTION

[0010] The specific implementation of the present invention is further described below through examples and in conjunction with the accompanying drawings.

[0011] Example 1

[0012] The ultra-high pressure reducing valve of the present invention is as follows Figure 1As shown, the ultra-high pressure relief valve is composed of a valve body 19, an upper valve sleeve 4, a middle valve sleeve 13, a lower valve sleeve 18, a slide valve 17, a valve seat 14, an output pressure regulating device, a filter element 15, a reset spring 16 and other parts, and the center lines of each part are on the same axis. The valve body 19 has a stepped cylinder with a larger diameter at the top and a smaller diameter at the bottom. The lower cylinder has a bottom wall, and a circular outer convex ring is provided below the bottom wall. The center of the outer convex ring has an inlet A1 and a through hole a. A filter element 15 is provided above the inlet A1 and is positioned by a retaining ring to prevent impurities from entering the valve and affecting the movement of the slide valve 17 and the sealing of the valve port V of the relief valve; one side of the upper cylinder has a circular outer convex ring, and the center of the outer convex ring has an outlet A2 and a through hole b; the upper end of the inner hole is machined with an internal thread, and the lower end is machined with a groove for setting an O-type sealing ring 12. The cylinder at the lower part of the lower valve sleeve 18 is transitionally matched with the inner hole of the lower cylinder of the valve body 19. The upper part is a cone, the lower end face of the cone rests on the upper end face of the corresponding hole, there is a stepped hole with a larger diameter at the top and a smaller diameter at the bottom in the center, and there is a through hole three c on the bottom wall. The outer diameter of the middle valve sleeve 13 is slidably matched with the inner hole in the upper cylinder of the valve body 19, and is provided with an O-type sealing ring 10 and an O-type sealing ring 2 12. There is a pit at the upper end and a tapered hole at the lower end. The taper of the tapered hole is the same as that of the cone at the upper part of the lower valve sleeve 18. There is a stepped hole above the tapered hole. The valve seat 14 is tightly fitted in the large hole. The through hole four d in the center connects the upper and lower pits. Four uniformly distributed radial through holes e are drilled on the central wall of the through hole four d. The outer diameter of the outer opening of the radial through hole e is provided with an annular groove f, which is connected with the through hole two b; the lower end face of the valve seat 14 has a tapered hole.The external thread in the middle section of the upper valve sleeve 4 is screwed with the internal thread at the upper end of the inner hole of the upper cylinder of the valve body 19, the outer diameter of the short cylinder at the lower end is slidably matched with the inner hole of the upper cylinder of the valve body 19, and there are two parallel planes (not shown in the figure) on both sides of the small cylinder at the upper end, which are used to tighten the upper valve sleeve 4 with a wrench, and there is a screw hole in the center of the top cover; the diaphragm 9 (made of 316L stainless steel) is arranged between the upper valve sleeve 4 and the middle valve sleeve 13, and tightening the upper valve sleeve 4 can make the lower valve sleeve 18, the middle valve sleeve 13, and the diaphragm 9 pressed against the upper end surface of the inner hole of the lower cylinder of the valve body 19, and press the diaphragm 9; the output pressure regulating mechanism is arranged in the inner cavity of the upper valve sleeve 4, and consists of an adjusting screw 1, a nut 2, an upper spring seat 3, a spring 5, and a lower The valve body 19 is composed of a spring seat 8, a diaphragm 9, a connecting screw 6, a sealing gasket 11 and a nut 7. The center line of each part is consistent with the center line of the valve body 19. The adjusting screw 1 is screwed into the screw hole of the top cover of the upper sliding sleeve 4 to adjust the tightness of the spring 5. The plunger of the lower section of the sliding valve 17 is slidably fitted in the small hole of the lower sliding sleeve 18. The cone angle of the middle section of the cone is the same as the cone angle of the cone hole below the valve seat 14. The two constitute the valve port V of the pressure reducing valve. Due to the close fit between the cone above the lower sliding sleeve 18 and the cone hole below the middle valve sleeve 13, the two cone surfaces of the valve port V of the pressure reducing valve can be completely fitted. The ball head of the upper section of the push rod is tightly pressed against the lower end surface of the connecting screw 6 under the thrust of the reset spring 16. Due to the sliding valve 17 It is not connected with the diaphragm 9, etc., so the additional friction caused by improper connection or installation to the movement of the slide valve 17 is eliminated. An annular channel g is formed between the outer diameter of the push rod and the through hole 4 d. There is a longitudinal blind hole h in the center of the lower end face of the slide valve 17. The upper section of the plunger has 4 evenly distributed upper radial holes m, and the two holes are connected to introduce the high-pressure medium into the front cavity of the valve port V of the pressure reducing valve. The middle and lower sections of the plunger have 4 evenly distributed lower radial holes j. The outer mouth of the lower radial hole j is machined with a wider annular groove k, so that the annular groove k is connected with the longitudinal blind hole h to guide the high-pressure medium to the matching gap between the plunger and the corresponding hole. The center line of the outer diameter of the plunger and the inner diameter of the annular groove k is on the same straight line, thereby eliminating the radial unbalanced force on the slide valve 17. In order to further reduce the friction coefficient, the contact part of the plunger surface and the corresponding hole is coated with TiN or CrN.

[0013] In order to ensure the sealing performance of the pressure reducing valve when the valve port V is closed, in addition to ensuring the concentricity of the tapered hole of the valve seat 14 and the tapered surface of the frustum of the middle section of the slide valve 17, the tapered surfaces of the two are also ground in pairs, with a surface roughness of ≤0.1μm, and one of the two is made of a relatively soft material, for example, the material of the slide valve 17 is stainless steel 316L, and the material of the valve seat 14 is copper alloy or aluminum alloy or synthetic resin (such as polyimide resin or Teflon). In this way, under high pressure, the deformation of the softer material makes the joint surface fit better.

[0014] The working principle of the pressure reducing valve is as follows: when the stop valve after the valve is closed and the medium supply is stopped, the outlet cavity of the valve port V of the pressure reducing valve, that is, the pressure in the lower cavity of the diaphragm 9, increases, the diaphragm 9 overcomes the pressure of the spring 5 to increase, and the slide valve 17 rises synchronously under the push of the return spring 16 until the valve port V of the pressure reducing valve is closed. After the valve port V of the pressure reducing valve is closed, the pressure in the outlet cavity no longer increases and always maintains a low pressure equivalent to the set pressure; when the stop valve after the valve is opened to provide the medium, the pressure in the lower cavity of the diaphragm 9 decreases, and under the push of the spring 5, the slide valve 17 moves downward to overcome the top force of the return spring 16. As the valve port V of the pressure reducing valve gradually opens, the pressure in the lower cavity of the diaphragm 9 gradually increases. When it is balanced with the set pressure of the spring 5, the opening size of the valve port V of the pressure reducing valve is constant, and the pressure reducing valve has a certain pressure output. Therefore, the output pressure can be adjusted by adjusting the tightness of the spring 5 through the screw 1, and it is locked with the nut 2 after adjustment. Once the output pressure is adjusted, if the input, output pressure or flow changes, the pressure reducing valve will use its own structure to automatically adjust so that the output pressure remains basically unchanged. If the input pressure decreases (or increases), the output pressure will inevitably decrease (or increase) at the moment of decrease (or increase), and the slide valve 17 moves downward (or upward) under the push of the spring 5, the opening of the valve port V of the pressure reducing valve increases (or decreases), and the throttling and pressure reducing effect decreases (or increases), so that the output pressure returns (or decreases) to the original set pressure; if the flow rate increases (or decreases), the flow velocity flowing through the valve port V of the pressure reducing valve also increases (or decreases), and the pressure loss also increases (or decreases), causing the output pressure to decrease (or increase), so that the slide valve 17 moves downward (or upward) under the push of the spring 5 (or the return spring 16), the opening of the valve port V of the pressure reducing valve increases (or closes), and the throttling and pressure reducing effect decreases (or increases), so that the output pressure returns (or decreases) to the original set value.

[0015] In addition to the above-mentioned embodiments, within the scope disclosed in the claims and the specification of the present invention, the technical features or technical data of the present invention can be reselected and combined to form new implementation modes. These implementation modes that are not described in detail in the present invention can be easily implemented by those skilled in the art without creative work. Therefore, these implementation modes that are not described in detail should also be regarded as specific embodiments of the present invention and are within the protection scope of the present invention.

Claims

1. An ultra-high pressure pressure reducing valve, comprising a valve body (19), Features: The valve body (19) is provided with an upper valve sleeve (4), a middle valve sleeve (13), a lower valve sleeve (18), a filter element (15), a slide valve (17), a return spring (16) and an output pressure regulating device, and the center lines of the above components are on the same axis; the plunger of the lower section of the slide valve (17) is slidably fitted in the small hole of the lower sleeve (18), and the surface is coated with TiN or CrN. The cone angle of the middle section cone is the same as the cone angle of the cone hole below the valve seat (14), and the two form the valve port (V) of the pressure reducing valve. The ball head of the upper section push rod is in the return spring (1 6), the slide valve (17) is tightly pressed against the lower end surface of the connecting screw (6), the center of the lower end surface of the slide valve (17) has a longitudinal blind hole (h), the upper section of the plunger has four upper radial holes (m) evenly distributed and connected to the longitudinal blind hole (h), the middle and lower section of the plunger has four lower radial holes (j) evenly distributed and connected to the longitudinal blind hole (h), and the outer opening of the lower radial hole (j) is provided with an annular groove (k); the material of the slide valve (17) is stainless steel, and the material of the valve seat (14) is copper alloy, aluminum alloy or resin with a lower hardness than the slide valve.

2. The ultra-high pressure reducing valve according to claim 1, Features: The valve body (19) is a stepped cylinder with a larger diameter at the top and a smaller diameter at the bottom. The bottom of the lower cylinder has a bottom wall, and a circular outer convex ring is provided below the bottom wall. The center of the outer convex ring has an inlet (A1) and a through hole (a). A filter element (15) is provided above the inlet (A1) and is positioned by a retaining ring. One side of the upper cylinder has a circular outer convex ring, and the center of the outer convex ring has an outlet (A2) and a through hole (b). The upper end of the inner hole of the upper cylinder is provided with an internal thread, and the lower end is provided with an O-ring (12) ); the cylinder at the bottom of the lower valve sleeve (18) is transitionally matched with the inner hole of the lower cylinder of the valve body (19); the lower end surface of the upper cone is against the upper end surface of the corresponding hole, and there is a stepped hole with a larger diameter at the top and a smaller diameter at the bottom in the center, and a through hole three (c) is provided on the bottom wall; the outer diameter of the middle valve sleeve (13) is slidably matched with the inner hole of the upper cylinder of the valve body (19), and is provided with upper and lower O-rings one (10) and O-ring two (12), with a pit at the upper end and a tapered hole at the lower end. The taper of the tapered hole is the same as the taper of the upper cone of the lower valve sleeve (18); the upper part of the tapered hole is a stepped hole, the large hole in the stepped hole is tightly fitted with the valve seat (14), the small hole in the stepped hole, namely the through hole four (d) is connected to the upper pit, and an annular channel (g) is formed between the through hole four (d) and the top rod of the upper section of the slide valve (17), and four evenly distributed radial through holes (e) are provided on the wall at the center of the through hole four (d), and an annular groove (f) is provided at the outer mouth of the radial through hole (e), and the annular groove The groove (f) is connected to the second through hole (b); the external thread of the middle section of the upper valve sleeve (4) is screwed with the internal thread of the upper end of the inner hole of the upper cylinder of the valve body (19); the cylinder at the lower end is slidably matched with the inner hole of the upper cylinder of the valve body (19); and a screw hole is provided in the top cover; the diaphragm (9) is arranged between the upper valve sleeve (4) and the middle valve sleeve (13); by tightening the upper valve sleeve (4), the valve body (19), the lower valve sleeve (18), the middle valve sleeve (13), the diaphragm (9) and the upper valve sleeve (4) can be pressed against each other.

3. The ultra-high pressure reducing valve according to claim 1 or 2, Features: The output pressure regulating mechanism is arranged in the inner cavity of the upper valve sleeve (4), and is composed of an adjusting screw (1), a nut (2), an upper spring seat (3), a spring (5), a lower spring seat (8), a diaphragm (9), a sealing gasket (11), a connecting screw (6) and a nut (7). The center lines of the various parts are on the same axis. The adjusting screw (1) is screwed into the screw hole of the top cover of the upper sliding sleeve (4). The adjusting screw (1) is turned to adjust the tightness of the spring (5), thereby adjusting the size of the output pressure. After adjustment, the adjusting screw (2) is used to lock it.

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