A double recoil spring safety valve

Abstract

The present invention relates to a double recoil spring safety valve, comprising: a valve body, a valve seat, a valve disc, a guide sleeve, a recoil disc, a valve cover, a valve stem and a spring pressure setting device; the valve is characterized in that a lifting device is arranged between the valve disc and the through hole of the recoil disc, when the medium pressure of the inlet channel reaches the set pressure value, the valve disc is slightly opened, and the push rod is pushed radially by the medium in the pressure-inducing hole, and moves along the inclined guide surface to assist the valve disc to open, and the medium pushes the recoil disc after passing through the sealing pair to drive the push rod and the valve disc to move upward, offsetting the influence of the preload spring on the valve disc, so that the valve disc can quickly reach a fully open state; when the medium pressure of the inlet channel drops, the push rod moves toward the inside of the valve disc under the action of the spring, and is out of contact with the recoil disc, reducing the medium resistance when the valve disc is closed and increasing the closing speed. It has the advantages of fast opening speed and return speed, high opening height, small opening and closing pressure difference, etc.

Description

Technical Field

[0001] The invention relates to a safety valve, in particular to a spring type safety valve. Background Art

[0002] The traditional spring-loaded safety valve uses the pressure of the pre-load spring on the valve disc to balance the thrust of the medium on the valve disc. The compression of the pre-load spring can be adjusted by turning the adjusting screw sleeve on it to set the set pressure value. Its disadvantage is that the force of the pre-load spring on the valve disc will change as the valve disc opens, that is, as the valve disc rises, the compression of the pre-load spring increases, and the force acting on the valve disc also increases, affecting the valve disc to quickly reach the fully open state. Moreover, during the closing process of the valve disc, the pre-load spring force gradually decreases, the valve disc returns to its seat slowly, and the opening and closing pressure difference is large. Summary of the invention

[0003] In view of the technical defects existing in the prior art, the present invention provides a double recoil spring safety valve which can quickly reach a fully open state when the valve disc is opened, quickly return to the seat when closed, and has a small opening and closing pressure difference.

[0004] The present invention is achieved through the following technical solutions:

[0005] A double recoil spring safety valve comprises: a valve body, a valve seat, a valve disc, a guide sleeve, a recoil disc, a valve cover, a valve stem and a spring pressure setting device. The valve body has an inlet channel and a discharge channel. The valve seat is installed in the inlet channel of the valve body. The spring pressure setting device comprises a preload spring, an upper spring seat, a lower spring seat and an adjusting screw sleeve. The upper end of the guide sleeve is fixedly installed between the valve body and the valve cover. The guide hole at the lower end thereof is dynamically matched with the guide column at the back of the valve disc. The lower end surface of the valve disc has a sealing surface that cooperates with the valve seat. The lower end of the valve stem is pressed against the central hole of the guide column at the back of the valve disc. The upper end passes through the lower spring seat, the preload spring, the upper spring seat and the adjusting screw sleeve in sequence. The adjusting screw sleeve is connected to the upper end screw hole of the valve cover through an external thread, and the lower end thereof is pressed against the upper end surface of the upper spring seat. The valve stem is characterized in that: The upper end of the recoil disc is installed on the outside of the valve disc through a guide device and a limit device, and a return spring is arranged between the upper end surface and the guide sleeve. The lower end surface of the recoil disc is provided with a through hole concentric with the valve disc, and the diameter of the through hole is larger than the outer diameter of the valve disc, and an auxiliary lifting device is arranged between the valve disc and the through hole of the recoil disc; the auxiliary lifting device is composed of a piston device radially symmetrically arranged in the valve disc, and the piston device is composed of a piston cavity, a piston, a push rod, and a spring. The outer cylindrical surface of the piston is dynamically sealed with the inner wall of the piston cavity. One end of the push rod is fixedly connected to the center of one side end surface of the piston, and the other end passes through the end cover of the piston cavity and touches the inner wall of the through hole of the recoil disc. The spring is installed between the piston outside the push rod and the end cover. The inner wall of the through hole of the recoil disc has a conical inclined surface, and the piston cavity on the other side of the piston is connected with the inlet channel of the valve body through the pressure-inducing hole.

[0006] Preferably, the guide device is composed of a guide plate arranged at the upper end of the recoil plate, a guide hole is arranged in the center of the guide plate, the outer cylindrical surface of the upper end of the recoil plate is movably matched with the guide hole, and the outer cylindrical surface of the guide plate is fixedly connected to the inner cavity of the valve body.

[0007] Preferably, the limiting device is composed of a limiting plate set at the upper end of the recoil plate, the outer cylindrical surface of the lower end of the limiting plate and the inner hole wall of the upper end of the recoil plate are fixedly connected to each other by threads, and a radial limiting boss is set at the upper end of the limiting plate, and the lower annular surface of the radial limiting boss is pressed into the upper plane of the guide plate.

[0008] Preferably, a spring installation groove is provided in the annular surface of the radial limiting boss of the limiting disk, and a return spring is installed between the spring installation groove and the guide sleeve.

[0009] Preferably, the limiting device is formed by setting a radial outer shoulder on the outer circumferential surface of the upper end of the recoil disk and cooperating with the guide disk, and the radial outer shoulder of the recoil disk is pressed into the upper plane of the guide disk.

[0010] Preferably, a spring installation groove is provided in the annular surface of the radially outer shoulder of the recoil disc, and a return spring is installed between the spring installation groove and the guide sleeve.

[0011] Preferably, the end of the push rod is spherical.

[0012] Compared with the prior art, the present invention has the following beneficial effects: a lifting device is arranged between the valve disc and the through hole of the recoil disc, when the medium pressure of the inlet channel reaches the set pressure value, the valve disc is slightly opened, the push rod is pushed radially by the medium in the pressure-inducing hole, moves along the inclined guide surface, and assists the valve disc to open, and the medium pushes the recoil disc through the sealing pair to drive the push rod and the valve disc to move upward, offsetting the influence of the preload spring on the valve disc, so that the valve disc can quickly reach the fully open state; when the medium pressure of the inlet channel drops, the push rod moves toward the inside of the valve disc under the action of the spring, and is out of contact with the recoil disc, reducing the medium resistance when the valve disc is closed and increasing the closing speed. It has the advantages of fast opening speed and return speed, high opening height, small opening and closing pressure difference, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the present invention.

[0014] In the figure: 1 valve body, 2 valve seat, 3 inlet channel, 4 adjusting ring, 5 valve disc, 6 spring, 7 push rod, 8 end cover, 9 recoil plate, 10 guide plate, 11 limit plate, 12 return spring, 13 guide sleeve, 14 lower spring seat, 15 preload spring, 16 valve stem, 17 valve cover, 18 upper spring seat, 19 adjusting screw sleeve, 20 valve cap, 21 discharge channel, 22 conical inclined surface, 23 piston, 24 pressure-inducing hole, 25 piston cavity. DETAILED DESCRIPTION

[0015] according to Figure 1 It can be seen that a double recoil spring safety valve comprises: a valve body 1, a valve seat 2, a valve disc 5, a guide sleeve 13, a recoil disc 9, a valve cover 17, a valve stem 16 and a spring pressure setting device. The valve body 1 has an inlet channel 3 and a discharge channel 21. The valve seat 2 is installed in the inlet channel of the valve body 1. The spring pressure setting device comprises a pre-compression spring 15, an upper spring seat 18, a lower spring seat 14 and an adjusting screw sleeve 19. The upper end of the guide sleeve 13 is fixedly installed between the valve body 1 and the valve cover 17, and the guide hole at the lower end thereof is dynamically matched with the guide column on the back of the valve disc 5. The lower end surface of the valve disc 5 has a sealing surface that cooperates with the valve seat 2. An adjusting ring 4 is arranged on the outer side of the sealing surface of the valve seat 2. The recoil disc 7 and the adjusting ring 4 are adjusted by manually rotating the adjusting ring 4. The vertical distance between them changes the flow direction of the medium during discharge, and the recoil disc 7 is quickly pushed upward to increase the opening height. The lower end of the valve stem 16 presses against the central hole of the guide column on the back of the valve disc 5, and the upper end passes through the lower spring seat 14, the preload spring 15, the upper spring seat 18 and the adjusting screw sleeve 19 in sequence, and extends into the valve cap 20. The adjusting screw sleeve 19 is connected to the screw hole at the upper end of the valve cover 17 through an external thread, and its lower end presses against the upper end surface of the upper spring seat 18. By adjusting the adjusting screw sleeve 19, the elastic force of the preload spring 15 is adjusted to set the set pressure value; it is characterized in that: the upper end of the recoil disc 9 is installed on the outer side of the valve disc 5 through a guide device and a limit device, and the guide device guides the recoil disc 9 axially to keep the recoil disc 9 can move freely up and down, the limit device limits the recoil disc 9 up and down, limits the moving distance of the recoil disc 9, the lower end surface of the recoil disc 9 is provided with a through hole concentric with the valve disc 5, the diameter of the through hole is larger than the outer diameter of the valve disc 5, so that the force area of ​​the medium is reduced when the valve disc 5 returns to its seat, the resistance of the valve disc 5 to return to its seat is reduced, and the return speed is increased. A lifting device is arranged between the valve disc 5 and the through hole of the recoil disc 9; the lifting device is composed of a piston device radially symmetrically arranged in the valve disc 5, the piston device is composed of a piston cavity 25, a piston 23, a push rod 7, and a spring 6, the outer cylindrical surface of the piston 23 is dynamically sealed with the inner wall of the piston cavity 25, one end of the push rod 7 is fixedly connected to the center of the end surface of one side of the piston 23, and the two can be integrally processed and formed. The other end passes through the end cover 8 of the piston chamber 25 and contacts the inner wall of the through hole of the recoil disk 9. The spring 6 is installed between the piston 23 and the end cover 8. The inner wall of the through hole of the recoil disk 9 has a conical inclined surface 22. The piston chamber 25 on the other side of the piston 23 is connected with the inlet channel 3 of the valve body 1 through the pressure-introducing hole 24. When the medium pressure of the inlet channel 3 reaches the set pressure, the medium pressure pushes the valve disc 5 to open and pushes the piston 23 to push the push rod 7 radially through the pressure-introducing hole 24. The push rod 7 rises along the conical inclined surface 22 to assist the valve disc 5 to open and offset the increase in the compression force of the pre-compression spring 15 as the valve disc 5 opens. When the medium pressure of the inlet channel drops, the push rod 7 retracts into the inside of the valve disc 5 under the action of the spring 6 and breaks away from the contact with the recoil disk 9. The piston device can be symmetrically arranged with two in the diameter direction of the valve disc 5, or more than two can be evenly arranged along the circumference of the valve disc 5.

[0016] The guide device is composed of a guide plate 10 arranged at the upper end of the recoil plate 9, a guide hole is arranged in the center of the guide plate 10, and the outer cylindrical surface of the upper end of the recoil plate 9 is movably matched with the guide hole, so that the recoil plate 9 can move up and down in the guide hole of the guide plate 10, and the outer cylindrical surface of the guide plate 10 is fixedly connected to the inner cavity of the valve body 1.

[0017] The limiting device is composed of a limiting plate 11 arranged at the upper end of the recoil plate 9, the outer cylindrical surface of the lower end of the limiting plate 11 and the inner hole wall of the upper end of the recoil plate 9 are fixedly connected to each other through threads, and a radial limiting boss is arranged on the upper end of the limiting plate 11, and the lower annular surface of the radial limiting boss is pressed into the upper plane of the guide plate 10 to limit the downward movement of the recoil plate 9.

[0018] A spring installation groove is arranged in the annular surface of the radial limiting boss of the limiting disk 11 , and a return spring 12 is installed between the spring installation groove and the guide sleeve 13 .

[0019] The limiting device is formed by setting a radial outer shoulder on the outer circumferential surface of the upper end of the recoil disc 9 and cooperating with the guide disc 10. The radial outer shoulder of the recoil disc 9 is pressed into the upper plane of the guide disc 10.

[0020] A spring installation groove is arranged in the annular surface of the radial outer shoulder of the recoil disc 9 , and a return spring 12 is installed between the spring installation groove and the guide sleeve 13 .

[0021] The end of the push rod 7 is spherical, which improves the movement performance of the push rod 7 on the conical inclined surface 22.

Claims

1. A double recoil spring safety valve, comprising: A valve body (1), a valve seat (2), a valve disc (5), a guide sleeve (13), a recoil disc (9), a valve cover (17), a valve stem (16) and a spring pressure setting device. The spring pressure setting device includes a preload spring (15), an upper spring seat (18), a lower spring seat (14) and an adjusting screw sleeve (19). The upper end of the guide sleeve (13) is fixedly mounted between the valve body (1) and the valve cover (17). The guide hole at the lower end thereof is movably engaged with a guide post on the back of the valve disc (5). The lower end surface of the valve disc (5) has a sealing surface that cooperates with the valve seat (2). The outer side of the sealing surface of the valve seat (2) is provided with a sealing surface. An adjusting ring (4) is provided, the lower end of the valve stem (16) is pressed against the central hole of the guide column on the back of the valve disc (5), and the upper end is passed through the lower spring seat (14), the preload spring (15), the upper spring seat (18) and the adjusting screw sleeve (19) in sequence, the adjusting screw sleeve (19) is connected to the upper end screw hole of the valve cover (17) through an external thread, and the lower end is pressed against the upper end surface of the upper spring seat (18); the feature is that the upper end of the recoil disc (9) is mounted on the outer side of the valve disc (5) through a guide device and a limit device, and the lower end surface of the recoil disc (9) is provided with a through hole concentric with the valve disc (5), and the diameter of the through hole is 1.1mm. The valve disc (5) has a diameter greater than the outer diameter of the valve disc (5), and a lifting device is provided between the valve disc (5) and the through hole of the recoil disc (9); the lifting device is composed of a piston device radially symmetrically arranged in the valve disc (5), the piston device comprising a piston chamber (25), a piston (23), a push rod (7), and a spring (6); the outer cylindrical surface of the piston (23) is dynamically sealed with the inner wall of the piston chamber (25); one end of the push rod (7) is fixedly connected to the center of one end surface of the piston (23), and the other end passes through the end cover (8) of the piston chamber (25) and contacts the inner wall of the through hole of the recoil disc (9); the spring (6) is arranged The recoil disc (9) is installed between the piston (23) and the end cover (8). The inner wall of the through hole of the recoil disc (9) has a conical inclined surface (22). The piston cavity (25) on the other side of the piston (23) is connected to the inlet channel (3) of the valve body (1) through the pressure-inducing hole (24). The guide device is composed of a guide disc (10) arranged on the upper end of the recoil disc (9). A guide hole is arranged at the center of the guide disc (10). The outer cylindrical surface of the upper end of the recoil disc (9) is movably matched with the guide hole. The outer cylindrical surface of the guide disc (10) is fixedly connected to the inner cavity of the valve body (1). The limit device limits the recoil disc (9) up and down.

2. The double recoil spring safety valve according to claim 1 is characterized in that: The limiting device is composed of a limiting plate (11) arranged at the upper end of the recoil plate (9), the outer cylindrical surface of the lower end of the limiting plate (11) and the inner hole wall of the upper end of the recoil plate (9) are fixedly connected to each other through threads, and a radial limiting boss is arranged at the upper end of the limiting plate (11), and the lower annular surface of the radial limiting boss is pressed into the upper plane of the guide plate (10).

3. The double recoil spring safety valve according to claim 1 is characterized in that: The limiting device is composed of a radial outer shoulder provided on the outer circumferential surface of the upper end of the recoil disc (9) and a guide disc (10) which cooperate with each other. The radial outer shoulder of the recoil disc (9) is pressed into the upper plane of the guide disc (10).

4. The double recoil spring safety valve according to claim 1, 2 or 3, characterized in that: A spring installation groove is provided in the annular surface of the radial limiting boss of the limiting disk (11), and a return spring (12) is installed between the spring installation groove and the guide sleeve (13).

5. The double recoil spring safety valve according to claim 4 is characterized in that: The end of the push rod (7) is spherical.

Images