Control valve

Abstract

The invention relates to the field of fluid adjustment, in particular to a control valve facilitating pressure balance between an outlet cavity and a balance cavity, the balance cavity and the outlet cavity are communicated through a communicating hole, the communicating hole comprises a first port, and the first port is located in a valve hole wall part corresponding to a first valve hole; or when the second valve element is located at the maximum valve opening position of the second valve element relative to the first valve element, the first port is located in the first valve hole, the pressure at the first port is always smaller than that at the inlet cavity, and pressure balance between the outlet cavity and the balance cavity is facilitated.

Description

[Technical field]

[0001] The invention relates to the field of fluid regulation, and in particular to a control valve. [Background technology]

[0002] A control valve includes an inlet, an outlet and a chamber. The control valve includes a large valve core and a small valve core. The large valve core and the small valve core are located in the chamber. A high-pressure fluid flows into the control valve through the inlet, passes through valve holes corresponding to the large valve core and / or the small valve core, and flows out of the control valve from the outlet. The pressure at the inlet is higher than the pressure at the outlet. The small valve core has a hole that conducts the chamber and the outlet to achieve pressure balance between the valve chamber and the outlet. In the process of opening the valve hole corresponding to the small valve core, the hole located in the small valve core moves with the movement of the small valve core. When the pressure at the port corresponding to the hole corresponds to the pressure at the inlet, the pressure at the port corresponding to the hole increases rapidly, resulting in an increase in the pressure in the valve chamber, which affects the pressure balance between the outlet and the valve chamber. [Summary of the invention]

[0003] The present invention provides a control valve to solve the above problems:

[0004] A control valve, the control valve includes a valve cavity, the valve cavity includes an inlet cavity, an outlet cavity and a balancing cavity, the control valve includes a valve body, a first valve core and a second valve core, the first valve core and the second valve core are located in the valve cavity, the first valve core includes a first valve hole portion, the first valve hole portion includes a first valve hole, at least part of the second valve core is located in the first valve hole, the control valve includes a conducting hole, the conducting hole conducts the balancing cavity and the outlet cavity, the conducting hole includes a first port, the first port is located in the valve hole wall portion corresponding to the first valve hole; or when the second valve core is located at the maximum valve opening position of the second valve core relative to the first valve core, the first port is located in the first valve hole.

[0005] Such a control valve connects the balancing chamber and the outlet chamber through a conducting hole, and the conducting hole includes a first port, and the first port is located at the valve hole wall corresponding to the first valve hole; or when the second valve core is at the maximum valve opening position of the second valve core relative to the first valve core, the first port is located in the first valve hole, so that the pressure at the first port is always lower than the pressure at the inlet chamber, which is beneficial to the pressure balance between the outlet chamber and the balancing chamber.

Brief Description of the Drawings

[0006] Figure 1 A cross-sectional view of a control valve according to an embodiment;

[0007] Figure 2 A partial cross-sectional view of an embodiment in which the second valve core is in a first relative position;

[0008] Figure 3 This is an enlarged view of region A of an embodiment;

[0009] Figure 4It is a partial cross-sectional view of another embodiment in which the second valve core is in a first relative position.

[0010] Reference numerals:

[0011] Valve chamber 1, inlet chamber 11, outlet chamber 12, balance chamber 13;

[0012] Valve body portion 2, second valve hole portion 21, valve body 22, valve seat 23;

[0013] First valve core 3, first valve hole portion 32, first valve hole 321, first section 3211, second section 3212, valve hole wall portion 322, body portion 33, protrusion 34, first portion 341, accommodating space 35, second portion 351, third portion 352, communication hole 36, first side wall 37;

[0014] The second valve core 4, a matching portion 41;

[0015] A conducting hole 5, a first port 51, and a second port 52;

[0016] Groove portion 6, first groove 61, second groove 62, third port 621, fourth port 622, fifth port 623;

[0017] Driving part 6; nut 7; screw rod 8; first limiting part 9; sealing assembly 010, first sealing part 011, second sealing part 012. [Specific implementation method]

[0018] The technical solution of the specific implementation is described below in conjunction with the accompanying drawings:

[0019] A control valve, the control valve comprises a valve cavity 1, the valve cavity 1 comprises an inlet cavity 11, an outlet cavity 12 and a balance cavity 13, the control valve comprises a valve body 2, a first valve core 3 and a second valve core 4, the first valve core 3 and the second valve core 4 are located in the valve cavity 1, the valve body 2 comprises a second valve hole 21, the first valve core 3 and the valve body 2 cooperate to control the conduction and blocking of the inlet cavity 11 and the outlet cavity 12 at the second valve hole 21; the first valve core 3 comprises a first valve hole 32, the cooperation of the first valve core 3 and the second valve core 4 controls The inlet chamber 11 and the outlet chamber 12 are connected and blocked in the first valve hole portion 32; the first valve core 3 has an accommodating space 35, the second valve core 4 has a matching portion 41, the matching portion 41 is movably limited in the accommodating space 35, the control valve also includes a driving portion 6, a nut 7 and a screw 8, at least part of the driving portion 6 is located in the valve cavity 1, the nut 7 and the screw 8 are located in the valve cavity 1, the nut 7 and the valve body portion 2 are limited and matched, the screw 8 and the nut 7 are threadedly matched, the screw 8 and the second valve core 4 are limited and matched, and the driving portion 6 drives The movable screw 8 rotates, and at the same time, the screw 8 drives the second valve core 4 to move in a straight line. It is defined that the moving direction of the second valve core 4 toward the side of the balance chamber 13 is the first direction 001; the first relative position 002 is defined as the second valve core 4 moves along the first direction 001 to the maximum valve opening position of the second valve core 4 relative to the first valve core 3; the second valve core 4 moves along the first direction 001 to achieve the conduction between the inlet chamber 11 and the outlet chamber 12 in the first valve hole portion 32; the control valve has a first limiting portion 9 that is limited by the first valve core 3. When the second valve core 4 moves along the first direction 001 to the first relative position 002, the matching portion 41 abuts against the first limiting portion 9. At this time, the first limiting portion 9 limits the relative movement of the second valve core 4 and the first valve core 3 along the first direction; when the second valve core 4 continues to move along the first direction 001 from the first relative position 002, the second valve core 4 drives the first valve core 3 to move along the first direction 001, so as to achieve the conduction between the inlet chamber 11 and the outlet chamber 12 at the second valve hole portion 21.

[0020] The control valve includes a sealing assembly 010, and the sealing assembly 010 includes a first sealing portion 011 and a second sealing portion 012. The first sealing portion 011 is located between the first valve core 3 and the valve body portion 2, and the second sealing portion 012 is located between the second valve core 4 and the first valve core 3. In this way, when the first valve core 3 and the second valve core 4 are in the valve closing position, that is, when the inlet chamber 11 and the outlet chamber 12 are blocked at the second valve hole portion 21 and the first valve hole portion 32, the inlet chamber 11 and the balance chamber 13 are blocked. When the high-pressure fluid flows into the inlet chamber 11, when the first valve core 3 and the second valve core 4 are in the valve closing position, the inlet chamber 11 and the balance chamber 13 are blocked to prevent the high-pressure fluid from flowing into the balance chamber 13, thereby preventing the pressure in the balance chamber 13 from increasing. In this way, if the inlet chamber 11 and the outlet chamber 12 are to be connected at the second valve hole portion 21, the first valve core 3 is easier to move.

[0021] The first valve hole portion 32 includes a first valve hole 321, at least a portion of the second valve core 4 is located in the first valve hole 321, the control valve includes a through hole 5, the through hole 5 connects the balance chamber 13 and the outlet chamber 12, the through hole 5 includes a first port 51, and the first port 51 is located in the valve hole wall portion 322 corresponding to the first valve hole 321; or when the second valve core 4 is located at the maximum valve opening position of the second valve core 4 relative to the first valve core 3, the first port 51 is located in the first valve hole 321.

[0022] Such a control valve conducts the balance chamber 13 and the outlet chamber 12 through the conducting hole 5, and the conducting hole 5 includes a first port 51, and the first port 51 is located at the valve hole wall portion 322 corresponding to the first valve hole 321; or

[0023] When the second valve core 4 is at the maximum valve opening position relative to the first valve core 3, the first port 51 is located in the first valve hole 321, so that the pressure at the first port 51 corresponds to the pressure at the outlet chamber 12, which is lower than the pressure in the inlet chamber 11, which is beneficial to the pressure balance between the outlet chamber 12 and the balance chamber 13.

[0024] It should be noted that: the cooperation between the first valve core 3 and the valve body 2 can be direct cooperation; for example, the second valve hole portion 21 is arranged on the valve body 22, and the valve body 22 and the first valve core 3 cooperate to achieve the conduction and blockage of the inlet cavity 11 and the outlet cavity 12 at the second valve hole portion 21; for another example, the valve body portion 2 includes a valve body 22 and a valve seat 23, and the second valve hole portion 21 is arranged on the valve seat 23, and the cooperation of the valve seat 23 and the first valve core 3 achieves the conduction and blockage of the inlet cavity 11 and the outlet cavity 12 at the second valve hole portion 21; the wear resistance of the corresponding material of the valve seat 23 can be greater than the wear resistance of the corresponding material of the valve body 22, thereby reducing the damage between the corresponding wall portions of the first valve core 3 and the second valve hole portion 21 due to mutual collision, and improving the reliability of the control valve inlet cavity 11 and the outlet cavity 12 when they are blocked at the second valve hole portion 21.

[0025] The first valve core 3 has a connecting hole 36, and the accommodating space 35 includes a second part 351 and a third part 352. The second part 351 is connected to the balancing chamber 13, and the connecting hole 36 is connected to the third part 352 and the inlet chamber 11. When the inlet chamber 11 and the outlet chamber 12 are in a blocking state at the first valve hole portion 32, the second sealing portion 012 blocks the second part 351 and the third part 352, and the fluid at the inlet chamber 11 flows into the third part 352 through the connecting hole 36, and the second sealing portion 012 blocks the fluid in the third part 352 from entering the second part 351. When the inlet chamber 11 and the outlet chamber 12 are in the process of being blocked and connected at the first valve hole portion 32, that is, when the second valve core 4 moves along the first direction 001, the fluid in the third part 352 is sprayed into the first valve hole 321 corresponding to the first valve hole portion 32, and the first valve hole 321 and the conducting hole 5 are connected to the third part 352 and the second part 351.

[0026] In one embodiment, reference Figure 4 , the conducting hole 5 is located in the second valve core 4, the conducting hole 5 has a first port 51 and a second port 52, the first port 51 is located at one end of the second valve core 4 away from the balance chamber 13 in the opposite direction of the first direction, when the second valve core is located at the maximum valve opening position of the second valve core 4 relative to the first valve core 3, the first port 51 is located at the first valve hole 321 or the outlet chamber 12, the first valve core 3 includes a first side wall 37, the first side wall 37 is connected to the valve hole wall portion 322, the first side wall 37 is located on the side of the valve hole wall portion 322 close to the balance chamber 13 along the first direction 001, specifically, the first side wall 37 is at least a part of the wall portion corresponding to the third part 352; when the second valve core is located at the maximum valve opening position of the second valve core 4 relative to the first valve core 3, along the first direction 001, the minimum distance between the wall portion corresponding to the first port 51 and the first side wall 37 is 1-12mm.

[0027] Such a control valve, when the second valve core is located at the maximum valve opening position of the second valve core 4 relative to the first valve core 3, the first port 51 is located at the first valve hole 321 or the outlet chamber 12, that is, when the second valve core 4 is located at the first relative position 002, the first port 51 is located at the first valve hole 321 or the outlet chamber 12, that is, the inlet chamber 11 and the outlet chamber 12 are blocked at the second valve hole portion 21, and when the inlet chamber 11 and the outlet chamber 12 are connected at the first valve hole portion 32, the pressure of the first port 51 corresponds to the pressure at the outlet chamber 12, which is less than the pressure at the inlet chamber 11, which is beneficial to the pressure balance between the outlet chamber 12 and the balance chamber 13. In addition, when the second valve core 4 is located at the maximum valve opening position of the second valve core 4 relative to the first valve core 3, along the first direction 001, the distance between the first port 51 and the first side wall 37 is 1-12 mm. When the fluid is sprayed from the inlet chamber 11 into the first valve hole 321, the speed increases, which is more conducive to the pressure reduction at the first port 51, thereby reducing the pressure in the balance chamber 13, which is more conducive to the movement of the first valve core 3.

[0028] In one embodiment, reference Figure 1-Figure 3 The conducting hole 5 is located in the first valve core 3, and the conducting hole 5 has a first port 51 and a second port 52. The first port 51 is located in the valve hole wall portion 322, and the second port 52 is connected to the balance chamber 13. The first valve core 3 includes a first side wall 37, and the first side wall 37 is connected to the valve hole wall portion 322. The first side wall 37 is located on a side of the valve hole wall portion 322 close to the balance chamber 13 along the first direction 001. Specifically, the first side wall 37 is at least a part of the wall portion corresponding to the third part 352; along the first direction 001, the minimum distance between the wall portion corresponding to the first port 51 and the first side wall 37 is 1-12mm.

[0029] Such a control valve, through the first port 51 located at the valve hole wall 322, that is, from the inlet chamber 11 and the outlet chamber blocking state at the first valve hole 32, to the process of the second valve core 4 moving to the first relative position, the position of the first port 51 is relatively static with the first valve core 3, so that the pressure of the first port 51 corresponds to the pressure at the outlet chamber 12, which is less than the pressure at the inlet chamber 11, which is conducive to the pressure balance between the outlet chamber 12 and the balance chamber 13. In addition, along the first direction 001, the distance between the first port 51 and the first side wall 37 is 1-12mm, when the fluid is sprayed from the inlet chamber 11 into the first valve hole 321, the speed increases, which is more conducive to the pressure reduction at the first port 51, thereby reducing the pressure in the balance chamber 13, and more conducive to the movement of the first valve core 3.

[0030] Of course, the volume of the first valve core 3 is greater than that of the second valve core 4. The through hole 5 is provided in the first valve core 3, which is more conducive to increasing the diameter of the through hole 5 and balancing the pressure between the outlet cavity 12 and the balancing cavity 13. More specifically, the number of the through holes 5 is at least 2, and the through holes 5 are distributed around the circumference of the axis corresponding to the first valve core 3. The provision of at least 2 through holes 5 can increase the speed of pressure balancing between the outlet cavity 12 and the balancing cavity 13.

[0031] More specifically, the conducting hole 5 extends from the first port 51 to the second port 52 along a straight line, and the distance between the first port 51 and the corresponding axis of the first valve core 3 is smaller than the distance between the second port 52 and the corresponding axis of the first valve core 3. Figure 1 Compared with the extending path of the via hole 5 being a broken line, the via hole 5 in this embodiment extends from the first port 51 to the second port 52 along a straight line, which is more conducive to the processing of the via hole 5.

[0032] The first valve hole portion 32 includes a groove portion 6 , which is located at the valve hole wall portion 322 , and at least a portion of the projection of the groove portion 6 along the axial direction corresponding to the first valve core 3 overlaps with at least a portion of the corresponding wall portion of the first port 51 .

[0033] Such a control valve is located on the valve hole wall 322 through the groove 6, and at least part of the projection of the groove 6 along the first direction 001 overlaps with at least part of the wall corresponding to the first port 51. High-pressure fluid is sprayed into the first valve hole 321 from the inlet chamber 11, and the fluid splashed on the valve hole wall 322 is guided by the groove 6 to prevent the fluid splashed on the valve hole wall 322 from sliding along the valve hole wall 322 to the first port 51. The fluid generates backflow at the first port 51, affecting the pressure balance between the balance chamber 13 and the outlet chamber 12.

[0034] Specifically, at least a portion of the projection of the groove portion 6 along the first direction 001 coincides with the corresponding wall portion of the first port 51, the groove portion 6 includes a first groove 61 and a second groove 62, the groove portion 6 includes a third port 621, a fourth port 622 and a fifth port 623, the third port 621 connects the first groove 61 and the second groove 62, the first groove 61 extends from the third port 621 to the fourth port 622, the second groove 62 extends from the third port 621 to the fifth port 623, and the third port 621 is located on the side of the first port 51 close to the balancing cavity 13 along the first direction 001.

[0035] In such a control valve, the third port 621 connects the first groove 61 and the second groove 62, the first groove 61 extends from the third port 621 to the fourth port 622, the second groove 62 extends from the third port 621 to the fifth port 623, the third port 621 is located on the side of the first port 51 close to the balancing chamber 13 along the first direction 001, and in the process from the inlet chamber 11 and the outlet chamber 12 being blocked to being connected at the first valve hole portion 32, the high-pressure fluid is sprayed from the inlet chamber 11 into the first valve hole 321, and the fluid splashed on the side wall of the channel is guided by the first groove 61 and the second groove 62 to prevent the fluid splashed on the side wall of the channel from sliding along the valve hole wall portion 322 to the first port 51, and the fluid generates backflow at the first port 51, affecting the pressure balance between the balancing chamber 13 and the outlet chamber 12.

[0036] In one embodiment, reference Figure 1 , Figure 2 and Figure 4 The first valve core 3 includes a main body 33 and a protrusion 34. The main body 33 is closer to the balance chamber 13 than the protrusion 34. The protrusion 34 protrudes from the main body 33 in the opposite direction of the first direction. The protrusion 34 has a first portion 341 located in the outlet chamber 12. At least part of the first valve hole 321 and at least part of the valve hole wall portion 322 are located in the first portion 341.

[0037] Such a control valve has a first portion 341 located in the outlet chamber 12 through the protrusion 34, and at least a portion of the first valve hole 321 and at least a portion of the valve hole wall portion 322 are located in the first portion 341, so that the pressure in the first valve hole 321 is consistent with the pressure in the outlet chamber 12; in the process of the inlet chamber 11 and the outlet chamber 12 being blocked at the first valve hole portion 32 to being connected, the high-pressure fluid flows rapidly through the first valve hole 321, and the protrusion 34 has the first portion 341 located in the outlet chamber 12, and at least a portion of the first valve hole 321 and at least a portion of the valve hole wall portion 322 are located in the first portion 341, which increases the flow path of the fluid in the first valve hole 321 and reduces the pressure.

[0038] Specifically, the valve hole wall portion 322 has a first section 3211, and the cross-sectional area of ​​the hole corresponding to the first section 3211 gradually increases in the opposite direction of the first direction 001, and one end of the first section 3211 in the opposite direction of the first direction is located at the outlet chamber 12. In this way, in the process of the inlet chamber 11 and the outlet chamber 12 being blocked and connected at the first valve hole portion 32, the high-pressure fluid quickly flows through the first valve hole 321, and the cross-sectional area of ​​the hole corresponding to the first section 3211 gradually increases in the opposite direction of the first direction 001. The high-pressure fluid is sprayed from the inlet chamber 11 into the first valve hole 321, which is conducive to the fluid being sprayed out from the first valve hole 321, so that the pressure at the first port 51 is reduced, and the pressure at the second port 52 is higher than the pressure at the first port 51. The second port 52 is located on the side close to the balance chamber 13, which is conducive to the pressure reduction in the balance chamber 13.

[0039] More specifically, the valve hole wall portion 322 has a second section 3212, the second section 3212 is connected to the first section 3211, the second section 3212 is farther away from the outlet chamber 12 relative to the first section 3211, and the cross-sectional area of ​​the corresponding hole of the second section 3212 gradually decreases in the opposite direction of the first direction 001. That is, in the process of the inlet chamber 11 and the outlet chamber 12 changing from the blocked state to the conductive state at the first valve hole portion 32, the high-pressure fluid quickly passes through the first valve hole 321, and the cross-sectional area of ​​the corresponding hole of the second section 3212 gradually decreases in the opposite direction of the first direction, which is conducive to the fluid being sprayed from the second section 3212 into the first section 3211 at a high speed, and is conducive to reducing the pressure at the first port 51.

[0040] It should be noted that: although this specification has described the present invention in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that technicians in the relevant technical field can still modify, combine or replace the present invention with equivalents, and all technical solutions and improvements thereto that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A control valve, comprising a valve chamber (1), wherein the valve chamber (1) comprises an inlet chamber (11), an outlet chamber (12) and a balance chamber (13), It is characterized in that The control valve comprises a valve body (2), a first valve core (3) and a second valve core (4), wherein the first valve core (3) and the second valve core (4) are located in the valve cavity (1), the first valve core (3) comprises a first valve hole portion (32), the first valve hole portion (32) comprises a first valve hole (321), at least part of the second valve core (4) is located in the first valve hole (321), the control valve comprises a conducting hole (5), the conducting hole (5) conducts the balancing cavity (13) and the outlet cavity (12), the conducting hole (5) comprises a first port (51), the first port (51) is located in the valve hole wall portion (322) corresponding to the first valve hole (321); or when the second valve core (4) is located in the maximum valve opening position of the second valve core (4) relative to the first valve core (3), the first port (51) is located in the first valve hole (321).

2. The control valve according to claim 1, It is characterized in that Definition: the moving direction of the second valve core (4) toward the side of the balancing chamber (13) is the first direction (001); the guide hole (5) is located at the second valve core (4); the first port (51) is located at an end of the second valve core (4) away from the balancing chamber (13) in the opposite direction of the first direction; when the second valve core (4) is at the maximum valve opening position of the second valve core (4) relative to the first valve core (3), the first port (51) is located at the first valve hole (321) or the outlet chamber (12); the first valve core (3) includes a first side wall (37), the first side wall (37) is connected to the valve hole wall portion (322), the first side wall (37) is located on the side of the valve hole wall portion (322) close to the balance chamber (13) along the first direction (001), and when the second valve core (4) is located at the maximum valve opening position relative to the first valve core (3), along the first direction (001), the minimum distance between the wall portion corresponding to the first port (51) and the first side wall (37) is in the range of 1-12 mm.

3. The control valve according to claim 1, It is characterized in that Definition: the moving direction of the second valve core (4) toward the side of the balancing chamber (13) is the first direction (001); the conducting hole (5) is located on the first valve core (3), the conducting hole (5) has a second port (52), the first port (51) is located on the valve hole wall (322), the second port (52) and the balancing chamber (13) are in conduction, the first valve core (3) includes a first side wall (37), the first side wall (37) and the valve hole wall (322) are connected, the first side wall (37) is located on the side of the valve hole wall (322) close to the balancing chamber (13) along the first direction (001), and along the first direction (001), the minimum distance between the wall corresponding to the first port (51) and the first side wall (37) is in the range of 1-12 mm.

4. The control valve according to claim 3, It is characterized in that The conducting hole (5) extends in a straight line from the first port (51) to the second port (52), and the distance between the wall portion corresponding to the first port (51) and the axis corresponding to the first valve core (3) is smaller than the distance between the wall portion corresponding to the second port (52) and the axis corresponding to the first valve core (3).

5. The control valve according to claim 3 or 4, It is characterized in that The number of the conducting holes (5) is at least 2, and the conducting holes (5) are distributed circumferentially around an axis corresponding to the first valve core (3).

6. The control valve according to claim 3 or 4, It is characterized in that The first valve hole portion (32) comprises a groove portion (6), the groove portion (6) is located on the valve hole wall portion (322), and at least a portion of a projection of the groove portion (6) along the first direction (001) overlaps with at least a portion of a corresponding wall portion of the first port (51).

7. The control valve according to claim 6, It is characterized in that At least part of the projection of the groove portion (6) along the first direction (001) overlaps with the wall portion corresponding to the first port (51); the groove portion (6) comprises a first groove (61) and a second groove (62); the groove portion (6) comprises a third port (621), a fourth port (622) and a fifth port (623); the third port (621) conducts the first groove (61) and the second groove (62); the first groove (61) extends from the third port (621) to the fourth port (622); the second groove (62) extends from the third port (621) to the fifth port (623); the third port (621) is located on a side of the first port (51) close to the balancing cavity (13) along the first direction (001).

8. The control valve according to any one of claims 2 to 4, It is characterized in that The first valve core (3) includes a main body (33) and a protrusion (34), the main body (33) is close to the balance chamber (13) relative to the protrusion (34), the protrusion (34) protrudes from the main body (33) in the opposite direction of the first direction (001), and the protrusion (34) has a first portion (341) located in the outlet chamber (12), and at least a portion of the first valve hole (321) and at least a portion of the valve hole wall portion (322) are located in the first portion (341).

9. The control valve according to claim 8, It is characterized in that The valve hole wall portion (322) has a first section (3211), the cross-sectional area of ​​the hole corresponding to the first section (3211) gradually increases in the opposite direction of the first direction (001), and one end of the first section (3211) in the opposite direction of the first direction (001) is located in the outlet cavity (12).

10. The control valve according to claim 9, It is characterized in that The valve hole wall portion (322) has a second section (3212), and the second section (3212) is connected to the first section (3211). The second section (3212) is farther away from the outlet cavity (12) relative to the first section (3211), and the cross-sectional area of ​​the corresponding hole of the second section (3212) gradually decreases in the opposite direction of the first direction (001).

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