Safety double block valve with self locking valve

Abstract

This invention proposes a safety double valve with a self-locking valve, comprising a main valve body consisting of two sets of two-position three-way solenoid valves connected in parallel. An air inlet, an air outlet, and an exhaust outlet are provided on the main valve body. A pilot solenoid valve is mounted on the upper part of each set of two-position three-way solenoid valves via a pilot valve seat. A valve chamber is provided inside the main valve body, and a main valve core capable of vertical movement is disposed within the valve chamber. A self-locking valve is disposed at the bottom of the valve chamber, and a return spring connects the main valve core and the self-locking valve. The self-locking valve includes a housing and a movable cavity therein, with a balance piston located within the movable cavity. The movable cavity communicates with the valve chamber and can be fixed within the movable cavity. A limit groove is provided on the balance piston. This invention, by incorporating a self-locking valve, achieves the safety function of the safety double valve under fault accumulation conditions while simultaneously locking the fault state mechanically through a pneumatic logic control circuit, thus achieving redundant control.

Description

Technical Field

[0001] This utility model relates to the field of safety double valve technology, and in particular to a safety double valve with a self-locking valve. Background Technology

[0002] The safety double solenoid valve for mechanical presses is a safety pneumatic functional component used to control the normal operation of the brakes and clutches of friction presses. With the implementation of the national standard GB27607-2011 "Safety Technical Requirements for Mechanical Presses," the safety performance level of manually operated mechanical presses should meet the standards of ENISO13849-1:2008 / AC:2009 and GB / T16855.13 (PLe, Cat4).

[0003] In the prior art, Chinese patent ZL201310454582.6 discloses a safety double valve, including a main valve assembly and a rear valve seat assembly. The main valve assembly includes two sets of two-position three-way solenoid valves, with a pilot solenoid valve installed on the upper part of each set of two-position three-way solenoid valves. The main valve assembly includes a main valve body, which has two valve chambers inside. The exhaust chamber and output chamber in the two valve chambers are connected together in parallel without obstruction. At the same time, two independent air intake chambers are also provided below. The two air intake chambers are connected in parallel to the air intake port of the safety double valve through air intake throttling orifices. The other end of the two air intake chambers is connected in parallel to the first and second air reservoir chambers through constant throttling orifice plugs. In addition, a main valve core is provided in the valve chamber, and an upper sealing plug and a lower sealing plug are provided on the main valve core. The lower sealing plug is connected to the main valve body via a main valve return spring; the rear valve seat assembly includes a rear valve seat with an air inlet and an exhaust port, and a first pilot air chamber and a second pilot air chamber are provided inside the rear valve seat; the air inlet chamber of the two-position three-way solenoid valve on one side of the main valve body is connected to the first pilot air chamber, and the first pilot air chamber is connected to the pilot solenoid valve on the other side; the air inlet chamber of the two-position three-way solenoid valve on the other side of the main valve body is connected to the second pilot air chamber, and the second pilot air chamber is connected to the pilot solenoid valve on one side; that is, the first pilot air chamber, the second pilot air chamber and the air inlet of the two pilot solenoid valves are cross-connected through two flow channels, and are connected in parallel to the air inlet chambers of the two main valves through two constant throttling plugs.

[0004] However, when any channel in the safety double valve machine control system malfunctions (referred to as a single fault), the safety double valve can maintain normal feedback in the air-only but non-energized state. When switching to the air-only and energized state, the pilot solenoid coil of one pilot solenoid valve of the safety double valve is energized, while the pilot solenoid coil of the other pilot solenoid valve is de-energized. The pilot core assembly below the energized pilot solenoid valve moves upward against the spring force. Compressed air from the intake chamber flows into the upper part of the main valve core on that side through the pilot intake channel and the pilot output channel, causing the main valve core on that side to move downward and connect the intake chamber and exhaust chamber on that side. Meanwhile, the pilot solenoid valve on the other side is de-energized. The pilot core assembly on that side closes the pilot intake valve port under the action of the spring force. The main valve core on that side connects the exhaust chamber and the outlet chamber under the action of the return spring. The compressed air from the intake chamber flows into the outlet chamber and then flows to the outlet while simultaneously being discharged from the open exhaust port, so that the pressure at the output port is below the clutch drive pressure. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the defects of the existing technology. This utility model proposes a safety double valve with a self-locking valve. The safety double valve realizes the safety function in the fault accumulation state by superimposing a pneumatic logic control circuit with a mechanical lock.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a safety double valve with a self-locking valve, including a main valve body, the main valve body is composed of two sets of two-position three-way solenoid valves connected in parallel, a pilot solenoid valve is installed on the upper part of each set of two-position three-way solenoid valves through a pilot valve seat, and a valve cavity is provided inside the main valve body, the valve cavity is composed of an air inlet cavity, an air outlet cavity and an exhaust cavity distributed from bottom to top;

[0007] An air inlet, an air outlet, and an exhaust outlet are provided on the main valve body. The air inlet is connected to the air inlet chamber, the air outlet is connected to the air outlet chamber, and the exhaust outlet is connected to the exhaust chamber.

[0008] A pressure-stabilizing gas container is also provided between the valve chamber and the pilot valve seat. The number of pressure-stabilizing gas containers is the same as that of the pilot solenoid valve, and the pressure-stabilizing gas container is connected to the air inlet chamber.

[0009] A main valve core capable of vertical reciprocating motion is provided in the valve cavity. The pressure stabilizing gas container is connected to the pilot air inlet channel and the pilot output channel of the pilot solenoid valve. The pilot air inlet channel and the pilot output channel can be blocked by the pilot core assembly of the pilot solenoid valve. The main valve core is controlled by the pilot output channel to move vertically downward.

[0010] A self-locking valve is provided at the bottom of the valve chamber. A return spring is connected between the main valve core and the self-locking valve. The self-locking valve includes a housing, in which a movable cavity is formed. A balance piston is movably disposed in the movable cavity. Air passages communicating with the air inlet chamber are formed on the left and right sides of the movable cavity. A damping hole is formed through the length of the balance piston. Elastic components are fixedly disposed between the left and right sides of the balance piston and the inner wall of the movable cavity. The balance piston can be fixed in the movable cavity. A limiting groove for limiting the position of the main valve core is formed on the balance piston.

[0011] Furthermore, the limiting groove is a valve core chamber, which includes a first chamber section and a second chamber section. The depth of the first chamber section is less than the depth of the second chamber section, which is used to accommodate the movement range of the main valve core. The first chamber section is located near the end of the balance piston.

[0012] Furthermore, the width of the second chamber section is not less than the sum of the valve core width and the distance between one side of the balance piston and the movable cavity when the balance piston is located at the center of the movable cavity; the width of the first chamber section is not less than the valve core width.

[0013] Furthermore, it also includes a self-locking rod assembly, which is movably fixed to the housing, and a locking hole is provided on the side of the balance piston facing the self-locking rod assembly;

[0014] It also includes a positioning protrusion, which is fixedly disposed at the center line of the balance piston. Locking holes are fixedly disposed on both sides of the positioning protrusion, and the width of the positioning protrusion is not less than the width of the self-locking rod assembly.

[0015] Furthermore, the self-locking rod assembly includes a rod body, a handle fixed to the rod body, and a spring fitted onto the rod body. The spring is disposed in a cavity opened on the outer shell, with one end of the spring contacting the inner wall of the cavity and the other end fixed by a push rod.

[0016] Furthermore, a first groove is provided at both ends of the balance piston for the elastic component to be embedded therein, and a second groove is provided at both ends of the movable cavity facing the balance piston for the other end of the elastic component to be fixed therein, and the damping hole passes through the first grooves on both sides.

[0017] Furthermore, a sealing ring is fitted onto the balance piston, and the sealing ring is located at the end of the first chamber section close to the balance piston.

[0018] Furthermore, the air inlet and the air inlet chamber are connected through a first air inlet throttle port. The first air inlet throttle port is fixedly set based on the width direction of the main valve body. One end of the first air inlet throttle port is connected to the air inlet, and the other end is fixedly set between the two sets of main valve cores and connected to the air inlet chamber.

[0019] Furthermore, a lower sealing plug, an upper sealing plug, and a sealing plug are sequentially arranged from bottom to top on the main valve core.

[0020] The lower sealing plug is located in the air inlet chamber and is used to block the air inlet chamber and the air outlet chamber. The return spring is fixedly disposed between the lower sealing plug and the outer shell.

[0021] The upper plug is located in the exhaust chamber and is used to block the exhaust chamber and the air outlet chamber;

[0022] The sealing plug is also located in the exhaust chamber, with its upper surface facing the pilot output channel, and is used to block the pilot output channel.

[0023] Furthermore, the intake chamber and the pressure-stabilizing gas container are connected via an intake channel, and at least one second intake throttle port is fixedly installed above the intake channel; the two sets of intake channels are fixedly installed in the main valve body in a cross manner.

[0024] Compared with the prior art, the beneficial effects of this utility model include: by using a pilot-operated cross-controlled main valve of the two parallel flow channels of the safety double valve, that is, by using a pneumatic logic control circuit to realize the safety function of the safety double valve in the fault accumulation state, a self-locking valve is added to the bottom of the safety double valve. This ensures that when any channel of the safety double valve and its control system fails (referred to as a single fault), as long as the fault is not eliminated or not confirmed after elimination, regardless of how many "energized" or "de-energized" signals are superimposed, the pressure at the output port of the safety double valve will be below the clutch drive pressure (≦0.04MPa). This again satisfies the conditions for the safety double valve to realize its main safety function in the fault accumulation state through mechanical means. It achieves the redundant control purpose of realizing the safety function of the safety double valve in the fault accumulation state through the pneumatic logic control circuit and the main safety function in the fault accumulation state through mechanical means. Attached Figure Description

[0025] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts. Wherein:

[0026] Figure 1The schematic diagram shows the front cross-sectional structure of a safety double valve with a self-locking valve, in the air-ventilated but non-energized state.

[0027] Figure 2 The schematic diagram shows the top cross-sectional view of the self-locking valve, in which the safety double valve is in normal working condition;

[0028] Figure 3 The schematic diagram shows the front cross-sectional structure of a safety double valve with a self-locking valve, in the air- and energized state.

[0029] Figure 4 The schematic diagram shows a front cross-sectional view of a safety double valve with a self-locking valve, in a single fault condition.

[0030] Figure 5 The schematic diagram shows a top cross-sectional view of the structure with a self-locking valve, in which the safety double valve is in a single fault state or a fault accumulation state.

[0031] Figure 6 The schematic diagram shows a front cross-sectional view of a safety double valve with a self-locking valve, in the state of fault accumulation.

[0032] Numbering in the diagram: 1-Main valve body, 2-Pilot solenoid valve, 3-Inlet chamber, 4-Outlet chamber, 5-Exhaust chamber, 6-Inlet port, 7-Outlet port, 8-Exhaust port, 9-Pressure stabilizing gas container, 10-Main valve core, 11-Pilot inlet channel, 12-Pilot outlet channel, 13-Pilot core assembly, 14-Self-locking valve, 141-Outer shell, 142-Moving cavity, 143-Balance piston, 144-Damping orifice, 145-Elastic component, 146-Valve core chamber, 14 61-First chamber section, 1462-Second chamber section, 147-Self-locking rod assembly, 1471-Rod body, 1472-Handle, 1473-Spring, 1474-Push rod, 148-Locking hole, 149-Positioning protrusion, 1410-First groove, 1411-Second groove, 1412-Sealing ring, 15-Reset spring, 16-First air inlet throttle port, 17-Second air inlet throttle port, 18-Lower plug, 19-Upper plug, 20-Sealing plug. Detailed Implementation

[0033] It is readily understood that, based on the technical solution of this utility model, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this utility model. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model and should not be considered as the entirety of this utility model or as limitations or restrictions on the technical solution of this utility model.

[0034] Figure 1The schematic diagram shows a front cross-sectional view of a safety double valve with a self-locking valve, such as... Figure 1 As shown, the device includes a main valve body 1, which consists of two sets of two-position three-way solenoid valves connected in parallel. A pilot solenoid valve 2 is installed on the upper part of each set of two-position three-way solenoid valves via a pilot valve seat. A valve chamber is provided inside the main valve body 1, which consists of an inlet chamber 3, an outlet chamber 4, and an exhaust chamber 5 distributed from bottom to top. An inlet port 6, an outlet port 7, and an exhaust port 8 are provided on the main valve body 1. The inlet port 6 is connected to the inlet chamber 3 and is used to supply compressed air to the valve chamber. The outlet port 7 is connected to the outlet chamber 4 and is used to output the compressed air that enters the valve chamber. The exhaust port 8 is connected to the exhaust chamber 5 and is used to discharge the compressed air in the valve chamber.

[0035] A pressure-stabilizing gas container 9 is also provided between the aforementioned valve chamber and the pilot valve seat. The number of pressure-stabilizing gas containers 9 is the same as the number of pilot solenoid valves 2, and the pressure-stabilizing gas containers 9 are connected to the inlet chamber 3. It is worth noting that the aforementioned inlet chamber 3, outlet chamber 4, and exhaust chamber 5 all include a left-side structure and a right-side structure. The left-side structure and the right-side structure are symmetrically distributed based on the centerline of the main valve body 1, and the shapes of the left-side structure and the right-side structure are completely identical. The aforementioned single pilot solenoid valve 2 and single pressure-stabilizing gas container 9 are fixedly installed above the inlet chamber 3, outlet chamber 4, and exhaust chamber 5 on one side, which facilitates the opening of related air passages and ensures that the overall structure of the main valve body 1 is simple and aesthetically pleasing.

[0036] A main valve core 10 capable of vertical reciprocating motion is disposed within the aforementioned valve cavity. The main valve core 10 also includes left and right sides with identical structures. The pressure regulating gas container 9 is connected to the pilot air intake channel 11 and pilot air output channel 12 of the pilot solenoid valve 2. The passage between the pilot air intake channel 11 and the pilot air output channel 12 can be blocked by the pilot core assembly 13 of the pilot solenoid valve 2. The main valve core 10 is regulated by whether compressed air is output from the pilot air output channel 12 to determine whether it reciprocates vertically. When the pilot valve core 13 moves vertically upward under the action of the pilot solenoid valve 2, the pilot intake channel 11 and the pilot output channel 12 are connected to the lower part of the pilot valve core 13. At this time, the main valve core 10 can output compressed air, thereby controlling its vertical downward movement. Conversely, when the pilot valve core 13 does not move upward, the pilot intake channel 11 and the pilot output channel 12 are blocked by the pilot valve core 13, and the main valve core 10 cannot move vertically downward.

[0037] A self-locking valve 14 is fixedly installed at the bottom of the valve chamber. A return spring 15 is connected between the main valve core 10 and the self-locking valve 14. When the main valve core 10 moves downward without the action of compressed air output from the pilot output channel 12 above, the return spring 15 provides elastic force to reset it. Figure 2The schematic diagram shows a top cross-sectional view of the self-locking valve, such as... Figure 2 As shown, the aforementioned self-locking valve 14 includes a housing 141, a movable cavity 142 is provided in the housing 141, a balance piston 143 is movably disposed in the movable cavity 142, air passages communicating with the air inlet cavity 3 are provided on the left and right sides of the movable cavity 142, and a damping hole 144 is provided through the length direction of the balance piston 143. The damping hole 144 can ensure that the gas inside the movable cavity 142 does not move around randomly, thus affecting the movement of the balance piston 143 in the movable cavity 142 under normal conditions; an elastic component 145 is fixedly disposed between the left and right sides of the balance piston 143 and the inner wall of the movable cavity 142. The self-locking valve 14 located at the bottom of the valve chamber provides conditions for the installation of the return spring 15. On the other hand, the balance piston 143 is movably located in the movable cavity 142, and the pressure on both sides of the balance piston 143 is regulated by the air passage connected to the air intake cavity 3, thereby regulating the position of the balance piston 143 in the movable cavity 142. The valve core chamber 146 above the balance piston 143 receives the lower end of the main valve core 10 on one side, while the main valve core 10 on the other side cannot fall because its lower end is in contact with the outer edge of the balance piston 143. Thus, self-locking is completed when the pressure in the valve cavities on the left and right sides is different.

[0038] The self-locking mechanism is explained in detail below. Since the lower end of the main valve core 10 normally extends into the movable cavity 142, the valve core chamber 146 includes a first chamber section 1461 and a second chamber section 1462. The depth of the first chamber section 1461 is less than the depth of the second chamber section 1462. The first chamber section 1461 is used to accommodate the position of the lower end of the main valve core 10, and the second chamber section 1462 is used to accommodate the extreme movement position of the lower end of the main valve core 10. The first chamber section 1461 is positioned close to the end of the balance piston 143, so that under normal conditions, i.e., when the pressure on both sides of the balance piston 143 is equal, the second chamber section 1462 is always below the main valve core 10; only when the balance piston 143 is at its limit... When the pressure on both sides of piston 143 is different, the balance piston 143 moves towards the side with less pressure under the pressure difference. For example, when the pressure on the right side of the balance piston 143 is greater, it will move to the left. At this time, the first chamber section 1461 of the right valve core 10 is below the right valve core chamber 146, while the second chamber section 1462 of the left valve core chamber 146 is below the left valve core 10. That is, the left main valve core 10 can still move normally in the vertical reciprocating motion, while the right main valve core 10 can only maintain its original position under the obstruction of the first chamber section 1461, thus completing the self-locking. And when the internal pressure does not change, its self-locking state will not be released.

[0039] In order for the aforementioned first chamber section 1461 and second chamber section 1462 to meet the aforementioned functional requirements, the width of the first chamber section 1461 must be no less than the width of the lower end of the main valve core 10, and the width of the second chamber section 1462 must be no less than the sum of the width of the lower end of the main valve core 10 and the distance between one side of the balance piston 143 and the inner wall of the movable cavity 142 when the balance piston 143 is located in the center of the movable cavity 142. This is to ensure that when the balance piston 143 moves to any side, the second chamber of the valve core chamber 146 on that side can still meet the limit movement position of the lower end of the main valve core 10.

[0040] In other embodiments, since the balance piston 143 can return to the center position of the movable cavity 142 after the internal pressure is restored to balance in the self-locking state, the restoration of the self-locking state makes it impossible to accurately determine the internal fault state. Therefore, a self-locking rod assembly 147 is also provided. The self-locking rod assembly 147 is movably fixed on the outer shell 141. A locking hole 148 is provided on the side of the balance piston 143 facing the self-locking rod assembly 147. The self-locking rod assembly 147 fixes the position of the balance piston 143 mechanically by embedding into the locking hole 148, so that the main safety function of the safety double valve can be realized and is not affected by any signal from the pilot solenoid valve 2. It should be noted that since the valve core chamber 146 is symmetrically distributed on the balance piston 143, the locking holes 148 must also be symmetrically distributed on the balance piston 143. Therefore, a positioning protrusion 149 is also provided on the balance piston 143, and locking holes 148 are fixedly provided on both sides of the positioning protrusion 149. The width of the positioning protrusion 149 is not less than the width of the self-locking rod assembly 147. The positioning protrusion 149 is fixedly set at the center line of the balance piston 143. When the safety double valve can be used normally, the self-locking rod assembly 147 is located on the positioning protrusion 149. When the balance piston 143 moves in the movable cavity 142, the position of the positioning protrusion 149 changes synchronously. At this time, the self-locking rod assembly 147 will fall into the locking hole 148 to lock the balance piston 143, thereby locking the valve core chamber 146 set on the balance piston 143 to the position of the main valve core 10, so that the main safety function of the safety double valve can be realized.

[0041] The self-locking lever assembly 147 is described in detail below. The aforementioned self-locking lever assembly 147 includes a lever body 1471, a handle 1472 fixed to the lever body 1471, and a spring 1473 fitted onto the lever body 1471. The spring 1473 is disposed in a cavity formed in the outer casing 141. One end of the spring 1473 contacts the inner wall of the cavity, and the other end is fixed by a push rod 1474. In the normal state, the lever body 1471 is pressed against the positioning protrusion 149, and the spring 1473 fitted onto it is in a compressed state. When the balance piston 143 moves, the position of the positioning protrusion 149 shifts, and the lever body 1471, under the elastic action of the spring 1473, abuts into the locking hole 148, thus locking the position of the balance piston 143.

[0042] The aforementioned balance piston 143 has first grooves 1410 at both ends for the elastic component 145 to be embedded therein, and the movable cavity 142 has second grooves 1411 at both ends facing the balance piston 143 for the other end of the elastic component 145 to be fixed. The damping hole 144 passes through the first grooves 1410 on both sides, and a sealing ring 1412 is fitted on the balance piston 143. The sealing ring 1412 is located at the end of the first chamber section 1461 close to the balance piston 143, so as to ensure that the pressure on both sides of the balance piston 143 can be relatively consistent only from the damping hole 144. The first grooves 1410 and the second grooves 1411 can effectively ensure the fixation of the elastic component 145, so that the balance piston 143 can return to its original position when it is not locked by the self-locking rod assembly 147.

[0043] The following provides supplementary explanation of the structure of the safety double valve. The provided air inlet 6 is connected via a first air inlet throttle port 16. The first air inlet throttle port 16 is fixedly positioned along the width of the main valve body 1. One end of the first air inlet throttle port 16 is connected to the air inlet 6, while the other end is fixedly positioned between the two sets of main valve cores 10 and connected to the air inlet chamber 3. Air intake through the provided air inlet 6 and then via the first air inlet throttle port 16 between the two sets of main valve cores 10 helps ensure that the amount of compressed air entering the air inlets 3 on both sides is essentially the same.

[0044] A lower sealing plug 18, an upper sealing plug 19, and a sealing plug 20 are arranged sequentially from bottom to top on the aforementioned main valve core 10. The lower sealing plug 18 is located in the air inlet chamber 3 and is used to block the air inlet chamber 3 and the air outlet chamber 4. The return spring 15 is fixedly arranged between the lower sealing plug 18 and the outer shell 141. The upper sealing plug 19 is located in the exhaust chamber 5 and is used to block the exhaust chamber 5 and the air outlet chamber 4. The sealing plug 20 is also located in the exhaust chamber 5, and the upper surface of the sealing plug 20 faces the pilot output channel 12 and is used to block the pilot output channel 12.

[0045] The aforementioned air intake chamber 3 and pressure regulating gas container 9 are connected by an air intake channel, and at least one second air intake throttle port 17 is fixedly installed on the air intake channel; the two sets of air intake channels are fixedly installed in the main valve body 1 in a cross manner and the two sets of air intake channels are not connected.

[0046] The following is a detailed description of the operating status of the safety double valve with self-locking valve 14.

[0047] Air-ventilated but not energized state

[0048] Figure 1 The schematic diagram shows a front cross-sectional view of a safety double valve with a self-locking valve in the air-vented but non-energized state. Figure 2 The schematic diagram shows the top cross-sectional view of the self-locking valve when the safety double valve is in normal operating condition. The following is combined with... Figure 1 and Figure 2 This section provides a detailed explanation of the state where air is supplied but no electricity is supplied.

[0049] Compressed air enters both the left and right intake chambers 3 simultaneously from the safety dual valve inlet 6 and the first intake throttle port 16. The compressed air entering the left and right intake chambers 3 then passes through the second intake throttle port and intake passage to reach the pressure stabilizing gas container 9. The compressed air reaching the pressure stabilizing gas container 9 flows through the pilot intake passage 11 to the pilot intake valve port of the pilot solenoid valve 2. Because the coil of the pilot solenoid valve 2 is de-energized and non-magnetized, the pilot core assembly 13 is in the lower position under the spring force of the spring 1473, thus closing the pilot intake valve port. At this time, the compressed air in the pressure stabilizing gas container 9 cannot be output through the pilot output passage 12, thus pushing the main valve core 10 downwards. Under the action of the return spring 15, the main valve core 10 closes the intake chamber 3 and the outlet chamber 4, while connecting the exhaust chamber 5 and the outlet chamber 4. At this time, the outlet chamber 4 reaches the exhaust chamber 5 and discharges the atmosphere from the exhaust port 8. The pressure at the outlet port 7 is zero, causing the clutch to disengage.

[0050] In addition, the compressed air entering the intake chamber 3 simultaneously reaches the movable chamber 142 through the air passage. Due to the effect of the balance damping hole 144, the influence of the instantaneous change of the compressed air in the intake chamber 3 on the movement state of the balance piston 143 is eliminated, ensuring that the balance piston 143 is in the intermediate state of the self-locking valve 14.

[0051] Since the balance piston 143 is in the middle state of the self-locking valve 14, the self-locking push rod 1474 is tightly attached to the positioning protrusion 149 of the balance piston 143 under the action of the self-locking spring 1473.

[0052] Ventilation and power supply status

[0053] Figure 3 The schematic diagram shows a front cross-sectional view of a safety double valve with a self-locking valve in the vented and energized state. Figure 2The schematic diagram shows the top cross-sectional view of the self-locking valve when the safety double valve is in normal operating condition. The following is combined with... Figure 3 and Figure 2 This section provides a detailed explanation of the ventilated but not energized state.

[0054] Compressed air enters both the left and right intake chambers 3 simultaneously from the intake port 6 through the first intake throttle port 16. The compressed air entering the left and right intake chambers 3 then passes through the second intake throttle port and intake passage to reach the pressure stabilizing gas container 9. The compressed air reaching the pressure stabilizing gas container 9 flows through the pilot intake passage 11 to the pilot intake valve port of the pilot solenoid valve 2. Because the coil of the pilot solenoid valve 2 is energized, the electromagnetic force generated by the coil overcomes the action on the pilot core assembly 13. The spring force of the return spring 15 causes the pilot core assembly 13 to move upward. The compressed air from the intake chamber 3 flows into the upper side of the main valve core 10 through the pilot intake valve port and the pilot output channel 12, causing the main valve core 10 to move downward, separating the exhaust chamber 5 from the outlet chamber 4, and connecting the intake chamber 3 and the outlet chamber 4. At this time, the two main valve cores 10 of the safety double valve are in the lower position. The compressed air from the intake chamber 3 enters the outlet port 7 through the outlet chamber 4 and flows to the clutch, causing the clutch to engage and the brake to disengage.

[0055] In addition, the compressed air entering the intake chamber 3 simultaneously reaches the control chamber of the self-locking valve 14 through the air passage. Due to the function of the balance damping orifice 144, the influence of the instantaneous change of the compressed air in the intake chamber 3 on the movement state of the balance piston 143 is eliminated, ensuring that the balance piston 143 is in the intermediate state of the self-locking valve 14.

[0056] Since the balance piston 143 is in the middle state of the self-locking valve 14, the self-locking push rod 1474 is tightly attached to the positioning protrusion 149 of the balance piston 143 under the action of the self-locking spring 1473; the lower ends of the valve cores 10 of both main valves fall into the second chamber section 1462.

[0057] Single Fault Condition

[0058] Figure 4 The schematic diagram shows a front cross-sectional view of a safety double valve with a self-locking valve in a single-failure condition. Figure 5 The schematic diagram shows the top cross-sectional view of the self-locking valve when the safety double valve is in a single fault state. The following is combined with... Figure 4 and Figure 5 This single fault condition will be described in detail.

[0059] When a single fault occurs in the safety double valve or the control safety double valve (such as...) Figure 6The diagram shows a fault in the right-side pilot solenoid valve. In the left-side safety double valve, the pilot solenoid coil of one of the pilot solenoid valves 2 is energized, while the pilot solenoid coil of the right-side pilot solenoid valve 2 is de-energized. The reverse is also a single fault condition.

[0060] Compressed air enters the left and right intake chambers 3 simultaneously from the intake port 6 through the first intake throttle port 16. The compressed air entering the left and right intake chambers 3 passes through the second intake throttle port 17 and the intake channel to reach the pressure stabilizing gas container 9. The compressed air reaching the pressure stabilizing gas container 9 flows through the pilot intake channel 11 to the pilot intake valve port of the pilot solenoid valve 2. Since the pilot solenoid coil on the left is in an energized state, the electromagnetic force generated by the pilot solenoid coil overcomes the spring force of the spring 1473 acting on the pilot core assembly 13, causing the pilot core assembly 13 on the left to move upward. The compressed air from the intake chamber 3 flows into the upper part of the main valve core 10 on the left through the pilot intake channel 11 and the pilot output channel 12, causing the main valve core 10 on the left to move downward, connecting the left intake chamber 3 with the exhaust chamber 5. At this time, the main valve core 10 of the safety double valve is in the lower position.

[0061] Because the pilot solenoid coil on the right is in a de-energized and non-excited state, the pilot core assembly 13 closes the pilot intake valve port under the spring force of spring 1473. Under the action of the reset spring 15, the main valve core 10 on the right connects the exhaust chamber 5 and the outlet chamber 4. At this time, the main valve core 10 of the safety double valve is in the upper position.

[0062] Compressed air from intake chamber 3 flows into exhaust chamber 4 and then flows towards exhaust port 7 while being discharged from the open exhaust port 8 to the atmosphere.

[0063] Because the effective cross-sectional area of ​​the first intake throttle port 16 is much smaller than the limited cross-sectional area of ​​the passage from the outlet port 7 to the exhaust port 8, most of the compressed air flowing out of the first intake throttle port 16 passes through the left intake chamber 3 and the left outlet chamber 4, and is then discharged into the atmosphere via the left exhaust chamber 5. At this time, the residual pressure at the output port of the safety double valve is less than 0.04 MPa, which cannot drive the clutch, thus realizing the main safety function of the safety double valve—"If a single passage in the safety double valve fails, the pressure at its output port should drop below the clutch drive pressure." In addition, at this time, the pressure in the left intake chamber 3 is less than 0.04 MPa, and the pressure in the right intake chamber 3 is basically the same as the pressure at the intake port 6 (high pressure).

[0064] Additionally, the compressed air entering the intake chamber 3 simultaneously reaches the control chamber of the self-locking valve 14 via the air passage. However, because the pressure in the compressed space on the right side of the balance piston 143 is much higher than that on the left, the balance piston 143 moves to the left under the action of high pressure until the rod 1471 is pressed into the locking hole 148 on the right side of the balance piston 143 by the action of the spring 1473, preventing the balance piston 143 from moving. The lower end of the left main valve core 10 falls into the second chamber section 1462 on the left, while the lower end of the right main valve core 10 falls on the first chamber section 1461 on the right to prevent it from falling. After confirming that the fault has been eliminated, the balance piston 143 can only be reset by manually pulling the reset handle 1472.

[0065] Fault accumulation

[0066] Figure 6 The schematic diagram shows a front cross-sectional view of a safety double valve with a self-locking valve in a fault accumulation state. Figure 5 The schematic diagram shows the top cross-sectional view of the self-locking valve when the safety double valve is in a fault accumulation state. The following is combined with... Figure 6 and Figure 5 The specific description of this single fault state is provided. The description of the fault accumulation state is based on the description of the single fault state in 3).

[0067] In addition, to prevent further misoperation, if the fault is not eliminated and the safety double valve is powered off and reset and then powered on again, according to the previous "single fault state", after a single fault occurs in one channel of the safety double valve and its control system, in addition to quickly reducing the output pressure to below the clutch drive pressure (≦0.04MPa), the rod 1471 is pressed into the locking hole 148 of the balance piston 143 under the action of the spring 1473, so that the balance piston 143 cannot move. The lower end of the main valve core 10 on the left side (the side without fault) falls into the second chamber section 1462 on the left side, and the lower end of the main valve core 10 on the right side (the side with fault) falls on the first chamber section 1461 on the right side. When the fault is not resolved and the safety double valve is de-energized and reset, the main valve core 10 of the safety double valve returns to the "air-accessible but not energized state". Both air inlet chambers 3 are under high pressure. The two pilot solenoid valves 2 are energized again, causing the two pilot moving iron core assemblies to move upward. After opening the two pilot air inlet channels 11, the compressed air from the air inlet chamber 3 flows into the pressure stabilizing gas container 9 through the air inlet channel and attempts to adjust the main valve core 10 to move downward through the pilot output channel 12. However, because the fault of the safety double valve has not been manually resolved, that is, no one manually pulled the reset handle 1472, the rod 1471 is in the locking hole 148, and the balance piston... On one side of the self-locking valve 143, only one of the two main valve cores 10 can normally move down into the second chamber section 1462 of the valve core chamber 146, while the lower end of the other main valve core 10 falls on the first chamber section 1461 of the valve core chamber 146 on this side, and can hardly reverse. At this time, the output pressure of the safety double valve is still less than 0.04MPa, and the clutch cannot be driven. Once again, the conditions for realizing the main safety function of the safety double valve under the fault accumulation state are met. The main safety function of the safety double valve under the fault accumulation state is obtained by mechanical means.

[0068] This safety double valve achieves its safety function under fault accumulation conditions by using a pilot-operated cross-controlled main valve with two parallel flow channels, i.e., by using a pneumatic logic control loop. Simultaneously, a self-locking valve 14 is added to the bottom of the safety double valve. This ensures that when any channel of the safety double valve and its control system malfunctions (referred to as a single fault), as long as the fault is not eliminated or not confirmed after elimination, regardless of the number of superimposed "energized" or "de-energized" signals, the pressure at the output port of the safety double valve remains below the clutch drive pressure (≤0.04MPa). This again satisfies the conditions for the main safety function of the safety double valve under fault accumulation conditions achieved mechanically. Thus, the safety double valve achieves redundant control by using a pneumatic logic control loop to realize both its safety function under fault accumulation conditions and its main safety function under fault accumulation conditions through mechanical means.

[0069] It should be understood that the use of the self-locking rod assembly 147 to lock the position of the balance piston 143 in this utility model, thereby satisfying the main safety function of the safety double valve in the state of fault accumulation through mechanical means, is only one embodiment of this utility model. It is only to clearly describe the position locking function of the self-locking rod assembly 147 for the balance piston 143, and is not a limitation on the structure in the self-locking valve 14 used to lock the position of the balance piston 143 in the movable cavity. The self-locking rod assembly 147 can also be replaced by a miniature cylinder or other elastic structure to lock the position of the balance piston 143. This should be regarded as an equivalent embodiment of the above embodiment.

[0070] The technical scope of this utility model is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the protection scope of this utility model.

Claims

1. A safety double valve with a self-locking valve, comprising a main valve body (1), wherein the main valve body (1) is composed of two sets of two-position three-way solenoid valves connected in parallel, and a pilot solenoid valve (2) is installed on the upper part of each set of two-position three-way solenoid valves via a pilot valve seat; a valve cavity is provided inside the main valve body (1), the valve cavity being composed of an inlet cavity (3), an outlet cavity (4), and an exhaust cavity (5) distributed from bottom to top; an inlet port (6), an outlet port (7), and an exhaust port (8) are provided on the main valve body (1), the inlet port (6) is connected to the inlet cavity (3), the outlet port (7) is connected to the outlet cavity (4), and the exhaust port (8) is connected to the exhaust cavity (5); the valve cavity and A pressure-stabilizing gas container (9) is also provided between the pilot valve seats. The number of pressure-stabilizing gas containers (9) is the same as that of the pilot solenoid valve (2), and the pressure-stabilizing gas container (9) is connected to the air inlet chamber (3). A main valve core (10) that can reciprocate vertically is provided in the valve chamber. The pressure-stabilizing gas container (9) is connected to the pilot air inlet channel (11) and the pilot output channel (12) of the pilot solenoid valve (2). The pilot air inlet channel (11) and the pilot output channel (12) can be blocked by the pilot core assembly (13) of the pilot solenoid valve (2). The main valve core (10) is controlled by the pilot output channel (12) to move vertically downward. A self-locking valve (14) is provided at the bottom of the valve chamber. A return spring (15) is connected between the main valve core (10) and the self-locking valve (14). The self-locking valve (14) includes a housing (141). A movable cavity (142) is provided in the housing (141). A balance piston (143) is movably disposed in the movable cavity (142). An air passage communicating with the air inlet cavity (3) is provided on the left and right sides of the movable cavity (142). A damping hole (144) is provided through the length direction of the balance piston (143). An elastic component (145) is fixedly provided between the left and right sides of the balance piston (143) and the inner wall of the movable cavity (142). The balance piston (143) can be fixed in the movable cavity (142). A limiting groove for limiting the main valve core (10) is provided on the balance piston (143).

2. The safety double block valve with self-locking valve according to claim 1, characterized in that The limiting groove is a valve core chamber (146), which includes a first chamber section (1461) and a second chamber section (1462). The depth of the first chamber section (1461) is less than the depth of the second chamber section (1462) to accommodate the movement range of the main valve core (10). The first chamber section (1461) is located near the end of the balance piston (143).

3. The safety double block valve with self-locking valve according to claim 2, characterized in that The width of the second chamber section (1462) is not less than the sum of the width of the valve core and the distance between one side of the balance piston (143) and the movable cavity (142) when the balance piston (143) is located at the center of the movable cavity (142); the width of the first chamber section (1461) is not less than the width of the valve core.

4. The safety double block valve with self-locking valve of claim 1, wherein, It also includes a self-locking rod assembly (147), which is movably fixed on the outer shell (141), and a locking hole (148) is provided on the side of the balance piston (143) facing the self-locking rod assembly (147); it also includes a positioning protrusion (149), which is fixedly disposed at the center line of the balance piston (143), and locking holes (148) are fixedly disposed on both sides of the positioning protrusion (149), and the width of the positioning protrusion (149) is not less than the width of the self-locking rod assembly (147).

5. The safety double block valve with self-locking valve according to claim 4, characterized in that The self-locking rod assembly (147) includes a rod body (1471), a handle (1472) fixed to the rod body (1471), and a spring (1473) fitted onto the rod body (1471). The spring (1473) is disposed in a cavity opened on the outer shell (141). One end of the spring (1473) contacts the inner wall of the cavity, and the other end is fixed by a push rod (1474).

6. The safety double block valve with self-locking valve of claim 1, wherein, The balance piston (143) has a first groove (1410) at both ends for the elastic component (145) to be embedded therein, and the movable cavity (142) has a second groove (1411) at both ends facing the balance piston (143) for the other end of the elastic component (145) to be fixed. The damping hole (144) passes through the first groove (1410) on both sides.

7. The safety double block valve with self-locking valve according to any one of claims 2 or 3, characterized in that, A sealing ring (1412) is fitted on the balance piston (143), and the sealing ring (1412) is located at the end of the first chamber section (1461) close to the balance piston (143).

8. The safety double valve with a self-locking valve according to claim 1, characterized in that, The air inlet (6) is connected to the air inlet chamber through the first air inlet throttle port (16). The first air inlet throttle port (16) is fixedly set based on the width direction of the main valve body (1). One end of the first air inlet throttle port (16) is connected to the air inlet (6), and the other end is fixedly set between the two sets of main valve cores (10) and connected to the air inlet chamber (3).

9. The safety double block valve with self-locking valve of claim 1, wherein, A lower sealing plug (18), an upper sealing plug (19), and a sealing plug (20) are arranged sequentially from bottom to top on the main valve core (10). The lower sealing plug (18) is located in the air inlet chamber (3) and is used to block the air inlet chamber (3) and the air outlet chamber (4). The return spring (15) is fixedly arranged between the lower sealing plug (18) and the outer shell (141). The upper sealing plug (19) is located in the exhaust chamber (5) and is used to block the exhaust chamber (5) and the air outlet chamber (4). The sealing plug (20) is also located in the exhaust chamber (5). The upper surface of the sealing plug (20) faces the pilot output channel (12) and is used to block the pilot output channel (12).

10. The safety double block valve with self-locking valve of claim 1, wherein, The air intake chamber (3) is connected to the pressure stabilizing gas container (9) through the air intake channel, and at least one second air intake throttle port (17) is fixedly provided on the air intake channel; the two sets of air intake channels are fixedly provided in the main valve body (1) in a cross manner.

Images