Compressed air aftertreatment unit

Abstract

The invention relates to the field of post-treatment devices for compressed air of railway vehicles, in particular to a compressed air post-treatment unit which comprises a double-tower dryer. The double-tower dryer comprises a first filtering unit, a second filtering unit, a first valve assembly, a second valve assembly and an electromagnetic valve; the first valve plate is used for cutting off or conducting the air inlet channel and the first filtering unit; the second valve plate is used for cutting off or conducting the second filter unit and the air inlet channel; the elastic force of the first spring and the elastic force of the third spring are matched with a preset elastic force threshold value. The first valve assembly is provided with the first valve plate and the first spring, the second valve assembly is provided with the second valve plate and the third spring, and when the pressure of compressed air in the air inlet channel cannot overcome the elastic force of the first spring or the elastic force of the third spring, the compressed air is prevented from entering the first filter unit or the second filter unit; the technical problem that in the prior art, a limiting structure is additionally arranged on low-pressure compressed air introduced into an air inlet is solved.

Description

Technical Field

[0001] The present invention relates to the field of compressed air post-processing devices for rail vehicles, in particular to a compressed air post-processing unit. Background Art

[0002] In the prior art, there is provided a patent document entitled "A Regenerative Double-Tower Dryer" with application number 202323402461.5.

[0003] In the above-mentioned prior art, before compressed air is introduced into a regenerative double-tower dryer, the two control valves are respectively in a first state; in the first state, the left seal of the left control valve cuts off the air inlet and the left drying tower, and the right seal of the right control valve connects the air inlet and the right drying tower; in the first state, if compressed air is introduced into the air inlet, the compressed air will pass through the right control valve to the right drying tower, and then after the compressed air is filtered by the right drying tower, the first part of the compressed air will be discharged from the air outlet, the second part of the compressed air will pass through a part of the regeneration channel to reach the control space, and the third part of the compressed air will pass through the regeneration channel to reach the left drying tower. In the first state, if the pressure of the compressed air introduced into the air inlet is low, the pressure of the compressed air flowing through the right drying tower will be low, and the filtering effect of the compressed air in the right drying tower will be weakened.

[0004] In the above-mentioned prior art, the two control valves in the first state are switched to a second state after their on-off states are changed. In the second state, the valve core of the left control valve connects the air inlet to the left drying tower, while the right control valve blocks the air inlet from the right drying tower. In the second state, if the compressed air entering the air inlet decreases, the compressed air will pass through the left control valve and reach the left drying tower. After being filtered by the left drying tower, a portion of the compressed air will be discharged from the air outlet. In the second state, if the pressure of the compressed air entering the air inlet decreases, the pressure of the compressed air flowing through the left drying tower will decrease, thereby reducing the filtering effect of the compressed air in the left drying tower.

[0005] In addition, if the pressure of the compressed air introduced into the air inlet is low, it may also cause the pressure of the compressed air in the control space to be low, thereby causing the two control valves of the prior art to fail to switch between the first state and the second state, wherein the low-pressure compressed air in the control space is not sufficient to overcome the elastic force of the left spring of the left control valve, or is not sufficient to overcome the elastic force of the right spring of the right control valve.

[0006] The negative phenomenon that the filtering effect of the left drying tower or the right drying tower is weakened or the switching of the two control valves fails occurs is essentially because the low-pressure compressed air entering the air inlet has no restriction structure.

[0007] Therefore, in the prior art, how to add a limiting structure to the low-pressure compressed air re-introduced into the air inlet has become a technical problem to be solved. Summary of the Invention

[0008] To solve the technical problem in the prior art of how to add a limiting structure to the low-pressure compressed air re-introduced into the air inlet, the present invention provides a compressed air post-treatment unit.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] According to one aspect of the present invention, there is provided a compressed air post-treatment unit, including a twin-tower dryer; the twin-tower dryer includes a first filtration unit, a second filtration unit, an air inlet passage, a regeneration passage, a control passage, a first valve assembly, a second valve assembly, a solenoid valve, a first working chamber, and a second working chamber; the solenoid valve is used to change the on-off state of the control passage, one end of the control passage communicates with the first filtration unit and the second filtration unit, and the other end of the control passage communicates with the first working chamber and the second working chamber; the regeneration passage is used to communicate the first filtration unit and the second filtration unit; the first valve assembly includes a first spring, a second spring, a first valve plate, and a first valve core, the first valve core includes a first piston protruding radially from the surface of the first valve core, and the first piston is located in the first working chamber; the first spring is located between the first valve plate and the first valve core, the first valve plate is located between the air inlet passage and the first valve core, and the direction from the first valve core to the first valve plate is defined as the first direction, along the first direction, the elastic force of the first spring forces the first valve plate to have a tendency to move, and the first valve plate is used to cut off or conduct the air inlet passage and the first filtration unit; the second spring is located in the first working chamber, along the reverse direction of the first direction, the elastic force of the second spring forces the first piston to have a tendency to move; the second valve assembly includes a third spring, a fourth spring, a second valve plate, and a second valve core, the second valve core includes a second piston protruding radially from the surface of the second valve core, and the second piston is located in the second working chamber; the third spring is located between the second valve plate and the second valve core, the second valve plate is located between the air inlet passage and the second valve core, and the direction from the second valve core to the second valve plate is defined as the second direction, along the second direction, the elastic force of the third spring forces the second valve plate to have a tendency to move, and the second valve plate is used to cut off or conduct the second filtration unit and the air inlet passage; the fourth spring is located in the second working chamber, along the second direction, the elastic force of the fourth spring forces the second piston to have a tendency to move; the elastic forces of the first spring and the third spring respectively match a preset elastic force threshold.

[0011] Further, the preset elastic force thresholds of the first spring and the third spring are both 300 - 600 kPa.

[0012] Further, the first valve core is provided with a first installation groove which is recessed from the surface of the first valve core towards the inside of the first valve core, and the axial center line direction of the first installation groove is parallel to the axial center line direction of the first valve core; one end of the first spring is arranged in the first installation groove, and the other end of the first spring is connected to the first valve plate; the second valve core is provided with a second installation groove which is recessed from the surface of the second valve core towards the inside of the second valve core, and the axial center line direction of the second installation groove is parallel to the axial center line direction of the second valve core; one end of the third spring is arranged in the second installation groove, and the other end of the third spring is connected to the second valve plate.

[0013] Further, define the chamber where the first valve plate is located as the first chamber, and the position where the first chamber communicates with the intake passage forms a first orifice; when the compressed air pressure at the position of the first orifice is less than the preset elastic force threshold, the first valve plate covers the first orifice, and the first valve plate cuts off the intake passage and the first filtering unit; when the compressed air pressure at the position of the first orifice is greater than the preset elastic force threshold and the compressed air pressure in the first working chamber is less than the elastic force of the second spring, the first valve plate separates from the first orifice, and the intake passage and the first filtering unit communicate with each other; when the compressed air pressure at the position of the first orifice is greater than the preset elastic force threshold and the compressed air pressure in the first working chamber is greater than the elastic force of the second spring, the first valve plate covers the first orifice, and the first valve plate cuts off the intake passage and the first filtering unit; define the chamber where the second valve plate is located as the second chamber, and the position where the second chamber communicates with the intake passage forms a second orifice; when the compressed air pressure at the position of the second orifice is less than the preset elastic force threshold, the second valve plate covers the second orifice, and the second valve plate cuts off the intake passage and the second filtering unit; when the compressed air pressure at the position of the second orifice is greater than the preset elastic force threshold and the compressed air pressure in the second working chamber is less than the elastic force of the fourth spring, the second valve plate covers the second orifice, and the second valve plate cuts off the intake passage and the second filtering unit; when the compressed air pressure at the position of the second orifice is greater than the preset elastic force threshold and the compressed air pressure in the second working chamber is greater than the elastic force of the fourth spring, the second valve plate separates from the second orifice, and the intake passage and the second filtering unit communicate with each other.

[0014] Further, the solenoid valve includes a moving iron core assembly; define the chamber where the moving iron core assembly is located as the third chamber, the third chamber divides the control passage into a first section of control passage and a second section of control passage, the third chamber communicates with the first section of control passage and the second section of control passage respectively, the other end of the first section of control passage communicates with the first filtering unit and the second filtering unit, the other end of the second section of control passage communicates with the first working chamber and the second working chamber, and the position where the third chamber communicates with the first section of control passage forms a third orifice; when the solenoid valve is de-energized, the moving iron core assembly covers the third orifice, and the first section of control passage and the second section of control passage are cut off; when the solenoid valve is energized, the moving iron core assembly separates from the third orifice, and the first section of control passage and the second section of control passage communicate with each other.

[0015] Further, the regeneration channel includes a first regeneration channel, a second regeneration channel, and a regeneration constriction hole. The two ends of the regeneration constriction hole communicate with the first regeneration channel and the second regeneration channel respectively. The other end of the first regeneration channel communicates with the first filtering unit, and the other end of the second regeneration channel communicates with the second filtering unit; the inner diameter of the regeneration constriction hole is smaller than the inner diameters of the first regeneration channel and the second regeneration channel.

[0016] Further, it further includes a water filter and a dust filter; the twin-tower dryer is provided with an air outlet channel, and the air outlet channel communicates with the dust filter, the first filtering unit, and the second filtering unit respectively; the air inlet channel communicates with the water filter, the first filtering unit, and the second filtering unit respectively; the air outlet channel and the air inlet channel are isolated by the first filtering unit and the second filtering unit.

[0017] Further, the water filter includes a first cylinder body. The top end of the first cylinder body is provided with a first air outlet, and a first one-way valve is arranged at the position of the first air outlet. Define the chamber where the first one-way valve is located as the fourth chamber. The fourth chamber communicates with the air inlet channel, and a fifth opening is formed at the position where the fourth chamber communicates with the inner cavity of the first cylinder body; when the first one-way valve is separated from the fifth opening, the fourth chamber communicates with the inner cavity; when the first one-way valve covers the fifth opening, the fourth chamber is truncated from the inner cavity; the bottom end of the first cylinder body is provided with a first air inlet, and the inner cavity is further provided with a first fan blade assembly and a water filter element. The first fan blade assembly is fixedly connected to the first cylinder body, and the first fan blade assembly is located between the first air inlet and the water filter element.

[0018] Further, the dust filter includes a second cylinder body. The second cylinder body is provided with a third air inlet. The inner cavity of the second cylinder body is provided with a dust filter element and a second fan blade assembly. The second fan blade assembly is fixedly connected to the second cylinder body, and the second fan blade assembly is located between the third air inlet and the dust filter element; an output port is further arranged on the second cylinder body.

[0019] Further, the solenoid valve further includes a static iron core and a valve sleeve. The valve sleeve is sleeved outside the static iron core and the moving iron core assembly. The gap between the valve sleeve and the moving iron core is the first exhaust channel. The first exhaust channel communicates with the second-stage control channel through the third chamber; an over-current chamber is arranged between the static iron core and the moving iron core assembly. The static iron core is provided with a second exhaust channel. The first exhaust channel and the second exhaust channel respectively extend to the over-current chamber, and the second exhaust channel intersects with the over-current chamber to form a fourth opening; when the solenoid valve is powered off, the fourth opening is separated from the moving iron core assembly, and the first exhaust channel communicates with the over-current chamber; when the solenoid valve is powered on, the moving iron core assembly covers the fourth opening, and the second exhaust channel is truncated from the over-current chamber.

[0020] The above technical solution has the following advantages or beneficial effects:

[0021] The compressed air post-treatment unit provided by the present invention is provided with a first valve plate and a first spring in the first valve assembly, and a second valve plate and a third spring in the second valve assembly. When the pressure of the compressed air in the intake passage cannot overcome the elastic force of the first spring or the elastic force of the third spring, it is avoided that the compressed air enters the first filtration unit or the second filtration unit, and the technical problem of how to add a limiting structure to the low-pressure compressed air introduced into the intake port in the prior art is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the compressed air post-treatment unit provided by an embodiment of the present invention;

[0023] Figure 2 is a schematic structural diagram of the compressed air post-treatment unit provided by an embodiment of the present invention;

[0024] Figure 3 is a schematic structural diagram of the compressed air post-treatment unit provided by an embodiment of the present invention;

[0025] Figure 4 is a schematic structural diagram of the first valve assembly provided by an embodiment of the present invention;

[0026] Figure 5 is a schematic structural diagram of the second valve assembly provided by an embodiment of the present invention;

[0027] Figure 6 is a schematic structural diagram of the solenoid valve provided by an embodiment of the present invention;

[0028] Figure 7 is a schematic structural diagram of the solenoid valve provided by an embodiment of the present invention;

[0029] Figure 8 is a schematic structural diagram of the regeneration channel provided by an embodiment of the present invention;

[0030] Figure 9 is a schematic structural diagram of the water filter provided by an embodiment of the present invention;

[0031] Figure 10 is a schematic structural diagram of the dust filter provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Embodiment 1: In this embodiment, a compressed air post-treatment unit is provided to solve the technical problem of how to add a limiting structure to the low-pressure compressed air introduced into the intake port again.

[0033] Specifically, refer to Figure 1 or Figure 2 or Figure 4 or Figure 5, the compressed air post-processing unit of this embodiment includes a double-tower dryer 1;

[0034] The double-tower dryer 1 includes a first filter unit 11, a second filter unit 12, an air inlet channel 13, a regeneration channel 14, a control channel 15, a first valve assembly 16, a second valve assembly 17, a solenoid valve 18, a first working chamber Q01 and a second working chamber Q02;

[0035] The solenoid valve 18 is used to change the on / off state of the control channel 15. One end of the control channel 15 is connected to the first filter unit 11 and the second filter unit 12, and the other end of the control channel 15 is connected to the first working chamber Q01 and the second working chamber Q02.

[0036] The regeneration channel 14 is used to connect the first filter unit 11 and the second filter unit 12;

[0037] The first valve assembly 16 includes a first spring 161, a second spring 162, a first valve plate 163 and a first valve core 164. The first valve core 164 includes a first piston 165 radially protruding from the surface of the first valve core 164. The first piston 165 is located in the first working chamber Q01.

[0038] The first spring 161 is located between the first valve disc 163 and the first valve core 164. The first valve disc 163 is located between the air intake passage 13 and the first valve core 164. The direction from the first valve core 164 to the first valve disc 163 is defined as a first direction. Along the first direction, the elastic force of the first spring 161 forces the first valve disc 163 to generate a movement trend. The first valve disc 163 is used to cut off or connect the air intake passage 13 and the first filter unit 11.

[0039] The second spring 162 is located in the first working chamber Q01. In the opposite direction of the first direction, the elastic force of the second spring 162 forces the first piston 165 to generate a movement trend.

[0040] The second valve assembly 17 includes a third spring 171, a fourth spring 172, a second valve plate 173 and a second valve core 174. The second valve core 174 includes a second piston 175 radially protruding from the surface of the second valve core 174. The second piston 175 is located in the second working chamber Q02.

[0041] The third spring 171 is located between the second valve disc 173 and the second valve core 174. The second valve disc 173 is located between the air intake passage 13 and the second valve core 174. The direction from the second valve core 174 to the second valve disc 173 is defined as the second direction. Along the second direction, the elastic force of the third spring 171 forces the second valve disc 173 to generate a movement trend. The second valve disc 173 is used to cut off or connect the second filter unit 12 and the air intake passage 13.

[0042] The fourth spring 172 is located within the second working chamber Q02. Along the second direction, the elastic force of the fourth spring 172 forces the second piston 175 to have a tendency to move;

[0043] The elastic forces of the first spring 161 and the third spring 171 respectively match a preset elastic force threshold.

[0044] See Figure 2 , in the compressed air post-treatment unit of this embodiment, an intake passage 13 is provided for receiving compressed air from an external air compressor and / or a gas storage device, and guiding the compressed air to the positions of the first valve assembly 16 and the second valve assembly 17; more specifically, the intake passage 13 guides the compressed air to the position of the first valve plate 163 of the first valve assembly 16 and to the position of the second valve plate 173 of the second valve assembly 17.

[0045] Initial state, before compressed air is introduced into the intake passage 13 and when the solenoid valve 18 is in a cut-off state, the first valve plate 163 of the first valve assembly 16 is subjected to the elastic force of the first spring 161, so that the first valve plate 163 is restricted at the top dead center, and the first valve plate 163 cuts off the intake passage 13 and the first filtering unit 11. The first valve core 164 of the first valve assembly 16 is subjected to the elastic force of the second spring 162, so that the first valve core 164 is restricted at the bottom dead center; the second valve plate 173 of the second valve assembly 17 is subjected to the combined elastic forces of the third spring 171 and the fourth spring 172, so that the second valve plate 173 is restricted at the top dead center, and the second valve plate 173 cuts off the intake passage 13 and the second filtering unit 12. The second valve core 174 is subjected to the acting force of the fourth spring 172, so that the second valve core 174 is restricted at the top dead center.

[0046] First intake state; after compressed air is introduced into the intake passage 13 and when the solenoid valve 18 remains in a cut-off state, if the pressure of the compressed air is less than the elastic force of the first spring 161, then, for the first valve assembly 16, the pressure of the compressed air cannot overcome the elastic force of the first spring 161, so that the first valve plate 163 is restricted at the top dead center, and the first valve plate 163 maintains the state of cutting off the intake passage 13 and the first filtering unit 11. Thus, the compressed air cannot enter the interior of the first filtering unit 11 from the intake passage 13, and the first valve core 164 is restricted at the bottom dead center; at the same time, for the second valve assembly 17, since the pressure of the compressed air is less than the combined elastic forces of the third spring 171 and the fourth spring 172, the second valve plate 173 is restricted at the top dead center, and the second valve plate 173 maintains the state of cutting off the intake passage 13 and the second filtering unit 12. Thus, the compressed air cannot enter the interior of the second filtering unit 12, and the second valve core 174 is restricted at the top dead center.

[0047] Second intake state: After compressed air is introduced into the intake passage 13 and the solenoid valve 18 remains in the cut-off state, if the pressure of the compressed air is greater than the elastic force of the first spring 161 and less than the sum of the elastic forces of the third spring 171 and the fourth spring 172, then, for the first valve assembly 16, the pressure of the compressed air overcomes the elastic force of the first spring 161, causing the first valve plate 163 pushed by the pressure of the compressed air to change from being restricted at the top dead center to being restricted at the bottom dead center. Thus, the intake passage 13 is communicated with the first filtration unit 11, and the compressed air enters the interior of the first filtration unit 11 from the intake passage 13; at this time, the first valve core 164 remains at the bottom dead center; correspondingly, for the second valve assembly 17, since the pressure of the compressed air is less than the sum of the elastic forces of the third spring 171 and the fourth spring 172, the second valve plate 173 is restricted at the top dead center, and the second valve plate 173 maintains the current state of blocking the intake passage 13 and the second filtration unit 12, so that the compressed air cannot enter the interior of the second filtration unit 12 from the intake passage 13. At this time, the second valve core 174 is restricted at the top dead center.

[0048] In the second intake state, since the compressed air enters the interior of the first filtration unit 11 from the intake passage 13, after the compressed air is filtered by the first filtration unit 11, the compressed air is divided into three portions of compressed air; among them,

[0049] The first portion of the compressed air is directly discharged to the outside of the compressed air post-treatment unit of this embodiment, and the discharged compressed air is used to supply the air-consuming devices of the rail vehicle (such as the braking system, the door control system, the air suspension system, etc.); the path of the first portion of the compressed air discharged to the compressed air post-treatment unit is described in detail later and will not be mentioned here for the time being;

[0050] The second portion of the compressed air flows through the control passage 15 to the position of the solenoid valve 18. Since the current solenoid valve 18 remains in the cut-off state, the second portion of the compressed air cannot continue to flow into the first working chamber Q01 and the second working chamber Q02, so that the second portion of the compressed air cannot act on the first piston 165 of the first valve core 164 located in the first working chamber Q01, and the second portion of the compressed air cannot act on the second piston 175 of the second valve core 174 located in the second working chamber Q02;

[0051] The third portion of the compressed air flows through the regeneration passage 14 to the second filtration unit 12. The third portion of the compressed air performs a regeneration operation on the second filtration unit 12, and after flowing out of the second filtration unit 12, it continues to flow in the direction of the second valve assembly 17; it should be understood that how the third portion of the compressed air is discharged to the outside of the compressed air post-treatment unit of this embodiment through the second valve assembly 17 or blocked at the position of the second valve assembly 17 is recorded in detail later and will not be mentioned here for the time being.

[0052] Third intake state: Compressed air is introduced into the intake passage 13, and the pressure of the compressed air is greater than the elastic force of the first spring 161 and less than the sum of the elastic forces of the third spring 171 and the fourth spring 172. Moreover, the solenoid valve 18 changes from the cut-off state to the conducting state. Then, the second portion of compressed air flowing to the position of the solenoid valve 18 enters the first working chamber Q01 and the second working chamber Q02 respectively. At this time, the pressure of the compressed air in the first working chamber Q01 acts on the first piston 165, and the first piston 165 overcomes the elastic force of the second spring 162, causing the first valve core 164 to change from being restricted at the lower dead center to being restricted at the upper dead center. In addition, the first valve core 164 pushes the first valve plate 163, causing the first valve plate 163 to change from being restricted at the lower dead center in the second intake state to being restricted at the upper dead center, and the first valve plate 163 cuts off the intake passage 13 and the first filtering unit 11. At the same time, the pressure of the compressed air in the second working chamber Q02 acts on the second piston 175, and the second piston 175 overcomes the elastic force of the fourth spring 172, causing the second valve core 174 to change from being restricted at the upper dead center to being restricted at the lower dead center. Since the pressure of the compressed air in the intake passage 13 at this time is greater than the elastic force of the third spring 171, the pressure of the compressed air in the intake passage 13 overcomes the elastic force of the third spring 171, causing the third valve plate driven by the pressure of the compressed air to change from being restricted at the upper dead center to being restricted at the lower dead center, and changing the intake passage 13 and the second filtering unit 12 from the cut-off state to the conducting state;

[0053] In the third intake state, since the compressed air enters the interior of the second filtering unit 12 from the intake passage 13, after the compressed air is filtered by the second filtering unit 12, the compressed air is divided into three portions of compressed air. Among them,

[0054] The fourth portion of compressed air is directly discharged to the outside of the compressed air post-treatment unit of this embodiment, and the discharged compressed air is used to supply air to the air-consuming devices of the rail vehicle (such as the braking system, the door control system, the air suspension system, etc.). The path of the fourth portion of compressed air discharged to the compressed air post-treatment unit is similar to the path of the first portion of compressed air discharged to the compressed air post-treatment unit, which will not be mentioned here for the time being;

[0055] The fifth portion of compressed air flows through the control passage 15 to the position of the solenoid valve 18. Since the current solenoid valve 18 remains in the conducting state, the fifth portion of compressed air flows into the first working chamber Q01 and the second working chamber Q02. The pressure of the compressed air in the first working chamber Q01 restricts the first valve core 164 at the upper dead center, and the pressure of the compressed air in the second working chamber Q02 restricts the second valve core 174 at the lower dead center;

[0056] The sixth portion of compressed air flows through the regeneration channel 14 towards the first filtration unit 11. Among them, the sixth portion of compressed air regenerates the first filtration unit 11, and after flowing out of the first filtration unit 11, it continues to flow towards the direction of the first valve assembly 16. It should be understood that how the sixth portion of compressed air is discharged to the outside of the compressed air post-treatment unit of this embodiment or blocked at the position of the first valve assembly 16 is detailed later, which will not be mentioned here for the time being.

[0057] In the compressed air post-treatment unit of this embodiment, when the pressure of the compressed air introduced into the intake channel 13 is less than the elastic force of the first spring 161 of the first valve assembly 16, the compressed air post-treatment unit is restricted to the first intake state; when the pressure of the compressed air introduced into the intake channel 13 is greater than the elastic force of the first spring 161 of the first valve assembly 16 and the pressure of the compressed air is less than the sum of the elastic forces of the third spring 171 and the fourth spring 172 of the second valve assembly 17, by the on-off state of the solenoid valve 18, the compressed air post-treatment unit switches between the second intake state and the third intake state, thereby forming the technical effect that one of the filtration units is used to filter the compressed air and the other filtration unit realizes the regeneration work.

[0058] In the prior art (the invention creation name is a regenerative twin-tower dryer, and the application number is 202323402461.5), when the regenerative twin-tower dryer is in the initial state, among its two control valves, the left seal of the left control valve (equivalent to the first valve plate 163 of this embodiment) is restricted at the upper dead center, and the left seal cuts off the intake port from the inside of the left drying tower. The right seal of the right control valve (equivalent to the second valve plate 173 of this application) is restricted at the lower dead center, so that the intake port is communicated with the inside of the right drying tower. When compressed air is introduced into the intake port of the prior art regenerative twin-tower dryer, if the pressure of the compressed air is low, this causes a relatively large amount of water vapor and / or impurities to still remain in the compressed air after it is discharged from the left drying tower and the right drying tower, which may cause malfunctions of the air-using device. In addition, if the pressure of the compressed air is low, it will cause the pressure of the compressed air in its control space to be low, and then the phenomenon of failure to change the positions of the left seal and the right seal will occur.

[0059] In the compressed air post-treatment unit of this embodiment, in the initial state, the first valve plate 163 of the first valve assembly 16 is restricted at the top dead center. The first valve plate 163 cuts off the intake passage 13 from the first filtration unit 11. The second valve plate 173 of the second valve assembly 17 is restricted at the top dead center. The second valve plate 173 cuts off the intake passage 13 from the second filtration unit 12. In the first intake state, the pressure of the compressed air cannot overcome the elastic force of the first spring 161, and even less can it overcome the sum of the elastic forces of the third spring 171 and the fourth spring 172, preventing the compressed air from entering the first filtration unit 11 and the second filtration unit 12. Thus, under the condition of insufficient pressure of the compressed air, it avoids problems such as "the filtration effect of the compressed air in the left drying tower and the right drying tower being weakened" in the above-mentioned prior art, and further avoids problems of "gas-using device" failures caused by the weakened filtration effect of the compressed air.

[0060] Therefore, in the compressed air post-treatment unit of this embodiment, by providing the first valve plate 163 and the first spring 161 in the first valve assembly 16, and the second valve plate 173 and the third spring 171 in the second valve assembly 17, when the pressure of the compressed air in the intake passage 13 cannot overcome the elastic force of the first spring 161 or cannot overcome the elastic force of the third spring 171, it prevents the compressed air from entering the first filtration unit 11 or the second filtration unit 12, solving the technical problem in the prior art of how to add a limiting structure to the low-pressure compressed air introduced into the intake port.

[0061] It should be understood that in the previous or subsequent text descriptions, the top dead center and the bottom dead center are descriptions of the positions of a certain movable component, rather than descriptions of the positions of all components. For example, the first valve plate 163 is a movable component. The elastic force of the first spring 161 causes the first valve plate 163 to have a tendency to move along the first direction. When the first valve plate 163 is blocked and in a static state, the position of the first valve plate 163 is the top dead center. When the pressure in the intake passage 13 overcomes the elastic force of the first spring 161, causing the first valve plate 163 to have a tendency to move in the opposite direction of the first direction, and when the first valve plate 163 is blocked and in a static state, the position of the first valve plate 163 is the bottom dead center.

[0062] It should be understood that the direction from the bottom dead center to the top dead center is the same as the first direction or the second direction proposed above.

[0063] It should be understood that the elastic forces of the first spring 161 and the third spring 171 respectively match a preset elastic force threshold value, which is a set of multiple elastic force values. When designing the compressed air post-treatment unit of this embodiment, designers can calculate and obtain multiple specific elastic force values of the preset elastic force threshold value, which is common general knowledge known to those skilled in the art and will not be elaborated here. Moreover, when manufacturing the first spring 161 and the third spring 171 of this embodiment, workers can select one of the elastic force values in the preset elastic force threshold value as a reference value to manufacture the first spring 161 and the third spring 171, which is common general knowledge known to those skilled in the art and will not be elaborated here.

[0064] It should be understood that in this embodiment, the first valve plate 163 and the second valve plate 173 are specifically rubber diaphragms.

[0065] Preferably, for the compressed air post-treatment unit of this embodiment, the preset elastic force threshold values of the first spring 161 and the third spring 171 are both 300 - 600 kPa.

[0066] More preferably, for the compressed air post-treatment unit of this embodiment, the elastic forces of the first spring 161 and the third spring 171 are limited to 400 kPa.

[0067] Furthermore, in the foregoing solution, the specific connection structures of the first valve core 164 and the first valve plate 163, and the specific connection structures of the second valve core 174 and the second valve plate 173 are preferably implemented by the following solutions.

[0068] See Figure 4 or Figure 5 , for the compressed air post-treatment unit of this embodiment, the first valve core 164 is provided with a first installation groove 166, the first installation groove 166 is recessed from the surface of the first valve core 164 towards the inside of the first valve core 164, and the axial center line direction of the first installation groove 166 is parallel to the axial center line direction of the first valve core 164;

[0069] One end of the first spring 161 is arranged in the first installation groove 166, and the other end of the first spring 161 is connected to the first valve plate 163;

[0070] The second valve core 174 is provided with a second installation groove 176, the second installation groove 176 is recessed from the surface of the second valve core 174 towards the inside of the second valve core 174, and the axial center line direction of the second installation groove 176 is parallel to the axial center line direction of the second valve core 174;

[0071] One end of the third spring 171 is arranged in the second installation groove 176, and the other end of the third spring 171 is connected to the second valve plate 173.

[0072] Among them, see Figure 4, a first mounting groove 166 is provided on the first valve core 164. When the first valve plate 163 is at the top dead center, one end of the first spring 161 is received in the first mounting groove 166, and the other end of the first spring 161 is located outside the first mounting groove 166. When the first valve plate 163 is at the bottom dead center, the first spring 161 is completely received in the first mounting groove 166; in other words, the function of the first mounting groove 166 is to receive the first spring 161 and to limit the telescopic direction of the first spring 161.

[0073] And, referring to Figure 5 , a second mounting groove 176 is provided on the second valve core 174. When the second valve plate 173 is at the top dead center, one end of the third spring 171 is received in the second mounting groove 176, and the other end of the third spring 171 is located outside the second mounting groove 176. When the second valve plate 173 is at the bottom dead center, the third spring 171 is completely received in the second mounting groove 176; in other words, the function of the second mounting groove 176 is to receive the third spring 171 and to limit the telescopic direction of the third spring 171.

[0074] Arranging the first spring 161 in the first mounting groove 166 and arranging the third spring 171 in the second mounting groove 176 can reduce the distance between the first valve plate 163 and the first valve core 164, and can reduce the distance between the second valve plate 173 and the second valve core 174, which is beneficial to reducing the overall volume of the compressed air post-treatment unit of this embodiment.

[0075] Further, referring to Figure 4 or Figure 5 , for the compressed air post-treatment unit of this embodiment, the chamber where the first valve plate 163 is located is defined as the first chamber, and a first orifice K1 is formed at the position where the first chamber communicates with the intake passage 13;

[0076] When the pressure of the compressed air at the position of the first orifice K1 is less than the preset elastic force threshold, the first valve plate 163 covers the first orifice K1, and the first valve plate 163 cuts off the intake passage 13 and the first filtering unit 11;

[0077] 1]When the pressure of the compressed air at the position of the first orifice K1 is greater than the preset elastic force threshold and the pressure of the compressed air in the first working chamber Q01 is less than the elastic force of the second spring 162, the first valve plate 163 is separated from the first orifice K1, and the intake passage 13 and the first filtering unit 11 communicate with each other; [[ID=]23]

[0078] When the pressure of the compressed air at the position of the first orifice K1 is greater than the preset elastic force threshold and the pressure of the compressed air in the first working chamber Q01 is greater than the elastic force of the second spring 162, the first valve plate 163 covers the first orifice K1, and the first valve plate 163 cuts off the intake passage 13 and the first filtering unit 11;

[0079] Define the chamber where the second valve plate 173 is located as the second chamber, and a second orifice K2 is formed at the position where the second chamber communicates with the intake passage 13;

[0080] When the compressed air pressure at the position of the second orifice K2 is less than the preset elastic force threshold, the second valve plate 173 covers the second orifice K2, and the second valve plate 173 cuts off the intake passage 13 and the second filtering unit 12;

[0081] When the compressed air pressure at the position of the second orifice K2 is greater than the preset elastic force threshold and the compressed air pressure in the second working chamber Q02 is less than the elastic force of the fourth spring 172, the second valve plate 173 covers the second orifice K2, and the second valve plate 173 cuts off the intake passage 13 and the second filtering unit 12;

[0082] When the compressed air pressure at the position of the second orifice K2 is greater than the preset elastic force threshold and the compressed air pressure in the second working chamber Q02 is greater than the elastic force of the fourth spring 172, the second valve plate 173 separates from the second orifice K2, and the intake passage 13 and the second filtering unit 12 communicate with each other.

[0083] It should be understood that an air compressor and an air storage tank are provided on the rail vehicle; under the condition that the air compressor fails, the compressed air in the air storage tank is used to supply the air-using device; however, the compressed air in the air storage tank is limited, so that when the compressed air in the air storage tank is supplied to the air-using device, the air pressure of the compressed air generally shows a gradually decreasing trend; this causes that when the compressed air from the air storage tank enters the compressed air post-treatment unit of this embodiment, the following two states may be formed:

[0084] The first state is that the pressure of the compressed air is greater than the elastic force of the first spring 161 and the elastic force of the second spring 162 respectively, and at the same time, the pressure of the compressed air is greater than the elastic force of the third spring 171 and the elastic force of the fourth spring 172 respectively; in the first state, the compressed air post-treatment unit of this embodiment can still realize the switching function of the filtration and regeneration work of the two filtering units, that is, the pressure of the compressed air overcomes the elastic force of the first spring 161, so that the first valve plate 163 moves in the direction from the upper dead center to the lower dead center, and the pressure of the compressed air overcomes the elastic force of the second spring 162, so that the first valve core 164 moves in the direction from the lower dead center to the upper dead center; correspondingly, the pressure of the compressed air overcomes the elastic force of the fourth spring 172, so that the second valve core 174 moves in the direction along the upper dead center to the lower dead center, and the pressure of the compressed air overcomes the elastic force of the third spring 171, so that the second valve core 174 moves in the direction from the upper dead center to the lower dead center.

[0085] In the second state, the pressure of the compressed air is greater than the elastic force of the first spring 161 and the elastic force of the third spring 171 respectively, but the pressure of the compressed air is less than the elastic force of the second spring 162 and the elastic force of the fourth spring 172 respectively; in the second state, considering the overall vehicle air consumption of the rail vehicle, the compressed air should be preferentially delivered to the air-using device instead of being used for switching the filtration and regeneration work of the two filtration units of the compressed air post-treatment unit of this embodiment.

[0086] Furthermore, how the solenoid valve 18 realizes changing the on-off state of the control channel 15 is preferably achieved by the following solution.

[0087] Refer to Figure 6 or Figure 7 For the compressed air post-treatment unit of this embodiment, the solenoid valve 18 includes a moving iron core assembly D00;

[0088] Define the chamber where the moving iron core assembly D00 is located as the third chamber Q03. The third chamber Q03 divides the control channel 15 into a first-stage control channel 151 and a second-stage control channel 152. The third chamber Q03 communicates with the first-stage control channel 151 and the second-stage control channel 152 respectively. The other end of the first-stage control channel 151 communicates with the first filtration unit 11 and the second filtration unit 12. The other end of the second-stage control channel 152 communicates with the first working chamber Q01 and the second working chamber Q02. The position where the third chamber Q03 communicates with the first-stage control channel 151 forms a third port K3;

[0089] When the solenoid valve 18 is de-energized, the moving iron core assembly D00 covers the third port K3, and the first-stage control channel 151 and the second-stage control channel 152 are truncated;

[0090] When the solenoid valve 18 is energized, the moving iron core assembly D00 separates from the third port K3, and the first-stage control channel 151 and the second-stage control channel 152 communicate with each other.

[0091] Among them, refer to Figure 6 or Figure 7, the solenoid valve 18 in this embodiment is a normally closed solenoid valve. When the coil of the solenoid valve 18 is not energized, the moving iron core assembly D00 of the solenoid valve 18 contacts and covers the third port K3. The third port K3 and the third chamber Q03 are cut off by the stationary iron core assembly D00, so that the first control channel 151 and the second control channel 152 of the control channel 15 are cut off by the stationary iron core assembly D00. At this time, the compressed air from the first filtration unit 11 or the second filtration unit 12 is restricted in the first control channel 151 and cannot enter the second control channel 152, so that the compressed air cannot reach the first working chamber Q01 and the second working chamber Q02. On the contrary, when the coil of the solenoid valve 18 is energized, the moving iron core assembly D00 of the solenoid valve 18 is attracted by the magnetic field of the coil, and the moving iron core assembly D00 moves away from the third port K3. At this time, the third port K3 communicates with the third chamber Q03, so that the first control channel 151 and the second control channel 152 communicate with each other. The compressed air from the first filtration unit 11 or the second filtration unit 12 reaches the first working chamber Q01 and the second working chamber Q02 through the second control channel 15.

[0092] Further, in the foregoing solution, for the compressed air located in the first working chamber Q01 and the compressed air located in the second working chamber Q02, how to discharge them from the compressed air post-treatment unit of this embodiment, preferably the following solution is adopted.

[0093] See Figure 6 or Figure 7 , for the compressed air post-treatment unit of this embodiment, the solenoid valve 18 further includes a stationary iron core D10 and a valve sleeve D20. The valve sleeve D20 is sleeved outside the stationary iron core D10 and the moving iron core assembly D00. The gap between the valve sleeve D20 and the moving iron core assembly D00 is the first exhaust channel D40. The first exhaust channel D40 communicates with the second control channel 152 through the third chamber Q03;

[0094] An overcurrent chamber D30 is provided between the stationary iron core D10 and the moving iron core assembly D00. The stationary iron core D10 is provided with a second exhaust channel D50. The first exhaust channel D40 and the second exhaust channel D50 respectively extend to the overcurrent chamber D30, wherein the second exhaust channel D50 intersects with the overcurrent chamber D30 to form a fourth port;

[0095] When the solenoid valve 18 is de-energized, the fourth port is separated from the moving iron core assembly D00, and the first exhaust channel D40 communicates with the overcurrent chamber D30;

[0096] When the solenoid valve 18 is energized, the moving iron core assembly D00 covers the fourth port, and the second exhaust channel D50 and the overcurrent chamber D30 are cut off.

[0097] Among them, see Figure 6 or Figure 7, the static iron core D10 is fixedly connected to the valve sleeve D20, and the ways of fixed connection include but are not limited to snap connection, threaded connection, etc. The moving iron core assembly D00 forms a clearance fit with the valve sleeve D20, so that the clearance formed between the moving iron core assembly D00 and the valve sleeve D20 serves as the first exhaust passage D40.

[0098] When the coil of the solenoid valve 18 is energized, the moving iron core assembly D00 moves away from the third port K3 and contacts and covers the fourth port. At this time, the fourth port and the flow-through cavity D30 are cut off by the moving iron core assembly D00, resulting in the first exhaust passage D40 and the second exhaust passage D50 being cut off. The compressed air from the first filtration unit 11 or the second filtration unit 12 can enter the first working chamber Q01 and the second working chamber Q02 through the aforementioned control passage 15. However, the compressed air in the first working chamber Q01 and the compressed air in the second working chamber Q02 cannot be discharged to the outside of the compressed air post-treatment unit of this embodiment through the second exhaust passage D50;

[0099] When the coil of the solenoid valve 18 is de-energized, the moving iron core assembly D00 moves away from the fourth port and contacts and covers the third port K3. At this time, the fourth port and the flow-through cavity D30 are conducted, so that the first exhaust passage D40 and the second exhaust passage D50 are conducted. Moreover, the third port K3 and the third chamber Q03 are cut off by the moving iron core assembly D00, resulting in the first-stage control passage 151 and the second-stage control passage 152 being cut off. The compressed air from the first filtration unit 11 or the second filtration unit 12 can only reach the first-stage control passage 151 and cannot enter the second-stage control passage 152, the first working chamber Q01 and the second working chamber Q02. However, the compressed air in the first working chamber Q01 and the compressed air in the second working chamber Q02 can be discharged to the outside of the compressed air post-treatment unit of this embodiment through the first exhaust passage D40, the flow-through cavity D30, the fourth port and the second exhaust passage D50.

[0100] Further, in the foregoing solution, in order to ensure the amount of compressed air of the air-using device of the rail vehicle and ensure the amount of air in the first working chamber Q01 and the second working chamber Q02, and reduce the gas volume loss during the regeneration work, the following solution is preferably adopted.

[0101] See Figure 8 , for the compressed air post-treatment unit of this embodiment, the regeneration passage 14 includes a first regeneration passage 141, a second regeneration passage 142 and a regeneration choke hole 143. The two ends of the regeneration choke hole 143 are respectively communicated with the first regeneration passage 141 and the second regeneration passage 142. The other end of the first regeneration passage 141 is communicated with the first filtration unit 11, and the other end of the second regeneration passage 142 is communicated with the second filtration unit 12;

[0102] The inner diameter of the regeneration choke hole 143 is smaller than the inner diameters of the first regeneration channel 141 and the second regeneration channel 142.

[0103] Among them, the diameter of the regeneration choke hole 143 is respectively smaller than the inner diameters of the first regeneration channel 141 and the second regeneration channel 142, which makes the air volume of the compressed air discharged from the first filtration unit 11 when flowing through the regeneration choke hole 143 smaller than the air volume of the compressed air discharged from the first filtration unit 11 to the compressed air post-treatment unit of this embodiment, and smaller than the air volume of the compressed air discharged from the first filtration unit 11 and transported to the control channel 15, so as to transport more compressed air to the air-using device of the rail vehicle, and transport more compressed air to the first working chamber Q01 and the second working chamber Q02;

[0104] Similarly, the air volume of the compressed air discharged from the second filtration unit 12 when flowing through the regeneration choke hole 143 is smaller than the air volume of the compressed air discharged from the second filtration unit 12 to the compressed air post-treatment unit of this embodiment, and smaller than the air volume of the compressed air discharged from the second filtration unit 12 and transported to the control channel 15, so as to transport more compressed air to the air-using device of the rail vehicle, and transport more compressed air to the first working chamber Q01 and the second working chamber Q02.

[0105] Furthermore, on the basis of the foregoing solution, in order to reduce the water content of the compressed air transported to the intake channel 13, and in order to reduce the dust particles in the compressed air transported from the compressed air post-treatment unit of this embodiment to the air-using device of the rail vehicle, the following technical solution is preferably adopted.

[0106] See Figures 1 to 3 , the compressed air post-treatment unit of this embodiment further includes a water filter 2 and a dust filter 3;

[0107] The twin-tower dryer 1 is provided with an air outlet channel 4, and the air outlet channel 4 is respectively communicated with the dust filter 3, the first filtration unit 11 and the second filtration unit 12;

[0108] The intake channel 13 is respectively communicated with the water filter 2, the first filtration unit 11 and the second filtration unit 12;

[0109] The air outlet channel 4 and the intake channel 13 are isolated by the first filtration unit 11 and the second filtration unit 12.

[0110] Among them, the compressed air transported from the air compressor or the air storage tank to the air post-treatment unit of this embodiment is first injected into the water filter 2;

[0111] The compressed air is filtered in the water filter 2 so that the water in the compressed air is filtered and retained inside the water filter 2; the compressed air filtered by the water filter 2 is conveyed to the first filtering unit 11 or the second filtering unit 12 through the air inlet passage 13.

[0112] The compressed air discharged from the first filtering unit 11 or the compressed air discharged from the second filtering unit 12 is injected into the dust filter 3 through the air outlet passage 4;

[0113] The compressed air is filtered in the dust filter 3 so that the dust particles in the compressed air are filtered by the dust filter 3 and retained inside the dust filter 3; the compressed air filtered by the dust filter 3 is discharged to the outside of the compressed air post-treatment unit of this embodiment and conveyed to the air-using device of the rail vehicle.

[0114] It should be understood that the function of the water filter 2 is to filter the liquid water in the compressed air; and the functions of the aforementioned first filtering unit 11 and second filtering unit 12 are to filter the water vapor in the compressed air.

[0115] Specifically, referring to Figure 9 , in the compressed air post-treatment unit of this embodiment, the water filter 2 includes a first cylinder body 201. A first air outlet 202 is provided at the top end of the first cylinder body 201. A first one-way valve 203 is provided at the position of the first air outlet 202. The chamber where the first one-way valve 203 is located is defined as the fourth chamber Q04. The fourth chamber Q04 communicates with the air inlet passage 13, and a fifth port K5 is formed at the position where the fourth chamber Q04 communicates with the inner cavity of the first cylinder body 201;

[0116] When the first one-way valve 203 is separated from the fifth port K5, the fourth chamber Q04 communicates with the inner cavity;

[0117] When the first one-way valve 203 covers the fifth port K5, the fourth chamber Q04 is truncated from the inner cavity;

[0118] A first air inlet 204 is provided at the bottom end of the first cylinder body 201. A first fan blade assembly 205 and a water filter element 206 are further provided in the inner cavity. The first fan blade assembly 205 is fixedly connected to the first cylinder body 201. The first fan blade assembly 205 is located between the first air inlet 204 and the water filter element 206.

[0119] Among them, the compressed air from the air compressor or the air storage tank first enters the first cylinder body 201 through the first air inlet 204;

[0120] Referring to Figure 9, within the first cylinder body 201, during the flow of compressed air from the first air inlet 204 to the first air outlet 202, the compressed air is filtered by the water filter element 206. The water filter element 206 causes the water in the compressed air to remain between the water filter element 206 and the first air inlet 204. The filtered compressed air reaches the first one-way valve 203 located in the fourth chamber Q04. The pressure of the compressed air overcomes the elastic force of the first one-way valve 203, so that the air inlet passage 13, the fourth chamber Q04 and the inner cavity of the first cylinder body 201 are communicated, enabling the compressed air to enter the air inlet passage 13.

[0121] See Figure 9 , within the first cylinder body 201, the filtered and retained water accumulates at the bottom of the first cylinder body 201; a drainage passage 207 and a drainage solenoid valve 21 are provided at the bottom of the first cylinder body 201. When the drainage solenoid valve 21 conducts the drainage passage 207 to the atmosphere, the water retained in the first cylinder body 201 flows out to the outside of the first cylinder body 201 through the drainage passage 207; conversely, when the drainage solenoid valve 21 cuts off the drainage passage 207 from the atmosphere, the water in the first cylinder body 201 cannot be discharged to the outside of the first cylinder body 201.

[0122] See Figure 9 , within the first cylinder body 201, the first fan blade assembly 205 located between the water filter element 206 and the first air inlet 204 actually serves to split the compressed air at the first air inlet 204. After the compressed air is split by the first fan blade assembly 205, it flows roughly evenly towards the circumferential surface of the water filter element 206, avoiding the accumulation of compressed air on one side in the radial direction within the first cylinder body 201.

[0123] Specifically, see Figure 10 , for the compressed air post-treatment unit of this embodiment, the dust filter 3 includes a second cylinder body 301. The second cylinder body 301 is provided with a third air inlet 302. The inner cavity of the second cylinder body 301 is provided with a dust filter element 303 and a second fan blade assembly 304. The second fan blade assembly 304 is fixedly connected to the second cylinder body 301. The second fan blade assembly 304 is located between the third air inlet 302 and the dust filter element 303;

[0124] An output port 305 is further provided on the second cylinder body 301.

[0125] Among them, see Figure 10 , the compressed air from the first filtration unit 11 or the second filtration unit 12 is injected into the second cylinder body 301 through the third air inlet 302;

[0126] See Figure 10, within the second cylinder 301, during the process of the compressed air flowing from the third air inlet 302 to the output port 305, the compressed air is filtered by the dust filter element 303, so that the dust particles in the compressed air are filtered by the dust filter element 303 and retained between the dust filter element 303 and the third air inlet 302;

[0127] The compressed air filtered by the dust filter element 303 is discharged through the output port 305 to the outside of the second cylinder 301 and is used to supply the air-using device of the rail vehicle.

[0128] See Figure 10 , the second fan assembly 304 at the third air inlet 302 functions to split the compressed air at the first air inlet 204. After the compressed air is split by the second fan assembly 304, it flows roughly evenly towards the circumferential surface of the dust filter element 303, avoiding the accumulation of compressed air on one side in the radial direction within the second cylinder 301.

[0129] See Figure 10 , a dust discharge valve 306 is further provided at the bottom of the second cylinder 301; the dust discharge valve 306 can be configured as a manual valve or an electric valve; when the dust discharge valve 306 conducts the inside of the second cylinder 301 to the atmosphere, under the pressure of the compressed air, the dust particles retained in the second cylinder 301 are driven by the pressure of the compressed air and discharged into the atmosphere; conversely, when the dust discharge valve 306 cuts off the inside of the second cylinder 301 from the atmosphere, the dust particles are retained in the second cylinder 301.

[0130] It has been proposed in the foregoing content that the paths for discharging the first portion of compressed air and the fourth portion of compressed air to the air post-treatment unit are specifically as follows. See Figure 3 , for the compressed air discharged from the first filtration unit 11, the first portion of compressed air and the second portion of compressed air are respectively injected into the second cylinder 301 through the air outlet channel 4. Among them, a first exhaust cavity 401 is formed at the intersection of the air outlet channel 4 and the first drying cylinder. A first air outlet check valve 402 is provided in the first exhaust cavity 401. The pressure of the compressed air discharged from the first filtration unit 11 overcomes the elastic force of the first air outlet check valve 402, enabling the compressed air to enter the air outlet channel 4; after the compressed air enters the air outlet channel 4, a part of the compressed air flows through the control channel 15 to the solenoid valve 18 and forms the aforementioned second portion of compressed air, and another part of the compressed air flows to the dust filter 3 and forms the aforementioned first portion of compressed air.

[0131] The discharge path of the compressed air of the second filtration unit 12 is roughly the same as the discharge path of the compressed air of the aforementioned first filtration unit 11, except that, see Figure 3, at the intersection of the air outlet channel 4 and the second drying cylinder, a second exhaust cavity 403 is formed. A second air outlet check valve 404 is arranged in the second exhaust cavity 403. The pressure of the compressed air discharged from the second filtering unit 12 overcomes the elastic force of the second air outlet check valve 404, enabling the compressed air to enter the air outlet channel 4. When flowing through the first exhaust cavity 401, the compressed air continues to flow towards the second cylinder 301 or the solenoid valve 18 through the gap between the first air outlet check valve 402 and the inner wall of the first exhaust cavity 401.

[0132] In addition to the foregoing, in the compressed air post-treatment unit of this embodiment, the first filtering unit 11 and the second filtering unit 12 are respectively provided with drying cylinders, a plurality of compression springs, molecular sieves, and flow-disturbing dust-filtering mechanisms;

[0133] In any one of the drying cylinders, a molecular sieve is respectively arranged; the upper end of the molecular sieve is connected to the drying cylinder through a plurality of compression springs, and a flow-disturbing dust-filtering mechanism is arranged at the lower end of the molecular sieve; wherein, the plurality of compression springs on the molecular sieve play a buffering role to avoid the molecular sieve hitting the drying cylinder, and the flow-disturbing dust-filtering mechanism at the lower end of the molecular sieve plays a role in diverting the compressed air, making the compressed air flow into the molecular sieve more evenly, and the flow-disturbing dust-filtering mechanism has a certain filtering function.

[0134] See Figure 1 or Figure 2 , at the upper part of the drying cylinder, an upper cover plate 5 is arranged, and outside the first filtering unit 11 and the second filtering unit 12, a main valve body 6 is further arranged; wherein, the main valve body 6 is manufactured as a shell structure for installing the first filtering unit 11 and the second filtering unit 12; a part of the regeneration channel 14, a part of the air outlet channel 4, and a part of the air inlet channel 13 are arranged between the upper cover plate 5 and the main valve body 6, and the main valve body 6 is detachably connected to the upper cover plate 5; the water filter 2 and the dust filter 3 are respectively connected to the upper cover plate 5;

[0135] See Figure 1 , a lifting bracket 7 is further arranged, and the main function of the lifting bracket 7 is to connect the compressed air post-treatment unit of this embodiment to the rail vehicle.

[0136] See Figure 2 , on the main valve body 6, an exhaust port 8 is arranged; the exhaust port 8 extends towards the inside of the main valve body 6 to form two channels, one of which is communicated with a third working cavity Q05 spaced from the first working cavity Q01 (see Figure 4 ), and the other of which is communicated with a fourth working cavity Q06 spaced from the second working cavity Q02 (see Figure 5) Among them, the first working chamber Q01 and the third working chamber Q05 are separated by the first piston 165. A first Y-shaped sealing ring is provided on the first piston 165 to seal the gap between the first piston 165 and the main valve body 6. Correspondingly, the second working chamber Q02 and the fourth working chamber Q06 are separated by the second piston 175. A second Y-shaped sealing ring is provided on the second piston 175 to seal the gap between the second piston 175 and the main valve body 6.

[0137] When the first filtration unit 11 is in the filtration state and the second filtration unit 12 is performing the regeneration operation, the third portion of compressed air discharged from the first filtration unit 11 enters the interior of the second filtration unit 12 through the regeneration channel 14 and blows the molecular sieve along the direction from the molecular sieve of the second filtration unit 12 to the turbulent flow dust filtering device. When the third portion of compressed air reaches the position of the second valve assembly 17, since the second valve plate 173 of the second valve assembly 17 is at the top dead center and the second valve core 174 is at the top dead center at this time, the second filtration unit 12 communicates with the fourth working chamber Q06. Since the fourth working chamber Q06 communicates with the aforementioned exhaust port 8, the third portion of compressed air is discharged to the outside of the compressed air post-treatment unit of this embodiment through the fourth working chamber Q06 and the exhaust port 8.

[0138] Similarly, when the first filtration unit 11 is performing the regeneration operation and the second filtration unit 12 is in the filtration state, the sixth portion of compressed air discharged from the second filtration unit 12 enters the interior of the first filtration unit 11 through the regeneration channel 14 and blows the molecular sieve along the direction from the molecular sieve of the first filtration unit 11 to the turbulent flow dust filtering device. When the sixth portion of compressed air reaches the position of the first valve assembly 16, since the first valve plate 163 of the first valve assembly 16 is at the top dead center and the first valve core 164 is at the top dead center at this time, the third working chamber Q05 communicates with the first filtration unit 11. Since the third working chamber Q05 communicates with the aforementioned exhaust port 8, the sixth portion of compressed air is discharged to the outside of the compressed air post-treatment unit of this embodiment through the third working chamber Q05 and the exhaust port 8.

[0139] It should be understood that when the third working chamber Q05 communicates with the first filtration unit 11, the fourth working chamber Q06 is cut off from the second filtration unit 12; conversely, when the third working chamber Q05 is cut off from the first filtration unit 11, the fourth working chamber Q06 communicates with the second filtration unit 12.

[0140] See Figure 4, what realizes the conduction and cutoff states between the third working chamber Q05 and the first filtering unit 11 is the first sealing plate 167 provided on the first valve core 164 and the first sealing ring 168 on the first sealing plate 167; at the position of the first sealing plate 167, the main valve body 6 is provided with a first fluid passage opening 169 for connecting the third working chamber Q05 and the first filtering unit 11, and the first sealing ring 168 is located between the first sealing plate 167 and the main valve body 6 at the first fluid passage opening 169. Thus, when the first sealing plate 167 approaches the first fluid passage opening 169, the first fluid passage opening 169 is blocked by squeezing the first sealing ring 168, realizing the cutoff between the third working chamber Q05 and the first filtering unit 11; conversely, when the first sealing plate 167 moves away from the first fluid passage opening 169, a gap is formed between the first sealing ring 168 and the main valve body 6 at the first fluid passage opening 169, realizing the conduction between the third working chamber Q05 and the first filtering unit 11.

[0141] Similarly, referring to Figure 5 , what realizes the conduction and cutoff states between the fourth working chamber Q06 and the second filtering unit 12 is the second sealing plate 177 provided on the second valve core 174 and the second sealing ring 178 on the second sealing plate 177; at the position of the second sealing plate 177, the main valve body 6 is provided with a second fluid passage opening 179 for connecting the fourth working chamber Q06 and the second filtering unit 12, and the second sealing ring 178 is located between the second sealing plate 177 and the main valve body 6 at the second fluid passage opening 179. Thus, when the second sealing plate 177 approaches the second fluid passage opening 179, the second fluid passage opening 179 is blocked by squeezing the second sealing ring 178, realizing the cutoff between the fourth working chamber Q06 and the second filtering unit 12; conversely, when the second sealing plate 177 moves away from the second fluid passage opening 179, a gap is formed between the second sealing ring 178 and the main valve body 6 at the second fluid passage opening 179, realizing the conduction between the fourth working chamber Q06 and the second filtering unit 12.

[0142] Referring to Figure 2 or Figure 3 , at the position of the exhaust port 8, a muffler 9 is provided, and the muffler 9 is used to reduce the noise of the compressed air discharged from the exhaust port 8; the muffler 9 can adopt the structure of the muffler in the prior art, which will not be elaborated here.

[0143] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. Compressed air post-treatment unit, characterized in that It includes a twin-tower dryer; The twin-tower dryer includes a first filtration unit, a second filtration unit, an air inlet channel, a regeneration channel, a control channel, a first valve assembly, a second valve assembly, a solenoid valve, a first working chamber, and a second working chamber; The solenoid valve is used to change the on-off state of the control channel. One end of the control channel communicates with the first filtration unit and the second filtration unit, and the other end of the control channel communicates with the first working chamber and the second working chamber; The regeneration channel is used to communicate the first filtration unit and the second filtration unit; The first valve assembly includes a first spring, a second spring, a first valve plate, and a first valve core. The first valve core includes a first piston protruding radially from the surface of the first valve core, and the first piston is located in the first working chamber; The first spring is located between the first valve plate and the first valve core. The first valve plate is located between the air inlet channel and the first valve core. The direction from the first valve core to the first valve plate is defined as the first direction. Along the first direction, the elastic force of the first spring forces the first valve plate to have a movement tendency. The first valve plate is used to cut off or conduct the air inlet channel and the first filtration unit; The second spring is located in the first working chamber. Along the reverse direction of the first direction, the elastic force of the second spring forces the first piston to have a movement tendency; The second valve assembly includes a third spring, a fourth spring, a second valve plate, and a second valve core. The second valve core includes a second piston protruding radially from the surface of the second valve core, and the second piston is located in the second working chamber; The third spring is located between the second valve plate and the second valve core. The second valve plate is located between the air inlet channel and the second valve core. The direction from the second valve core to the second valve plate is defined as the second direction. Along the second direction, the elastic force of the third spring forces the second valve plate to have a movement tendency. The second valve plate is used to cut off or conduct the second filtration unit and the air inlet channel; The fourth spring is located in the second working chamber. Along the second direction, the elastic force of the fourth spring forces the second piston to have a movement tendency; The elastic force of the first spring and the elastic force of the third spring respectively match a preset elastic force threshold value.

2. The compressed air post-treatment unit according to claim 1, wherein The preset elastic force threshold value of the first spring and the preset elastic force threshold value of the third spring are both 300 - 600 kPa.

3. The compressed air post-treatment unit according to claim 1, characterized in that, The first valve core is provided with a first installation groove, which is recessed from the surface of the first valve core towards the inside of the first valve core. The axial direction of the first installation groove is parallel to the axial direction of the first valve core; One end of the first spring is arranged in the first installation groove, and the other end of the first spring is connected to the first valve plate; The second valve core is provided with a second installation groove, which is recessed from the surface of the second valve core towards the inside of the second valve core. The axial direction of the second installation groove is parallel to the axial direction of the second valve core; One end of the third spring is arranged in the second installation groove, and the other end of the third spring is connected to the second valve plate.

4. The compressed air post-treatment unit according to claim 1, characterized in that, Define the chamber where the first valve plate is located as the first chamber, and a first orifice is formed at the position where the first chamber communicates with the intake passage; When the compressed air pressure at the position of the first orifice is less than the preset elastic force threshold, the first valve plate covers the first orifice, and the first valve plate cuts off the intake passage and the first filtering unit; When the compressed air pressure at the position of the first orifice is greater than the preset elastic force threshold and the compressed air pressure in the first working chamber is less than the elastic force of the second spring, the first valve plate separates from the first orifice, and the intake passage and the first filtering unit communicate with each other; When the compressed air pressure at the position of the first orifice is greater than the preset elastic force threshold and the compressed air pressure in the first working chamber is greater than the elastic force of the second spring, the first valve plate covers the first orifice, and the first valve plate cuts off the intake passage and the first filtering unit; Define the chamber where the second valve plate is located as the second chamber, and a second orifice is formed at the position where the second chamber communicates with the intake passage; When the compressed air pressure at the position of the second orifice is less than the preset elastic force threshold, the second valve plate covers the second orifice, and the second valve plate cuts off the intake passage and the second filtering unit; When the compressed air pressure at the position of the second orifice is greater than the preset elastic force threshold and the compressed air pressure in the second working chamber is less than the elastic force of the fourth spring, the second valve plate covers the second orifice, and the second valve plate cuts off the intake passage and the second filtering unit; When the compressed air pressure at the position of the second orifice is greater than the preset elastic force threshold and the compressed air pressure in the second working chamber is greater than the elastic force of the fourth spring, the second valve plate separates from the second orifice, and the intake passage and the second filtering unit communicate with each other.

5. The compressed air post-treatment unit according to claim 1, characterized in that, The solenoid valve includes a moving iron core assembly; Define the chamber where the moving iron core assembly is located as the third chamber. The third chamber divides the control passage into a first-stage control passage and a second-stage control passage. The third chamber communicates with the first-stage control passage and the second-stage control passage respectively. The other end of the first-stage control passage communicates with the first filtering unit and the second filtering unit, and the other end of the second-stage control passage communicates with the first working chamber and the second working chamber. A third orifice is formed at the position where the third chamber communicates with the first-stage control passage; When the solenoid valve is de-energized, the moving iron core assembly covers the third orifice, and the first-stage control passage and the second-stage control passage are cut off; When the solenoid valve is energized, the moving iron core assembly separates from the third orifice, and the first-stage control passage and the second-stage control passage communicate with each other.

6. The compressed air post-treatment unit according to claim 1, characterized in that, The regeneration channel includes a first regeneration channel, a second regeneration channel, and a regeneration constriction hole. The two ends of the regeneration constriction hole communicate with the first regeneration channel and the second regeneration channel respectively. The other end of the first regeneration channel communicates with the first filtration unit, and the other end of the second regeneration channel communicates with the second filtration unit; The inner diameter of the regeneration constriction hole is smaller than the inner diameters of the first regeneration channel and the second regeneration channel.

7. The compressed air post-treatment unit according to any one of claims 1-6, characterized in that, It further includes a water filter and a dust filter; The twin-tower dryer is provided with an air outlet channel, and the air outlet channel communicates with the dust filter, the first filtration unit, and the second filtration unit respectively; The air inlet channel communicates with the water filter, the first filtration unit, and the second filtration unit respectively; The air outlet channel and the air inlet channel are separated by the first filtration unit and the second filtration unit.

8. The compressed air post-treatment unit according to claim 7, characterized in that, The water filter includes a first cylinder body. The top end of the first cylinder body is provided with a first air outlet, and a first one-way valve is arranged at the position of the first air outlet. Define the chamber where the first one-way valve is located as the fourth chamber. The fourth chamber communicates with the air inlet channel, and a fifth opening is formed at the position where the fourth chamber communicates with the inner cavity of the first cylinder body; When the first one-way valve is separated from the fifth opening, the fourth chamber communicates with the inner cavity; When the first one-way valve covers the fifth opening, the fourth chamber is truncated from the inner cavity; The bottom end of the first cylinder body is provided with a first air inlet. The inner cavity is further provided with a first fan blade assembly and a water filter element. The first fan blade assembly is fixedly connected to the first cylinder body, and the first fan blade assembly is located between the first air inlet and the water filter element.

9. The compressed air post-treatment unit according to claim 7, characterized in that The dust filter includes a second cylinder body. The second cylinder body is provided with a third air inlet. The inner cavity of the second cylinder body is provided with a dust filter element and a second fan blade assembly. The second fan blade assembly is fixedly connected to the second cylinder body, and the second fan blade assembly is located between the third air inlet and the dust filter element; An output port is further arranged on the second cylinder body.

10. The compressed air post-treatment unit according to claim 5, characterized in that, The solenoid valve further includes a static iron core and a valve sleeve. The valve sleeve is sleeved outside the static iron core and the moving iron core assembly. The gap between the valve sleeve and the moving iron core is a first exhaust channel, and the first exhaust channel communicates with the second-stage control channel through the third chamber; An over-current chamber is arranged between the static iron core and the moving iron core assembly. The static iron core is provided with a second exhaust channel. The first exhaust channel and the second exhaust channel extend to the over-current chamber respectively, and the second exhaust channel intersects with the over-current chamber to form a fourth opening; When the solenoid valve is powered off, the fourth opening is separated from the moving iron core assembly, and the first exhaust channel communicates with the over-current chamber; When the solenoid valve is powered on, the moving iron core assembly covers the fourth opening, and the second exhaust channel is truncated from the over-current chamber.

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