Servo slide valve and valve opening oil cylinder comprising same

Abstract

The utility model discloses a valve opening oil cylinder which comprises a valve body and a valve rod located in the valve body, and the valve rod is connected with a driving piece. An axially-arranged oil passing channel is arranged in the valve rod, a rodless oil return cavity, an oil inlet cavity and a rod oil return cavity are sequentially defined by a plurality of protruding shoulders and the valve body in the axial direction outside the valve rod, and the rod oil return cavity and the rodless oil return cavity are communicated with the oil passing channel. The valve body is provided with an oil inlet and an oil return port which are communicated with an oil tank, a first oil port communicated with a rodless cavity of the oil cylinder, and a second oil port communicated with a rod cavity of the oil cylinder; the oil inlet is located between the first oil port and the second oil port, the convex shoulder of the valve rod can block the first oil port and the second oil port at the same time, and when the oil inlet is communicated with one of the first oil port and the second oil port, the oil return port is communicated with the other oil port. The number of cavities in the servo slide valve can be reduced to three, a hydraulic oil flowing path is simple and reliable, the outer shape of the valve rod is regular, and machining difficulty is low.

Description

Technical Field

[0001] The utility model relates to the technical field of oil cylinders, in particular to a servo slide valve and a valve-opening oil cylinder comprising the same. Background Art

[0002] When a traditional oil cylinder stops working, it needs to use seals, such as plugs or sealing joints, to block the oil inlet and oil return port, and the sealing effect is poor. For this reason, a structure that controls the movement of the oil cylinder through a sliding valve has been developed. The sliding valve can block the oil inlet and oil return port of the oil cylinder through its own structure, and mechanical seals are used to replace traditional seals and hard-connected seals, which reduces the manufacturing precision requirements and material requirements of components.

[0003] The sliding valve serves as a medium between the oil cylinder and the oil tank, and the sliding valve relies on external power to move. However, the connection channel between the sliding valve and the oil tank in the prior art is relatively complicated. For example, each chamber in the sliding valve disclosed in the patent "Electro-hydraulic servo cylinder and CNC machine tool using the same" with application number CN200710062676.3 needs to be respectively provided with pipelines on the outside. For example, the left high-pressure oil chamber, the right high-pressure oil chamber and the oil inlet chamber connected to the oil tank need to be respectively provided with connecting pipelines on the outside, resulting in complicated external pipelines.

[0004] The patent "Servo mechanism for turbine regulating valve" with application number CN201220319648.1 uses an integrated setting of the sliding valve and the cylinder to simplify the external connection structure, but the structural improvements to the sliding valve and the traditional cylinder are relatively large, and the cost of maintenance and replacement is also higher. The sliding valve in the patent is respectively provided with an oil inlet and an oil inlet cavity for the upper cavity and the lower cavity of the cylinder, and the adjacent cavities are connected by the special-shaped design of the sliding valve to realize the connection between the oil tank and the cylinder. Therefore, a total of five chambers need to be designed from top to bottom in the sliding valve part of the patent, and the shape of the sliding valve is also irregular, which increases the complexity of the internal structure.

[0005] In summary, how to design a valve opening cylinder with a simple internal structure and simplified external pipeline layout is a technical problem that needs to be solved at present. Utility Model Content

[0006] In order to solve the technical problems in the prior art that the valve opening cylinder has a complex external connecting pipeline structure or a complex internal sliding valve structure, and has high production and use costs, the utility model provides a servo sliding valve and a valve opening cylinder containing the same to solve the above problems.

[0007] The utility model proposes a servo sliding valve, comprising a valve body and a valve stem located inside the valve body, the valve stem being connected to a driving member; an axially arranged oil passage is provided inside the valve stem, and a plurality of bosses outside the valve stem are axially surrounded by the valve body to form a rodless oil return chamber, an oil inlet chamber and a rod oil return chamber, the rod oil return chamber and the rodless oil return chamber are connected with the oil passage, the valve body has an oil inlet port and an oil return port connected with an oil tank, and a first oil port connected with the rodless chamber of an oil cylinder and a second oil port connected with the rod chamber of the oil cylinder; the oil inlet port is located between the first oil port and the second oil port, the boss of the valve stem can block the first oil port and the second oil port at the same time, and when the oil inlet port is connected with one of the first oil port and the second oil port, the oil return port is connected with the other oil port.

[0008] Furthermore, the oil return port is located at the end of the valve body, and the oil passage passes through one end of the valve stem toward the end where the oil return port is located.

[0009] Furthermore, the outer peripheral surface of the valve stem and the outer peripheral surface of the boss are both cylindrical surfaces.

[0010] Furthermore, the valve stem has a radial channel which is arranged in one-to-one correspondence with the rod oil return chamber and the rodless oil return chamber and is used to communicate with the oil passage.

[0011] Furthermore, the boss of the valve stem includes a first boss, a second boss, a third boss and a fourth boss which are arranged along the axial direction and arranged in sequence from the rodless oil return chamber to the rod oil return chamber, the distance between the center of the second boss and the center of the third shoulder is equal to the distance between the center of the first oil port and the center of the second oil port, and radial channels are respectively provided on the valve stem between the first boss and the second shoulder and the valve stem between the third shoulder and the fourth shoulder.

[0012] Furthermore, the boss of the valve stem can block one of the first oil port and the second oil port, so that the piston rod of the oil cylinder is in a stationary state.

[0013] Furthermore, the distances between the center of the first boss and the center of the second boss, the center of the third boss and the center of the fourth boss, the center of the first oil port and the center of the oil inlet, and the center of the second oil port and the center of the oil inlet are all equal.

[0014] The utility model also provides a valve-opening oil cylinder, comprising an oil cylinder and the above-mentioned servo slide valve located outside the oil cylinder.

[0015] Furthermore, the oil cylinder comprises a cylinder body and a piston and a piston rod which axially reciprocate in the cylinder body, and the piston divides the interior of the cylinder body into a rodless chamber and a rod chamber.

[0016] Furthermore, a return spring is provided in the rodless cavity, and two ends of the return spring are connected to two ends of the rodless cavity. When the return spring is in a free state, the first oil port and the second oil port are blocked at the same time.

[0017] The beneficial effects of the utility model are:

[0018] (1) The utility model realizes the connection between the servo slide valve, the oil cylinder and the oil tank through an oil inlet and an oil return port, and at the same time, an oil passage that can simultaneously connect the rod oil return chamber and the rodless oil return chamber is provided in the valve stem of the servo slide valve, thereby reducing the number of cavities in the servo slide valve to three, making the hydraulic oil flow path simple and reliable, and the external shape of the valve stem is regular, with low processing difficulty.

[0019] (2) The utility model separates the servo slide valve from the oil cylinder, which does not require structural improvement of the traditional oil cylinder, facilitates separate processing, assembly and maintenance, and reduces manufacturing and use costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0021] Figure 1 It is a schematic axial cross-sectional view of a specific implementation of the servo slide valve described in the utility model;

[0022] Figure 2 This is a front view of the valve opening oil cylinder of the utility model;

[0023] Figure 3 It is a schematic diagram of the axial cross section of the valve opening oil cylinder of the utility model;

[0024] Figure 4 is a schematic diagram of the servo slide valve shown in the first embodiment when the valve stem is retracted to the maximum stroke;

[0025] Figure 5 is a schematic diagram of the servo slide valve shown in the second embodiment when the valve stem is extended to the maximum stroke;

[0026] Figure 6 It is a schematic diagram of the servo slide valve shown in the second embodiment when the valve stem is retracted to the maximum stroke.

[0027] In the figure, 1, servo slide valve, 2, valve body, 3, valve stem, 4, oil passage, 5, rodless oil return chamber, 6, oil inlet chamber, 7, rod oil return chamber, 8, oil inlet port, 9, oil return port, 10, first oil port, 11, second oil port, 13, oil cylinder, 14, rodless chamber, 15, rod chamber, 16, radial channel, 17, first boss, 18, second boss, 19, third boss, 20, fourth boss, 21, cylinder body, 22, piston, 23, piston rod, 24, return spring, 25, first pipeline, 26, second pipeline. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] Embodiment 1

[0030] like Figure 1 As shown, a servo slide valve includes a valve body 2 and a valve stem 3 located inside the valve body 2, wherein the valve stem 3 is connected to a driving member; the driving member controls the valve stem 3 to move to a specified position, and the valve stem 3 realizes different movement forms of the oil cylinder 13 at different positions.

[0031] An axially arranged oil passage 4 is provided inside the valve stem 3, and the valve stem 3 is surrounded by a plurality of bosses and the valve body 2 in the axial direction to form a rodless oil return chamber 5, an oil inlet chamber 6 and a rod oil return chamber 7, the rod oil return chamber 7 and the rodless oil return chamber 5 are connected to the oil passage 4, the valve body 2 has an oil inlet port 8 and an oil return port 9 connected to the oil tank, and a first oil port 10 connected to the rodless chamber 14 of the oil cylinder 13 and a second oil port 11 connected to the rod chamber 15 of the oil cylinder 13; the oil inlet port 8 is located between the first oil port 10 and the second oil port 11, the rodless oil return chamber 5 is connected to the rodless chamber 14 through the first oil port 10, and the rod oil return chamber 7 is connected to the rod chamber 15 through the second oil port 11 (such as Figure 2 As shown, the first oil port 10 is connected to the oil cylinder 13 through the first pipe 25, and the second oil port is connected to the oil cylinder 13 through the second pipe 26). The rod oil return chamber 7 and the rodless oil return chamber 5 can be connected to the oil inlet port 8 to form an oil inlet cavity, and can also be connected to the oil return port 9 to form an oil inlet cavity, which is specifically determined by the position of the valve stem 3.

[0032] The boss of the valve stem 3 can block the first oil port 10 and the second oil port 11 at the same time. At this time, the oil cylinder 13 is in a silent sealing state, that is, the oil port is blocked by the boss structure to achieve mechanical sealing. When the oil inlet 8 is connected to one of the first oil port 10 and the second oil port 11, the oil return port 9 is connected to the other oil port, so that the oil cylinder 13 and the oil tank form a flow circulation through the first oil inlet 10, the second oil inlet 11, the oil inlet 8 and the oil return port 9.

[0033] The oil return port 9 can be opened in the radial direction. To simplify the structure, the oil return port 9 is preferably located at the end of the valve body 2. The oil passage 4 passes through one end of the valve stem 3 toward the end where the oil return port 9 is located. At this time, the return hydraulic oil flows straightly to the oil return port 9 through the oil passage 4. There are few changes in direction during the flow process, less energy loss, a simple path, and low processing costs. Figure 1As shown, the oil return port 9 is located at the left end of the valve body 2, the rodless oil return chamber 5, the oil inlet chamber 6 and the rod oil return chamber 7 are arranged from left to right, and the first oil port 10, the oil inlet port 8 and the second oil port 11 are arranged from left to right.

[0034] The outer circumferential surface of the valve stem 3 and the outer circumferential surface of the boss are both cylindrical surfaces. In this case, the outer surface of the valve stem 3 is a regular shape, which is easy to process.

[0035] The valve stem 3 has a radial channel 16 which is arranged in one-to-one correspondence with the rod oil return chamber 7 and the rodless oil return chamber 5 and is used to communicate with the oil passage 4.

[0036] Working principle: Figure 1 As shown, when the valve stem 3 is in the middle position, the boss blocks both the first oil port 10 and the second oil port 11, and the oil inlet chamber 6 is connected to the oil tank through the oil inlet port 8. At this time, the oil cylinder 13 is not connected to the servo slide valve 1, and the oil cylinder 13 is in a sealed closed state. When the valve stem 3 is stretched outward by the pulling force of the driving member, the first oil port 10 and the second oil port 11 are gradually opened, the second oil port 11 is connected to the oil inlet chamber 6, and is disconnected from the rod oil return chamber 7, and the oil tank inputs hydraulic oil to the rod chamber 15. At the same time, the first oil port 10 is connected to the rodless oil return chamber 5 and is disconnected from the oil inlet chamber 6. The hydraulic oil in the rodless chamber 14 returns through the first oil port 10 and flows back to the oil tank through the oil return port 9, causing the piston rod 23 to retract inward. On the contrary, when the valve stem 3 is retracted inward from the middle position by the thrust of the driving member, the first oil port 10 and the second oil port 11 are gradually opened, the first oil port 10 is connected with the oil inlet chamber 6 and disconnected from the rodless oil return chamber 5, the oil tank inputs hydraulic oil to the rodless chamber 14, and at the same time the second oil port 11 is connected with the rod oil return chamber 7 and disconnected from the oil inlet chamber 6 (such as Figure 4 As shown in FIG. 1 , the hydraulic oil in the rod chamber 15 returns through the first oil port 10 and flows back into the oil tank through the oil return port 9, causing the piston rod 23 to extend outward.

[0037] like Figure 1 As described above, the bosses located on both sides of the rodless oil return chamber 5 are used to make the rodless oil return chamber 5 communicate with other chambers only through the radial channel 16 therebetween, and the bosses located on both sides of the rod oil return chamber 7 are used to make the rod oil return chamber 7 communicate with other chambers only through the radial channel 16 therebetween, that is, there are four bosses in total. Specifically, the bosses of the valve stem 3 include a first boss 17, a second boss 18, a third boss 19, and a fourth boss 20 that are arranged axially and arranged in sequence from the rodless oil return chamber 5 to the rod oil return chamber 7. The distance between the center of the second boss 18 and the center of the third boss 19 is equal to the distance between the center of the first oil port 10 and the center of the second oil port 11, so that the second boss 18 and the third boss 19 can block the first oil port 10 and the second oil port 11 at the same time.

[0038] The distance that the valve stem 3 is extended or retracted can also control the opening degree of the first oil port 10 and the second oil port 11, thereby controlling the speed at which the piston rod 23 is extended or retracted, thereby adjusting the movement speed of the oil cylinder 13.

[0039] Embodiment 2

[0040] On the basis of the first embodiment, the boss of the valve stem can block one of the first oil port 10 and the second oil port 11, so that the piston rod 23 of the oil cylinder 13 is in a stationary state. That is, during the extension or retraction process of the piston rod 23, the extension or retraction movement is stopped by blocking the corresponding oil port.

[0041] like Figure 1 , Figure 5 and Figure 6 As shown, the bosses located on both sides of the rodless oil return chamber 5 are used to block the first oil port 10, and the bosses located on both sides of the rod oil return chamber 7 are used to block the second oil port 11. When one of the first oil port 10 and the second oil port 11 is blocked, the oil inlet 8 can be in a blocked state or in an open state. When the oil inlet 8 is opened, there may be two situations according to the position setting of the bosses: the first situation is that the unblocked oil port of the first oil port 10 and the second oil port 11 is connected to the oil inlet 8 and disconnected from the oil return port 9; the other situation is that the first oil port 10 and the second oil port 11 are both disconnected from the oil inlet 8 and the oil return port 9, and the oil inlet 8 is connected to the oil return port 9.

[0042] In the above two situations, there will be a slight buffer in the short time when one of the first oil port 10 and the second oil port 11 is blocked, so the piston rod 23 cannot accurately reach the specified position. Therefore, as a preferred embodiment, when one of the first oil port 10 and the second oil port 11 is blocked, the oil inlet 8 is also blocked at the same time, so that the hydraulic oil in the oil cylinder 13 and the oil tank stops flowing at the same time, and the piston rod 23 can stop immediately. This is specifically achieved through the following structure:

[0043] The distances between the center of the first boss 17 and the center of the second boss 18, the center of the third boss 19 and the center of the fourth boss 20, the center of the first oil port 10 and the center of the oil inlet 8, and the center of the second oil port 11 and the center of the oil inlet 8 are all equal.

[0044] When the valve stem 3 is in the middle position, the second boss 18 and the third boss 19 block the first oil port 10 and the second oil port 11 respectively (as shown in FIG. Figure 1 As shown in FIG. 1 , when the valve stem 3 is extended to the second oil port 11 and is fully opened, the first boss 17 and the second boss 18 respectively block the first oil port 10 and the oil inlet 8 (as shown in FIG. 1 ). Figure 5 As shown in FIG. 1 , when the valve stem 3 is retracted to the point where the first oil port 10 is fully opened, the third boss 19 and the fourth boss 20 block the oil inlet 8 and the second oil port 11, respectively (as shown in FIG. 1 ). Figure 6 shown).

[0045] Embodiment 3

[0046] A valve opening cylinder 13, such as Figure 2 and Figure 3 As shown, it includes an oil cylinder 13 and the above-mentioned servo slide valve 1 located outside the oil cylinder 13 .

[0047] The oil cylinder 13 includes a cylinder body 21 and a piston 22 and a piston rod 23 that axially reciprocate in the cylinder body 21. The piston 22 divides the interior of the cylinder body 21 into a rodless chamber 14 and a rod chamber 15. The oil cylinder 13 and the servo slide valve 1 are arranged separately. The cylinder body 21 of the oil cylinder 13 is fixed to the valve body 2 of the servo slide valve 1.

[0048] Preferably, a return spring 24 is provided in the rodless chamber 14, and both ends of the return spring 24 are connected to both ends of the rodless chamber 14. In the free state, the valve stem 3 is in the middle position, and the return spring 24 is used to automatically return the valve stem 3 to the middle position. For example, when the valve stem 3 is extended by the driving member, the piston rod 23 is retracted by the servo slide valve 1, and the return spring 24 is stretched and deformed. When the driving force of the driving member disappears, the elastic force of the return spring 24 causes the piston rod 23 to move in the opposite direction. At this time, the oil cylinder 13 provides the driving force, and the movement direction of the hydraulic oil inside the valve stem 3 is also opposite. For example, the hydraulic oil in the rod chamber 15 flows back to the oil tank through the second oil port 11, the oil inlet chamber 6 and the oil inlet 8, and the rodless oil return chamber 5 replenishes the hydraulic oil into the rodless chamber 14 until the valve stem 3 reaches the middle position, the whole system reaches automatic balance, and the oil cylinder 13 is automatically closed.

[0049] In the case of the first embodiment, the driving member only provides thrust to the valve stem 2, so that the valve stem 2 is retracted to Figure 4 The state shown in the figure pushes the piston rod 23 to extend until the hydraulic pressure and the elastic force of the return spring 24 reach a balance. When the thrust of the driving member disappears, the valve stem 2 returns to the initial position shown in the figure under the action of the return spring 24.

[0050] In the case of the second embodiment, when the valve stem 3 is stretched outward from the middle position, the piston rod 23 is retracted inward under the action of the servo slide valve 1 until the second oil port 11 is fully opened, the first oil port 10 is blocked again, the rodless chamber 14 cannot return oil, and the piston rod 23 no longer retracts (such as Figure 5 As shown), after the external force disappears, the valve stem 3 and the piston rod 23 return to the original position under the action of the return spring 24. Figure 1 On the contrary, when the valve stem 3 is retracted inward from the middle position, the piston rod 23 extends outward until the first oil port 10 is fully opened and the second oil port 11 is blocked again (as shown in FIG. Figure 6As shown in the figure), the rod chamber 15 cannot return oil, the piston rod 23 no longer extends, and after the external force disappears, the valve stem 3 and the piston rod 23 return to the initial position shown in the figure under the action of the return spring 24.

[0051] The valve opening cylinder of the utility model can be used for adjusting the pitch of the propeller. For example, the propeller is connected to the piston rods 23 of the two valve opening cylinders, and the two valve opening cylinders are used to adjust the propeller from two directions to advance a specified distance in a specified direction.

[0052] In the description of the present invention, it should be understood that the terms "center", "left", "right", "inside", "outside", "axial", "radial", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0053] Furthermore, the terms “first”, “second”, etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0054] In this specification, the schematic representation of the terms does not necessarily refer to the same embodiment. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in one or more embodiments.

[0055] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A servo slide valve, characterized in that: It includes a valve body and a valve stem located inside the valve body, wherein the valve stem is connected to a driving member; The valve stem is provided with an axially arranged oil passage, and the outside of the valve stem is axially surrounded by a plurality of bosses and the valve body to form a rodless oil return chamber, an oil inlet chamber and a rod oil return chamber in sequence. The rod oil return chamber and the rodless oil return chamber are connected to the oil passage, and the valve body has an oil inlet port and an oil return port connected to the oil tank, and a first oil port connected to the rodless chamber of the oil cylinder and a second oil port connected to the rod chamber of the oil cylinder; the oil inlet port is located between the first oil port and the second oil port, and the boss of the valve stem can block the first oil port and the second oil port at the same time. When the oil inlet port is connected to one of the first oil port and the second oil port, the oil return port is connected to the other oil port.

2. The servo slide valve according to claim 1, characterized in that: The oil return port is located at the end of the valve body, and the oil passage passes through one end of the valve stem toward the end where the oil return port is located.

3. The servo slide valve according to claim 1, characterized in that: The outer peripheral surface of the valve stem and the outer peripheral surface of the boss are both cylindrical surfaces.

4. The servo slide valve according to claim 1, characterized in that: The valve stem has a radial channel which is arranged in one-to-one correspondence with the rod oil return chamber and the rodless oil return chamber and is used to communicate with the oil passage.

5. The servo slide valve according to claim 4, characterized in that: The boss of the valve stem includes a first boss, a second boss, a third boss and a fourth boss which are arranged along the axial direction and in sequence from the rodless oil return chamber to the rod oil return chamber. The distance between the center of the second boss and the center of the third shoulder is equal to the distance between the center of the first oil port and the center of the second oil port. Radial channels are respectively provided on the valve stem between the first boss and the second shoulder and the valve stem between the third shoulder and the fourth shoulder.

6. The servo slide valve according to claim 5, characterized in that: The boss of the valve stem can block one of the first oil port and the second oil port to keep the piston rod of the oil cylinder in a stationary state.

7. The servo slide valve according to claim 6, characterized in that: The distances between the center of the first shoulder and the center of the second shoulder, the center of the third shoulder and the center of the fourth shoulder, the center of the first oil port and the center of the oil inlet, and the center of the second oil port and the center of the oil inlet are all equal.

8. A valve opening cylinder, characterized in that: The utility model comprises an oil cylinder and a servo slide valve according to any one of claims 1 to 7 and located outside the oil cylinder.

9. The valve opening cylinder according to claim 8, characterized in that: The oil cylinder comprises a cylinder body, a piston and a piston rod which axially reciprocate in the cylinder body, and the piston divides the interior of the cylinder body into a rodless chamber and a rod chamber.

10. The valve opening cylinder according to claim 9, characterized in that: A return spring is arranged in the rodless cavity, and two ends of the return spring are connected to two ends of the rodless cavity. When the return spring is in a free state, the first oil port and the second oil port are blocked at the same time.

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