Plug-in mounting type manual unloading valve

Abstract

The utility model discloses a plug-in mounting type manual unloading valve which comprises a first through hole, a fourth through hole, a second through hole, a third through hole and a fourth through hole, the one-way valve is arranged between the first through hole and the fourth through hole; the valve rod reciprocates between at least one opening position and at least one closing position, and the inner end of the valve rod pushes the one-way valve to be opened at the opening position so as to allow fluid to flow from the first through hole to the fourth through hole; the flow limiting valve element is movably and elastically installed in the main channel. According to the plug-in mounting type manual unloading valve, the valve rod, the one-way valve and the flow limiting valve element are arranged on the main channel, so that the flow limiting function and the unloading function are integrated, and the unloading valve has the flow limiting function at the same time. And therefore, the number of components is reduced, the compactness of the whole system applying the unloading valve is improved, and the unloading valve has wide market prospects and application value.

Description

Technical Field

[0001] The utility model relates to the technical field of non-powered hydraulic systems, and more specifically, to a cartridge-type manual unloading valve. Typical products related to this technology include: manual vertical or horizontal hydraulic jacks, manual hydraulic stackers, manual hydraulic pallet trucks, manual hydraulic platform trucks, etc., and also involve similar hydraulic machinery operated by foot stepping. Background Art

[0002] Generally, for similar non-powered hydraulic machinery, a manual or foot-controlled operation valve for controlling lifting or unloading needs to be configured inside its hydraulic system, which is called an unloading valve. The basic working mode of the valve generally exists in three types:

[0003] 1 Normally closed type, that is, when there is no external force operation or the operation force disappears, the unloading valve is in the closed state. Only under the action of external force or after operation, the unloading valve can be opened, so as to control the internal work of the hydraulic system. Once the operation force disappears, the valve immediately returns to the closed state. Manual hydraulic stackers, manual hydraulic pallet trucks, manual hydraulic platform trucks, etc. are mostly equipped with such unloading valves.

[0004] 2 Normally open type, that is, when there is no external force operation or the operation force disappears, the unloading valve is in the open state. Only under the action of external force or after operation, the unloading valve can be closed, so as to control the internal work of the hydraulic system. Once the operation force disappears, the valve immediately returns to the open state. This type of unloading valve is only used in a few special requirement machinery.

[0005] 3 Random type, the opening and closing of the unloading valve depend on the last operation. It is related to the last operation whether it is open or closed, and then it must be operated by the operator again to reach the required state. The most widely used hydraulic vertical jacks or horizontal jacks are equipped with such unloading valves inside.

[0006] In addition to the above three types of unloading valves, they can also be divided into the following two types according to their installation forms: one is integrated with the machine, that is, the valve is directly configured in the hydraulic cylinder seat, and the other is pre-made into a valve unit, and then the whole valve unit is assembled into the hydraulic cylinder seat. The industry generally calls it a cartridge valve.

[0007] Small cartridge valves are mostly made into threaded cartridge type, and larger cartridge valves are mostly made into flange cartridge type.

[0008] In some hydraulic machinery with higher safety requirements, in order to prevent improper operation or ensure the safety of goods and machinery even in case of misoperation, especially for some high-lifting machinery such as manual hydraulic high-lifting pallet trucks, manual hydraulic stackers, hand-pushed hydraulic lifting platform trucks, etc., in order to prevent or eliminate the free-fall of their carriers and goods, it is often necessary to additionally set a self-limiting flow throttle valve in the hydraulic system to achieve the purpose of safe slow descent.

[0009] Based on the above safety requirements and considerations of combined convenience, integrating the flow-limiting valve and the unloading valve becomes a new design concept. By integrating these two functional valves into an integrated cartridge structure, not only can the number of components be reduced, but also the compactness of the overall system can be improved. Summary of the Invention

[0010] The utility model aims to solve one of the technical problems in the related art to a certain extent. For this purpose, the utility model provides a cartridge-type manual unloading valve.

[0011] The technical solution adopted by the utility model is as follows: Provide a cartridge-type manual unloading valve, including:

[0012] A first through hole and a fourth through hole arranged to communicate with each other through a main channel;

[0013] A check valve arranged between the first through hole and the fourth through hole;

[0014] A valve stem that reciprocates between at least one open position and at least one closed position. At the open position, the inner end of the valve stem pushes the check valve open to allow fluid to flow from the first through hole to the fourth through hole;

[0015] A flow-limiting valve core that is movably and elastically installed in the main channel.

[0016] After adopting the above structure, by arranging a valve stem, a check valve and a flow-limiting valve core on the main channel, the functions of flow-limiting and unloading are integrated, that is, the unloading valve in the utility model simultaneously has the function of flow-limiting. Furthermore, the number of components is reduced, and the compactness of the overall system applying the unloading valve is improved, having broad market prospects and application value.

[0017] According to an embodiment of the utility model, it further includes a valve body. The first through hole is arranged on the flow-limiting valve core, the fourth through hole is arranged on the valve body, the valve stem is movably installed at one end of the valve body, and the flow-limiting valve core is movably installed at the other end of the valve body; the first through hole is used to connect the hydraulic working cylinder, that is, the first through hole is used as the inlet of the main channel, and the fourth through hole is used to connect the fuel tank, that is, the fourth through hole is used as the outlet of the main channel.

[0018] According to an embodiment of the present utility model, the valve body is provided with a second through hole and a third through hole, and the second through hole and the third through hole are located between the first through hole and the fourth through hole.

[0019] According to an embodiment of the present utility model, when the fluid inflow pressure of the first through hole is greater than the fluid outflow pressure, under the action of the pressure difference, the flow-limiting valve core moves to a position blocking the second through hole to limit the flow of the main channel.

[0020] According to an embodiment of the present utility model, a third spring is provided between the flow-limiting valve core and the valve body; the third spring has an elastic tendency to keep the flow-limiting valve core in the initial position, and is used to balance the acting force of the flow-limiting valve core.

[0021] According to an embodiment of the present utility model, the valve body is used to be installed in the pre-installation hole of the unloading valve. When the valve body is installed in the pre-installation hole, the second through hole and the third through hole are communicated through the gap between the valve body and the pre-installation hole: the pre-installation hole includes a hydraulic cylinder seat. For example, hydraulic machinery such as manual vertical or horizontal hydraulic jacks, manual hydraulic stackers, manual hydraulic pallet trucks, and manual hydraulic platform trucks all have hydraulic cylinder seats, and the hydraulic cylinder seat is generally also a basic component of the hydraulic working cylinder and the fuel tank.

[0022] According to an embodiment of the present utility model, a first spring is provided between the valve stem and the valve body; and / or

[0023] The valve body is connected with a sealing cover;

[0024] and / or a first sealing ring is provided on the valve stem.

[0025] According to an embodiment of the present utility model, the one-way valve includes a steel ball, a second spring and a screw. The two ends of the second spring respectively abut against the steel ball and the screw, and the second spring has an elastic tendency to keep the steel ball blocking the main channel.

[0026] According to an embodiment of the present utility model, the valve body is used to be installed in the pre-installation hole of the unloading valve, and a second sealing ring and / or a third sealing ring are provided between the valve body and the pre-installation hole.

[0027] According to an embodiment of the present utility model, the valve body is connected with a retaining ring, and one end of the flow-limiting valve core away from the valve stem abuts against the retaining ring. Description of the Drawings

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0029] Figure 1 It is a cross-sectional view of the unloading valve in the embodiment of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the unloading valve in the embodiment of the present invention;

[0031] Figure 3 It is a three-dimensional view of the unloading valve in the embodiment of the present invention.

[0032] Explanation of the reference numerals in the figure:

[0033] 1. Valve stem; 2. Sealing cover; 3. First sealing ring; 4. Valve body; 5. Second sealing ring; 6. First spring; 7. Steel ball; 8. Third sealing ring; 9. Second spring; 10. Screw; 11. Third spring; 12. Flow-limiting valve core; 13. Retaining ring;

[0034] A. First through hole; B. Second through hole; C. Third through hole; D. Fourth through hole; G. External force. Specific embodiments

[0035] The following will describe in detail the embodiments of the present invention. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as a limitation to the present invention.

[0036] In this specific embodiment, the flow direction of the liquid in the unloading valve is only allowed to flow from the first through hole to the fourth through hole, and cannot flow back from the fourth through hole to the first through hole. The principles or mechanisms described hereinafter refer to the allowed flow state. Embodiment 1

[0037] As Figures 1-3 shown, in this embodiment, an inserted manual unloading valve is disclosed, including:

[0038] A first through hole A and a fourth through hole D that are arranged to communicate with each other through a main channel;

[0039] A one-way valve arranged between the first through hole A and the fourth through hole D;

[0040] The valve stem 1 reciprocates between at least one open position and at least one closed position. At the open position, the inner end of the valve stem 1 pushes against the check valve to open it, allowing fluid to flow from the first through-hole A to the fourth through-hole D.

[0041] The flow-limiting valve core 12 is movably and elastically installed in the main channel.

[0042] Specifically, the plug-in type manual unloading valve further includes a valve body 4. The first through-hole A is provided on the flow-limiting valve core 12, and the fourth through-hole D is provided on the valve body 4. The valve stem 1 is movably installed at one end of the valve body 4, and the flow-limiting valve core 12 is movably installed at the other end of the valve body 4. The valve body 4 is provided with a second through-hole B and a third through-hole C, and the second through-hole B and the third through-hole C are located between the first through-hole A and the fourth through-hole D. When the fluid inflow pressure in the first through-hole A is greater than the fluid outflow pressure, under the action of the pressure difference, the flow-limiting valve core 12 moves to block the second through-hole B to limit the flow of the main channel. A third spring 11 is provided between the flow-limiting valve core 12 and the valve body 4. The valve body 4 is used to be installed in the pre-installation hole of the unloading valve. When the valve body 4 is installed in the pre-installation hole, the second through-hole B and the third through-hole C are communicated through the gap between the valve body 4 and the pre-installation hole. A first spring 6 is provided between the valve stem 1 and the valve body 4; the valve body 4 is connected with a sealing cover 2; a first sealing ring 3 is provided on the valve stem 1.

[0043] Specifically, the check valve includes a steel ball 7, a second spring 9 and a screw 10. The two ends of the second spring 9 respectively abut against the steel ball 7 and the screw 10, and the second spring 9 has an elastic tendency to keep the steel ball 7 blocking the main channel. The valve body 4 is used to be installed in the pre-installation hole of the unloading valve. A second sealing ring 5 and a third sealing ring 8 are provided between the valve body 4 and the pre-installation hole. The valve body 4 is connected with a retaining ring 13, and one end of the flow-limiting valve core 12 away from the valve stem 1 abuts against the retaining ring 13.

[0044] Further, in this embodiment, the outer periphery of the valve body 4 is provided with an external thread, and the valve body 4 is installed in the pre-installation hole through this external thread structure. The pre-installation hole includes a hydraulic cylinder seat. For example, hydraulic machinery such as manual vertical or horizontal hydraulic jacks, manual hydraulic stackers, manual hydraulic pallet trucks, and manual hydraulic platform trucks all have hydraulic cylinder seats, and the hydraulic cylinder seats are provided with hydraulic working cylinders and fuel tanks. Combine Figure 1As shown, in this embodiment, both ends of the valve body 4 are internally hollow and have openings at both ends. The outer end of the valve body 4 is threadedly connected with a sealing cover 2. The free end of the valve stem 1 extends out of the sealing cover 2, and the sealing cover 2 is used to prevent the valve stem 1 from sliding out during standby. A first spring 6 is sleeved on the inner end of the valve stem 1. One end of the first spring 6 abuts against the shoulder of the valve stem 1, and the other end abuts against the inner wall of the opening of the valve body 4. The end of the valve stem 1 is coaxially arranged with the upper steel ball 7 of the one-way valve. When the valve stem 1 moves inward, the first spring 6 is compressed, and the inner end of the valve stem 1 pushes the steel ball 7 to open the one-way valve. Two first sealing rings 3 are arranged on the outer circumference of the valve stem 1. The first sealing rings 3 are double-set to ensure reliable sealing and prevent the liquid inside the valve stem 1 and the valve body 4 from leaking out.

[0045] Further, a screw 10 of the one-way valve is connected to the middle of the valve body 4. The valve stem 1, the first spring 6, the steel ball 7, the second spring 9, the screw 10, the third spring 11, and the flow-limiting valve core 12 are coaxially arranged. Second sealing rings 5 and third sealing rings 8 are arranged on the outer circumference of the valve body 4. Among them, the second sealing ring 5 is located at the thread of the valve body 4 and is used to prevent the liquid from leaking out at the thread of the valve body 4. The third sealing ring 8 is used to block the oil on both sides of the one-way valve from communicating. The screw 10 abuts against the second spring 9 and is used to block the liquid communication between the one-way valve cavity and the flow-limiting valve cavity. The second through hole B is communicated with the flow-limiting valve cavity, and the third through hole C is communicated with the one-way valve cavity. When the valve body 4 is installed in the pre-installation hole, the flow-limiting valve cavity is communicated with the one-way valve cavity through the following channels in sequence: the second through hole B, the gap between the valve body 4 and the pre-installation hole, and the third through hole C.

[0046] Further, in this embodiment, the flow-limiting valve core 12 is slidably installed in the flow-limiting valve cavity of the valve body 4. One end of the flow-limiting valve core 12 facing the valve stem 1 is provided with a blind hole, and a first through hole A is provided at the bottom of the blind hole. The first through hole A communicates the blind hole with the external space. Part of the third spring 11 is located in the blind hole, and the protruding end of the third spring 11 abuts against the screw 10. In other embodiments, the protruding end of the third spring 11 abuts against the side wall of the flow-limiting valve cavity.

[0047] Further, in this embodiment, the working principle of the plug-in type manual unloading valve is as follows:

[0048] 1. In the standby state, the valve stem 1 is pushed to one side by the first spring 6. The inner end of the valve stem 1 leaves the one-way valve and does not contact the steel ball 7. The one-way valve is closed under the dual action of the second spring 9 and the system liquid pressure. The third spring 11 pushes the flow-limiting valve core 12 to the right. There is no liquid flow in the main channel, and the flow-limiting valve does not work at this time. The unloading valve is in the cut-off condition.

[0049] 2. Press the valve stem 1. The valve stem 1 pushes open the check valve steel ball 7, the check valve opens, and the main channel is in a connected state. The unloading valve is opened. Under the push of the external force G of the hydraulic working cylinder, the liquid in the hydraulic working cylinder flows back to the fuel tank through the first through hole A → the second through hole B → the third through hole C → the check valve orifice → the fourth through hole D on the flow limiting valve core 12, as shown by the streamline of "→→→" in the figure.

[0050] 3. Flow limiting working principle: After the check valve is opened, during the process of the liquid flowing through the first through hole A, a pressure difference is generated on both sides of the hole, with the right side greater than the left side. As a result, the flow limiting valve core 12 is pushed and tends to move to an appropriate position on the left. After the flow limiting valve core 12 moves to the left, a part of the area of the second through hole B is covered by the flow limiting valve core 12, and the actual flow cross-section decreases accordingly. Then the flow rate also decreases, and the pressure difference on both sides of the flow limiting valve core 12 also becomes smaller. Then, under the balance of the elastic force of the third spring 11, finally, the flow limiting valve core 12 displaces to the critical position and then fixes. At this point, the throttling area of the second through hole B is also limited to the current size. After that, the flow rate and flow velocity of the liquid are relatively stable, and the flow rate is limited within the set range, thus achieving the function of automatically limiting the flow rate.

[0051] 4. The magnitude of the elastic force of the third spring 11 and the size of the aperture of the first through hole A will directly affect the flow rate and flow velocity. In actual applications, it must be calculated and verified in advance and then experimentally verified. Then, after making targeted adjustments to the relevant parameters, the requirements of the set indicators can be met.

[0052] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and 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 thus cannot be understood as a limitation to the present invention.

[0053] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0054] In the present utility model, unless otherwise clearly specified and defined, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or capable of communicating with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0055] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. An inserted manual unloading valve, characterized in that, Comprising: A first through-hole and a fourth through-hole which are arranged to communicate with each other through a main channel; A one-way valve arranged between the first through-hole and the fourth through-hole; A valve stem which reciprocates between at least one open position and at least one closed position, and at the open position, the inner end of the valve stem pushes the one-way valve open to allow fluid to flow from the first through-hole to the fourth through-hole; A flow-limiting valve core which is movably and elastically mounted in the main channel.

2. The in-line manual unloading valve according to claim 1, wherein: It further comprises a valve body, the first through-hole is arranged on the flow-limiting valve core, the fourth through-hole is arranged on the valve body, the valve stem is movably mounted at one end of the valve body, and the flow-limiting valve core is movably mounted at the other end of the valve body.

3. The cartridge-type manual unloading valve according to claim 2, characterized in that: The valve body is provided with a second through-hole and a third through-hole, and the second through-hole and the third through-hole are located between the first through-hole and the fourth through-hole.

4. The in-line manual unloading valve according to claim 3, characterized in that: When the fluid inflow pressure of the first through-hole is greater than the fluid outflow pressure, under the action of the pressure difference, the flow-limiting valve core moves to a position blocking the second through-hole to limit the flow of the main channel.

5. The cartridge-type manual unloading valve according to claim 4, characterized in that: A third spring is arranged between the flow-limiting valve core and the valve body.

6. The in-line manual unloading valve according to claim 3, characterized in that: The valve body is used for being installed in a pre-installation hole of a unloading valve. When the valve body is installed in the pre-installation hole, the second through-hole and the third through-hole communicate through a gap between the valve body and the pre-installation hole.

7. The in-line manual unloading valve according to claim 2, characterized in that: A first spring is arranged between the valve stem and the valve body; and / or The valve body is connected with a sealing cover; and / or A first sealing ring is arranged on the valve stem.

8. The in-line manual unloading valve according to claim 1, characterized in that: The one-way valve comprises a steel ball, a second spring and a screw. The two ends of the second spring respectively abut against the steel ball and the screw, and the second spring has an elastic tendency to keep the steel ball blocking the main channel.

9. The cartridge-type manual unloading valve according to claim 2, wherein: The valve body is used for being installed in a pre-installation hole of a unloading valve, and a second sealing ring and / or a third sealing ring are arranged between the valve body and the pre-installation hole.

10. The cartridge type manual unloading valve according to claim 2, characterized in that: The valve body is connected with a retaining ring, and one end of the flow-limiting valve core away from the valve stem abuts against the retaining ring.

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