Fluid flow direction switching valve and automatic control switching direct stroke reciprocating power device

Abstract

The present invention relates to a fluid flow direction switching valve and an automatic control switching direct-stroke reciprocating power device. The fluid flow direction switching valve is a two-position five-way reversing valve, and pilot mechanisms are arranged on both sides thereof. A pilot fluid inlet and a pressure discharge port are arranged in the pilot mechanism, and a check valve is arranged at the pilot fluid inlet; the power device includes the fluid flow direction switching valve and a direct-stroke reciprocating power cylinder block, and small holes are formed in the cylinder barrel for communicating with the pilot mechanism of the fluid flow direction switching valve to obtain a pilot signal. In the automatic control switching direct-stroke reciprocating power device provided by the present invention, there is no coil, no need for electric control, and no mechanical collision type reversing mechanism.

Description

Technical Field

[0001] The present invention relates to a multi-way valve and a piston machine for driving a workpiece, and more particularly to a fluid flow direction switching valve and an automatic control switching direct stroke reciprocating power device. Background Art

[0002] In the prior art, for example, the cylinder of a pneumatic plunger pump belongs to a direct stroke automatic reciprocating cylinder. There is an in-built reversing valve on the piston, which is designed on the top of the piston. During commutation, the piston assembly will impact the compression spring on the front cylinder head of the cylinder and the conical spiral spring on the rear cylinder head of the cylinder. Springs have a certain fatigue limit. High-frequency mechanical collisions not only generate large noise but also greatly reduce the service life of the product. In addition, for a booster pump used for fluid boosting, the power part is also a direct stroke reciprocating cylinder with an in-built mechanical reversing valve, which is not designed on the piston but on the front and rear cylinder heads of the cylinder. When the cylinder moves linearly, after the piston hits the valve needle of this in-built reversing valve, it obtains a commutation signal. However, due to the running inertia of the piston and the execution air source obtained after commutation being insufficient to immediately commutate the piston, the piston will maintain its original moving direction and run for a certain distance. Although this distance is very small, the piston will still directly impact the front or rear cylinder head, resulting in a pure mechanical collision and generating quite a lot of noise. This is also a design flaw or a defect of the product.

[0003] In the prior art, a power pump for medium (fluid) transportation using a direct stroke reciprocating power unit is limited to the transportation function. Because it cannot start at low pressure (for example, it cannot start at 0.15 - 0.3 MPa because the reversing valve core in the prior art cannot move and commutate at a pressure of 0.3 MPa and below), some cannot start again after being at low pressure, and can only start again after major disassembly and reassembly (during secondary assembly, the reversing valve core is manually fixed at the extreme position after commutation). Therefore, it can only be started at high air pressure (requiring 0.5 - 0.8 MPa for use). As a boosting function, the adjustable range of the output pressure is small, a relatively wide output pressure range cannot be obtained, and there are few choices for the operating pressure. Therefore, it is not very suitable for boosting and pressure maintaining. In a direct stroke automatic reciprocating plunger pump, during operation, the piston assembly will impact the compression spring on the front cylinder head of the cylinder and the conical spiral spring on the rear cylinder head of the cylinder. Springs have a certain fatigue limit. High-frequency mechanical collisions not only generate large noise but also greatly reduce the service life of the product.

[0004] For the pneumatically controlled valves in the prior art, the models of five-port two-position double-acting pneumatically controlled valves are: 4A120, 4A220, 4A320, 4A420; EAV220, EAV320, EAV420, EAV620. Even if signals can be obtained from ports A and B for these pneumatically controlled valves currently available on the market, they cannot be controlled independently by their own units and can only operate after being controlled by other valves. Because the compressed air obtained from ports A and B cannot be discharged by itself and can only be exhausted through the solenoid valve, manual valve, hand-operated valve, hand-rotating valve, mechanical valve and foot valve that control it. Without exhausting the air, the reversing spool of the pneumatically controlled valve cannot reverse. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a fluid flow direction switching valve and an automatic control switching linear reciprocating power device.

[0006] To solve the above problems, the technical solutions adopted by the present invention are:

[0007] A fluid flow direction switching valve, the switching valve is a two-position five-way reversing valve, which includes a valve body, a valve cavity formed in the valve body, a reversing spool slidably arranged in the valve cavity, and pilot mechanisms respectively arranged on the left and right sides of the valve body. Five valve ports are arranged on the valve body, and the five valve ports are a pressure input port P, two fluid output ports and two fluid return ports;

[0008] The pilot mechanism includes a pilot chamber housing, a pilot chamber formed in the pilot chamber housing, and a pilot piston arranged in the pilot chamber. The pilot piston is used to push the reversing spool to move and reverse. The pilot piston divides the pilot chamber into an inner chamber on one side of the reversing spool and an outer chamber on the other side;

[0009] A pilot fluid inlet communicating with the outer chamber and a fluid pressure discharge hole are arranged on the pilot chamber housing, and a check valve is arranged on the internal or external air path of the pilot fluid inlet.

[0010] As a further improvement of the present invention, the outer chamber of at least one of the pilot mechanisms is communicated with the pressure input port through an adjustment channel, and a control mechanism for controlling the on-off of the adjustment channel is arranged on this pilot mechanism.

[0011] As a further improvement of the present invention, the control mechanism includes a control button arranged on the pilot chamber housing of this pilot mechanism and a pilot spool arranged in the pilot chamber housing of this pilot mechanism. In the static state, the pilot spool closes the adjustment channel, and pressing down the control button makes the pilot spool move to open the adjustment channel.

[0012] As a further improvement of the present invention, a fluid nozzle and a pilot valve core seat are fixedly arranged in the pilot chamber housing of the pilot mechanism provided with the control mechanism. A fluid outlet is arranged on the fluid nozzle. The end of the adjustment channel is communicated with the fluid outlet. The pilot valve core is slidably arranged on the pilot valve core seat. A valve core return spring is arranged between the pilot valve core and the pilot valve core seat. The valve core return spring makes the pilot valve core seal the fluid outlet in a static state.

[0013] As a further improvement of the present invention, the pilot chamber housing of the pilot mechanism provided with the control mechanism includes a pilot chamber main housing and a pilot chamber end cover. The pilot chamber is arranged in the pilot chamber main housing. The pilot fluid inlet is arranged on the pilot chamber end cover. A valve core installation hole is arranged in the pilot chamber main housing and the pilot chamber end cover. The pilot valve core and the pilot valve core seat are arranged in the valve core installation hole. The control button is arranged on the pilot chamber main housing. The fluid nozzle is arranged in the pilot chamber main housing.

[0014] As a further improvement of the present invention, a first hole is arranged in the pilot chamber main housing to communicate with the fluid outlet. A second hole is arranged in the valve body to communicate with the pressure input port. The first hole is communicated with the second hole. The first hole and the second hole constitute the adjustment channel.

[0015] As a further improvement of the present invention, the one-way valve is arranged in the internal air path of the pilot fluid inlet. A one-way valve installation hole is arranged in the pilot chamber housing. The one-way valve includes a one-way valve rod arranged in the one-way valve installation hole. A sealing ring is arranged on the top of the one-way valve rod. The one-way valve plug and the sealing ring are used to seal the pilot fluid inlet from the inside. A spring is sleeved on the one-way valve rod. A cylindrical adjusting screw is arranged in the one-way valve installation hole. The spring is arranged between the adjusting screw and the one-way valve rod. The adjusting screw is in threaded fit with the one-way valve installation hole. An installation hole plug is arranged at the outermost end of the one-way valve installation hole.

[0016] The present invention also provides an automatic control switching direct-stroke reciprocating power device, which includes the fluid flow direction switching valve as described above and a direct-stroke reciprocating power cylinder body. The direct-stroke reciprocating power cylinder body includes a cylinder barrel, a front end cover and a rear end cover hermetically arranged at both ends of the cylinder barrel, and a piston arranged in the cylinder barrel. A piston chamber for accommodating the piston is formed in the cylinder barrel. The piston divides the piston chamber into a front piston chamber and a rear piston chamber. A first pilot fluid output hole and a second pilot fluid output hole are arranged on the barrel wall of the cylinder barrel.

[0017] As a further improvement, the first pilot fluid output hole and the second pilot fluid output hole are respectively arranged on both sides of the midline in the length direction of the cylinder barrel; preferably, the first pilot fluid output hole and the second pilot fluid output hole are symmetrically arranged with respect to the midline in the length direction of the cylinder barrel.

[0018] The number of the first pilot fluid output holes and the second pilot fluid output holes is N, where N is a positive integer greater than or equal to 1; the first pilot fluid output holes and the second pilot fluid output holes can be round holes or threaded holes, or can also be waist-shaped holes, and the N first pilot fluid output holes and the second pilot fluid output holes are respectively arranged along the circumferential direction of the cylinder barrel;

[0019] When the piston moves to the front end of the cylinder barrel, the piston closes the second pilot fluid output hole, and the first pilot fluid output hole communicates with the rear piston cavity;

[0020] When the piston moves to the rear end of the cylinder barrel, the piston closes the first pilot fluid output hole, and the second pilot fluid output hole communicates with the front piston cavity;

[0021] A front fluid inlet and outlet communicating with the front piston cavity is arranged on the front end cover, and a rear fluid inlet and outlet communicating with the rear piston cavity is arranged on the rear end cover;

[0022] The front fluid inlet and outlet and the rear fluid inlet and outlet are respectively communicated with two fluid output ports on the fluid flow direction switching valve, and the first pilot fluid output hole and the second pilot fluid output hole are respectively communicated with the pilot fluid inlets of the pilot mechanisms on the corresponding sides of the fluid flow direction switching valve.

[0023] Further, a piston rod is fixedly arranged on the piston, the piston rod passes through the front end cover and extends outside the piston cavity, and a sealing mechanism is arranged between the piston rod and the front end cover.

[0024] Further, when the piston moves to the front end of the cylinder barrel to make the first pilot fluid output hole communicate with the rear piston cavity, there is a buffer gap between the front end of the piston and the front end cover;

[0025] When the piston moves to the rear end of the cylinder barrel to make the second pilot fluid output hole communicate with the front piston cavity, there is a buffer gap between the rear end of the piston and the rear end cover.

[0026] The beneficial effects of adopting the above technical solutions are as follows:

[0027] In the fluid flow direction switching valve provided by the present invention, since the pilot mechanisms on both sides are provided with pilot fluid inlets and fluid pressure discharge holes, and a check valve is provided on the internal or external air path of the pilot fluid inlet, the pilot fluid inlet only allows fluid to enter and cannot discharge. The fluid pressure discharge hole is used to discharge the fluid in the pilot chamber to play a role in pressure relief. Therefore, when using the fluid flow direction switching valve provided by the present invention, there is no need to separately provide a reversing mechanism on the air path of the pilot mechanism to switch the fluid flow direction in the pilot fluid pipeline. The pilot mechanism can work normally through the single-action pilot fluid inlet and fluid pressure discharge hole. Therefore, using the fluid flow direction switching valve provided by the present invention can save costs and simplify operations.

[0028] In the case where a control mechanism is provided in the pilot mechanism, since the outer chamber of the pilot mechanism is communicated with the pressure input port through the adjustment channel, when the system stops under an uncontrolled state and the reversing spool stops at the middle position of the valve body so that the pressure input port is not communicated with both fluid output ports, the pilot mechanism can obtain pressure from the pressure input port through the control mechanism, and then the pilot piston can push the reversing spool to move, and then the system can be started again. This kind of operation is simple and convenient, avoiding the workload and losses caused by disassembling and assembling the fluid flow direction switching valve.

[0029] The automatic control switching linear reciprocating power device provided by the present invention utilizes the fluid flow direction switching valve provided by the present invention to cooperate with the linear reciprocating power device. The pilot mechanism of the fluid flow direction switching valve obtains the pilot fluid source from the pilot fluid output hole opened on the cylinder barrel of the linear reciprocating power device, and outputs the pilot fluid source to the fluid flow direction switching valve provided by the present invention through the pilot fluid output hole. The corresponding pilot mechanism of the fluid flow direction switching valve pushes the reversing spool to move to realize commutation under the action of the pilot fluid source. There is no need to set a mechanical commutation device in the linear reciprocating power device during the whole process. There is no mechanical collision when the piston commutes, the noise is small, and the service life is long. The automatic control switching linear reciprocating power device provided by the present invention realizes automatic commutation operation through the change of the position during the movement of the piston, and does not need to add other control valves or reversing valves to assist in commutation.

[0030] The automatic control switching linear reciprocating power device provided by the present invention can be started under a low-pressure state. Therefore, the adjustable range of the output pressure of the device is relatively wide, which is suitable for the working conditions of pressurizing and maintaining pressure of the medium (fluid), and is also suitable for transporting the medium (for fluid use). Brief Description of the Drawings

[0031] Figure 1 It is a schematic structural diagram of Embodiment 1 of the fluid flow direction switching valve of the present invention.

[0032] Figure 2 is Figure 1Schematic diagram of the pilot mechanism in

[0033] Figure 3 is the schematic diagram of the structure of Embodiment 2 of the fluid flow direction switching valve of the present invention.

[0034] Figure 4 is Figure 3 schematic diagram of the structure of the pilot mechanism provided with a control mechanism in

[0035] Figure 5 is Figure 4 partial enlarged view of part C in

[0036] Figure 6 is the schematic diagram of the structure of Embodiment 2 of the fluid flow direction switching valve of the present invention from another perspective.

[0037] Figure 7 is the schematic diagram of the structure of Embodiment 3 of the fluid flow direction switching valve of the present invention.

[0038] Figure 8 is the schematic diagram of the structure of Embodiment 3 of the fluid flow direction switching valve of the present invention from another perspective.

[0039] Figure 9 is the schematic diagram of the structure of Embodiment 4 of the fluid flow direction switching valve of the present invention.

[0040] Figure 10 is the schematic diagram of the structure of the automatic control switching linear reciprocating power device of the present invention.

[0041] Figure 11 is the schematic diagram of the structure of the automatic control switching linear reciprocating power device in another state.

[0042] Figure 12 and Figure 13 are respectively the schematic diagrams of the structures of one embodiment of the check valve in the pilot mechanism.

[0043] Wherein: 100 is a fluid flow direction switching valve, 1 is a valve body, 2 is a valve cavity, 3 is a reversing valve core, 4 is a pilot mechanism, 4-1 is a pilot chamber housing, 4-1-1 is a pilot chamber end cover, 4-1-2 is a main pilot chamber housing, 4-2 is a pilot chamber, 4-2-1 is an outer chamber, 4-2-2 is an inner chamber, 4-3 is a pilot piston, 4-4 is a screw, 4-5 is a check valve, 4-5-2 is a sealing ring, 4-5-3 is a check valve stem, 4-5-4 is a spring, 4-5-5 is a steel ball, 4-5-6 is a check valve core, 4-6 is an adjusting screw, 4-7 is a mounting hole plug, 4-8 is a sealing ring, 4-9 is a first passage, 4-10 is a control button, 4-11 is a pilot valve core, 4-12 is a fluid nozzle, 4-13 is a fluid outlet, 4-14 is a pilot valve core seat, 4-15 is a valve core return spring, 4-16 is a through hole, 4-17 is a valve core mounting hole, 4-18 is a check valve mounting hole, 5 is a second passage, P is a pressure input port, A is a first fluid output port, B is a second fluid output port, R is a first fluid return port, S is a second fluid return port, Y is a first pilot fluid inlet, Z is a second pilot fluid inlet, W is a first fluid pressure discharge hole, U is a second fluid pressure discharge hole;

[0044] 200 is a direct stroke reciprocating power cylinder block, 6 is a cylinder barrel, 7 is a front end cover, 8 is a rear end cover, 9 is a piston cavity, 9-1 is a front piston cavity, 9-2 is a rear piston cavity, 10 is a piston, 11 is a piston rod, M is a center line, F is a first pilot fluid output hole, V is a second pilot fluid output hole, Q is a front fluid inlet and outlet, H is a rear fluid inlet and outlet. Specific embodiments

[0045] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be clearly and completely described below in conjunction with specific embodiments. Among them, the terms "center", "vertical", "horizontal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "first", "second", etc. indicate the orientation or position or order relationship based on the orientation or position shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention.

[0046] Embodiment 1

[0047] As Figure 1A fluid flow direction switching valve as shown, the switching valve is a two-position five-way reversing valve, which includes a valve body 1, a valve cavity 2 formed in the valve body 1, a reversing valve core 3 slidably disposed in the valve cavity 2, and pilot mechanisms respectively disposed on the left and right sides of the valve body 1. Five valve ports are provided on the valve body 1, and the five valve ports are respectively a pressure input port P (abbreviated as P or P port), a first fluid output port A (abbreviated as A or A port), a second fluid output port B (abbreviated as B or B port), a first fluid return port R (abbreviated as R or R port), and a second fluid return port S (abbreviated as S or S port). The A port and the B port can be threaded holes, light holes or cylindrical counterbored holes.

[0048] As Figure 1 and Figure 2 shown, the pilot mechanism includes a pilot chamber housing 4-1, a pilot chamber 4-2 formed in the pilot chamber housing 4-1, and a pilot piston 4-3 disposed in the pilot chamber 4-2. Both sides of the valve cavity 2 are penetrated, so that both ends of the reversing valve core 3 communicate with the pilot mechanisms on both sides respectively. The pilot piston 4-3 is used to push the reversing valve core 3 to move to implement commutation. A sealing ring 4-8 is disposed on the outer circumference of the pilot piston 4-3. The pilot piston 4-3 divides the pilot chamber 4-2 into an outer chamber 4-2-1 and an inner chamber 4-2-2. The inner chamber 4-2-2 is located on one side of the reversing valve core 3, and the outer chamber 4-2-1 is located on one side of the pilot mechanism. A pilot fluid inlet and a fluid pressure discharge hole communicating with the outer chamber 4-2-1 are provided on the pilot chamber housing 4-1. A one-way valve 4-5 is disposed on the internal or external air path of the pilot fluid inlet. In this embodiment, the one-way valve 4-5 is disposed in the internal air path of the pilot fluid inlet, that is, the one-way valve 4-5 is integrated in the pilot chamber housing 4-1. Between the pilot chamber housing 4-1 and the valve body 1, there is a rubber gasket seal, or an O-ring seal can also be used.

[0049] As Figure 1 and Figure 2 shown, the pilot fluid inlet of the pilot mechanism on the left side is defined as the first pilot fluid inlet Y (abbreviated as Y or Y port), and the fluid pressure discharge hole is defined as the first fluid pressure discharge hole W (abbreviated as W or W port); the pilot fluid inlet of the pilot mechanism on the right side is defined as the second pilot fluid inlet Z (abbreviated as Z or Z port), and the fluid pressure discharge hole is defined as the second fluid pressure discharge hole U (abbreviated as U or U port). The first pilot fluid inlet Y and the second pilot fluid inlet Z can be in the form of threaded holes, light holes or cylindrical counterbored holes, etc.

[0050] In this embodiment, the structures of the pilot mechanisms on the left and right sides are the same. As Figure 2As shown, taking the pilot mechanism on the left side as an example, the pilot chamber housing 4-1 is fixedly arranged on the valve body 1 through screws 4-4. The pilot chamber housing 4-1 is provided with a through hole that penetrates up and down at its end. The upper part of this through hole is the first pilot fluid inlet Y, and the lower part is a check valve mounting hole 4-18 for mounting the check valve 4-5. The first pilot fluid inlet Y and the check valve mounting hole 4-18 are communicated through a small-diameter fine hole, that is, a step is formed at the connection between the top end of the check valve mounting hole 4-18 and the first pilot fluid inlet Y.

[0051] The check valve 4-5 includes a check valve stem 4-5-3 arranged in the check valve mounting hole 4-18. A sealing ring 4-5-2 is arranged on the top of the check valve stem 4-5-3. The check valve stem 4-5-3 and the sealing ring 4-5-2 are used to close the first pilot fluid inlet Y from the inside. A spring 4-5-4 is sleeved on the check valve stem 4-5-3. A cylindrical adjusting screw 4-6 is arranged in the check valve mounting hole 4-18. The spring 4-5-4 is arranged between the adjusting screw 4-6 and the check valve stem 4-5-3. The adjusting screw 4-6 is in threaded fit with the check valve mounting hole 4-18. An installation hole plug 4-7 is arranged at the outermost end of the check valve mounting hole 4-18. The spring 4-5-4 is used to make the check valve stem 4-5-3 lean against the connection between the top end of the check valve mounting hole 4-18 and the first pilot fluid inlet Y in the static state, so that the first pilot fluid inlet Y is in a closed state and the internal pressure cannot open the check valve 4-5. When the pilot fluid with a certain pressure enters from the first pilot fluid inlet Y, under the action of the pilot fluid, the check valve stem 4-5-3 is pushed to move downward, so that the first pilot fluid inlet Y is opened. At this time, the spring 4-5-4 is further compressed. When the pilot fluid disappears, under the action of the spring 4-5-4, the check valve stem 4-5-3 moves upward to reset, so that the first pilot fluid inlet Y is closed.

[0052] By screwing the adjusting screw 4-6, the position of the regulator in the check valve mounting hole 4-18 can be adjusted to adjust the pressure of the spring 4-5-4, and then the self-pressure of the check valve 4-5 can be adjusted, so that the minimum commutation pressure of the pneumatic control valve reaches a preset pressure, such as 0.15 MPa. Then, when the pressure greater than or equal to 0.15 MPa is obtained at the pilot fluid inlet, the entire check valve 4-5 can be pushed to open, and the fluid can flow to the switching valve to realize commutation. The side wall of the pilot chamber housing 4-1 of the pilot mechanism on the left side is provided with the first fluid pressure relief hole W, and the first fluid pressure relief hole W is communicated with the check valve mounting hole 4-18 and then communicated with the outer chamber 4-2-1. As another implementation manner, the first fluid pressure relief hole W and the second fluid pressure relief hole U can also be arranged on the installation hole plug 4-7 or other positions.

[0053] As Figure 12 and Figure 13 shown, as an equivalent replacement form, the check valve stem 4-5-3 in the check valve 4-5 is interchangeable with Figure 12 the steel ball 4-5-5 shown and Figure 13 the check valve core 4-5-6 shown.

[0054] Since the pilot mechanism on the right side has the same structure as the pilot mechanism on the left side, for the convenience of describing the working process in detail later, only the second pilot fluid inlet Z and the second fluid discharge pressure hole U are distinguished in terms of name and reference numeral.

[0055] Taking the pressure source fluid as gas as a specific embodiment for description, when the fluid flow direction switching valve described in this embodiment is working, the first pilot fluid inlet Y gets gas, and the pilot piston 4-3 on the left side is pushed to move to the right. At this time, a certain amount of gas is discharged from the first fluid discharge pressure hole W. However, compared with the intake air volume of the first pilot fluid inlet Y, the small amount of gas discharged from the first fluid discharge pressure hole W will not affect the movement of the pilot piston 4-3. Therefore, the reversing valve core 3 is pushed by the pilot piston 4-3 on the left side to move to the right. During this process, the second pilot fluid inlet Z is closed, and when the pilot piston 4-3 on the right side is pushed to move to the right by the reversing valve core 3, the gas in the outer chamber on the right side is discharged from the second fluid discharge pressure hole U. When the reversing valve core 3 moves to the right, the reversing is achieved. When the second pilot fluid inlet Z gets gas, the pilot piston 4-3 on the right side moves to the left, pushing the reversing valve core 3 to move to the left to achieve reversing.

[0056] The working process of the fluid flow direction switching valve described in this embodiment continuously repeats the above process.

[0057] Since the execution of reversing only depends on the first pilot fluid inlet Y and the second pilot fluid inlet Z getting gas alternately, under the action of the check valve and the fluid discharge pressure hole, there is no need for other control mechanisms to switch the on-off and air flow direction of the first pilot fluid inlet Y and the second pilot fluid inlet Z. Therefore, the fluid flow direction switching valve provided by the present invention can achieve reversing control by itself without relying on electric control or being controlled by other valve types.

[0058] As can be seen from the above specific implementation process, the function of the first fluid pressure discharge hole W is that when the reversing spool 3 moves to the left for reversing, the first fluid pressure discharge hole W discharges the fluid in the left pilot chamber 4-2, so that the left pilot piston 4-3 can move smoothly to the left. During this process, the left pilot chamber is depressurized, and the faster the first fluid pressure discharge hole W discharges the fluid, the better; when the first pilot fluid inlet Y enters the pilot fluid, at this time, the outer chamber of the left pilot chamber 4-2 is under the pressure of the entering pilot fluid, pushing the left pilot piston 4-3 to move to the right. During this process, the left pilot chamber needs to maintain pressure, and the slower the first fluid pressure discharge hole W discharges the fluid, the better. Similarly, the function of the second fluid pressure discharge hole U is the same. Therefore, neither the first fluid pressure discharge hole W nor the second fluid pressure discharge hole U is the larger the better, nor the smaller the better. The fluid discharge efficiency of the first fluid pressure discharge hole W and the second fluid pressure discharge hole U should take into account that the pilot chamber where they are located can meet the operating conditions during the depressurization and pressure maintenance processes.

[0059] When the working pressure of the fluid is greater, the diameters of the first fluid pressure discharge hole W and the second fluid pressure discharge hole U can also increase accordingly, and the fluid flow direction switching valve can be maintained to complete the reversing operation. Taking compressed air as the fluid pressure source as an example, for instance, when the input air pressure is 0.15 Mpa and the inner diameter of the first pilot fluid inlet Y is 2.5 mm, the inner diameter of the corresponding first fluid pressure discharge hole W can be 1.8 mm. At this time, the fluid flow direction switching valve is almost in the critical state of being able to complete the reversing operation. When the input air pressure increases, the fluid flow direction switching valve can complete the reversing operation. However, since the cross-sectional area of the first fluid pressure discharge hole W exceeds 50% of the cross-sectional area of the first pilot fluid inlet Y at this time, a large amount of compressed air loss will be caused, resulting in the problem of uneconomical operation of the device. The relationship between the second fluid pressure discharge hole U and the second pilot fluid inlet Z is the same.

[0060] Therefore, as a preferred implementation manner, the cross-sectional areas of the nominal diameters of the first fluid pressure discharge hole W and the second fluid pressure discharge hole U are 4%-10% of the cross-sectional areas of the nominal diameters of the first pilot fluid inlet Y and the second pilot fluid inlet Z, and more preferably 5%-7%. For example, when the inner diameter of the first pilot fluid inlet Y is 2.5 mm, the inner diameter of the corresponding first fluid pressure discharge hole W is preferably 0.5 mm - 0.8 mm. The relationship between the second fluid pressure discharge hole U and the second pilot fluid inlet Z is the same.

[0061] As an equivalent replacement form, an adjustment mechanism can be provided at the fluid pressure discharge holes (W, U) to adjust the opening degree of the fluid pressure discharge holes. Under different working conditions, the opening degree of the fluid pressure discharge holes can be adjusted through the adjustment mechanism so that the fluid flow direction switching valve can smoothly complete the switching operation without causing a large amount of energy consumption. Although the structure is complex in this way, it is convenient to use, has a wide application range, and strong controllability.

[0062] Embodiment 2

[0063] As Figures 3 to 6 shown, another embodiment of the fluid flow direction switching valve is provided.

[0064] Based on Embodiment 1, in this embodiment, a control mechanism for forced commutation and forced start is provided on the pilot mechanism on the right side. Specifically, the outer chamber of the pilot mechanism on the right side is communicated with the pressure input port P through an adjustment channel, and a control mechanism for controlling the on / off of the adjustment channel is provided on the pilot mechanism.

[0065] The control mechanism includes a control button 4-10 provided on the pilot chamber housing 4-1 of the pilot mechanism and a pilot valve core 4-11 provided in the pilot chamber housing 4-1 of the pilot mechanism. In the stationary state, the pilot valve core 4-11 closes the adjustment channel, and pressing down the control button 4-10 causes the pilot valve core 4-11 to move and open the adjustment channel. The stationary state described in this embodiment specifically refers to the state where the pilot mechanism is not affected by other external forces.

[0066] The pilot chamber housing 4-1 of the pilot mechanism provided with the control mechanism includes a pilot chamber main housing 4-1-2 and a pilot chamber end cover 4-1-1. The pilot chamber end cover 4-1-1 and the pilot chamber main housing 4-1-2 are fixedly arranged on the valve body 1 through screws 4-4.

[0067] In this embodiment, the pilot mechanisms on the left and right sides further include check valves 4-5 provided in the pilot housing 4-1. In the pilot mechanism provided with the control mechanism, the check valves 4-5 are provided in the pilot chamber end cover 4-1-1, and the specific setting structures of the two check valves 4-5 are the same as those in Embodiment 1.

[0068] The pilot chamber 4-2 is provided in the pilot chamber main housing 4-1-2, the pilot fluid inlet Z is provided on the pilot chamber end cover 4-1-1, and a valve core mounting hole 4-17 is provided in the pilot chamber main housing 4-1-2 and the pilot chamber end cover 4-1-1. The pilot valve core 4-11 and the pilot valve core seat 4-14 are provided in the valve core mounting hole 4-17, dividing the pilot chamber housing 4-1 into the pilot chamber main housing 4-1-2 and the pilot chamber end cover 4-1-1, and a valve core mounting hole 4-17 for installing the pilot valve core 4-11 is provided between the two, which is convenient for the assembly of the pilot valve core 4-11 and the pilot valve core seat 4-14.

[0069] The control button 4-10 is arranged on the main housing 4-1-2 of the pilot chamber. A return spring is sleeved on the control button 4-10, and the return spring keeps the control button 4-10 in a state of bouncing outward. That is, when the control button 4-10 is pressed downward, the control button 4-10 moves downward to compress the return spring, and the return spring keeps the control button 4-10 in a state of bouncing upward when no other external force is applied.

[0070] A fluid nozzle 4-12 and a pilot valve core seat 4-14 are fixedly arranged in the pilot chamber housing 4-1 of the pilot mechanism provided with the control mechanism. Specifically, an outer wall plate is arranged outside the pilot chamber 4-2, and the outer wall plate separates the pilot chamber 4-2 from the valve core mounting hole 4-17. The fluid nozzle 4-12 is arranged in the main housing 4-1-2 of the pilot chamber. Specifically, the fluid nozzle 4-12 is frustum-shaped and formed on the outer wall plate. A fluid outlet 4-13 is arranged on the axis of the fluid nozzle 4-12. The fluid outlet 4-13 is a blind hole, that is, one end thereof communicates with the valve core mounting hole 4-17 and the other end is closed. The end of the adjustment channel is communicated with the fluid outlet 4-13, and the fluid outlet 4-13 communicates with the valve core mounting hole 4-17.

[0071] The pilot valve core 4-11 is slidably arranged on the pilot valve core seat 4-14. A groove is arranged on the pilot valve core 4-11, and a boss adapted to the groove is arranged on the pilot valve core seat 4-14, and the gap between the two allows fluid to pass through. That is to say, even though the pilot valve core seat 4-14 and the pilot valve core 4-11 are arranged in the valve core mounting hole 4-17, the pilot fluid inlet is still communicated with the pilot chamber 4-2 through the valve core mounting hole 4-17. Two through holes 4-16 are formed on the outer wall plate for communicating the valve core mounting hole 4-17 with the pilot chamber 4-2.

[0072] A spool return spring 4-15 is arranged between the pilot spool 4-11 and the pilot spool seat 4-14. The spool return spring 4-15 seals the fluid outlet 4-13 when the pilot spool 4-11 is in a static state. That is, the spool return spring 4-15 is always in a compressed state. Without other external forces, the spool return spring 4-15 makes the pilot spool 4-11 abut against the fluid nozzle 4-12. The rubber body at the end of the pilot spool 4-11 blocks the fluid outlet 4-13, closing the adjustment channel. When the control button 4-10 is pressed downward, the inclined surface at the bottom of the control button 4-10 pushes the pilot spool 4-11 to move outward, away from the fluid nozzle 4-12, opening the fluid outlet 4-13. Then, the adjustment channel communicates with the pilot chamber 4-2 through the spool mounting hole 4-17 and the through hole 4-16. The pressure from the fluid source at port P causes the pilot piston 4-3 to move, further pushing the reversing spool 3 to achieve forced commutation.

[0073] A first hole 4-9 communicating with the fluid outlet 4-13 is arranged in the main housing 4-1-2 of the pilot chamber. A second hole 5 communicating with the pressure input port P is arranged in the valve body 1. The first hole 4-9 communicates with the second hole 5. The first hole 4-9 and the second hole 5 form the adjustment channel.

[0074] As Figure 3 shown, in this embodiment, a control mechanism is arranged in the pilot mechanism on the right side. The second fluid pressure discharge hole U in the pilot mechanism on the right side is arranged on the main housing 4-1-2 of the pilot chamber.

[0075] In this embodiment, since a control mechanism for forced start of forced commutation is arranged on the pilot mechanism on the right side, if the air source is at low pressure during use, causing the reversing valve to stop working, when the air source returns to normal pressure, if the reversing spool 3 just stops at the middle position of the valve body 1, port P is not connected to port A or port B, then the air source cannot be output through the reversing valve, so the system cannot be started. In this case, the fluid flow direction switching valve (reversing valve) provided in this embodiment can open the adjustment channel by pressing the control button 4-10 to push the pilot spool 4-11 to move. At this time, the right pilot chamber 4-2 obtains the pilot air source from the pressure input port P. The pilot air source pushes the right pilot piston 4-3 to move to the left, further pushing the reversing spool 3 to move to the left to achieve the air path switching of the reversing valve. After the air path of the reversing valve is unblocked, the system starts to resume normal operation. It should be particularly noted that when pressing the control button 4-10, only press it briefly and then release it immediately to reset it. The pilot piston 4-3 can move instantly when pressed to push the reversing spool 3 to move and commutate. The pressing time is usually 1-2 seconds.

[0076] This embodiment is described by taking gas as the fluid pressure source. Under the same principle, the same effect can be achieved when liquid (such as hydraulic oil) is used as the fluid pressure source.

[0077] like Figure 3 As shown, in this embodiment, a control mechanism for forced reversing and forced starting is provided on the right pilot mechanism. As an equivalent implementation, the control mechanism can be provided in the left pilot mechanism to achieve the same effect.

[0078] like Figure 6 As shown, two channels 2 5 are symmetrically arranged on the valve body 1, the left channel 2 leads to the left pilot mechanism, and the right channel 2 leads to the right pilot mechanism. The right channel 2 is connected to the channel 1 4-9 in the pilot chamber main housing 4-1-2 of the right pilot mechanism, and an O-ring is arranged at the connection. In this embodiment, Figure 3 In the structure shown, since the left pilot mechanism is not provided with a control mechanism, the left channel 2 has no practical function and is sealed with a rubber pad or an O-ring at its end.

[0079] In this embodiment, the opening positions of the five valve ports (P port, A port, B port, R port, and S port) are as follows: Figure 3 As shown, the P port, R port, and S port are arranged on one side of the bottom surface, while the A port and B port are arranged on the side of the top surface opposite to the bottom surface. Figure 6 shown.

[0080] The reason why two channels 2 5 are symmetrically arranged on the valve body 1 is that when the two implementation methods of the reversing valve with a control mechanism on one side and the control mechanism on both sides are simultaneously produced and processed, the valve bodies of the two products can be completely interchangeable, and the only difference is whether one of the channels 2 needs to be blocked. However, there is no need to distinguish them in the process of valve body production and distribution, which greatly saves the management cost of the processing process.

[0081] Example 3

[0082] like Figure 7 and Figure 8 FIG. 2 is another embodiment of the fluid flow direction switching valve of the present invention. The structure and working principle of this embodiment are exactly the same as those of the second embodiment, that is, the left pilot mechanism is not provided with a control mechanism, and the right pilot mechanism is provided with a control mechanism.

[0083] The difference between this embodiment and embodiment 2 is that the structure of the valve body 1 is different, specifically, the opening positions of the five valve ports (P port, A port, B port, R port, S port) are different. Figure 7As shown, the P port, R port, and S port are arranged on one side of the bottom surface, while the A port and B port are arranged on the side surface perpendicular to the bottom surface. In this embodiment, due to the relationship of the positions of the five valve ports, the opening method of the second hole 5 is as Figure 8 shown. The principle of this valve body is also applicable to Embodiments 1, 2, and 4.

[0084] Embodiment 4

[0085] As Figure 9 shown, as another implementation method, control mechanisms for forced start can be arranged on both the left and right sides of the pilot mechanism. Referring to Figure 3 shown, the structure of this embodiment is to replace the left pilot mechanism shown in Figure 3 with the right pilot mechanism, and at the same time, a second hole 5 is also arranged on the left side of the valve body 1. In this way, control mechanisms for forced start are arranged in both the left and right pilot mechanisms. When encountering a working condition where secondary start cannot be achieved after low-pressure shutdown, any one of the control buttons 4-10 is pressed to achieve secondary start. The two control buttons 4-10 provide greater convenience. Under normal conditions, any one of the control buttons 4-10 is pressed to achieve restart. If the expected restart effect cannot be achieved when one of the control buttons is pressed under uncontrolled conditions, the other control button can be selected to press.

[0086] In this embodiment, the structure of the valve body 1 adopts the structure of the valve body 1 as shown in Figure 3 and Figure 6 shown, the difference is that the gasket at the end of the second hole 5 on the left side is replaced with an O-ring to open the second hole 5.

[0087] Embodiment 5

[0088] As Figure 10 and Figure 11 shown is a specific implementation method of an automatically controlled switching direct-stroke reciprocating power device disclosed by the present invention.

[0089] The automatically controlled switching direct-stroke reciprocating power device described in this embodiment includes the fluid flow direction switching valve 100 described in any one of Embodiments 1 to 4, and a direct-stroke reciprocating power cylinder body 200. The direct-stroke reciprocating power cylinder body can be a pneumatic cylinder or a hydraulic cylinder. Similarly, the corresponding fluid flow direction switching valve uses a gas reversing valve or a hydraulic reversing valve. For the convenience of description, the situation of using gas as the fluid power source is described in detail in this embodiment.

[0090] As Figure 10 and Figure 11 shown, the fluid flow direction switching valve illustrated in this embodiment adopts the fluid flow direction switching valve described in Embodiment 2 or Embodiment 3, that is, a control mechanism for forced commutation and forced start is arranged in one of the pilot mechanisms on one side.

[0091] The direct-stroke reciprocating power cylinder block includes a cylinder barrel 6, a front end cover 7 and a rear end cover 8 which are hermetically arranged at both ends of the cylinder barrel 6, and a piston 10 arranged in the cylinder barrel 6. A piston cavity 9 for accommodating the piston 10 is formed in the cylinder barrel 6. The piston 10 divides the piston cavity 9 into a front piston cavity 9-1 and a rear piston cavity 9-2. A first pilot fluid output hole F (abbreviation: F or F port) and a second pilot fluid output hole V (abbreviation: V or V port) are arranged on the barrel wall of the cylinder barrel 6. As a further improvement, the first pilot fluid output hole F and the second pilot fluid output hole V are respectively arranged on both sides of the midline in the length direction of the cylinder barrel 6; preferably, the first pilot fluid output hole F and the second pilot fluid output hole V are symmetrically arranged with respect to the midline M in the length direction of the cylinder barrel.

[0092] The number of the first pilot fluid output hole F and the second pilot fluid output hole V is N, and N is a positive integer greater than or equal to 1. When N>1, N first pilot fluid output holes F and second pilot fluid output holes V are respectively arranged in a circumferential distribution along the cylinder barrel 6. The first pilot fluid output hole F and the second pilot fluid output hole V can be round holes, or can be kidney-shaped holes or threaded holes. The first pilot fluid output hole F and the second pilot fluid output hole V are preferably such that they are convenient to communicate with the first pilot fluid inlet Y and the second pilot fluid inlet Z of the fluid flow direction switching valve 100 and provide sufficient pilot fluid to them.

[0093] Preferably, the total cross-sectional area of the first pilot fluid output hole F is equivalent to the cross-sectional area of the first pilot fluid inlet Y; similarly, the total cross-sectional area of the second pilot fluid output hole V is equivalent to the cross-sectional area of the second pilot fluid inlet Z.

[0094] As Figure 10 shown, when the piston 10 moves to the front end of the cylinder barrel 6, the piston 10 closes the second pilot fluid output hole V, and the first pilot fluid output hole F communicates with the rear piston cavity 9-2; as Figure 11 shown, when the piston 10 moves to the rear end of the cylinder barrel 6, the piston 10 closes the first pilot fluid output hole F, and the second pilot fluid output hole V communicates with the front piston cavity 9-1; when the piston 10 is located in the middle of the cylinder barrel 6, both the first pilot fluid output hole F and the second pilot fluid output hole V are blocked by the piston 10 so that they do not communicate with the piston cavity 9. During the operation of the piston 10, there is no position where the first pilot fluid output hole F and the second pilot fluid output hole V communicate with the piston cavity 9 at the same time.

[0095] The front end cover 7 is provided with a front fluid inlet / outlet Q communicating with the front piston chamber 9-1, and the rear end cover 8 is provided with a rear fluid inlet / outlet H communicating with the rear piston chamber 9-2; the front fluid inlet / outlet Q (abbreviation: Q or Q port) and the rear fluid inlet / outlet H (abbreviation: H or H port) are respectively communicated with a fluid output port on the fluid flow direction switching valve. In this embodiment, the front fluid inlet / outlet Q is communicated with the first fluid output port A, and the rear fluid inlet / outlet H is communicated with the second fluid output port B.

[0096] The first pilot fluid output hole F and the second pilot fluid output hole V are respectively communicated with the pilot fluid inlets of the pilot mechanisms on the corresponding sides of the fluid flow direction switching valve. In this embodiment, the second pilot fluid output hole V is communicated with the second pilot fluid inlet Z, and the first pilot fluid output hole F is communicated with the first pilot fluid inlet Y.

[0097] The first pilot fluid output hole F and the second pilot fluid output hole V are used to provide pilot air sources for the corresponding pilot mechanisms. When the pressure and flow rate of the required pilot air sources are certain, the more the number of the first pilot fluid output hole F and the second pilot fluid output hole V, the smaller the hole diameter, and the smaller the curve formed by their intersection with the cylinder barrel 6. Therefore, the damage to the piston 10 during operation caused by these holes opened is smaller. The number of the first pilot fluid output hole F and the second pilot fluid output hole V opened should not only consider the influence degree on the smoothness of the inner wall of the cylinder barrel 6, but also consider the strength of the cylinder barrel 6. Therefore, the number of the first pilot fluid output hole F and the second pilot fluid output hole V opened should not significantly affect the strength of the cylinder barrel 6. Therefore, it is appropriate that the number of the first pilot fluid output hole F and the second pilot fluid output hole V is 1-4.

[0098] If the direct stroke reciprocating power cylinder body adopted in this embodiment uses a pneumatic cylinder. This embodiment Figure 10 and Figure 11 shown is a single-rod pneumatic cylinder. A piston rod 11 is fixedly arranged on the piston 10. The piston rod 11 passes through the front end cover 7 and extends outside the piston chamber 9. A sealing mechanism is arranged between the piston rod 11 and the front end cover 7.

[0099] In order to avoid the piston 10 hitting the front end cover 7 and the rear end cover 8 during forward and reverse switching, when the piston 10 moves to the front end of the cylinder barrel 6 and the first pilot fluid output hole F is communicated with the rear piston chamber 9-2, there is a buffer gap between the front end of the piston 10 and the front end cover 7; when the piston 10 moves to the rear end of the cylinder barrel 6 and the second pilot fluid output hole V is communicated with the front piston chamber 9-1, there is a buffer gap between the rear end of the piston 10 and the rear end cover 8.

[0100] The following combines Figure 10 and Figure 11The working process of the automatic control switching linear reciprocating power device described in this embodiment will be described in detail.

[0101] Initially, it is set that the gas in the pilot chamber on the right side is discharged through the second fluid pressure relief hole U, and the P port is communicated with the A port. Compressed gas enters the front piston chamber 9-1 in the cylinder 6 through P-A-Q, and the piston 10 moves to the right. The gas in the rear piston chamber 9-2 is discharged through H-B-S. Until the piston 10 passes through the second pilot fluid output hole V, that is, Q-V-Z is communicated (as Figure 11 shown), the Z port intakes air, and compressed air enters the outer chamber of the pilot mechanism on the right side. At this time, a part of the pilot air source entering from the Z port will flow out through the U port, but since the U port is small, it will not affect the pushing of the pilot piston 4-3 on the right side. The compressed air pushes the pilot piston 4-3 on the right side to move to the left, and pushes the reversing spool 3 to move to the left. The reversing spool 3 then pushes the pilot piston 4-3 on the left side to move to the left synchronously, and the air in the left pilot chamber is discharged through the W port. At this time, the reversing spool 3 instantaneously completes a complete commutation, that is, the reversing spool is in the leftmost extreme position. At this time, the P port is the same as the B port, and compressed air enters the cylinder 6 through P-B-H, and the piston 10 moves to the left. The gas in the front piston chamber 9-1 is discharged through Q-A-R. Until the piston 10 passes through the first pilot fluid output hole F, that is, H-F-Y is communicated (as Figure 10 shown), the Y port intakes air, and compressed air enters the outer chamber of the left pilot mechanism. At this time, a part of the pilot air source entering from the Y port will flow out through the W port, but since the W port is small, it will not affect the pushing of the pilot piston on the left side. The compressed air pushes the pilot piston on the left side to move to the right, driving the reversing spool to move to the right. The reversing spool then pushes the pilot piston on the right side to move to the right synchronously, and the air in the right pilot chamber is discharged through the U port. At this time, the reversing spool moves to the rightmost to complete a complete commutation. At this time, the P port is communicated with the A port, and compressed air enters the front piston chamber 9-1 in the cylinder 6 through P-A-Q (returning to the initial setting), and the piston 10 moves to the right. The gas in the rear piston chamber 9-2 is discharged through H-B-S. Continue to repeat the above cycle process to realize the reciprocating operation of the automatic control switching linear reciprocating power device.

[0102] During the reciprocating operation of the above-mentioned automatic control switching linear reciprocating power device provided by the present invention, the pilot air sources of the pilot mechanisms on the left and right sides of the fluid flow direction switching valve 100 are taken from the V port and F port opened on the cylinder barrel 6. As the piston 10 moves, the V port and F port are alternately opened to obtain the air source in the piston chamber 9. After the corresponding pilot mechanism obtains the pilot air source, the fluid flow direction switching valve 100 performs a commutation operation. During this process, there is no mechanical commutation device provided in the linear reciprocating power cylinder block 200, and no mechanism such as a solenoid valve is provided on the air path of the pilot air source to switch the air flow direction. Therefore, the automatic control switching linear reciprocating power device provided in this embodiment avoids the impact of the piston on the front and rear end covers, can reduce the noise generated during the operation of the equipment, and can improve the service life of the device.

[0103] It should be noted that in the normal operation state of the above device, the control mechanism for secondary start in the pilot mechanism on the right side does not need to perform any operation. Therefore, in the above process, the structure of the fluid flow direction switching valve 100 described in Embodiment 1 can be completely adopted, and the device can also operate normally.

[0104] The control mechanism only comes into play when the forced start push button 4-10 is pressed. The working principle of the button forced start is described in detail below:

[0105] First of all, it should be noted that when the fluid flow direction switching valve 100 is a pneumatic control valve, when the input air pressure is too low, the commutation spool cannot be completely commutated, resulting in the P port being unable to communicate with the A port or B port, causing the linear automatic reciprocating cylinder to be unable to start for the second time. This is a common situation in the prior art. The fluid flow direction switching valve 100 provided by the present invention with a control mechanism can solve the problem that the linear automatic reciprocating cylinder cannot start for the second time due to the inability to completely commutate the commutation spool caused by too low pressure.

[0106] The following uses three different positions of the piston 10 in the linear reciprocating power cylinder block 200, namely the extreme position of the front end cover, the extreme position of the rear end cover, and the middle position, to illustrate the role of the control mechanism when the fluid flow direction switching valve 100 with a control mechanism as described in Embodiment 2 and Embodiment 3 cannot start for the second time after low-pressure shutdown.

[0107] As Figure 10As shown, when the piston 10 is at the extreme position on the side of the front end cover 7 of the direct-stroke reciprocating power cylinder block 200, the P port can be connected to the right pilot chamber through the control button on the right. When performing a secondary start after shutdown in this state, observe carefully. When the pressure of the air inlet source is above 0.15 MPa, the no-load start can be operated according to the following steps. If there is a load, according to the medium viscosity, the higher the viscosity, the higher the start pressure. It is also possible to observe the pressure gauge according to the actual working pressure. When the air source pressure reaches the working pressure, start the operation.

[0108] The specific operation method is as follows: Press the control button 4-10 on the right. When pressing, pay attention that it needs to be released instantly after pressing. At this time, the right pilot valve core moves to the right, and compressed air enters the outer chamber of the right pilot chamber from the P port through the adjustment channel. Because of the sealing of the check valve, the gas will not flow out along the Z port, but a part of the gas will be discharged through the U port. Set a reasonable aperture for the U port or set a damping mechanism so that its exhaust volume will not affect the movement of the pilot piston. The compressed air pushes the pilot piston in the right pilot mechanism to move to the left, and then pushes the reversing valve core to move to the left. The reversing valve core then pushes the left pilot piston to move to the left synchronously. The air in the left pilot chamber is discharged through the W port, and the reversing valve core instantly completes a complete reversal, that is, the reversing valve core is at the leftmost extreme position. At this time, the P port is connected to the B port, and the compressed air passes through P-B-H to the rear piston chamber in the cylinder barrel, and then through the F port to the Y port. Enter the left pilot chamber through the Y port. At this time, a part of the gas will be discharged through the W port. Set a reasonable aperture for the W port or set a damping mechanism so that its exhaust volume will not affect the movement of the pilot piston. The pilot air flow pushes the left pilot piston to move to the right, pushing the reversing valve core to move to the right. The reversing valve core then pushes the right pilot piston to move to the right synchronously. The air in the right pilot chamber is discharged through the U port. At this time, the reversing valve core instantly completes a complete reversal, that is, the valve core is at the rightmost extreme position.

[0109] The commutation is completed when the commutation spool is in the rightmost extreme position. At this time, port P is connected to port A. Compressed gas enters the front piston chamber 9-1 in the cylinder 6 through P-A-Q. The compressed air pushes the piston 10 to move to the right, and the gas in the rear piston chamber 9-2 is discharged through H-B-S. Until the piston moves to the right of port V, making port V communicate with the front piston chamber 9-1, that is, Q-V-Z is connected, and gas enters from port Z. The compressed gas enters the outer chamber of the right pilot mechanism. At this time, a part of the gas is discharged through port U. The compressed air pushes the right pilot piston to move to the left, and the pilot piston pushes the commutation spool to move to the left. The commutation spool then pushes the left pilot piston to move to the left synchronously, and the air in the left pilot chamber is discharged through port W. At this time, the spool instantly completes a complete commutation, that is, the commutation spool is in the leftmost extreme position. Port P is connected to port B, and the compressed air enters the rear piston chamber 9-2 in the cylinder 6 through P-B-H. The piston 10 moves to the left, and the gas in the front piston chamber 9-1 is discharged through Q-A-R. Until the piston 10 passes port F, that is, H-F-Y is connected, and gas enters from port Y. The compressed gas enters the outer chamber of the left pilot mechanism. At this time, a part of the gas is discharged through port W. The compressed air pushes the left pilot piston to move to the right, pushing the commutation spool to move to the right. The commutation spool then pushes the right pilot piston to move to the right synchronously, and the air in the right pilot chamber is discharged through port U. At this time, the commutation spool instantly completes a complete commutation, that is, after the commutation spool is in the rightmost extreme position, port P is connected to port A, and the compressed air enters the front piston chamber in the cylinder through P-A-Q, the piston 10 moves to the right, and the gas in the rear piston chamber is discharged through H-B-S. When the air source pressure is stable, the device will continue to repeat the above process to achieve automatic reciprocating motion.

[0110] It can be seen that when the fluid flow direction switching valve 100 cannot be restarted for the second time after low-pressure shutdown, since neither port A nor port B can communicate with port P, it is impossible to start again. However, through the automatic control switching linear reciprocating power device provided in this embodiment, by pressing the control button 4-10 in the fluid flow direction switching valve 100, the corresponding pilot mechanism can obtain a pilot air source signal from port P, and then the pilot piston of the pilot mechanism is used to push the commutation spool to move to achieve commutation, so that port P is connected to port A or port B and continuous commutation actions are realized, achieving automatic reciprocating motion and completing the second start.

[0111] When pressing the control button, the pressing time should not be too long and should not exceed the single stroke time of the piston 10. If the control button cannot be released instantly after being pressed, as a result, the left and right pilot chambers will be filled with pressurized gas, and the pressures on both sides will cancel each other out, and the left and right pilot pistons cannot push the commutation spool to achieve commutation.

[0112] Such as Figure 11As shown, when the piston 11 is at the extreme position of the rear end cover of the linear reciprocating power cylinder block 200, the specific implementation process of the secondary start is as follows. Since the working principles of all parts in the device are the same as those in the previous process, some repeated content in the following description will not be elaborated.

[0113] During startup, press the control button 4-10 of the right pilot mechanism. At this time, the right pilot spool moves to the right, opening the adjustment passage. Compressed air enters the outer chamber of the right pilot mechanism from port P through the adjustment passage (for its detailed structure and principle, refer to Embodiment 2). The compressed air pushes the right pilot piston to move to the left, pushing the reversing spool to move to the left. The reversing spool then pushes the left pilot piston to move to the left synchronously. Subsequently, the spool completes a complete reversal, that is, the reversing spool is at the extreme left position. Port P is connected to port B. Compressed air enters the rear piston chamber in the cylinder barrel 6 through P-B-H. The piston 10 moves to the left. Subsequently, the working processes of each component are the same as those in the previous process. At this time, the device realizes a secondary start and resumes normal reciprocating motion.

[0114] The following is the specific implementation process of the secondary start when the piston 10 is at the middle position (not shown in the figure) in the linear reciprocating power cylinder block 200.

[0115] During startup, press the control button on the right. At this time, the right pilot spool moves to the right. Compressed air enters the outer chamber of the right pilot chamber from port P. The compressed air pushes the piston of the right pilot chamber to move to the left, pushing the reversing spool to move to the left. The reversing spool then pushes the left pilot piston to move to the left synchronously. The reversing spool instantly completes a complete reversal. At this time, the reversing spool is at the extreme left position. Port P is connected to port B. Compressed air enters the right chamber of the cylinder through P-B-H. The piston 10 moves to the left. The gas in the front piston chamber is discharged through Q-A-R. Subsequently, the working processes of each component are the same as those in the previous process. At this time, the device realizes a secondary start and resumes normal reciprocating motion.

[0116] As described above, when the piston is at different positions of front, middle, and rear, by pressing the control button on the right, the right pilot mechanism obtains the pilot air source from port P, thereby pushing the reversing spool to move to the left to achieve commutation, making port P connected to port B. Subsequently, the device can realize normal reciprocating motion. Similarly, when the control mechanism is set on the left, the above-mentioned secondary start can also be achieved.

[0117] It should be noted that in this embodiment, in order to facilitate the representation of the air circuit connection principle of the device, the air circuit pipelines are represented by dashed lines. In actual products, usually only the intake pipe of port P can be seen, and other air pipes are transmitted through the connecting plate and the manifold (not shown in the figure).

[0118] In the above embodiments, the fluid pressure source is described by taking compressed air as an example. The present invention is equally applicable to hydraulic control. When the fluid pressure source is hydraulic oil, the linear reciprocating power cylinder body 200 of the executing part is replaced with an oil cylinder, and the fluid flow direction switching valve 100 is replaced with a hydraulic valve.

[0119] In the automatic control switching linear reciprocating power device provided by the present invention, there is no coil and no electric control is required. When compressed air is used as the power source, the W port and the U port exhaust air, which can be directly discharged into the atmospheric environment. When hydraulic oil is used as the fluid power source, the hydraulic oil discharged from the W port and the U port returns to the oil tank.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fluid flow direction switching valve, characterized in that: The switching valve is a two-position five-way directional valve, which includes a valve body, a valve cavity formed in the valve body, a reversing valve core slidably disposed in the valve cavity, and pilot mechanisms respectively disposed on the left and right sides of the valve body. Five valve ports are provided on the valve body, and the five valve ports are a pressure input port, two fluid output ports, and two fluid return ports; The pilot mechanism includes a pilot chamber housing, a pilot chamber formed in the pilot chamber housing, and a pilot piston disposed in the pilot chamber. The pilot piston is used to push the reversing valve core to move and reverse. The pilot piston divides the pilot chamber into an inner chamber on one side of the reversing valve core and an outer chamber on the other side; A pilot fluid inlet and a fluid pressure relief hole communicating with the outer chamber are provided on the pilot chamber housing. A check valve is provided in the internal or external air path of the pilot fluid inlet; The outer chamber of at least one of the pilot mechanisms is communicated with the pressure input port through an adjustment channel, and a control mechanism for controlling the on-off of the adjustment channel is provided on the pilot mechanism; The control mechanism includes a control button provided on the pilot chamber housing of the pilot mechanism and a pilot valve core provided in the pilot chamber housing of the pilot mechanism. In the stationary state, the pilot valve core closes the adjustment channel, and pressing down the control button causes the pilot valve core to move and then opens the adjustment channel; A fluid nozzle and a pilot valve core seat are fixedly provided in the pilot chamber housing of the pilot mechanism provided with the control mechanism. A fluid outlet is provided on the fluid nozzle. The end of the adjustment channel is communicated with the fluid outlet. The pilot valve core is slidably disposed on the pilot valve core seat. A valve core return spring is provided between the pilot valve core and the pilot valve core seat, and the valve core return spring causes the pilot valve core to seal the fluid outlet in the stationary state; The check valve is provided in the internal air path of the pilot fluid inlet. A check valve mounting hole is provided in the pilot chamber housing. The check valve includes a check valve rod disposed in the check valve mounting hole. A sealing ring is provided on the top of the check valve rod. The check valve rod and the sealing ring are used to close the pilot fluid inlet from the inside. A spring is sleeved on the check valve rod. A cylindrical adjusting screw is provided in the check valve mounting hole. The spring is provided between the adjusting screw and the check valve rod, and the adjusting screw is in threaded engagement with the check valve mounting hole; A rubber gasket seal is provided between the pilot chamber housing and the valve body.

2. The fluid flow direction switching valve according to claim 1, wherein: The pilot chamber housing of the pilot mechanism provided with the control mechanism includes a pilot chamber main housing and a pilot chamber end cover. The pilot chamber is provided in the pilot chamber main housing. The pilot fluid inlet is provided on the pilot chamber end cover. A valve core mounting hole is provided in the pilot chamber main housing and the pilot chamber end cover. The pilot valve core and the pilot valve core seat are provided in the valve core mounting hole. The control button is provided on the pilot chamber main housing, and the fluid nozzle is provided in the pilot chamber main housing.

3. The fluid flow direction switching valve according to claim 2, characterized in that: A first channel communicating with the fluid outlet is arranged in the main housing of the pilot chamber. A second channel communicating with the pressure input port is arranged in the valve body. The first channel is communicated with the second channel, and the first channel and the second channel form the adjustment channel.

4. An automatic control switching linear reciprocating power device, characterized in that: It includes a linear reciprocating power cylinder body and a fluid flow direction switching valve according to any one of claims 1-3. The linear reciprocating power cylinder body includes a cylinder barrel, a front end cover and a rear end cover hermetically arranged at both ends of the cylinder barrel, and a piston arranged in the cylinder barrel. A piston chamber for accommodating the piston is formed in the cylinder barrel. The piston divides the piston chamber into a front piston chamber and a rear piston chamber. A first pilot fluid output hole and a second pilot fluid output hole are arranged on the barrel wall of the cylinder barrel. A piston rod is fixedly arranged on the piston. The piston rod passes through the front end cover and extends outside the piston chamber. A sealing mechanism is arranged between the piston rod and the front end cover. When the piston moves to the front end of the cylinder barrel, the piston closes the second pilot fluid output hole, and the first pilot fluid output hole communicates with the rear piston chamber. When the piston moves to the rear end of the cylinder barrel, the piston closes the first pilot fluid output hole, and the second pilot fluid output hole communicates with the front piston chamber. A front fluid inlet and outlet communicating with the front piston chamber is arranged on the front end cover, and a rear fluid inlet and outlet communicating with the rear piston chamber is arranged on the rear end cover. The front fluid inlet and outlet and the rear fluid inlet and outlet are respectively communicated with two fluid output ports on the fluid flow direction switching valve. The first pilot fluid output hole and the second pilot fluid output hole are respectively communicated with the pilot fluid inlets of the pilot mechanisms on the corresponding sides of the fluid flow direction switching valve.

5. The automatic control switching linear reciprocating power device according to claim 4, characterized in that: The number of the first pilot fluid output holes and the second pilot fluid output holes is N, and N is a positive integer greater than or equal to 1. The N first pilot fluid output holes and the second pilot fluid output holes are respectively arranged along the circumferential direction of the cylinder barrel.

6. The automatic control switching linear reciprocating power device according to claim 4, characterized in that: When the piston moves to the front end of the cylinder barrel to make the first pilot fluid output hole communicate with the rear piston chamber, there is a buffer gap between the front end of the piston and the front end cover. When the piston moves to the rear end of the cylinder barrel to make the second pilot fluid output hole communicate with the front piston chamber, there is a buffer gap between the rear end of the piston and the rear end cover.

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