Hydraulic slide valve, hydraulic system and engineering machinery

Abstract

The utility model relates to the technical field of hydraulic components, in particular to a hydraulic slide valve, a hydraulic system with the hydraulic slide valve and engineering machinery. The hydraulic slide valve comprises a valve body and a valve element located in the valve body, and the valve element is connected with the valve body in a sliding mode. A first working opening, a second working opening, an oil inlet and an oil return opening are formed in the valve body; the hydraulic slide valve comprises an unloading position, and when the hydraulic slide valve is located at the unloading position, the first working opening, the second working opening and the oil inlet are all communicated with the oil return opening. Compared with the prior art, the hydraulic slide valve has the advantages that on one hand, the oil inlet impact of a system can be reduced, and on the other hand, the oil inlet and the working port are pre-unloaded, the oil return flow change gradient is reduced, and the oil return impact is reduced, so that different overflowing area curves can be obtained through the combination of different unloading hole positions and hole diameter sizes; and different control functions are realized.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic components, in particular to a hydraulic slide valve and a hydraulic system and engineering machinery having the hydraulic slide valve. Background Art

[0002] The hydraulic valve is a control element in the hydraulic system, which is used to control the pressure, flow rate and flow direction of the fluid in the hydraulic system. It is one of the most important components in the hydraulic system. The hydraulic control slide valve is a commonly used hydraulic component in engineering machinery, which is used to control the hydraulic actuator. The common hydraulic control slide valve has three working positions: left position, middle position and right position. There is an oil-filled control chamber at each end of the valve stem in the valve body. When the control chamber is filled with oil, the valve stem is pushed to move, so that the hydraulic control slide valve is in the corresponding working position. A return spring is usually set in the control chamber. When the control front view at both ends of the valve stem is not filled with pressure oil, the valve stem is in the middle position under the elastic force of the return spring. The common hydraulic control slide valve realizes reversing by pushing the valve core to move by the pilot pressure. When the valve core returns to the middle position, the return springs at both ends push the valve core back to the middle position. Since the spring pushes the valve core to move at a fast speed, resulting in a large reversing shock. In order to solve the problem of large reversing shock, the common countermeasure is to add damping to the pilot oil circuit of the valve core, and limit the speed of the valve core reversing to achieve the purpose of reducing the shock. The problems of the above related technologies are: 1. It is not possible to simultaneously reduce the oil return shock and the oil inlet shock; 2. While reducing the switching shock, it affects the switching speed. Therefore, for those skilled in the art, how to provide a hydraulic slide valve with a new structure to solve or improve the above technical problems has become a technical problem that needs to be solved in this field. Utility Model Content

[0003] According to the embodiments of the present utility model, it is intended to solve or improve at least one of the technical problems existing in the prior art or related art.

[0004] Therefore, according to an embodiment of the present utility model, one object is to provide a hydraulic slide valve.

[0005] According to an embodiment of the present utility model, another object is to provide a hydraulic system.

[0006] According to an embodiment of the present utility model, another object is to provide an engineering machine.

[0007] In order to achieve the above-mentioned purpose, according to an embodiment of the first aspect of the utility model, a hydraulic sliding valve is provided, including a valve body and a valve core located in the valve body, and the valve core and the valve body are slidingly connected; the valve body is provided with a first working port, a second working port, an oil inlet and an oil return port; the hydraulic sliding valve includes an unloading position, and when the hydraulic sliding valve is in the unloading position, the first working port, the second working port, the oil inlet are all connected to the oil return port.

[0008] As an improvement in one aspect of the hydraulic slide valve of the utility model, the hydraulic slide valve includes a first working position, a second working position and a middle position; when the hydraulic slide valve is in the first working position, the first working port is connected to the oil inlet, and the second working port is connected to the oil return port; when the hydraulic slide valve is in the second working position, the second working port is connected to the oil inlet, and the first working port is connected to the oil return port; when the hydraulic slide valve is in the middle position, the first working port, the second working port, the oil inlet and the oil return port are cut off from each other.

[0009] As an improvement in one aspect of the hydraulic sliding valve of the utility model, the hydraulic sliding valve is configured so that during the switching process between the first working position and the middle position, one of the hydraulic sliding valves is first switched to the unloading position and then switched to the other from the unloading position; the hydraulic sliding valve is configured so that during the switching process between the second working position and the middle position, one of the hydraulic sliding valves is first switched to the unloading position and then switched to the other from the unloading position.

[0010] As an improvement in one aspect of the hydraulic slide valve of the utility model, the oil return port includes a first oil return port and a second oil return port, the unloading position includes a first unloading position and a second unloading position, when the hydraulic slide valve is in the first unloading position, the first working port, the oil inlet and the first oil return port are connected to each other, and the second working port and the second oil return port are connected, when the hydraulic slide valve is in the second unloading position, the first working port and the first oil return port are connected, and the second working port, the oil inlet and the second oil return port are connected to each other.

[0011] As an improvement of the hydraulic sliding valve of the utility model in one aspect, when the valve core slides from one end of the valve body to the other end of the valve body, the hydraulic sliding valve switches its state in the order of the first working position, the first unloading position, the middle position, the second unloading position and the second working position.

[0012] As an improvement in one aspect of the hydraulic sliding valve of the utility model, the outer wall of the valve core is provided with a shaft shoulder and a groove, the valve core is provided with a flow channel, the opening of the flow channel is provided on the outer wall of the valve core, and the inner wall of the valve body is provided with a pit, and the hydraulic sliding valve is switched between the first working position, the second working position, the unloading position and the middle position through the coordination of the shaft shoulder, the groove, the flow channel and the pit.

[0013] As an improvement of the hydraulic sliding valve of the utility model in one aspect, the valve core is cylindrical, the valve body is cylindrical, and the shaft shoulder, the groove and the pit are all annular.

[0014] As an improvement in one aspect of the hydraulic slide valve of the utility model, the flow channel includes a first flow channel and a second flow channel. When the hydraulic slide valve is in a first unloading position, the first working port, the oil inlet and the first oil return port are connected to each other through the first flow channel, and the second working port and the second oil return port are connected to each other through the second flow channel. When the hydraulic slide valve is in a second unloading position, the first working port and the first oil return port are connected to each other through the first flow channel, and the second working port, the oil inlet and the second oil return port are connected to each other through the second flow channel.

[0015] Compared with the prior art, the hydraulic slide valve of the utility model can reduce the oil inlet shock of the system by connecting the first working port, the second working port, the oil inlet and the oil return port when the hydraulic slide valve is in the unloading position. On the other hand, the oil inlet and the working port are pre-unloaded to reduce the gradient of the return oil flow rate and the return oil shock. Therefore, the hydraulic slide valve of the utility model can obtain different flow area curves through different combinations of unloading hole positions and aperture sizes, thereby realizing different control functions.

[0016] According to an embodiment of the second aspect of the utility model, a hydraulic system is provided, comprising a hydraulic slide valve as described in any one of the above solutions.

[0017] The hydraulic system in this solution has all the beneficial effects of the hydraulic slide valve in the embodiment of the first aspect described above, which will not be described in detail here.

[0018] According to an embodiment of the third aspect of the utility model, there is provided an engineering machine, comprising a hydraulic slide valve or a hydraulic system as described in any one of the above schemes.

[0019] The engineering machinery in this solution has all the beneficial effects of the hydraulic slide valve in the embodiment of the first aspect or all the beneficial effects of the hydraulic system in the embodiment of the second aspect, which will not be repeated here.

[0020] Additional aspects and advantages of the embodiments of the present invention will become apparent in the following description or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the embodiments of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0022] Figure 1 A structural schematic diagram of a hydraulic slide valve in a first working position according to an embodiment of the utility model is shown.

[0023] Figure 2 The figure shows a structural schematic diagram of a hydraulic slide valve in a first unloading position according to an embodiment of the utility model.

[0024] Figure 3 A structural schematic diagram of a hydraulic slide valve in a neutral position according to an embodiment of the utility model is shown.

[0025] Figure 4 The schematic diagram shows the structure of a hydraulic slide valve in a second unloading position according to an embodiment of the utility model.

[0026] Figure 5 The figure shows a structural schematic diagram of a hydraulic slide valve in a second working position according to an embodiment of the utility model.

[0027] Figure 6 A structural schematic diagram of a hydraulic slide valve according to an embodiment of the utility model is shown.

[0028] Figure 7 A schematic diagram of a hydraulic system according to an embodiment of the utility model is shown.

[0029] Figure 8 A schematic diagram of a framework of an engineering machine according to an embodiment of the utility model is shown.

[0030] Figures 1 to 6 The corresponding relationship between the reference numerals and components is as follows:

[0031] 1. Valve body; 2. Valve core; 3. First working port; 4. Second working port; 5. Oil inlet; 6. Oil return port; 7. First oil return port; 8. Second oil return port; 9. Shoulder; 10. Groove; 11. Flow channel; 12. Pit; 13. First flow channel; 14. Second flow channel. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] In the description of the embodiments of the present utility model, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present utility model 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 understood as limiting the embodiments of the present utility model. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0034] In order to solve or improve one of the technical problems existing in the prior art or related technology, in some specific embodiments of the present utility model, such as Figures 1 to 6 As shown, the present application provides a hydraulic slide valve, including a valve body 1 and a valve core 2 located in the valve body 1, wherein the valve core 2 and the valve body 1 are slidably connected; the valve body 1 is provided with a first working port 3, a second working port 4, an oil inlet 5 and an oil return port 6; the hydraulic slide valve includes an unloading position, and when the hydraulic slide valve is in the unloading position, the first working port 3, the second working port 4, the oil inlet 5 are all connected to the oil return port 6. It should be noted that, if Figures 1 to 5 As shown, letters A, B, P, and T represent the first working port 3, the second working port 4, the oil inlet 5, and the oil return port 6, respectively.

[0035] In the above embodiment, when the hydraulic slide valve is in the unloading position, by connecting the first working port 3, the second working port 4, the oil inlet 5 and the oil return port 6, on the one hand, the system oil inlet shock can be reduced, and on the other hand, the oil inlet 5 and the working port are pre-unloaded to reduce the gradient of the return oil flow rate and the return oil shock. Therefore, the hydraulic slide valve of the utility model can obtain different flow area curves through different combinations of unloading hole positions and aperture sizes, thereby realizing different control functions.

[0036] In some embodiments of the utility model, the hydraulic slide valve includes a first working position, a second working position and a middle position; when the hydraulic slide valve is in the first working position, the first working port 3 is connected to the oil inlet 5, and the second working port 4 is connected to the oil return port 6; when the hydraulic slide valve is in the second working position, the second working port 4 is connected to the oil inlet 5, and the first working port 3 is connected to the oil return port 6; when the hydraulic slide valve is in the middle position, the first working port 3, the second working port 4, the oil inlet 5 and the oil return port 6 are cut off from each other.

[0037] In some embodiments of the utility model, the hydraulic slide valve is configured so that during the switching process between the first working position and the middle position, one of them is first switched to the unloading position and then switched from the unloading position to the other; the hydraulic slide valve is configured so that during the switching process between the second working position and the middle position, one of them is first switched to the unloading position and then switched from the unloading position to the other. In the above embodiments, the unloading position is a transition position. Whether it is switching from the first working position to the middle position or the middle position to the first working position, or from the second working position to the middle position or the middle position to the second working position, it is necessary to first switch to the unloading position and then switch from the unloading position to the target state, thereby realizing early unloading during the switching process, achieving the purpose of reducing the switching shock, and at the same time pre-unloading the oil inlet 5 and the working port, reducing the gradient of the return oil flow change, and reducing the return oil shock.

[0038] In some embodiments of the utility model, the oil return port 6 includes a first oil return port 7 and a second oil return port 8, and the unloading position includes a first unloading position and a second unloading position. When the hydraulic slide valve is in the first unloading position, the first working port 3, the oil inlet 5 and the first oil return port 7 are interconnected, and the second working port 4 and the second oil return port 8 are interconnected. When the hydraulic slide valve is in the second unloading position, the first working port 3 and the first oil return port 7 are interconnected, and the second working port 4, the oil inlet 5 and the second oil return port 8 are interconnected. In some embodiments of the utility model, when the valve core 2 slides from one end of the valve body 1 to the other end of the valve body 1, the hydraulic slide valve switches its state in the order of the first working position, the first unloading position, the middle position, the second unloading position and the second working position. Figures 1 to 5 As shown, when the valve core 2 slides from right to left along the axial direction of the valve body 1, the hydraulic slide valve switches its state in the order of the first working position, the first unloading position, the middle position, the second unloading position, and the second working position. It can be understood that when the valve core 2 slides from left to right along the axial direction of the valve body 1, the hydraulic slide valve switches its state in the order of the second working position, the second unloading position, the middle position, the first unloading position, and the first working position. Such an arrangement can improve the coordination of the action.

[0039] In some embodiments of the utility model, the outer wall of the valve core 2 is provided with a shoulder 9 and a groove 10, the valve core 2 is provided with a flow channel 11, the opening of the flow channel 11 is provided on the outer wall of the valve core 2, and the inner wall of the valve body 1 is provided with a pit 12. Through the coordination of the shoulder 9, the groove 10, the flow channel 11 and the pit 12, the hydraulic slide valve can switch between the first working position, the second working position, the unloading position and the middle position. The utility model does not require additional increase in the structural size of the valve group and does not affect the switching time of the valve core 2. In some embodiments of the utility model, the flow channel 11 includes a first flow channel 13 and a second flow channel 14. When the hydraulic slide valve is in a first unloading position, the first working port 3, the oil inlet 5 and the first oil return port 7 are interconnected through the first flow channel 13, and the second working port 4 and the second oil return port 8 are connected through the second flow channel 14. When the hydraulic slide valve is in a second unloading position, the first working port 3 and the first oil return port 7 are connected through the first flow channel 13, and the second working port 4, the oil inlet 5 and the second oil return port 8 are connected through the second flow channel 14.

[0040] In some embodiments of the utility model, the valve core 2 is cylindrical, the valve body 1 is cylindrical, and the shaft shoulder 9, the groove 10 and the pit 12 are all annular. In this example, the pressure oil at various locations on the same circumference can communicate with each other, so that the center of the valve core 2 is positioned, the friction force and the hydraulic clamping force are reduced, and the axial movement of the valve core 2 along the valve body 1 is improved. Preferably, as Figures 1 to 5 As shown, the valve core 2 is a left-right symmetrical structure, and the valve body 1 is a left-right symmetrical structure. The left-right symmetrical structure is adopted to facilitate the processing of the valve core 2 and the valve body 1 and simplify the process.

[0041] It can be seen from the above content that, compared with the prior art, the hydraulic slide valve of the utility model can reduce the oil inlet shock of the system by connecting the first working port 3, the second working port 4, the oil inlet 5 and the oil return port 6 when the hydraulic slide valve is in the unloading position. On the other hand, the oil inlet 5 and the working port are pre-unloaded to reduce the gradient of the return oil flow rate and reduce the return oil shock. Therefore, the hydraulic slide valve of the utility model can obtain different flow area curves through different combinations of unloading hole positions and aperture sizes, thereby realizing different control functions.

[0042] In some specific embodiments of the present invention, Figure 7As shown, the utility model provides a hydraulic system, which includes the hydraulic slide valve described in any one of the above embodiments. The hydraulic system of the utility model has all the technical effects of the above hydraulic slide valve because it has the above hydraulic slide valve. When the hydraulic slide valve is in the unloading position, by connecting the first working port 3, the second working port 4, the oil inlet 5 and the oil return port 6, on the one hand, the oil inlet shock of the system can be reduced. On the other hand, the oil inlet 5 and the working port are pre-unloaded to reduce the gradient of the return oil flow rate and reduce the return oil shock.

[0043] In some specific embodiments of the present invention, Figure 8 As shown, the utility model provides an engineering machine, which includes the hydraulic slide valve described in any one of the above embodiments or the hydraulic system described in any one of the above embodiments.

[0044] The engineering machinery of the utility model has all the technical effects of the hydraulic slide valve or the hydraulic system mentioned above. When the hydraulic slide valve is in the unloading position, by connecting the first working port 3, the second working port 4, the oil inlet 5 and the oil return port 6, on the one hand, the system oil inlet shock can be reduced, and on the other hand, the oil inlet 5 and the working port are pre-unloaded to reduce the return oil flow rate gradient and the return oil shock. Therefore, different flow area curves can be obtained by combining different unloading hole positions and aperture sizes to achieve different control functions.

[0045] In the description of the embodiments of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to specific circumstances.

[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model embodiment. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0047] Finally, it should be noted that the above implementation modes are only used to illustrate the present invention, rather than to limit the present invention. Although the present invention is described in detail with reference to the embodiments, a person skilled in the art should understand that various combinations, modifications or equivalent replacements of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should be included in the scope of the claims of the present invention.

Claims

1. A hydraulic slide valve, characterized in that: It comprises a valve body (1) and a valve core (2) located in the valve body (1), wherein the valve core (2) and the valve body (1) are slidably connected; The valve body (1) is provided with a first working port (3), a second working port (4), an oil inlet (5) and an oil return port (6); The hydraulic slide valve comprises an unloading position. When the hydraulic slide valve is in the unloading position, the first working port (3), the second working port (4), and the oil inlet (5) are all connected to the oil return port (6).

2. The hydraulic slide valve according to claim 1, characterized in that: The hydraulic slide valve comprises a first working position, a second working position and a middle position; when the hydraulic slide valve is in the first working position, the first working port (3) is connected to the oil inlet (5), and the second working port (4) is connected to the oil return port (6); when the hydraulic slide valve is in the second working position, the second working port (4) is connected to the oil inlet (5), and the first working port (3) is connected to the oil return port (6); when the hydraulic slide valve is in the middle position, the first working port (3), the second working port (4), the oil inlet (5) and the oil return port (6) are mutually blocked.

3. The hydraulic slide valve according to claim 2, characterized in that: The hydraulic sliding valve is configured so that during the switching process between the first working position and the middle position, one of the hydraulic sliding valves is first switched to the unloading position and then switched to the other from the unloading position; the hydraulic sliding valve is configured so that during the switching process between the second working position and the middle position, one of the hydraulic sliding valves is first switched to the unloading position and then switched to the other from the unloading position.

4. The hydraulic slide valve according to claim 3, characterized in that: The oil return port (6) comprises a first oil return port (7) and a second oil return port (8); the unloading position comprises a first unloading position and a second unloading position; when the hydraulic slide valve is in the first unloading position, the first working port (3), the oil inlet port (5) and the first oil return port (7) are connected to each other, and the second working port (4) and the second oil return port (8) are connected to each other; when the hydraulic slide valve is in the second unloading position, the first working port (3) and the first oil return port (7) are connected to each other, and the second working port (4), the oil inlet port (5) and the second oil return port (8) are connected to each other.

5. The hydraulic slide valve according to claim 4, characterized in that: When the valve core (2) slides from one end of the valve body (1) to the other end of the valve body (1), the hydraulic slide valve switches its state in the order of a first working position, a first unloading position, a middle position, a second unloading position, and a second working position.

6. The hydraulic slide valve according to any one of claims 1 to 5, characterized in that: The outer wall of the valve core (2) is provided with a shaft shoulder (9) and a groove (10), the valve core (2) is provided with a flow channel (11), the opening of the flow channel (11) is provided on the outer wall of the valve core (2), and the inner wall of the valve body (1) is provided with a pit (12). The hydraulic slide valve can be switched between a first working position, a second working position, a unloading position and a middle position through the coordination of the shaft shoulder (9), the groove (10), the flow channel (11) and the pit (12).

7. The hydraulic slide valve according to claim 6, characterized in that: The valve core (2) is cylindrical, the valve body (1) is cylindrical, and the shaft shoulder (9), the groove (10) and the pit (12) are all annular.

8. The hydraulic slide valve according to claim 6, characterized in that: The flow channel (11) comprises a first flow channel (13) and a second flow channel (14); when the hydraulic slide valve is in a first unloading position, the first working port (3), the oil inlet (5) and the first oil return port (7) are connected to each other through the first flow channel (13); the second working port (4) and the second oil return port (8) are connected to each other through the second flow channel (14); when the hydraulic slide valve is in a second unloading position, the first working port (3) and the first oil return port (7) are connected to each other through the first flow channel (13); the second working port (4), the oil inlet (5) and the second oil return port (8) are connected to each other through the second flow channel (14).

9. A hydraulic system, characterized in that: Comprising the hydraulic slide valve according to any one of claims 1 to 8.

10. An engineering machine, characterized in that: The hydraulic slide valve comprises the hydraulic slide valve according to any one of claims 1 to 8 or the hydraulic system according to claim 9.

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