A spool valve device

Abstract

A kind of spool valve device, including valve body and the end cap of sealed assembly at both ends, valve body and end cap are respectively provided with coaxial arrangement containing cavity and pilot cavity, hollow cylindrical valve stem is slidably installed in containing cavity, cylindrical valve stem axial movement controls main oil passage on-off, X,Y control oil port connected with pilot control valve is respectively set up on both end end cap, control oil port is communicated with pilot cavity by built-in oil passage, pilot push rod, buffer spring and guide valve rod are coaxially installed in pilot cavity, pilot push rod and guide valve rod are connected by buffer spring, protrusion is arranged in the middle of pilot push rod, annular pilot groove is formed by protrusion outer circle and is connected with X,Y control oil port corresponding;Under normal circumstances, protrusion is attached to end cap inner wall, guide valve rod abuts against the end of cylindrical valve stem, guide valve rod is provided with throttle hole, which is communicated with the oil passage in the middle of cylindrical valve stem and pilot cavity, the device can reduce or avoid impact pressure wave recoil pilot control valve to cause valve core vibration or misoperation, meet the effect of heavy hydraulic piling equipment large flow, fast and stable.

Description

Technical Field

[0001] This invention relates to the field of hydraulic piling equipment technology, and in particular to a slide valve device. Background Technology

[0002] Currently, common heavy-duty pile foundation construction equipment in engineering machinery includes hydraulic hammers, hydraulic vibratory hammers, and diesel hammers. Because pile drivers are high-load dynamic vibration devices, the dynamic output control design of high-flow-rate directional control valves has particularly high requirements. This is especially true for heavy-duty engineering equipment and large-scale marine engineering equipment, where harsh construction environments and long continuous operation times necessitate that the directional control valve, as a key control component in the hydraulic system, meet the requirements of high flow rate, high response, and high stability. Common directional control valves are generally cylindrical bodies with multiple annular grooves. As the working flow rate of the hydraulic system increases… The larger the required diameter of the directional control valve, the greater its weight. This increased weight leads to several problems: First, under continuous rapid directional control conditions, the kinetic energy impact generated by the valve's movement intensifies, and the resulting impact pressure wave can reverse-impact the pilot control valve, causing valve core vibration and malfunction. Alternating loads exceeding the rated range can easily cause end cap breakage and fastening screw failure. Second, increased weight also increases frictional resistance, accelerating wear on the valve core and cavity surfaces, reducing the response speed of the valve assembly, and decreasing the reliability of the directional control. Summary of the Invention

[0003] This invention addresses the shortcomings of existing technologies by providing a spool valve device that reduces or avoids valve core vibration or malfunction caused by backflow of shock pressure waves in the pilot control valve.

[0004] To achieve the above objectives, the present invention provides a slide valve device, including end caps and a valve body. The valve body is sealed to both ends with end caps. The valve body has a receiving cavity, and the end caps have a pilot cavity. The receiving cavity and the pilot cavity are coaxially arranged. A cylindrical valve stem is slidably installed within the receiving cavity. The cylindrical valve stem is open at both ends and hollow inside, forming a central oil passage. Axial movement of the cylindrical valve stem relative to the valve body achieves the opening and closing of the main valve block oil passage. The two end caps are respectively provided with an X control port and a Y control port for connection to a pilot control valve. The X control port and the Y control port communicate with the pilot cavity through a pilot control oil passage within the end caps. The pilot cavities of the end caps are sequentially coaxially arranged. The device is equipped with a pilot push rod, a buffer spring, and a guide valve stem. Both the pilot push rod and the guide valve stem are slidably connected to the inner wall of the pilot cavity. The pilot push rod and the guide valve stem are connected by a buffer spring. The pilot push rod has a protrusion in the middle of the side facing the inner wall of the bottom end of the end cap. The outer periphery of the protrusion forms an annular pilot groove. In the initial position, under the action of the buffer spring, the protrusion of the pilot push rod abuts against the inner wall of the bottom end of the end cap. The head end of the guide valve stem abuts against the end opening of the cylindrical valve stem. The two annular pilot grooves are connected to the X control oil port and the Y control oil port, respectively. The guide valve stem is equipped with a throttling orifice, which connects the middle oil passage of the cylindrical valve stem to the pilot cavity.

[0005] In this embodiment, a wear-resistant ring extending radially outward is provided on the outer wall of the guide valve stem, and the guide valve stem is slidably connected to the inner wall of the pilot cavity through the wear-resistant ring.

[0006] In this embodiment, the throttling orifice includes a first throttling orifice and a second throttling orifice. The guide valve stem is provided with at least one first throttling orifice that penetrates axially and at least one second throttling orifice that penetrates radially. The first throttling orifice and the second throttling orifice are interconnected.

[0007] In this embodiment, a first cavity is formed between the pilot push rod and the guide valve rod. The outer wall of the guide valve rod, the side of the wear-resistant ring facing the cylindrical valve rod, the inner wall of the pilot cavity, and the end face of the valve body form a second cavity. The second throttling orifice is connected to the second cavity, and the first throttling orifice connects the first cavity to the middle oil passage of the cylindrical valve rod.

[0008] In this embodiment, a cross-shaped countersunk groove is formed on the contact surface between the guide valve stem and the pilot push rod, and the cross-shaped countersunk groove is connected to the first throttling orifice.

[0009] In this embodiment, the solenoid directional valve is a two-position four-way solenoid directional valve.

[0010] In this embodiment, a sealing groove is provided on the end face of the end cap, and a sealing ring is installed in the sealing groove. The end cap is sealed to the valve body through the sealing ring.

[0011] In this embodiment, the outer wall of the cylindrical valve stem is provided with multiple sets of pressure equalization grooves arranged axially.

[0012] In this embodiment, both the pilot push rod and the guide valve rod are provided with spring limiting steps. The portion of the pilot push rod and the guide valve rod between the two spring limiting steps forms a guide post that matches the inner diameter of the buffer spring. The two ends of the buffer spring are coaxially mounted on the guide posts of the pilot push rod and the guide valve rod and abut against the spring limiting steps of both.

[0013] In this embodiment, the cross-sectional area of ​​the pilot control oil circuit inside the end cover is S1. In the initial position, a throttling groove is formed at the connection between the pilot control oil circuit and the annular pilot groove of the pilot push rod. The area of ​​the throttling groove is 5% to 8% of S1.

[0014] Due to the above structure, the present invention has the following advantages:

[0015] 1. This device adopts a cylindrical valve stem with open ends and a hollow interior forming a central oil passage. The central cavity of the cylindrical valve stem forms a central oil passage, which ensures the flow capacity while significantly reducing the overall weight of the cylindrical valve stem. On the one hand, the reduced weight can reduce friction and avoid creeping during the reversing process, increasing the reversing response speed. On the other hand, it can reduce the wear of the cylindrical valve stem, reduce the risk of valve core jamming, and further improve the reversing response speed.

[0016] 2. The cylindrical valve stem has guide valve stems at both ends to close the openings at both ends. A pilot push rod and a buffer spring are also provided to cooperate with the guide valve stem. The pilot push rod is moved by the pilot oil entering the end cover, thereby pushing the cylindrical valve stem to move and realize the reversing function. When there is no pilot oil pressure at both end covers, the buffer spring can restore the initial position of the cylindrical valve stem in time. The hydraulic oil in the pilot cavity inside the valve body can return smoothly through the cylindrical valve stem, avoiding failure of the reversing function.

[0017] 3. The guide valve stem is provided with a throttling orifice, which connects the middle oil passage of the cylindrical valve stem to the pilot chamber. When the cylindrical valve stem moves in reversing direction, the throttling orifice cooperates with the first and second chambers. During the reciprocating motion, the volume of the first and second chambers increases and decreases accordingly. During the rapid decrease in the volume of the two chambers, the hydraulic oil is rapidly compressed into the cylindrical valve stem through the damping orifice, thereby buffering the hydraulic shock force generated during the reversing movement of the cylindrical valve stem and avoiding concentrated stress on the end cover.

[0018] 4. The cross-sectional area of ​​the pilot control oil circuit inside the end cover is S1. In the initial position, a throttling groove of about 5% to 8%S1 is formed at the connection between the pilot control oil circuit and the annular pilot groove of the pilot push rod. When the pilot hydraulic oil enters through the X control port, it will first enter the annular pilot groove through the throttling groove. After sufficient pressure is built up in the annular pilot groove, it will push the pilot push rod to move. As the pilot push rod moves, the area of ​​the throttling groove will gradually increase, the flow rate into the annular pilot groove will also increase, and the speed of the pilot push rod will also be faster. When the pilot hydraulic oil enters through the Y port, the pilot push rod begins to reset. During the reset process, the cavity of the annular pilot groove shrinks rapidly. When the pilot push rod is close to the bottom of the end cover, the area of ​​the throttling groove gradually decreases. The rapidly released hydraulic oil is restricted by the throttling groove, thereby reducing or avoiding the impact pressure wave backflow into the pilot control valve, which may cause valve core vibration or malfunction.

[0019] In summary, under continuous reversing conditions, the cylindrical valve stem moves rapidly under the pilot thrust of this device, reducing the impact generated between the end cover and the valve body during continuous impact, which can meet the requirements of heavy-duty hydraulic piling equipment, high flow rate, fast speed and stable operation. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the invention in its initial position.

[0021] Figure 2 This is a cross-sectional view of the invention in a second position.

[0022] Figure 3 This is a cross-sectional view of the invention in the third position.

[0023] Figure 4 This is a schematic diagram of the present invention.

[0024] Figure 5 This is a schematic diagram of the guide valve stem of the present invention.

[0025] Figure 6 This is a side view of the guide valve stem of the present invention.

[0026] Figure 7 This is a schematic diagram of the pilot push rod of the present invention.

[0027] Figure 8 In this invention Figure 1 Enlarged image.

[0028] In the attached diagram: 1. End cap; 11. Pilot chamber; 12. Pilot control oil circuit; 2. Pilot push rod; 21. Protrusion; 22. Annular pilot groove; 3. Buffer spring; 4. Wear-resistant ring; 5. Sealing ring; 6. Guide valve stem; 61. First throttling orifice; 62. Second throttling orifice; 63. Cross countersunk groove; 7. Valve body; 71. Receiving cavity; 72. Oil groove; 8. Cylindrical valve stem; 81. Annular groove; 9. Main valve block; 101. Spool valve device; 102. Solenoid directional valve. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0031] like Figures 1 to 8 As shown, a spool valve device includes an end cap 1, a pilot push rod 2, a buffer spring 3, a wear-resistant ring 4, a sealing ring 5, a guide valve stem 6, a valve body 7, and a cylindrical valve stem 8. The valve body 7 is sealed to both ends with the end cap 1. Further, the end cap 1 has a sealing groove on its end face, and a sealing ring 5 is installed in the sealing groove. The end cap 1 is sealed to the valve body 7 through the sealing ring 5. The valve body 7 has a receiving cavity 71, and the end cap 1 has a pilot cavity 11. The receiving cavity 71 and the pilot cavity 11 are coaxially arranged. The cylindrical valve stem 8 is slidably installed in the receiving cavity 71. Further, the cylindrical valve stem... The cylindrical valve stem 8 has openings at both ends and is hollow inside, forming a central oil passage. Multiple sets of annular grooves 81 arranged axially are provided on the side wall of the cylindrical valve stem 8. The annular grooves 81 are connected to the central oil passage. This device is used in conjunction with a dedicated main valve block to form a functional block. A sealing element group is provided at the connection between the valve body 7, the end cover 1 and the main valve block 9 to ensure the sealing performance between the components. Multiple sets of oil grooves 72 arranged axially are provided on the inner wall of the valve body 7. The oil grooves 72 are arranged in conjunction with the annular grooves 81. The axial movement of the cylindrical valve stem 8 relative to the valve body 7 is achieved by the cooperation of the oil grooves 72 and the annular grooves 81 to realize the opening and closing of the main valve block oil passage.

[0032] like Figure 5 , 6 The outer wall of the cylindrical valve stem 8 shown is provided with multiple sets of pressure equalizing grooves arranged along the axial direction, thereby balancing the radial hydraulic pressure distribution, eliminating hydraulic clamping force, reducing leakage and improving the sensitivity of moving parts;

[0033] like Figure 8 As shown, two end caps 1 are respectively provided with X control oil ports and Y control oil ports for connection with pilot control valves. The X control oil ports and Y control oil ports are connected to the pilot cavity through the pilot control oil passage 12 inside the end cap 1. The pilot push rod 2, the buffer spring 3, and the guide valve rod 6 are arranged coaxially in sequence in the pilot cavity 11 of the end cap 1. The pilot push rod 2 and the guide valve rod 6 are slidably connected to the inner wall of the pilot cavity 11. The pilot push rod 2 and the guide valve rod 6 are connected by the buffer spring 3. In this embodiment, both the pilot push rod 2 and the guide valve rod 6 are provided with spring limiting steps. The portion of the pilot push rod 2 and the guide valve rod 6 between the two spring limiting steps forms a guide post that matches the inner diameter of the buffer spring 3. The two ends of the buffer spring 3 are coaxially fitted onto the guide posts of the pilot push rod 2 and the guide valve rod 6 and abut against the spring limiting steps of both. In this embodiment, the pilot control valve is an electromagnetic directional valve 102, which is a two-position four-way electromagnetic directional valve.

[0034] like Figure 7 , 8 As shown, a protrusion 21 is provided in the middle of the side of the pilot push rod 2 facing the inner wall of the bottom end of the end cover 1. When the protrusion 21 contacts the inner wall of the end cover 1, an annular pilot groove 22 is formed between the outer groove of the protrusion 21 and the inner wall of the end cover 1. The protrusion of the pilot push rod near the bottom of the end cover and the annular pilot groove formed by the end cover are in the initial position. Under the action of the buffer spring 3, the protrusion 21 of the pilot push rod 2 abuts against the inner wall of the bottom end of the end cover 1, and the head end of the guide valve rod 6 abuts against the end opening of the cylindrical valve rod 8 and seals the end opening. At this time, the two annular pilot grooves 22 are connected to the X control oil port and the Y control oil port respectively. In the initial position, the cross-sectional area of ​​the pilot control oil passage 12 inside the end cover is S1. A groove is formed between the pilot control oil passage 12 and the annular pilot groove 22 of the pilot push rod. The throttling groove has an area of ​​5% to 8% of S1. When the pilot hydraulic oil enters through the X control port, it first passes through the throttling groove into the annular pilot groove 22. After sufficient pressure is built up in the annular pilot groove 22, it pushes the pilot push rod 2 to move. As the pilot push rod 2 moves, the area of ​​the throttling groove gradually increases, the flow rate into the annular pilot groove 22 also increases, and the moving speed of the pilot push rod 2 also increases. When the pilot hydraulic oil enters again through the Y port, the original pilot push rod 2 begins to reset. During the reset process, the cavity of the annular pilot groove 22 rapidly shrinks. When the pilot push rod 2 is close to the bottom of the end cover, the area of ​​the throttling groove gradually decreases, and the rapidly withdrawn hydraulic oil is restricted by the throttling groove, thereby reducing or avoiding the impact pressure wave backflow into the pilot control valve, which could cause valve core vibration or malfunction. Figure 5As shown, a wear-resistant ring 4 extending radially outward is provided on the outer wall of the guide valve stem 6. The guide valve stem 6 is slidably connected to the inner wall of the pilot cavity 11 through the wear-resistant ring 4. The guide valve stem 6 is provided with at least one first throttling hole 61 penetrating axially and at least one second throttling hole 62 penetrating radially. The first throttling hole 61 and the second throttling hole 62 are connected. A cross-shaped countersunk groove 63 is opened on the contact surface between the guide valve stem 6 and the pilot push rod 2. The cross-shaped countersunk groove 63 is connected to the first throttling hole 61. Furthermore, a first cavity is formed between the pilot push rod 2 and the guide valve stem 6. The outer wall of the guide valve stem 6, the side of the wear-resistant ring 4 facing the cylindrical valve stem 8, and the pilot cavity are all connected. The inner wall of valve 11 and the end face of valve body 7 enclose a second cavity. The second throttling orifice 62 is connected to the second cavity. The first throttling orifice 61 connects the first cavity to the middle oil passage of the cylindrical valve stem 8. When the pilot push rod 2 moves, the pilot oil in the first cavity and the second cavity is discharged into the middle oil passage of the cylindrical valve stem 8 through the first throttling orifice 61 and the second throttling orifice 62. In this way, while realizing the pilot reversal, the pilot oil will not directly impact the spring and will not affect the stability of the spring. Moreover, the first cavity and the second cavity are used to buffer the final impact force of the pilot reversal, thereby improving the stability of the reversal.

[0035] With the above structure, the working principle of this device is as follows:

[0036] like Figure 4 As shown, the control oil of the slide valve device 101 is connected to the solenoid directional valve 102 through the X port and the Y port;

[0037] like Figure 1 As shown, in the initial position, under the action of the buffer spring 3, the pilot push rod 2 and the guide valve rod 6 are moved away from each other. One end of the pilot push rod 2 abuts against the end cover 1, and one end of the guide valve rod 6 abuts against the end face of the cylindrical valve rod 8. The guide valve rod 6 closes the openings at both ends of the cylindrical valve rod 8. At this time, the cylindrical valve rod 8 is in the middle position, and the oil circuit of the main valve block 9 is disconnected.

[0038] like Figure 2 As shown, in the second position, the electromagnetic reversing valve 102 transmits the pilot pressure to the annular pilot groove 22 of the left pilot push rod 2 through the X port, so that the pilot force acts on the left pilot push rod 2, driving the left pilot push rod 2 to move. While compressing the left buffer spring 3, the pilot push rod 2 gradually approaches the left guide valve rod 6. Subsequently, the left guide valve rod 6 pushes the cylindrical valve rod 8 and the right guide valve rod 6 to move to the right together, realizing the reversal.

[0039] like Figure 3As shown, in the third position, the electromagnetic reversing valve transmits the pilot pressure to the annular pilot groove 22 of the right pilot push rod 2 through the Y port, so that the pilot force acts on the right pilot push rod 2, the right pilot push rod 2 moves, compresses the right buffer spring 3, the right pilot push rod 2 gradually approaches the right guide valve rod 6, and at the same time the right guide valve rod 6 pushes the cylindrical valve rod 8 and the left guide valve rod 6 to move to the left together, realizing the reversal.

[0040] During the reversing process, the device moves from the initial position to the second or third position. The pressure oil acts on the annular pilot groove 22 of the pilot push rod 2 on one side of the cylindrical valve stem 8. The first throttling orifice 61 and the second throttling orifice 62 cooperate with the first cavity and the second cavity to buffer the impact force of the pilot reversing, thereby improving the stability of the reversing. In addition, with the gradual change of the throttling groove area, the rapid movement of the cylindrical valve stem under the pilot thrust under continuous reversing conditions is further buffered, thereby reducing or avoiding the impact pressure wave backflow into the pilot control valve, which may cause valve core vibration or malfunction.

[0041] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made under the concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A slide valve device, characterized in that: The valve body includes end caps and a valve body. End caps are sealed to both ends of the valve body. The valve body contains a receiving cavity, and the end caps contain a pilot cavity. The receiving cavity and the pilot cavity are coaxially arranged. A cylindrical valve stem is slidably installed within the receiving cavity. The cylindrical valve stem is open at both ends and hollow inside, forming a central oil passage. Axial movement of the cylindrical valve stem relative to the valve body controls the opening and closing of the main valve block oil passage. The two end caps are respectively provided with X control ports and Y control ports for connection to the pilot control valve. The X control ports and Y control ports are connected to the pilot cavity through the pilot control oil passage within the end caps. A pilot push rod and a buffer are coaxially arranged sequentially within the pilot cavity of the end caps. The spring and guide valve stem, the pilot push rod and the guide valve stem are all slidably connected to the inner wall of the pilot cavity. The pilot push rod and the guide valve stem are connected by a buffer spring. The pilot push rod has a protrusion in the middle of the side facing the inner wall of the bottom end of the end cover. The outer periphery of the protrusion forms an annular pilot groove. In the initial position, under the action of the buffer spring, the protrusion of the pilot push rod abuts against the inner wall of the bottom end of the end cover. The head end of the guide valve stem abuts against the end opening of the cylindrical valve stem. The two annular pilot grooves are respectively connected to the X control oil port and the Y control oil port. The guide valve stem is provided with a throttling orifice, which connects the middle oil passage of the cylindrical valve stem to the pilot cavity.

2. The slide valve device according to claim 1, characterized in that: The outer wall of the guide valve stem is provided with a wear-resistant ring extending radially outward, and the guide valve stem is slidably connected to the inner wall of the pilot cavity through the wear-resistant ring.

3. The slide valve device according to claim 2, characterized in that: The throttling orifice includes a first throttling orifice and a second throttling orifice. The guide valve stem is provided with at least one first throttling orifice that penetrates axially and at least one second throttling orifice that penetrates radially. The first throttling orifice and the second throttling orifice are interconnected.

4. The slide valve device according to claim 3, characterized in that: A first cavity is formed between the pilot push rod and the guide valve stem. The outer wall of the guide valve stem, the side of the wear-resistant ring facing the cylindrical valve stem, the inner wall of the pilot cavity, and the end face of the valve body form a second cavity. The second throttling orifice is connected to the second cavity. The first throttling orifice connects the first cavity to the middle oil passage of the cylindrical valve stem.

5. The slide valve device according to claim 3, characterized in that: A cross-shaped countersunk groove is formed on the contact surface between the guide valve stem and the pilot push rod, and the cross-shaped countersunk groove is connected to the first throttling orifice.

6. The slide valve device according to claim 1, characterized in that: The solenoid directional valve is a two-position four-way solenoid directional valve.

7. The slide valve device according to claim 1, characterized in that: The end cover has a sealing groove on its end face, and a sealing ring is installed in the sealing groove. The end cover is sealed to the valve body through the sealing ring.

8. The slide valve device according to claim 1, characterized in that: The outer wall of the cylindrical valve stem is provided with multiple sets of pressure equalization grooves arranged axially.

9. The slide valve device according to claim 1, characterized in that: Both the pilot push rod and the guide valve rod are provided with spring limiting steps. The portion of the pilot push rod and the guide valve rod between the two spring limiting steps forms a guide post that matches the inner diameter of the buffer spring. The two ends of the buffer spring are coaxially mounted on the guide posts of the pilot push rod and the guide valve rod and abut against the spring limiting steps of both.

10. The slide valve device according to claim 1, characterized in that: The cross-sectional area of ​​the pilot control oil circuit inside the end cover is S1. In the initial position, a throttling groove is formed at the connection between the pilot control oil circuit and the annular pilot groove of the pilot push rod. The area of ​​the throttling groove is 5% to 8% of S1.

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