Nine-circuit protection valve and air handling unit for commercial vehicles

Abstract

The present invention relates to the field of protection valves for commercial vehicles, specifically to a nine-circuit protection valve and an air handling unit for a commercial vehicle. The nine-circuit protection valve includes a valve body, first to third control valve assemblies; the valve body is processed with first to sixth chambers for circulating compressed air; the fourth chamber and the surface of the valve body form a P29 port; the fifth chamber and the surface of the valve body form a P21 port, and the sixth chamber and the surface of the valve body form a P22 port. The nine-circuit protection valve provided by the present invention is provided with a P29 port, through which compressed air can be delivered to the air-driven urea circuit of the commercial vehicle, so that the nine-circuit protection valve and the urea mechanism can form a pneumatic control system; because the nine-circuit protection valve is provided with a P29 port, the number of integrated output ports of the nine-circuit protection valve of this embodiment is greater than that of the four-circuit protection valve in the prior art, and the nine-circuit protection valve of the present invention has a higher degree of integration.

Description

Technical Field

[0001] The present invention relates to the field of protection valves for commercial vehicles, in particular to a nine-circuit protection valve and an air processing unit for a commercial vehicle. Background Art

[0002] In the prior art, a four-circuit protection valve with an integrated pressure-limiting valve is provided, with patent application number 202023332985.8. In this prior art, an input port and four output ports (P21, P22, P23, and P24) are provided on the body of the four-circuit protection valve. Compressed gas enters the four-circuit protection valve from the input port and first enters P21 and P22. A portion of the compressed gas flowing through P21 and P22 is used to deliver to an external device (service brake system). The remaining compressed air flowing through P21 and P22 enters the pressure-limiting valve and then enters P23 and P24. Due to the limiting effect of the pressure-limiting valve, the pressure of the compressed gas entering P23 and P24 is lower than the pressure of the compressed gas entering P21 and P22.

[0003] In addition, the above-mentioned prior art also has output ports P25 and P26. The pressure of the compressed gas flowing out of P23 overcomes the resistance of the one-way valve, allowing the compressed gas to enter P25. Correspondingly, the pressure of the compressed gas flowing out of P24 overcomes the resistance of the one-way valve, allowing the compressed gas to enter P26. Due to the restrictive effect of the one-way valve, the pressure of the compressed gas entering P25 and P26 is lower than the pressure of the compressed gas entering P23 and P24.

[0004] The four-circuit protection valve of the prior art has a small number of output ports, resulting in a low integration level of the four-circuit protection valve. Therefore, how to improve the integration level of the four-circuit protection valve becomes a technical problem to be solved. Summary of the Invention

[0005] In order to solve the technical problem of how to improve the integration of a four-circuit protection valve in the prior art, the present invention provides a nine-circuit protection valve and an air handling unit for a commercial vehicle.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] According to one aspect of the present invention, there is provided a nine-circuit protection valve, comprising a valve body, a first control valve assembly, a second control valve assembly and a third control valve assembly;

[0008] The valve body is processed with a first chamber, a second chamber, a third chamber, a fourth chamber, a fifth chamber and a sixth chamber for circulating compressed air, wherein the first chamber intersects with the second chamber and the fourth chamber respectively, the third chamber intersects with the second chamber respectively, the fifth chamber intersects with the first chamber and the second chamber respectively, and the sixth chamber intersects with the first chamber and the second chamber respectively;

[0009] The first control valve assembly is provided at the intersection of the first chamber and the fourth chamber, wherein the first chamber and the surface of the valve body form an air inlet, and the fourth chamber and the surface of the valve body form a P29 port for connecting to an air-driven urea circuit;

[0010] The second control valve assembly is provided at the intersection of the fifth chamber and the first chamber, the third control valve assembly is provided at the intersection of the sixth chamber and the first chamber, the fifth chamber and the surface of the valve body form a P21 port for connecting to the rear service brake circuit, and the sixth chamber and the surface of the valve body form a P22 port for connecting to the front service brake circuit.

[0011] Furthermore, the fourth chamber and the surface of the valve body also form a P29.1 port for connecting to an air suspension circuit, and the P29 port and the P29.1 port do not interfere with each other.

[0012] Furthermore, it also includes a first one-way valve and a second one-way valve;

[0013] One section of the fourth chamber located at the P29 port is configured as a first installation chamber, and another section of the fourth chamber located at the P29.1 port is configured as a second installation chamber. The first one-way valve is disposed in the first installation chamber through the P29 port, and the second one-way valve is disposed in the second installation chamber through the P29.1 port.

[0014] The one-way conduction direction of the first one-way valve is limited to the direction from the first chamber to the P29 port;

[0015] The one-way conduction direction of the second one-way valve is limited to the direction from the first chamber to the P29.1 port.

[0016] Furthermore, it also includes a third one-way valve and a fourth one-way valve;

[0017] The third one-way valve is provided at the intersection of the fifth chamber and the second chamber, and the fourth one-way valve is provided at the intersection of the sixth chamber and the second chamber;

[0018] The one-way conduction direction of the third one-way valve is limited to the direction from the fifth chamber to the second chamber;

[0019] The one-way conduction direction of the fourth one-way valve is limited to a direction from the sixth chamber to the second chamber.

[0020] Furthermore, the first control valve assembly includes a first valve and a first telescopic mechanism, wherein the first valve is located at the intersection of the fourth chamber and the first chamber, the first valve is provided with a first hollow channel, the first hollow channel is used to connect the first chamber and the fourth chamber, and the first telescopic mechanism covers the first hollow channel;

[0021] The second control valve assembly includes a second valve and a second telescopic mechanism, wherein the second valve is located at the intersection of the first chamber and the fifth chamber, the second valve is provided with a second hollow channel, the second hollow channel is used to communicate the first chamber and the fifth chamber, the second telescopic mechanism covers the second hollow channel, a first gap channel and a second gap channel are further provided between the second valve and the inner wall of the valve body, a third gap channel is provided on the side wall of the second valve, and the first gap channel, the second gap channel, the third gap channel and the first hollow channel intersect in sequence, and a second Y-shaped sealing ring is provided in the second gap channel, and the unidirectional conduction direction of the second Y-shaped sealing ring is limited to the direction from the first gap channel to the third gap channel;

[0022] The third control valve assembly includes a third valve and a third telescopic mechanism, wherein the third valve is located at the intersection of the first chamber and the sixth chamber, the third valve is provided with a third hollow channel, the third hollow channel is used to connect the first chamber and the fifth chamber, the third telescopic mechanism covers the third hollow channel, a fourth gap channel and a fifth gap channel are further provided between the third valve and the inner wall of the valve body, the side wall of the third valve is provided with a sixth gap channel passing through the side wall, the fourth gap channel, the fifth gap channel, the sixth gap channel and the second hollow channel intersect in sequence, a third Y-shaped sealing ring is provided in the fifth gap channel, and the unidirectional conduction direction of the third Y-shaped sealing ring is limited to the direction along the fourth gap channel to the sixth gap channel.

[0023] Furthermore, it also includes a pressure limiting valve;

[0024] The valve body is provided with a valve cavity for arranging the pressure-limiting valve, the second cavity and the inner surface of the valve cavity form an air inlet, and the third cavity and the inner surface of the valve cavity form an air outlet;

[0025] The pressure-limiting valve includes a pressure-limiting valve cover and a valve core assembly, wherein the pressure-limiting valve cover is detachably covered on the valve cavity, and the valve core assembly is confined within a space defined by the pressure-limiting valve cover and the valve cavity, wherein an air vent is provided on the pressure-limiting valve cover;

[0026] The valve core assembly has a first state in which the air inlet and the air outlet are connected, and a second state in which the air inlet and the air outlet are blocked, and the valve core assembly switches between the first state and the second state according to the pressure of the compressed air injected into the second chamber and the pressure of the compressed air injected into the third chamber;

[0027] The valve core assembly also has a third state in which the air outlet and the air leak are connected, and a fourth state in which the air outlet and the air leak are blocked. The valve core assembly switches between the third state and the fourth state by the pressure of the compressed air injected into the third chamber.

[0028] Furthermore, the valve core assembly includes a first pressure-limiting valve, a second pressure-limiting valve, a first spring, a second spring, a pressure-limiting valve seat and a pressure-limiting piston;

[0029] The pressure-limiting valve seat is sleeve-shaped, and an active cavity is provided inside the pressure-limiting valve seat. A first annular door portion is provided in the active cavity. Along the radial direction of the active cavity, the first door portion protrudes toward the center line of the pressure-limiting valve seat. Along the direction from the pressure-limiting valve cover to the valve cavity, the first door portion protrudes toward the air inlet.

[0030] The first pressure-limiting valve, the second pressure-limiting valve, and the first spring are respectively disposed in the movable chamber, wherein the first pressure-limiting valve is located between the first spring and the second pressure-limiting valve, the first pressure-limiting valve and the inner surface of the pressure-limiting valve seat form a first air gap, and the second pressure-limiting valve and the inner surface of the pressure-limiting valve seat form a second air gap;

[0031] The second pressure-limiting valve comprises a sleeve-shaped first section and a sleeve-shaped second section, the first section and the second section being coaxially integrally formed, the diameter of the first section being larger than the diameter of the second section, a sealing ring for covering the first door portion being provided on a surface of the first section facing the first door portion, and a second annular door portion being provided on a surface of the first section facing the pressure-limiting valve seat, forming a third air gap between the pressure-limiting valve seat and the second door portion;

[0032] The diameter of the first door portion is greater than the diameter of the second door portion;

[0033] The pressure-limiting piston includes an integrally formed head section, a middle section, and a tail section. A pressure relief channel is provided along the center line of the pressure-limiting piston. The pressure relief channel passes through the head section, the middle section, and the tail section respectively.

[0034] The tail section is inserted into the active cavity, the minimum diameter of the middle section is larger than the diameter of the tail section, a step portion is formed at the intersection of the head section and the middle section, the second pressure-limiting valve is sleeved on the tail section, and a fifth air gap is formed between the second pressure-limiting valve and the tail section, a sixth air gap is formed between the second pressure-limiting valve and the step portion, and a seventh air gap is formed between the middle section and the pressure-limiting valve seat;

[0035] The second spring is confined between the pressure-limiting piston and the pressure-limiting valve cover, one end of the second spring contacts the pressure-limiting valve cover, and the other end of the second spring contacts the head section.

[0036] Furthermore, it also includes a fourth control valve assembly and a fifth control valve assembly;

[0037] A seventh chamber and an eighth chamber are further processed in the valve body, and the seventh chamber and the eighth chamber intersect with the third chamber respectively, and the seventh chamber and the second chamber do not interfere with each other, wherein the fourth control valve assembly is provided at the intersection of the seventh chamber and the third chamber, and the fifth control valve assembly is provided at the intersection of the eighth chamber and the third chamber;

[0038] The seventh chamber and the surface of the valve body form a P23 port for connecting to the trailer valve and a P23.1 port for connecting to the parking mechanism, and the P23 port and the P23.1 port do not interfere with each other. The eighth chamber and the surface of the valve body form a P24 port and a P24.2 port for connecting to the auxiliary circuit, as well as a P24.1 port for connecting to the gearbox, and the P24 port, the P24.2 port and the P24.1 port do not interfere with each other.

[0039] Furthermore, it also includes a fifth one-way valve and a sixth one-way valve;

[0040] A section of the seventh chamber located at the P23.1 port is configured as a third installation chamber, and a section of the eighth chamber located at the P24.1 port is configured as a fourth installation chamber. The fifth one-way valve is disposed in the third installation chamber through the P23.1 port, and the sixth one-way valve is disposed in the fourth installation chamber through the P24.1 port.

[0041] The one-way conduction direction of the fifth one-way valve is limited to the direction from the third chamber to the P23.1 port;

[0042] The one-way conduction direction of the sixth one-way valve is limited to the direction from the third chamber to the P24.1 port.

[0043] According to one aspect of the present invention, there is provided an air handling unit for a commercial vehicle, comprising a dryer and the aforementioned nine-circuit protection valve;

[0044] The output port of the dryer is communicated with the air inlet of the nine-circuit protection valve.

[0045] The above technical solution has the following advantages or beneficial effects:

[0046] The nine-circuit protection valve provided by the present invention is provided with a P29 port, through which compressed air can be delivered to the air-driven urea circuit of a commercial vehicle, so that the nine-circuit protection valve and the urea mechanism can form a pneumatic control system; because the nine-circuit protection valve is provided with the P29 port, the number of integrated output ports of the nine-circuit protection valve of this embodiment is greater than that of the four-circuit protection valve in the prior art, and the nine-circuit protection valve of the present invention has a higher degree of integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic structural diagram of a nine-circuit protection valve provided in Example 1 of the present invention;

[0048] Figure 2 A schematic structural diagram of a portion of a nine-circuit protection valve provided in Example 1 of the present invention;

[0049] Figure 3 A schematic structural diagram of a portion of a nine-circuit protection valve provided in Example 1 of the present invention;

[0050] Figure 4 A schematic structural diagram of a portion of a nine-circuit protection valve provided in Example 1 of the present invention;

[0051] Figure 5 A schematic structural diagram of a portion of a nine-circuit protection valve provided in Example 1 of the present invention;

[0052] Figure 6 A schematic structural diagram of a portion of a nine-circuit protection valve provided in Example 1 of the present invention;

[0053] Figure 7 A schematic structural diagram of a portion of a nine-circuit protection valve provided in Example 1 of the present invention;

[0054] Figure 8 A schematic structural diagram of a portion of a nine-circuit protection valve provided in Example 1 of the present invention;

[0055] Figure 9A schematic structural diagram of a portion of a nine-circuit protection valve provided in Example 1 of the present invention;

[0056] Figure 10 A schematic structural diagram of a portion of a nine-circuit protection valve having a single-valve pressure-limiting valve provided as a comparative example of the present invention;

[0057] Reference numerals:

[0058] 1-valve body; 2-first control valve assembly; 3-second control valve assembly; 4-third control valve assembly; 5-first one-way valve; 6-second one-way valve; 7-third one-way valve; 8-fourth one-way valve; 9-pressure limiting valve; 10-fourth control valve assembly; 11-fifth control valve assembly; 12-fifth one-way valve; 13-sixth one-way valve;

[0059] 100 - air inlet; 101 - first chamber; 102 - second chamber; 103 - third chamber; 104 - fourth chamber; 105 - fifth chamber; 106 - sixth chamber; 107 - air inlet; 108 - air outlet; 109 - seventh chamber; 110 - eighth chamber; 111 - P29 port; 112 - P21 port; 113 - P22 port; 114 - P29.1 port; 115 - P23 port; 116 - P23.1 port; 117 - P24 port; 118 - P24.2 port; 119 - P24.1 port;

[0060] 200 - first telescopic mechanism; 201 - first valve; 202 - first hollow channel; 203 - diaphragm; 204 - spring seat; 205 - telescopic spring; 206 - spring pressure cap; 207 - adjusting screw; 208 - regulating valve cover;

[0061] 300 - second telescopic mechanism; 301 - second valve; 302 - second hollow channel; 331 - first gap channel; 332 - second gap channel; 333 - third gap channel; 334 - second Y-shaped sealing ring;

[0062] 900 - valve core assembly; 901 - pressure-limiting valve cover; 902 - first pressure-limiting valve; 903 - second pressure-limiting valve; 904 - first spring; 905 - second spring; 906 - pressure-limiting valve seat; 907 - pressure-limiting piston; 908 - first door; 909 - sealing ring; 910 - second door; 912 - pressure relief channel; 913 - step;

[0063] 921 - first air gap; 922 - second air gap; 923 - third air gap; 924 - fifth air gap; 925 - sixth air gap; 926 - seventh air gap; 931 - fourth air gap;

[0064] 951 - diameter of the first valve; 952 - diameter of the second door portion; 953 - diameter of the second valve; 954 - diameter of the first door portion;

[0065] 1000-Section A; 2000-Section B; 3000-Section C; 4000-Comparison valve; 4001-Comparison valve diameter. DETAILED DESCRIPTION

[0066] Example 1:

[0067] In this embodiment, a nine-circuit protection valve is provided to solve the problem of how to improve the integration of four-circuit protection valves.

[0068] For details, see Figure 1 The nine-circuit protection valve of this embodiment includes a valve body 1, a first control valve assembly 2, a second control valve assembly 3 and a third control valve assembly 4;

[0069] The valve body 1 is processed with a first chamber 101, a second chamber 102, a third chamber 103, a fourth chamber 104, a fifth chamber 105 and a sixth chamber 106 for circulating compressed air, wherein the first chamber 101 intersects with the second chamber 102 and the fourth chamber 104 respectively, the third chamber 103 intersects with the second chamber 102, the fifth chamber 105 intersects with the first chamber 101 and the second chamber 102 respectively, and the sixth chamber 106 intersects with the first chamber 101 and the second chamber 102 respectively;

[0070] A first control valve assembly 2 is provided at the intersection of the first chamber 101 and the fourth chamber 104, wherein the first chamber 101 and the surface of the valve body 1 form an air inlet 100, and the fourth chamber 104 and the surface of the valve body 1 form a P29 port 111 for connecting to the air-driven urea circuit;

[0071] A second control valve assembly 3 is provided at the intersection of the fifth chamber 105 and the first chamber 101, a third control valve assembly 4 is provided at the intersection of the sixth chamber 106 and the first chamber 101, the fifth chamber 105 and the surface of the valve body 1 form a P21 port 112 for connecting to the rear service brake circuit, and the sixth chamber 106 and the surface of the valve body 1 form a P22 port 113 for connecting to the front service brake circuit.

[0072] In this embodiment, see Figure 1A first chamber 101, a second chamber 102 and a third chamber 103 are provided in the valve body 1 of the nine-circuit protection valve; in terms of the position of the valve body 1, along the length direction of the valve body 1, the valve body 1 is roughly divided into three adjacent sections, namely section A 1000, section B 2000 and section C 3000, the outline of the first chamber 101 is roughly limited to the outline of section A 1000, the outline of the second chamber 102 is roughly limited to the outline of section B 2000, and the outline of the third chamber 103 is roughly limited to the outline of section C 3000; the arrangement of the first chamber 101 to the third chamber 103 enables the valve body 1 to have sufficient surface area, which is used to set multiple control valve assemblies, and the multiple control valve assemblies do not interfere with each other.

[0073] In this embodiment, the position of the air inlet 100 of the valve body 1 is located in section A 1000; the flow path of the compressed air in the valve body 1 is roughly injected from the outside (dryer) through the air inlet 100 into the first chamber 101, the compressed air in the first chamber 101 tends to flow into the second chamber 102, and the compressed air in the second chamber 102 tends to flow into the third chamber 103.

[0074] In this embodiment, see Figure 1 , the compressed air injected into the first chamber 101, after overcoming the resistance of the second control valve assembly 3, the compressed air in the first chamber 101 flows into the fifth chamber 105, and is transported to the rear service brake circuit from the P21 mouth 112; wherein, the second control valve assembly 3 has a first conducting state for connecting the first chamber 101 and the fifth chamber 105, and a first shut-off state for shutting off the first chamber 101 and the fifth chamber 105, and the second control valve assembly 3 is switched between the first conducting state and the first shut-off state by the pressure of the compressed air injected into the first chamber 101.

[0075] Correspondingly, in this embodiment, see Figure 1 , the compressed air injected into the first chamber 101, after overcoming the resistance of the third control valve assembly 4, the compressed air in the first chamber 101 flows into the sixth chamber 106, and is delivered to the front service brake circuit from the P22 mouth 113; wherein, the third control valve assembly 4 has a second conducting state for connecting the first chamber 101 and the sixth chamber 106, and a second shut-off state for shutting off the first chamber 101 and the sixth chamber 106, and the pressure of the compressed air injected into the first chamber 101 causes the third control valve assembly 4 to switch between the second conducting state and the second shut-off state.

[0076] And, in this embodiment, see Figure 1, the compressed air injected into the first chamber 101, after overcoming the resistance of the first control valve assembly 2, the compressed air in the first chamber 101 flows into the fourth chamber 104, and is transported to the gas-driven urea circuit from the P29 port 111; wherein, the first control valve assembly 2 has a third conducting state for connecting the first chamber 101 and the fourth chamber 104, and a third shutoff state for shutting off the first chamber 101 and the fourth chamber 104. The pressure of the compressed air injected into the first chamber 101 causes the first control valve assembly 2 to switch between the third conducting state and the third shutoff state.

[0077] From the above content, it can be seen that the compressed air output by P21 port 112, P22 port 113 and P29 port 111 to the external circuit is sourced from the first chamber 101; from another perspective, the priority of using compressed air by P21 port 112, P22 port 113 and P29 port 111 is respectively the first priority (which should be understood as the highest priority for using compressed air in the nine-circuit protection valve). This is because P21 port 112 and P22 port 113 are respectively used for the front and rear service brake circuits, which represent the braking safety of the commercial vehicle during the journey. Therefore, the priority of using compressed air by P21 port 112 and P22 port 113 must be the first priority; P29 port 111 is used to drive urea to neutralize the exhaust gas discharged from the engine, which represents that the commercial vehicle can meet environmental protection regulations during driving. Therefore, the priority of using compressed air by P29 port 111 must be the first priority.

[0078] In the prior art (a four-circuit protection valve with an integrated pressure-limiting valve, application number 202023332985.8), the four-circuit protection valve does not have the P29 port 111 of this embodiment, so compressed air cannot be delivered to the gas-driven urea circuit through the four-circuit protection valve.

[0079] The nine-circuit protection valve of this embodiment is provided with a P29 port 111, through which compressed air can be delivered to the air-driven urea circuit of the commercial vehicle, so that the nine-circuit protection valve and the urea mechanism can form a pneumatic control system; because the nine-circuit protection valve is provided with the P29 port 111, the number of integrated output ports of the nine-circuit protection valve of this embodiment is greater than the number of the four-circuit protection valve of the above-mentioned prior art. Therefore, the nine-circuit protection valve of this embodiment has a higher degree of integration, solving the problem of how to improve the integration degree of the four-circuit protection valve.

[0080] For further information, see Figure 1 In the nine-circuit protection valve of this embodiment, the fourth chamber 104 and the surface of the valve body 1 also form a P29.1 port 114 for connecting to the air suspension circuit, and the P29 port 111 and the P29.1 port 114 do not interfere with each other.

[0081] The compressed air output from P29 port 111 to the air-driven urea circuit and the compressed air output from P29.1 port 114 to the air suspension circuit each originate from fourth chamber 104. P29 port 111 and P29.1 port 114 are located adjacent to each other and communicate with fourth chamber 104 because the compressed air usage of the air-driven urea circuit and the compressed air usage of the air suspension circuit are relatively low. Furthermore, P29.1 port 114 is used to supply compressed air to the air suspension, which is crucial for the stability and safety of the commercial vehicle during driving. Therefore, the use of compressed air by P29.1 port 114 must be prioritized.

[0082] In addition, a distance is left between the P29 port 111 and the P29.1 port 114, so that the pipeline connected to the P29 port 111 and the pipeline connected to the P29.1 port 114 do not interfere with each other.

[0083] By providing the P29.1 port 114 and communicating the P29.1 port 114 with the fourth chamber 104, the integration of the nine-circuit protection valve of this embodiment is further improved.

[0084] For further information, see Figure 1 , the nine-circuit protection valve of this embodiment further includes a first one-way valve 5 and a second one-way valve 6;

[0085] One section of the fourth chamber 104 located at the P29 port 111 is configured as a first installation chamber, and another section of the fourth chamber 104 located at the P29.1 port 114 is configured as a second installation chamber. The first one-way valve 5 is disposed in the first installation chamber through the P29 port 111, and the second one-way valve 6 is disposed in the second installation chamber through the P29.1 port 114.

[0086] The one-way flow direction of the first one-way valve 5 is limited to the direction from the first chamber 101 to the P29 port 111;

[0087] The one-way flow direction of the second one-way valve 6 is limited to the direction from the first chamber 101 to the P29.1 port 114 .

[0088] During use of the nine-circuit protection valve of this embodiment, it is necessary to consider how to prevent a large amount of compressed air from being discharged from the output port corresponding to the faulty circuit when a certain circuit fails, thereby causing insufficient pressure or amount of compressed air in other circuits.

[0089] It should be understood that a failure in a certain circuit should be understood as a phenomenon in which the pipeline connected to a certain port of the nine-circuit protection valve bursts, or the pipeline is disconnected from the port, or other phenomena cause the compressed air to leak from the port to the atmosphere.

[0090] In the aforementioned solution, since the P29 port 111 and the P29.1 port 114 are located adjacent to each other and communicate with the fourth chamber 104 respectively, if at least one of the air-drive urea circuit and the air suspension circuit fails, the following three scenarios will occur:

[0091] In the first scenario, only the air drive urea circuit fails, while the air suspension circuit is intact.

[0092] In the first scenario, the problem is how to prevent the compressed air in the fourth chamber 104 from leaking into the atmosphere through the P29 port 111 in large quantities;

[0093] Since the first one-way valve 5 is provided at the position of the P29 port 111, under the condition of a fault or a normal fault of the gas-driven urea circuit, the resistance of the first one-way valve 5 encountered by the compressed air flowing from the fourth chamber 104 to the P29 port 111 remains unchanged, thereby avoiding the problem of a large amount of compressed air in the fourth chamber 104 leaking into the atmosphere through the P29 port 111.

[0094] In the second scenario, only the air suspension circuit fails, while the urea gas drive circuit remains intact.

[0095] The problem posed in the second scenario is how to prevent the compressed air in the fourth chamber 104 from leaking into the atmosphere in large quantities through the P29.1 port 114;

[0096] Since a second one-way valve 6 is provided at the position of the P29.1 port 114, the resistance of the second one-way valve 6 encountered by the compressed air flowing from the fourth chamber 104 to the P29.1 port 114 remains unchanged under conditions of failure or normal operation of the air suspension circuit, thereby avoiding the problem of a large amount of compressed air in the fourth chamber 104 leaking into the atmosphere through the P29.1 port 114.

[0097] In the third scenario, both the air-drive urea circuit and the air suspension circuit fail simultaneously.

[0098] The problem that arises in the third scenario is: how to prevent the compressed air in the first chamber 101 from leaking to the atmosphere through the P29 port 111 and the P29.1 port 114;

[0099] On the one hand, the P29 port 111 and the P29.1 port 114 are respectively provided with a one-way valve, so the resistance of the compressed air to be discharged from the P29 port 111 and the P29.1 port 114 remains unchanged;

[0100] On the other hand, since the first control valve assembly 2 is provided at the intersection of the first chamber 101 and the fourth chamber 104, regardless of whether the air-drive urea circuit and the air suspension circuit fail at the same time, the resistance of the first control valve assembly 2 encountered by the compressed air flowing from the first chamber 101 to the fourth chamber 104 remains unchanged, thereby avoiding the problem of the compressed air in the first chamber 101 leaking into the atmosphere through the P29 port 111 and the P29.1 port 114.

[0101] The specific structure of the first one-way valve 5 and the specific structure of the second one-way valve 6 can be configured as the same structure or different structures;

[0102] In this embodiment, the specific structure of the first one-way valve 5 and the specific structure of the second one-way valve 6 are configured to be the same structure, and the two respectively include a valve core, a spring, and a valve seat. In particular, along the direction from the first chamber 101 to the mouth of P29 111 or the mouth of P29.1 114, the first installation cavity and the second installation cavity are respectively provided with flared openings;

[0103] When the valve core covers the flared opening, so that the gap between the valve core and the inner wall of the first installation cavity or the inner wall of the second installation cavity is eliminated, the path for circulating compressed air between the first chamber 101 and the P29 port 111 is cut off by the valve core, or the path for circulating compressed air between the first chamber 101 and the P29.1 port 114 is cut off by the valve core; on the contrary, when the valve core does not cover the flared opening, so that a gap is generated between the valve core and the inner wall of the first installation cavity or the inner wall of the second installation cavity, the path for circulating compressed air between the first chamber 101 and the P29 port 111 is opened, or the path for circulating compressed air between the first chamber 101 and the P29.1 port 114 is opened;

[0104] The main function of the spring is to apply elastic force between the valve core and the valve seat, and the valve seat has two functions. The first function is that the valve seat is connected to the inner wall of the first installation cavity or the inner wall of the second installation cavity, so that the valve core and the spring are confined in the first installation cavity or the second installation cavity. The second function is that an opening for compressed air circulation is provided on the valve seat, which allows the fourth chamber 104 to communicate with the atmosphere.

[0105] It should be understood that the connection structure between the valve seat and the inner wall of the first installation cavity or the second installation cavity may first use a connection structure in the prior art, including but not limited to a threaded connection or a snap-fit ​​connection.

[0106] For further information, see Figure 1 The nine-circuit protection valve of this embodiment further includes a third one-way valve 7 and a fourth one-way valve 8;

[0107] A third one-way valve 7 is provided at the intersection of the fifth chamber 105 and the second chamber 102 , and a fourth one-way valve 8 is provided at the intersection of the sixth chamber 106 and the second chamber 102 ;

[0108] The one-way flow direction of the third one-way valve 7 is limited to the direction from the fifth chamber 105 to the second chamber 102;

[0109] The one-way flow direction of the fourth one-way valve 8 is limited to a direction from the sixth chamber 106 to the second chamber 102 .

[0110] In this embodiment, see Figure 1 There are two flow paths of compressed air from the first chamber 101 to the second chamber 102, namely:

[0111] The first path is configured as the first chamber 101, the second control valve assembly 3, the third one-way valve 7 and the second chamber 102;

[0112] The second path is configured as the first chamber 101 , the third control valve assembly 4 , the fourth check valve 8 and the second chamber 102 .

[0113] It can be obtained from the first and second paths mentioned above that the third one-way valve 7 and the fourth one-way valve 8 are in a parallel relationship, and the third one-way valve 7 and the fourth one-way valve 8 can respectively generate gaps with the valve body 1, which makes the sum of the areas of the gaps between the third and fourth one-way valves greater than the area of ​​the gap of a single third or fourth one-way valve 8, thereby improving the efficiency of injecting compressed air in the first chamber 101 into the second chamber 102.

[0114] The specific structure of the third one-way valve 7 and the fourth one-way valve 8 can adopt the structure of the one-way valve in the prior art. In this embodiment, a preferred one-way valve structure is provided, specifically: a second valve core made of rubber material, and a second valve seat made of metal or hard plastic;

[0115] In the preferred one-way valve structure described above, the second valve core has a block-shaped positioning portion located at the center and an umbrella-shaped deformation portion located in the circumferential direction of the positioning portion; the deformation portion is configured to have an inner conical surface and an outer conical surface, wherein, in the initial state (the state in which the deformation portion does not receive the pressure of the compressed air), the deformation portion forms a head end with a smaller diameter and a tail end with a larger diameter, the head end is connected to the positioning portion, and a gap is formed between the head end and the inner surface of the valve body 1 where the one-way valve is located, and a space for deformation is formed between the tail end and the positioning portion, and the tail end and the inner surface of the valve body 1 where the one-way valve is located are mutually closed. contact; from another perspective, the head end of the deformation portion faces the second control valve assembly 3, especially the positioning portion and the second control valve assembly 3 are in contact with each other, and the end of the positioning portion faces the second valve seat, and along the opposite direction of the contact direction between the second valve seat and the positioning portion, the second valve seat contacts the inner surface of the valve body 1, which makes the structure of the above-mentioned one-way valve, when it is used as the third one-way valve 7, be jointly restricted by the second control valve assembly 3 and the valve body 1 to form an assembly structure; similarly, when the structure of the above-mentioned one-way valve is used as the fourth one-way valve 8, it is jointly restricted with the third control valve assembly 4 and the valve body 1 to form an assembly structure.

[0116] See also Figure 1 When the pressure of the compressed air from the first chamber 101 is greater than the pressure of the compressed air in the second chamber 102, the pressure of the compressed air from the first chamber 101 causes the deformable portion to contract along the direction from its circumference to the center of the circle. When the deformable portion contracts, a gap is generated between the deformable portion and the valve body 1, allowing the compressed air to be injected into the second chamber 102 through the gap.

[0117] See also Figure 1 When the pressure of the compressed air in the second chamber 102 is greater than the pressure of the compressed air from the first chamber 101, the pressure of the compressed air from the first chamber 101 is not enough to cause the deformation part to contract. At this time, no gap can be generated between the deformation part and the valve body 1, so that the compressed air is blocked by the deformation part and cannot be injected into the second chamber 102.

[0118] The main function of the third one-way valve 7 and the fourth one-way valve 8 is to ensure the priority of using compressed air at the ports directly related to the first chamber 101; specifically, the P29 port 111, the P29.1 port 114, the P21 port 112 and the P22 port 113 are directly related to the first chamber 101 respectively, and these four ports are respectively set as the first priority for safety requirements and environmental protection requirements; if the above four ports use a relatively large amount of compressed air, which causes the pressure of the compressed air in the first chamber 101 to be reduced, the compressed air in the first chamber 101 will be reduced. If the pressure is less than the pressure of the compressed air in the second chamber 102, then, on the one hand, the first path and the second path between the first chamber 101 and the second chamber 102 are respectively cut off by the third one-way valve 7 and the fourth one-way valve 8, so that the compressed air in the first chamber 101 is limited to supply compressed air only to the above-mentioned four ports, and on the other hand, the compressed air in the second chamber 102 is prevented from being transported to the first chamber 101, so as to ensure the use requirements of compressed air at other ports (see the following content) except the above-mentioned four ports.

[0119] For further information, see Figure 1 or Figure 2 In the nine-circuit protection valve of this embodiment, the first control valve assembly 2 includes a first valve 201 and a first telescopic mechanism 200, wherein the first valve 201 is located at the intersection of the fourth chamber 104 and the first chamber 101, and the first valve 201 is provided with a first hollow channel 202, which is used to connect the first chamber 101 and the fourth chamber 104, and the first telescopic mechanism 200 covers the first hollow channel 202.

[0120] For the first control valve assembly 2 , whether the first telescopic mechanism 200 covers or is away from the first valve 201 is determined by the pressure of the compressed air in the first chamber 101 and the resistance of the first telescopic mechanism 200 ;

[0121] See also Figure 2 When the pressure of the compressed air in the first chamber 101 is greater than the resistance of the first telescopic mechanism 200, the pressure of the compressed air in the first chamber 101 forces the first telescopic mechanism 200 to separate from the first valve 201. At this time, a first temporary gap for the circulation of compressed air is generated between the first telescopic mechanism 200 and the first valve 201. The first temporary gap is now connected to the first chamber 101, the first hollow channel 202, and the fourth chamber 104, respectively, so that the compressed air in the first chamber 101 is injected into the fourth chamber 104 through the first temporary gap.

[0122] See also Figure 2When the pressure of the compressed air in the first chamber 101 is less than the resistance of the first telescopic mechanism 200, the pressure of the compressed air in the first chamber 101 cannot separate the first telescopic mechanism 200 from the first valve 201. At this time, the first temporary gap between the first telescopic mechanism 200 and the first valve 201 is eliminated, so that the compressed air in the first chamber 101 cannot be injected into the fourth chamber 104.

[0123] The first valve 201 is configured to have an annular structure and a cylindrical structure, wherein the annular structure is located outside the cylindrical structure and the two are integrally formed, wherein a majority of the cylindrical structure is inserted into the fourth chamber 104, while a small portion of the cylindrical structure and the annular structure are located outside the fourth chamber 104;

[0124] See also Figure 2 The first telescopic assembly includes a diaphragm 203, a spring seat 204, a telescopic spring 205, a spring pressure cap 206, an adjusting screw 207 and a regulating valve cover 208; the regulating valve cover 208 is detachably mounted on the valve body 1, and the regulating valve cover 208 covers the fourth chamber 104 for mounting the first valve 201; the diaphragm 203 covers the mounting valve cavity of the regulating valve cover 208, and the diaphragm 203 is located between the first valve 201 and the valve cover; along the direction from the first valve 201 to the valve cover, the spring seat 204, the telescopic spring 205 and the spring pressure cap 206 are respectively arranged in the mounting valve cavity, wherein the spring seat 204 is located between the diaphragm 203 and the telescopic spring 205, and the spring pressure cap 206 is located between the regulating valve cover 208 and the telescopic spring 205; the adjusting screw 207 is threadedly connected to the valve cover, and one end of the adjusting screw 207 is inserted into the mounting valve cavity and contacts the spring pressure cap 206.

[0125] For further information, see Figure 1 、 Figure 3 or Figure 4 In the nine-circuit protection valve of this embodiment, the second control valve assembly 3 includes a second valve 301 and a second telescopic mechanism 300, wherein the second valve 301 is located at the intersection of the first chamber 101 and the fifth chamber 105. The second valve 301 is provided with a second hollow channel 302, which is used to connect the first chamber 101 and the fifth chamber 105. The second telescopic mechanism 300 covers the second hollow channel 302. A first gap channel 331 and a second gap channel 332 are further provided between the second valve 301 and the inner wall of the valve body 1. A third gap channel 333 is provided on the side wall of the second valve 301, which passes through the side wall. The first gap channel 331, the second gap channel 332, the third gap channel 333, and the second hollow channel 302 intersect in sequence. A second Y-shaped sealing ring 334 is provided in the second gap channel 332. The unidirectional flow direction of the second Y-shaped sealing ring 334 is limited to the direction from the first gap channel 331 to the third gap channel 333.

[0126] See also Figure 3 or Figure 4 When the pressure of the compressed air in the first chamber 101 is greater than the resistance of the second telescopic mechanism 300, the pressure of the compressed air in the first chamber 101 forces the second telescopic mechanism 300 to separate from the second valve 301. At this time, a second temporary gap for the circulation of compressed air is generated between the second telescopic mechanism 300 and the second valve 301. The compressed air in the first chamber 101 flows into the fifth chamber 105 through two flow paths. The first flow path is through the second temporary gap and the second hollow channel 302, so that the compressed air in the first chamber 101 flows into the fifth chamber 105. The second flow path is through the first gap channel 331, the second gap channel 332, and the third hollow channel 303. The gap channel 333 and the second hollow channel 302 allow the compressed air in the first chamber 101 to flow into the fifth chamber 105, wherein the pressure of the compressed air from the first chamber 101 is required to overcome the elastic force of the second Y-shaped sealing ring 334, so that the second Y-shaped sealing ring 334 contracts, thereby making the first gap channel 331, the second gap channel 332, the third gap channel 333 and the second hollow channel 302 communicate with each other; conversely, if the pressure of the compressed air from the first chamber 101 is not sufficient to overcome the elastic force of the second Y-shaped sealing ring 334, then the second gap channel 332 is cut off, so that the first gap channel 331, the third gap channel 333 and the second hollow channel 302 are cut off.

[0127] When the pressure of the compressed air in the first chamber 101 is lower than the resistance of the second telescopic mechanism 300, the pressure of the compressed air in the first chamber 101 is unable to separate the second telescopic mechanism 300 from the second valve 301. At this time, the second temporary gap between the second telescopic mechanism 300 and the second valve 301 is eliminated. However, the compressed air in the first chamber 101 still flows into the fifth chamber 105 through the first gap channel 331, the second gap channel 332, the third gap channel 333, and the second hollow channel 302.

[0128] In the above solution, if the pressure of the compressed air in the first chamber 101 can overcome the resistance of the second telescopic mechanism 300, it means that the pressure of the compressed air in the first chamber 101 is sufficient, so that the pressure of the compressed air output from the P21 port 112 can maximize the pressure of the compressed air required by the rear service brake circuit.

[0129] In the above scheme, if the pressure of the compressed air in the first chamber 101 cannot overcome the resistance of the second telescopic mechanism 300, it means that the pressure of the compressed air in the first chamber 101 is low. However, the compressed air in the first chamber 101 still flows into the fifth chamber 105 through the aforementioned first gap channel 331, second gap channel 332, third gap channel 333 and second hollow channel 302, so that the pressure of the compressed air output from the P21 port 112 can minimize the pressure of the compressed air required by the rear service brake circuit.

[0130] Furthermore, in the nine-circuit protection valve of this embodiment, the third control valve assembly 4 includes a third valve and a third telescopic mechanism, wherein the third valve is located at the intersection of the first chamber 101 and the sixth chamber 106, and the third valve is provided with a third hollow channel, which is used to connect the first chamber 101 and the fifth chamber 105, and the third telescopic mechanism covers the third hollow channel. A fourth gap channel and a fifth gap channel are also provided between the third valve and the inner wall of the valve body 1, and the side wall of the third valve is provided with a sixth gap channel passing through the side wall, and the fourth gap channel, the fifth gap channel, the sixth gap channel and the third hollow channel intersect in sequence, and a third Y-type sealing ring is provided in the fifth gap channel, and the unidirectional conduction direction of the third Y-type sealing ring is limited to the direction along the fourth gap channel to the sixth gap channel.

[0131] It should be understood that the structure, principle and technical effects produced by the third control valve assembly 4 are respectively the same as those of the aforementioned second control valve assembly 3 , and will not be repeated here.

[0132] Similarly, if the air pressure of the compressed air in the first chamber 101 is sufficient, the pressure of the compressed air output from the P22 mouth 113 can ensure the pressure of the compressed air required by the front vehicle brake circuit at the highest loudness; and if the pressure of the compressed air in the first chamber 101 is low, the compressed air in the first chamber 101 still flows into the sixth chamber 106 through the fourth gap, the fifth gap, the sixth gap and the third hollow channel, so that the pressure of the compressed air output from the P22 mouth 113 can ensure the pressure of the compressed air required by the front vehicle brake circuit at the lowest loudness.

[0133] In this embodiment, the specific structures of the second telescopic mechanism 300 and the third telescopic mechanism are respectively the same as the specific structures of the aforementioned first telescopic mechanism 200 , and are not described again here.

[0134] In this embodiment, the structure of the second valve 301 is the same as that of the third valve. However, the structure of the second valve 301 and the structure of the third valve are different from the structure of the first valve 201 described above. Specifically, multiple gaps are formed between the second valve 301 and the third valve and the inner wall of the valve body 1, and a Y-shaped sealing ring (i.e., the second Y-shaped sealing ring 334 and the third Y-shaped sealing ring described above) is respectively provided in one of the gaps.

[0135] For further information, see Figure 1 or Figure 5 , the nine-circuit protection valve of this embodiment further includes a pressure limiting valve 9;

[0136] The valve body 1 is provided with a valve cavity for arranging the pressure limiting valve 9. The second chamber 102 and the inner surface of the valve cavity form an air inlet 107, and the third chamber 103 and the inner surface of the valve cavity form an air outlet 108.

[0137] The pressure-limiting valve 9 includes a pressure-limiting valve cover 901 and a valve core assembly 900. The pressure-limiting valve cover 901 detachably covers the valve cavity, and the valve core assembly 900 is confined within the space defined by the pressure-limiting valve cover 901 and the valve cavity. The pressure-limiting valve cover 901 is provided with an air vent (not shown).

[0138] The valve core assembly 900 has a first state in which the air inlet 107 and the air outlet 108 are connected, and a second state in which the air inlet 107 and the air outlet 108 are blocked. The valve core assembly 900 switches between the first state and the second state by the pressure of the compressed air injected into the second chamber 102 and the pressure of the compressed air injected into the third chamber 103.

[0139] The valve core assembly 900 also has a third state in which the air outlet 108 and the air leak port are connected, and a fourth state in which the air outlet 108 and the air leak port are cut off. The valve core assembly 900 switches between the third state and the fourth state by the pressure of the compressed air injected into the third chamber 103.

[0140] In this embodiment, the main function of the pressure-limiting valve 9 is to control the pressure of the compressed air in the third chamber 103;

[0141] Specifically, when the pressure of the compressed air in the third chamber 103 is lower than the pressure threshold of the compressed air in the third chamber 103 (hereinafter, the four words "pressure threshold" refer to the pressure threshold of the compressed air in the third chamber 103), the valve core assembly 900 of the pressure limiting valve 9 is used to connect the air inlet 107 and the air outlet 108 to form a first state, so that the compressed air in the second chamber 102 flows through the air inlet 107 and the air outlet 108 and is injected into the third chamber 103; at the same time, the air outlet 108 is in a fourth state relative to the air vent through the valve core assembly 900, thereby preventing the compressed air in the third chamber 103 from leaking into the atmosphere through the air vent.

[0142] When the pressure of the compressed air in the third chamber 103 meets the pressure threshold, the valve core assembly 900 of the pressure limiting valve 9 is used to cut off the air inlet 107 and the air outlet 108 to form the second state, thereby preventing the compressed air in the third chamber 103 from further increasing. At the same time, the air outlet 108 is in the fourth state relative to the air vent through the valve core assembly 900, thereby preventing the compressed air in the third chamber 103 from leaking into the atmosphere through the air vent.

[0143] When the pressure of the compressed air in the third chamber 103 is higher than the pressure threshold, the valve core assembly 900 of the pressure limiting valve 9 is used to cut off the air inlet 107 and the air outlet 108 to form the second state on the one hand, and on the other hand, the valve core assembly 900 is pushed by the pressure of the compressed air in the third chamber 103, so that the air outlet 108 and the air bleed port are changed from the fourth state to the third state, so that the compressed air in the third chamber 103 is discharged into the atmosphere through the air outlet 108, the valve core assembly 900 and the air bleed port.

[0144] When the pressure of the compressed air in the third chamber 103 changes from being higher than the pressure threshold to meeting the pressure threshold, the valve core assembly 900 is affected by the pressure reduction of the compressed air in the third chamber 103, causing the valve core assembly 900 to move in the reverse direction, and then the air outlet 108 and the air release port are cut off and the valve core assembly 900 changes from the third state to the fourth state.

[0145] It should be understood that, in the following content, it is proposed that the third chamber 103 delivers compressed air to the air cylinder through at least one mouth, and there is a high- and low-pressure combined air cylinder on the market, the interior of which is divided into a high-pressure chamber and a low-pressure chamber by a partition. When the air pressure in the high-pressure chamber is too high, the partition will be pushed toward the low-pressure chamber, which causes the compressed air in the low-pressure chamber to be squeezed out and injected back into the third chamber 103 in this embodiment, so that the air pressure in the third chamber 103 is higher than the pressure threshold; for this phenomenon, this embodiment sets an air vent and a pressure limiting valve 9 to cooperate with each other, so that the compressed air with excessive pressure is discharged from the air vent until the compressed air in the third chamber 103 recovers to meet the pressure threshold.

[0146] It should be understood that the pressure threshold is a collection of multiple pressure parameters, and the pressure threshold includes at least the lowest pressure parameter and the highest pressure parameter.

[0147] Preferably, participate Figure 5 or Figure 6 In this embodiment, the valve core assembly 900 includes a first pressure-limiting valve 902, a second pressure-limiting valve 903, a first spring 904, a second spring 905, a pressure-limiting valve seat 906 and a pressure-limiting piston 907;

[0148] The pressure-limiting valve seat 906 is sleeve-shaped and has an active cavity disposed therein. A first annular door portion 908 is disposed within the active cavity. Along the radial direction of the active cavity, the first door portion 908 protrudes toward the center line of the pressure-limiting valve seat 906 . Along the direction from the pressure-limiting valve cover 901 to the valve cavity, the first door portion 908 protrudes toward the air inlet 107 .

[0149] The first pressure-limiting valve 902, the second pressure-limiting valve 903, and the first spring 904 are respectively disposed in the movable chamber. The first pressure-limiting valve 902 is located between the first spring 904 and the second pressure-limiting valve 903. The first pressure-limiting valve 902 and the inner surface of the pressure-limiting valve seat 906 form a first air gap 921. The second pressure-limiting valve 903 and the inner surface of the pressure-limiting valve seat 906 form a second air gap 922.

[0150] The second pressure-limiting valve 903 includes a sleeve-shaped first section and a sleeve-shaped second section. The first section and the second section are coaxially integrally formed. The diameter of the first section is larger than that of the second section. A sealing ring 909 is provided on the surface of the first section facing the first gate portion 908 to cover the first gate portion 908. A circular second gate portion 910 is provided on the surface of the first section facing the pressure-limiting valve seat 906. A third air gap 923 is formed between the pressure-limiting valve seat 906 and the second gate portion 910.

[0151] The diameter of the first door portion 908 is greater than the diameter of the second door portion 910;

[0152] The pressure-limiting piston 907 includes an integrally formed head section, a middle section, and a tail section. A pressure relief passage 912 is provided along the center line of the pressure-limiting piston 907 . The pressure relief passage 912 passes through the head section, the middle section, and the tail section respectively.

[0153] The tail section is inserted into the active cavity. The minimum diameter of the middle section is larger than the diameter of the tail section. A step portion 913 is formed at the intersection of the head section and the middle section. The second pressure-limiting valve 903 is sleeved on the tail section. A fifth air gap 924 is formed between the second pressure-limiting valve 903 and the tail section. A sixth air gap 925 is formed between the second pressure-limiting valve 903 and the step portion 913. A seventh air gap 926 is formed between the middle section and the pressure-limiting valve seat 906.

[0154] The second spring 905 is confined between the pressure-limiting piston 907 and the pressure-limiting valve cover 901 , one end of the second spring 905 contacts the pressure-limiting valve cover 901 , and the other end of the second spring 905 contacts the head section.

[0155] For the convenience of description, the direction from the air inlet 107 to the air release port is defined as the first direction, and conversely, the direction from the air release port to the air inlet 107 is defined as the second direction; Figure 1 , Figure 1 The vertical downward direction is the first direction mentioned above. Conversely, Figure 1 The vertical upward direction is the aforementioned second direction.

[0156] From the perspective of the pressure-limiting piston 907, along the first direction, the pressure-limiting piston 907 is subjected to the elastic force of the second spring 905 (applied to the pressure-limiting piston 907 through the first pressure-limiting valve 902 and the second pressure-limiting valve 903), the pressure applied to the first pressure-limiting valve 902 by the compressed air in the second chamber 102 (applied to the pressure-limiting piston 907 through the first pressure-limiting valve 902 and the second pressure-limiting valve 903), and the pressure applied to the pressure-limiting piston 907 by the compressed air in the third chamber 103. Furthermore, along the second direction, the pressure-limiting piston 907 is subjected to the elastic force of the first spring 904.

[0157] See also Figure 5When the pressure of the compressed air in the third chamber 103 is less than the pressure threshold, the sum of the forces acting on the pressure-limiting piston 907 in the first direction and the elastic force of the first spring 904 in the second direction form a two-force balance phenomenon. At this time, the air inlet 107 and the air outlet 108 form the aforementioned first state; it should be noted that in the first state, due to the elastic force of the second spring 905 and the elastic force of the second spring 905, the first pressure-limiting valve 902, the second pressure-limiting valve 903 and the pressure-limiting piston 907 are adjacent to each other. The second pressure-limiting valve 903 and the first pressure-limiting valve 908 are in close contact with each other, and a distance is maintained between the sealing ring 909 on the second pressure-limiting valve 903 and the first port portion 908. The second port portion 910 of the second pressure-limiting valve 903 is covered by the first pressure-limiting valve 902, so that the compressed air can only be injected into the third gap but cannot flow from the third gap to the air passage; at this time, the compressed air flows from the air inlet 107, the active cavity, the first air gap 921 and the second air gap 922 to the air outlet 108, so that the compressed air is injected into the third chamber 103.

[0158] When the pressure of the compressed air in the third chamber 103 meets the pressure threshold, the pressure of the compressed air in the third chamber 103 at this time is greater than the pressure of the compressed air in the third chamber 103 "when the pressure of the compressed air in the third chamber 103 is less than the pressure threshold". As a result, the sum of the forces acting on the pressure-limiting piston 907 in the first direction is slightly greater than the elastic force of the first spring 904 in the second direction at this time, which makes the pressure-limiting piston 907 have a movement trend and move close to the air vent; after the pressure-limiting piston 907 moves, and the sum of the forces acting on the pressure-limiting piston 907 in the first direction and the elastic force of the first spring 904 restore to a two-force balance phenomenon, the pressure-limiting piston 907 loses its movement trend and stops moving; it should be noted that in the limit During the movement of the pressure piston 907, the first pressure limiting valve 902 and the second pressure limiting valve 903 are always synchronized with the pressure limiting piston 907 under the elastic force of the second spring 905. When the pressure limiting piston 907 returns to the parallel force phenomenon and stops moving, the first pressure limiting valve 902 and the second pressure limiting valve 903 also stop moving. In addition, the sealing ring 909 on the second pressure limiting valve 903 contacts and covers the first door portion 908 of the pressure limiting valve seat 906, so that the flow path between the second air gap 922 and the air outlet 108 is cut off. At the same time, the second door portion 910 of the second pressure limiting valve 903 is covered by the first pressure limiting valve 902, so that the compressed air can only be injected into the third gap, but cannot flow from the third gap to the air passage.

[0159] See also Figure 8, when the pressure of the compressed air in the third chamber 103 is greater than the pressure threshold, the pressure of the compressed air in the third chamber 103 at this time is greater than the pressure of the compressed air in the third chamber 103 "when the pressure of the compressed air in the third chamber 103 is less than the pressure threshold", and greater than the pressure of the compressed air in the third chamber 103 "when the pressure of the compressed air in the third chamber 103 meets the pressure threshold". As a result, the sum of the forces acting on the pressure-limiting piston 907 in the first direction is slightly greater than the elastic force of the first spring 904 in the second direction at this time, which makes the pressure-limiting piston 907 have a movement trend and move closer to the air vent again; after the pressure-limiting piston 907 moves, due to the second pressure-limiting The valve 903 is blocked by the first door portion 908, and its first pressure-limiting valve 902 is blocked by the second pressure-limiting valve 903, so that the first pressure-limiting valve 902 and the pressure-limiting piston 907 are separated from each other. At this time, since the first pressure-limiting valve 902 and the pressure-limiting piston 907 are separated from each other, a fourth air gap 931 is formed between the second pressure-limiting valve 903 and the tail end of the pressure-limiting piston 907; at this time, the air outlet 108, the seventh air gap 926, the sixth air gap 925, the fifth air gap 924, the fourth air gap 331931 and the pressure relief channel 912 are connected in sequence to form a pressure relief path, and the compressed air in the third chamber 103 reaches the air relief port from the pressure relief path and is finally discharged into the atmosphere.

[0160] When the pressure of the compressed air in the third chamber 103 changes from meeting the pressure threshold to being less than the pressure threshold, that is, when the air inlet 107 and the air outlet 108 change from the second state to the first state through the pressure limiting assembly, the pressure limiting piston 907 first drives the first pressure limiting valve 902 to move in the second direction under the elastic force of the second spring 905, and then drives the second pressure limiting valve 903 to move in the second direction. This is because there is a sixth air gap 925 between the second pressure limiting valve 903 and the step portion 913 of the pressure limiting piston 907, thereby forming a time difference between the pressure limiting piston 907 driving the first pressure limiting valve 902 and the second pressure limiting valve 903;

[0161] See also Figure 9 Under the condition that the first pressure-limiting valve 902 moves in the second direction while the second pressure-limiting valve 903 remains relatively stationary, the first pressure-limiting valve 902 and the second pressure-limiting valve 903 separate from each other, so that the third air gap 923 and the fifth air gap 924 are the same. This allows the compressed air from the second chamber 102 to pass through the first air gap 921, the third air gap 923, the fifth air gap 924, the sixth air gap 925, and the seventh air gap 926 to reach the position of the air outlet 108;

[0162] After the first pressure-limiting valve 902 and the second pressure-limiting valve 903 respectively move in the second direction, the sealing ring 909 on the second piston separates from the first door portion 908, which allows the compressed air from the second chamber 102 to pass through the first air gap 921, the second air gap 922, and the seventh air gap 926 to reach the position of the air outlet 108.

[0163] In this embodiment, the pressure limiting valve 9 is configured as a double-valve pressure limiting valve 9; in the process of replenishing compressed air to the third chamber 103, the response speed of the double-valve pressure limiting valve 9 is faster than the response speed of the single-valve pressure limiting valve 9.

[0164] For details, see Figure 7 In this embodiment, a third gap is defined between the first pressure-limiting valve 902 and the second pressure-limiting valve 903. The side of the first pressure-limiting valve 902 facing the air inlet 107 is defined as the front side, and the side of the first pressure-limiting valve 902 facing the second pressure-limiting valve 903 is defined as the back side. On the one hand, the pressure of the compressed air from the second chamber 102 is applied to the front side of the first pressure-limiting valve 902, and on the other hand, the pressure of the compressed air from the second chamber 102 is applied to the back side located at the third gap.

[0165] In this embodiment, see Figure 7 The diameter of the second gate portion 910 is smaller than the diameter of the first gate portion 908 , which makes the area of ​​the back surface of the first pressure-limiting valve 902 outside the outline of the second gate portion 910 (this area is defined as the first area) larger than the area of ​​the end surface of the second pressure-limiting valve 903 outside the outline of the first gate portion 908 (this area is defined as the second area);

[0166] Specifically, in this embodiment, see Figure 7 , Figure 7 The diameter 951 of the first valve 902, the diameter 952 of the second gate portion 910, the diameter 953 of the second valve 903, and the diameter 954 of the first gate portion 908 are shown in FIG. Therefore, the first area is actually , the second area is actually R1 is the radius of the second gate portion 910, R2 is the radius of the first valve 902, R3 is the radius of the first gate portion 908, and R4 is the radius of the second valve 903. Under the condition that the diameter 951 of the first valve 902 is equal to the diameter 953 of the second valve 903, since the diameter 952 of the second gate portion 910 is smaller than the diameter 954 of the first gate portion 908, the first area is greater than the second area.

[0167] Because the first area is larger than the second area, when the pressure of the compressed air from the second chamber is applied to the back surface of the first valve and the end surface of the second valve respectively, along the second direction, the force generated by the air pressure on the first area (defined as the first force) is greater than the force generated by the air pressure on the second area (defined as the second force).

[0168] When the second area of ​​this embodiment is the same as the third area in the comparative example described later, the aforementioned second force is the same as the force generated by "the pressure of the compressed air from the second chamber, which causes the comparative valve of the comparative example described later to move along the second direction" (this force is defined as the third force);

[0169] Specifically, in this embodiment, the second area is , and in the comparative example described later, the third area is (See Figure 10 and the comparative example described later), wherein the diameter 953 of the second valve 903 of this embodiment is the same as the diameter 4001 of the comparative valve 4000 in the comparative example described later, and the diameter 954 of the first door portion 908 of this embodiment is the same as the diameter 954 of the first door portion 908 in the comparative example described later. Therefore, the second area of ​​this embodiment is the same as the third area in the comparative example described later; when the pressure of the compressed air from the second chamber applied to the second area is the same as the pressure of the compressed air from the second chamber applied to the third area, the second force along the second direction in this embodiment is the same as the third force in the comparative example described later;

[0170] On the basis that the second force and the third force are the same, since the first force is greater than the second force, the first force is greater than the third force. This proves that the acceleration of the first pressure-limiting valve 902 in this embodiment along the second direction is greater than the acceleration of the comparative valve 4000 in the comparative example described later along the second direction.

[0171] Therefore, the response speed of the dual-valve pressure-limiting valve 9 is faster than the response speed of the single-valve pressure-limiting valve.

[0172] For further information, see Figure 1 The nine-circuit protection valve of this embodiment further includes a fourth control valve assembly 10 and a fifth control valve assembly 11;

[0173] A seventh chamber 109 and an eighth chamber 110 are further formed in the valve body 1. The seventh chamber 109 and the eighth chamber 110 intersect with the third chamber 103 respectively. The seventh chamber 109 and the second chamber 102 do not interfere with each other. The fourth control valve assembly 10 is provided at the intersection of the seventh chamber 109 and the third chamber 103, and the fifth control valve assembly 11 is provided at the intersection of the eighth chamber 110 and the third chamber 103.

[0174] The seventh chamber 109 and the surface of the valve body 1 form a P23 port 115 for connecting to the trailer valve and a P23.1 port 116 for connecting to the parking mechanism. The P23 port 115 and the P23.1 port 116 do not interfere with each other. The eighth chamber 110 and the surface of the valve body 1 form a P24 port 117 and a P24.2 port 118 for connecting to the auxiliary circuit, as well as a P24.1 port 119 for connecting to the gearbox. The P24 port 117, the P24.2 port 118 and the P24.1 port 119 do not interfere with each other.

[0175] In this embodiment, the specific structure of the fourth control valve assembly 10 and the specific structure of the fifth control valve assembly 11 are respectively the same as the specific structure of the aforementioned first control valve assembly 2, and play similar roles; the only difference is that the control object of the fourth control valve assembly 10 is the third chamber 103 and the seventh chamber 109, and the control object of the fifth control valve assembly 11 is the third chamber 103 and the eighth chamber 110, and the rest will not be repeated.

[0176] As mentioned above, the priority of using compressed air at the P21 port 112, the P22 port 113, and the P29 port 111 is respectively the first priority, and the source of the compressed air is the first chamber 101. From the perspective of priority, the priority of using compressed air at the first chamber 101 is higher than the priority of using compressed air at the third chamber 103. Therefore, in this embodiment, the priority of using compressed air at the P23 port 115, the P23.1 port 116, the P24 port 117, the P24.1 port 119, and the P24.2 port 118 is respectively low priority.

[0177] Among them, the P23 port 115 is used to connect the trailer valve (specifically, the air tank of the trailer valve), and the P23.1 port 116 is used to connect the parking mechanism (specifically, the air tank of the parking mechanism). Both of them need to use compressed air when the commercial vehicle is not in driving state; and, the P24 port 117 and the P24.2 port 118 are used to connect the auxiliary circuit (specifically, the air tank of the auxiliary circuit, which is used to supply compressed air to the air horn or other air-consuming mechanisms), and the P24.1 port 119 is used to connect the gearbox (specifically, the air tank of the gearbox). The air consumption of these ports is relatively small, and the time of using compressed air is relatively short; therefore, the use of compressed air by the above-mentioned P23 port 115, P23.1 port 116, P24 port 117, P24.1 port 119 and P24.2 port 118 does not involve safety requirements and environmental protection requirements, and can therefore be set to low priority.

[0178] By providing the P23 port 115 , the P23.1 port 116 , the P24 port 117 , the P24.1 port 119 and the P24.2 port 118 , the integration level of the nine-circuit protection valve of this embodiment is further improved.

[0179] For further information, see Figure 1 , the nine-circuit protection valve of this embodiment, the fifth one-way valve 12 and the sixth one-way valve 13;

[0180] A section of the seventh chamber 109 at the P23.1 port 116 is configured as a third installation chamber, and a section of the eighth chamber 110 at the P24.1 port 119 is configured as a fourth installation chamber. The fifth one-way valve 12 is disposed in the third installation chamber through the P23.1 port 116, and the sixth one-way valve 13 is disposed in the fourth installation chamber through the P24.1 port 119.

[0181] The one-way flow direction of the fifth one-way valve 12 is limited to the direction from the third chamber 103 to the P23.1 port 116;

[0182] The one-way flow direction of the sixth one-way valve 13 is limited to the direction from the third chamber 103 to the P24.1 port 119 .

[0183] The specific structures of the fifth one-way valve 12 and the sixth one-way valve 13 are respectively the same as the specific structures of the aforementioned first one-way valve 5 and the second one-way valve 6, and are not repeated here.

[0184] The P23 port 115 is used to connect the trailer valve, and the P23.1 port 116 is used to connect the parking mechanism. The compressed air output to the outside by these two ports comes from the seventh chamber 109; from another perspective, since the fifth one-way valve 12 is provided in the third installation cavity of the P23.1 port 116, and the P23 port 115 is not provided with a one-way valve, two priorities for using compressed air are formed in the air usage area of ​​the seventh chamber 109, that is, the priority of the P23 port 115 is higher than the priority of the P23.1 port 116.

[0185] Similarly, the compressed air output to the outside by the P24 port 117, the P24.1 port 119 and the P24.2 port 118 all comes from the eighth chamber 110. From another perspective, since the fourth installation cavity of the P24.1 port 119 is provided with the sixth one-way valve 13, while the P24 and P24.2 ports 118 are not provided with a one-way valve, the P24 port 117, the P24.1 port 119 and the P24.2 port 118 also form two priorities for using compressed air, that is, the priority of the P24 and P24.2 ports 118 is higher than the priority of the P24.1 port 119.

[0186] Comparative Example;

[0187] This comparative example adopts a single-valve pressure-limiting valve to replace the double-valve pressure-limiting valve 9 in the aforementioned embodiment 1. The rest of the structure is the same as that in the aforementioned embodiment 1.

[0188] See also Figure 10 The valve of the single-valve pressure limiting valve is defined as a comparison valve 4000, the side of the comparison valve 4000 facing the air inlet 107 is defined as the front side, and the side of the comparison valve 4000 facing the first door portion 908 is defined as the back side. On the one hand, the pressure of the compressed air from the second chamber 102 is applied to the front side of the comparison valve 4000, and on the other hand, the pressure of the compressed air from the second chamber 102 is applied to the back side outside the outline of the first door portion 908.

[0189] In this comparative example, the air inlet 107 and the air outlet 108 pass through the single-valve pressure-limiting valve 9, and have the same first state and second state as those in the aforementioned embodiment 1. Similarly, the air outlet 108 and the air relief port pass through the single-valve pressure-limiting valve 9, and have the same third state and fourth state as those in the aforementioned embodiment 1, which will not be repeated here.

[0190] In this comparative example, when the air inlet 107 and the air outlet 108 are in the second state through the single-valve pressure-limiting valve 9, the compressed air from the second chamber 102 acts on the front and back surfaces of the comparative valve 4000. At this time, the front surface of the comparative valve 4000 has a larger contact area with the compressed air. Correspondingly, because the back surface of the comparative valve 4000 covers the first door portion 908, only the back surface outside the outline of the first door portion 908 contacts the compressed air, resulting in a smaller contact area between the back surface of the comparative valve 4000 and the compressed air. The area of ​​the back surface of the comparative valve 4000 outside the outline of the first door portion 908 is defined as the third area.

[0191] See also Figure 10 , Figure 10 The diameter 4001 of the comparison valve 4000 and the diameter 954 of the first gate portion 908 are shown in FIG. Then, along the second direction, the third area of ​​the back surface of the comparison valve 4000 is: , R5 is the radius of the first gate portion 908 , and R6 is the radius of the comparison valve 4000 .

[0192] The third area in this comparative example is the same as the second area of ​​the second pressure-limiting valve 903 in the aforementioned embodiment 1. More specifically, since the diameter 954 of the first door portion 908 in this comparative example is the same as the diameter 954 of the first door portion 908 in the aforementioned embodiment 1, and the diameter 4001 of the comparison valve 4000 in this comparative example is the same as the diameter 953 of the second valve 903 in the aforementioned embodiment 1, the third area in this comparative example is the same as the second area in the aforementioned embodiment 1.

[0193] Example 2:

[0194] In this embodiment, an air handling unit for a commercial vehicle is provided, comprising a dryer and a nine-circuit protection valve as in the aforementioned embodiment 1;

[0195] The output port of the dryer is communicated with the air inlet 100 of the nine-circuit protection valve.

[0196] The connection structure between the dryer and the nine-circuit protection valve can adopt the connection structure between the dryer and the four-circuit protection valve in the prior art, which will not be described here.

[0197] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. Nine-circuit protection valve, characterized in that, It includes a valve body, a first control valve assembly, a second control valve assembly and a third control valve assembly; The valve body is processed with a first chamber, a second chamber, a third chamber, a fourth chamber, a fifth chamber and a sixth chamber for circulating compressed air, wherein the first chamber intersects with the second chamber and the fourth chamber respectively, the third chamber intersects with the second chamber respectively, the fifth chamber intersects with the first chamber and the second chamber respectively, and the sixth chamber intersects with the first chamber and the second chamber respectively; The first control valve assembly is provided at the intersection of the first chamber and the fourth chamber, wherein the first chamber and the surface of the valve body form an air inlet, and the fourth chamber and the surface of the valve body form a P29 port for connecting to an air-driven urea circuit; The second control valve assembly is provided at the intersection of the fifth chamber and the first chamber, and the third control valve assembly is provided at the intersection of the sixth chamber and the first chamber. The fifth chamber and the surface of the valve body form a P21 port for connecting to the rear service brake circuit, and the sixth chamber and the surface of the valve body form a P22 port for connecting to the front service brake circuit. Also included is a pressure limiting valve; The valve body is provided with a valve cavity for arranging the pressure-limiting valve, the second cavity and the inner surface of the valve cavity form an air inlet, and the third cavity and the inner surface of the valve cavity form an air outlet; The pressure-limiting valve includes a pressure-limiting valve cover and a valve core assembly, wherein the pressure-limiting valve cover is detachably covered on the valve cavity, and the valve core assembly is confined within a space defined by the pressure-limiting valve cover and the valve cavity, wherein an air vent is provided on the pressure-limiting valve cover; The valve core assembly has a first state in which the air inlet and the air outlet are connected, and a second state in which the air inlet and the air outlet are blocked, and the valve core assembly switches between the first state and the second state according to the pressure of the compressed air injected into the second chamber and the pressure of the compressed air injected into the third chamber; The valve core assembly further has a third state in which the air outlet and the air leak are connected, and a fourth state in which the air outlet and the air leak are blocked, and the valve core assembly switches between the third state and the fourth state by the pressure of the compressed air injected into the third chamber; The valve core assembly includes a first pressure-limiting valve, a second pressure-limiting valve, a first spring, a second spring, a pressure-limiting valve seat and a pressure-limiting piston; The pressure-limiting valve seat is sleeve-shaped, and an active cavity is provided inside the pressure-limiting valve seat. A first annular door portion is provided in the active cavity. Along the radial direction of the active cavity, the first door portion protrudes toward the center line of the pressure-limiting valve seat. Along the direction from the pressure-limiting valve cover to the valve cavity, the first door portion protrudes toward the air inlet. The first pressure-limiting valve, the second pressure-limiting valve, and the first spring are respectively disposed in the movable chamber, wherein the first pressure-limiting valve is located between the first spring and the second pressure-limiting valve, the first pressure-limiting valve and the inner surface of the pressure-limiting valve seat form a first air gap, and the second pressure-limiting valve and the inner surface of the pressure-limiting valve seat form a second air gap; The second pressure-limiting valve comprises a sleeve-shaped first section and a sleeve-shaped second section, the first section and the second section being coaxially integrally formed, the diameter of the first section being larger than the diameter of the second section, a sealing ring for covering the first door portion being provided on a surface of the first section facing the first door portion, and a second annular door portion being provided on a surface of the first section facing the pressure-limiting valve seat, forming a third air gap between the pressure-limiting valve seat and the second door portion; The diameter of the first door portion is greater than the diameter of the second door portion; The pressure-limiting piston includes an integrally formed head section, a middle section, and a tail section. A pressure relief channel is provided along the center line of the pressure-limiting piston. The pressure relief channel passes through the head section, the middle section, and the tail section respectively. The tail section is inserted into the active cavity, the minimum diameter of the middle section is larger than the diameter of the tail section, a step portion is formed at the intersection of the head section and the middle section, the second pressure-limiting valve is sleeved on the tail section, and a fifth air gap is formed between the second pressure-limiting valve and the tail section, a sixth air gap is formed between the second pressure-limiting valve and the step portion, and a seventh air gap is formed between the middle section and the pressure-limiting valve seat; The second spring is confined between the pressure-limiting piston and the pressure-limiting valve cover, one end of the second spring contacts the pressure-limiting valve cover, and the other end of the second spring contacts the head section; Also included are a fourth control valve assembly and a fifth control valve assembly; A seventh chamber and an eighth chamber are further processed in the valve body, and the seventh chamber and the eighth chamber intersect with the third chamber respectively, and the seventh chamber and the second chamber do not interfere with each other, wherein the fourth control valve assembly is provided at the intersection of the seventh chamber and the third chamber, and the fifth control valve assembly is provided at the intersection of the eighth chamber and the third chamber; The seventh chamber and the surface of the valve body form a P23 port for connecting to the trailer valve and a P23.1 port for connecting to the parking mechanism, and the P23 port and the P23.1 port do not interfere with each other. The eighth chamber and the surface of the valve body form a P24 port and a P24.2 port for connecting to the auxiliary circuit, and a P24.1 port for connecting to the transmission, and the P24 port, the P24.2 port, and the P24.1 port do not interfere with each other. Also included are a fifth one-way valve and a sixth one-way valve; A section of the seventh chamber located at the P23.1 port is configured as a third installation chamber, and a section of the eighth chamber located at the P24.1 port is configured as a fourth installation chamber. The fifth one-way valve is disposed in the third installation chamber through the P23.1 port, and the sixth one-way valve is disposed in the fourth installation chamber through the P24.1 port. The one-way conduction direction of the fifth one-way valve is limited to the direction from the third chamber to the P23.1 port; The one-way conduction direction of the sixth one-way valve is limited to the direction from the third chamber to the P24.1 port.

2. The nine-circuit protection valve according to claim 1, characterized in that: The fourth chamber and the surface of the valve body also form a P29.1 port for connecting to an air suspension circuit, and the P29 port and the P29.1 port do not interfere with each other.

3. The nine-circuit protection valve according to claim 2, characterized in that: Also included are a first one-way valve and a second one-way valve; One section of the fourth chamber located at the P29 port is configured as a first installation chamber, and another section of the fourth chamber located at the P29.1 port is configured as a second installation chamber. The first one-way valve is disposed in the first installation chamber through the P29 port, and the second one-way valve is disposed in the second installation chamber through the P29.1 port. The one-way conduction direction of the first one-way valve is limited to the direction from the first chamber to the P29 port; The one-way conduction direction of the second one-way valve is limited to the direction from the first chamber to the P29.1 port.

4. The nine-circuit protection valve according to claim 1, characterized in that: Also included are a third one-way valve and a fourth one-way valve; The third one-way valve is provided at the intersection of the fifth chamber and the second chamber, and the fourth one-way valve is provided at the intersection of the sixth chamber and the second chamber; The one-way conduction direction of the third one-way valve is limited to the direction from the fifth chamber to the second chamber; The one-way conduction direction of the fourth one-way valve is limited to a direction from the sixth chamber to the second chamber.

5. The nine-circuit protection valve according to claim 1, characterized in that: The first control valve assembly includes a first valve and a first telescopic mechanism, wherein the first valve is located at the intersection of the fourth chamber and the first chamber, the first valve is provided with a first hollow channel, the first hollow channel is used to connect the first chamber and the fourth chamber, and the first telescopic mechanism covers the first hollow channel; The second control valve assembly includes a second valve and a second telescopic mechanism, wherein the second valve is located at the intersection of the first chamber and the fifth chamber, the second valve is provided with a second hollow channel, the second hollow channel is used to communicate the first chamber and the fifth chamber, the second telescopic mechanism covers the second hollow channel, a first gap channel and a second gap channel are further provided between the second valve and the inner wall of the valve body, a third gap channel is provided on the side wall of the second valve, and the first gap channel, the second gap channel, the third gap channel and the first hollow channel intersect in sequence, and a second Y-shaped sealing ring is provided in the second gap channel, and the unidirectional conduction direction of the second Y-shaped sealing ring is limited to the direction from the first gap channel to the third gap channel; The third control valve assembly includes a third valve and a third telescopic mechanism, wherein the third valve is located at the intersection of the first chamber and the sixth chamber, the third valve is provided with a third hollow channel, the third hollow channel is used to connect the first chamber and the fifth chamber, the third telescopic mechanism covers the third hollow channel, a fourth gap channel and a fifth gap channel are further provided between the third valve and the inner wall of the valve body, the side wall of the third valve is provided with a sixth gap channel passing through the side wall, the fourth gap channel, the fifth gap channel, the sixth gap channel and the second hollow channel intersect in sequence, a third Y-shaped sealing ring is provided in the fifth gap channel, and the unidirectional conduction direction of the third Y-shaped sealing ring is limited to the direction along the fourth gap channel to the sixth gap channel.

6. An air handling unit for a commercial vehicle, including a dryer, characterized in that Also includes a nine-circuit protection valve according to any one of claims 1 to 5; The output port of the dryer is communicated with the air inlet of the nine-circuit protection valve.

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