Pressure compensation flow control valve and working machine

Abstract

The utility model belongs to the technical field of hydraulic pressure and provides a pressure compensation flow control valve and an operation machine, the valve comprises a valve body and a valve rod, the valve body is provided with an axial channel, a first oil port and a second oil port, and the first oil port and the second oil port are respectively communicated with the axial channel; the valve rod is arranged in the axial channel and is provided with a conducting valve position and a stopping valve position, and a conducting groove is formed in the circumferential wall of the valve rod and used for conducting or stopping the first oil port and the second oil port; and when the oil pressure of hydraulic oil flowing into the conduction groove from the first oil port or the second oil port at the conduction valve position changes, the hydraulic oil acts on the opposite groove side wall of the conduction groove and can drive the valve rod to move towards the conduction valve position or the stop valve position, so that the conduction opening degree of the conduction groove to the first oil port and / or the second oil port is changed. The pressure compensation flow adjusting function of the valve can be achieved by means of an existing communicating groove in the valve rod.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic technology, specifically relating to a pressure-compensated flow control valve and a working machine. Background Technology

[0002] Work machinery such as cranes, excavators, and telescopic boom aerial work platforms inevitably use pressure-compensated flow control valves (also known as pressure compensation valves) for flow control. The working principle of a pressure compensation valve is to adaptively adjust the valve opening based on the pressure change at the working port.

[0003] Taking the luffing of a telescopic boom as an example, when the luffing cylinder drives the boom to luff, the load borne by the cylinder varies significantly at different tilt angles. At small angles, the cylinder needs to overcome a large gravitational torque, resulting in higher pressure in the rodless chamber. At large angles, the load torque of the cylinder drops sharply, resulting in lower pressure in the rodless chamber. To suppress fluctuations in the oil inlet / outlet rate of the rodless chamber caused by load changes, existing technologies generally employ pressure compensation valves to dynamically balance the flow rate in and out of the rodless chamber according to the load pressure.

[0004] To achieve load pressure compensation, existing solutions typically involve machining independent control oil passages (such as load feedback oil passages or pilot control oil passages) inside the valve body or stem. These passages are then guided to the control chamber at the valve stem reversing end. By sensing the load pressure, the pressure in the control oil passages is increased or decreased, thereby dynamically adjusting the valve opening. However, such oil passages often require high-precision deep-hole machining, leading to increased manufacturing costs and low process tolerance. Furthermore, the additional oil passages significantly weaken the wall thickness uniformity of the valve body / stem, resulting in reduced structural strength. Utility Model Content

[0005] In view of the above-mentioned defects or deficiencies, this utility model provides a pressure-compensated flow control valve and operating machinery, aiming to solve the technical problems of high processing cost and poor structural performance of existing flow control valves with pressure compensation function.

[0006] To achieve the above objectives, this utility model provides a pressure-compensated flow control valve, which includes a valve body and a valve stem. The valve body has an axial channel and a first oil port and a second oil port respectively connected to the axial channel. The first oil port and the second oil port are respectively connected to the axial channel. The valve stem is movably disposed in the axial channel and has a conducting valve position and a shut-off valve position. A conducting groove is provided on the peripheral wall of the valve stem. The conducting groove is used to conduct the first oil port and the second oil port in the conducting valve position, and to conduct the second oil port and shut off the first oil port in the shut-off valve position. In the conducting valve position, when the oil pressure of the hydraulic oil flowing into the conducting groove from the first oil port or the second oil port changes, the hydraulic oil acts on the side wall of the conducting groove facing the groove, which will drive the valve stem to move toward the conducting valve position or the shut-off valve position, so as to change the opening degree of the conducting groove to the first oil port and / or the second oil port.

[0007] In this embodiment, the first oil port and the second oil port are axially spaced apart, and the bottom wall of the guide groove and the inner wall of the axial channel are radially spaced to form a throttling channel. In the axial direction, the throttling channel is located between the first oil port and the second oil port.

[0008] In this embodiment, the guide groove includes an axially adjacent body groove area and a throttling groove area. The body groove area is always aligned and connected with one of the first oil port and the second oil port in the open valve position and the shut-off valve position. The throttling groove area is at least partially located in the axial channel between the first oil port and the second oil port. The throttling groove area is used to be aligned and connected with the other of the first oil port and the second oil port when the valve stem is in the open valve position, and is used to be offset and shut off from the other of the first oil port and the second oil port when the valve stem is in the shut-off valve position. The throttling channel is formed between the bottom wall of the throttling groove area and the inner wall of the axial channel located between the first oil port and the second oil port.

[0009] In this embodiment, the radial distance from the bottom wall of the body groove to the central axis of the valve stem is less than the radial distance from the bottom wall of the throttling groove to the central axis of the valve stem.

[0010] In this embodiment, in the direction of hydraulic oil flowing from the body groove area to the throttling groove area, the radial distance from the bottom wall of the throttling groove area to the central axis of the valve stem gradually increases.

[0011] In this embodiment, the pressure-compensated flow control valve further includes a sealing seat, which is disposed in the axial channel between the first oil port and the second oil port and is arranged around the valve stem. The sealing seat is used to seal against the peripheral wall of the valve stem when the valve stem is in the shut-off valve position, so as to isolate the throttling groove area from the corresponding one of the first oil port and the second oil port. When the valve stem is in the open valve position, the sealing seat is radially against the bottom wall of the groove located in the throttling groove area or the body groove area.

[0012] In this embodiment, a first shoulder and a second shoulder are formed at both ends of the axial direction of the guide groove, and the diameter of the first shoulder is equal to the diameter of the second shoulder.

[0013] In this embodiment, the second oil port is used to connect to the actuator of the hydraulic system. The valve body is also provided with a one-way channel connecting the first oil port and the second oil port. A one-way control device is provided in the one-way channel. The one-way control device is used to conduct when the hydraulic oil flows from the first oil port to the second oil port and to cut off in the reverse direction.

[0014] In this embodiment, the second oil port is used to connect to the actuator of the hydraulic system. One axial end of the valve body is provided with a conduction drive device, which acts on one axial end of the valve stem and is used to drive the valve stem to move toward the conduction valve position. The other axial end of the valve body is provided with a reset drive device, which acts on the other axial end of the valve stem and is used to drive the valve stem to move toward the shut-off valve position.

[0015] To achieve the above objectives, this utility model also provides a working machine, wherein the working machine includes a pressure-compensated flow control valve as described above.

[0016] Through the above technical solution, the pressure-compensated flow control valve provided in this utility model embodiment has the following beneficial effects:

[0017] Hydraulic oil flowing into the guide groove from either the first or second port acts on the opposite sidewalls of the groove. According to the pressure-pressure formula F = P*S, the valve stem experiences two opposing thrusts in the axial direction. These two thrusts are configured to have a thrust difference, which causes the valve core to stop at a certain equilibrium position. When the oil pressure of the hydraulic oil flowing into the guide groove changes, the thrust difference changes, driving the valve stem to move towards the shut-off or open position until the valve stem reaches a new equilibrium position. This movement of the valve stem increases or decreases the opening between the first and second ports, thus achieving the valve's pressure-compensated flow regulation function.

[0018] In summary, the pressure-compensated flow control valve in this embodiment achieves its pressure-compensated flow regulation function by utilizing the existing guide groove on the valve stem, eliminating the need for additional drilling. This fundamentally eliminates the cost, process, and structural strength drawbacks associated with additional drilling. It significantly reduces manufacturing costs, enhances the product's market competitiveness, and also contributes to improving the safety and reliability of the machinery.

[0019] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] The accompanying drawings are provided to illustrate the present invention and form part of the specification. They are used together with the following detailed description to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a schematic diagram of the pressure-compensated flow control valve in the on position according to the first embodiment of this utility model.

[0022] Figure 2 This is a schematic diagram of the valve stem of the pressure-compensated flow control valve according to the first embodiment of the present utility model.

[0023] Figure 3 This is a schematic diagram of the pressure-compensated flow control valve in the shut-off position according to the second embodiment of this utility model.

[0024] Explanation of reference numerals in the attached figures

[0025] 1. Valve body; 11. First oil port; 12. Second oil port; 13. One-way passage; 2. Valve stem; 21. Guide groove; 211. Body groove area; 212. Throttling groove area; 21a. Right-facing groove side wall; 21b. Left-facing groove side wall; 21c. Groove bottom wall; 22. First groove shoulder; 23. Second groove shoulder; 3. Sealing seat; 4. First valve sleeve; 51. Second valve sleeve; 52. One-way valve core; 53. One-way valve plug; 6. Conducting drive device; 61. End cap; 61a. Drive chamber; 62. Piston; 7. Reset drive device; 71. Guide sleeve; 72. Reset spring; 73. Screw; 8. Electro-proportional pressure reducing valve. Detailed Implementation

[0026] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0027] The pressure-compensated flow control valve of this utility model is described below with reference to the accompanying drawings.

[0028] This utility model provides a pressure-compensated flow control valve, such as Figure 1 and Figure 3 As shown, the pressure-compensated flow control valve includes a valve body 1 and a valve stem 2.

[0029] The valve body 1 is provided with an axial channel extending along the axial direction, and the valve body 1 is also provided with a first oil port 11 and a second oil port 12 that are respectively connected to the axial channel.

[0030] The valve stem 2 is movably disposed in the axial channel and has a conducting valve position and a shut-off valve position relative to the valve body 1. A conducting groove 21 is provided on the peripheral wall of the valve stem 2. The conducting groove 21 is used to conduct the first oil port 11 and the second oil port 12 when the valve stem 2 is in the conducting valve position, and to control the second oil port 12 and the first oil port 11 to shut off when the valve stem 2 is in the shut-off valve position.

[0031] When the hydraulic oil pressure changes as it flows from the first port 11 or the second port 12 into the guide groove 21 in the open valve position, the hydraulic oil acts on the guide groove 21 relative to the side wall of the groove, which will drive the valve stem 2 to move toward the open valve position or the shut-off valve position, thereby changing the opening degree of the guide groove 21 to the first port 11 and / or the second port 12.

[0032] Hydraulic oil flowing into the guide groove 21 from the first port 11 or the second port 12 acts on the opposite sidewalls of the guide groove 21. According to the pressure-pressure formula F=P*S, the valve stem 2 will be subjected to two opposing thrusts in the axial direction. These two thrusts are configured to have a thrust difference, which will cause the valve core to stop at a certain equilibrium position. When the oil pressure of the hydraulic oil flowing into the guide groove 21 changes, the thrust difference will change, driving the valve stem 2 to move towards the shut-off valve position or the open valve position until the valve stem 2 reaches a new equilibrium position. The movement of the valve stem 2 will increase or decrease the opening between the first port 11 and the second port 12, thereby realizing the valve's pressure compensation and flow regulation function.

[0033] In summary, the pressure-compensated flow control valve in this embodiment can achieve pressure-compensated flow regulation by utilizing the existing guide groove 21 on the valve stem 2, eliminating the need for additional drilling. This fundamentally eliminates a series of cost, process, and structural strength drawbacks caused by additional drilling. It significantly reduces manufacturing costs, enhances the product's market competitiveness, and also helps improve the safety and reliability of the machinery.

[0034] In this embodiment, when the pressure-compensated flow control valve is in use, one of the first port 11 and the second port 12 can be connected to the actuator of the hydraulic system, and the other can be connected to the main working oil circuit of the system (e.g., it can be connected to the pressure oil circuit and return oil circuit of the system through a directional valve). Depending on the connection position of the two ports, this pressure-compensated flow control valve can perform load pressure-compensated flow control as well as other forms of pressure-compensated flow control.

[0035] In this embodiment, the first oil port 11 and the second oil port 12 can be spaced apart along the axial direction.

[0036] In order to generate a thrust difference on both sides of the axial direction of the guide groove 21, in this embodiment, the depth of the guide groove 21 can be changed so that the bottom wall 21c of the guide groove 21 is radially spaced from the inner wall of the axial channel to form a throttling channel. In the axial direction, the throttling channel is located between the first oil port 11 and the second oil port 12.

[0037] Taking the actuator connected to the hydraulic system via the second oil port 12 as an example, when the hydraulic oil in the actuator returns through the pressure compensation flow control valve, the valve stem 2 switches to the open valve position. At this time, the hydraulic oil in the actuator will return through the second oil port 12, the throttling channel, and the first oil port 11 in sequence.

[0038] Due to the existence of the throttling channel, according to Bernoulli's equation: According to the continuity equation V1*S1=V2*S2 in fluid mechanics, when fluid flows in a pipeline, the smaller the cross-section of the flow channel, the greater the flow velocity. Conversely, the greater the flow velocity, the lower the static pressure. Furthermore, in practical situations, the throttling of the throttling channel causes a certain pressure loss. Therefore, the oil pressure on the side of the throttling oil passage near the second port 12 will be greater than the oil pressure on the side of the throttling oil passage near the first port 11. Hydraulic oil of different pressures acts on the opposite sidewalls of the guide groove 21. According to the pressure-pressure formula F=P*S, under the premise that the effective area difference of the opposite sidewalls of the guide groove 21 is equal, the hydraulic oil will generate a first thrust that drives the valve stem 2 towards the open valve position and a second thrust that drives it towards the shut-off valve position. There is a thrust difference between the second thrust and the first thrust, which will cause the valve core to stop at a certain equilibrium position.

[0039] When the change in oil pressure of the actuator exceeds a certain threshold, the change in thrust difference will also exceed a certain threshold. At this time, the pressure difference will drive the valve stem 2 to move toward the corresponding open valve position or shut-off valve position until the valve stem 2 reaches a new equilibrium position. The movement of the valve stem 2 will change the opening degree of the guide groove 21 to the first oil port 11 or the second oil port 12, thereby realizing the valve's load compensation and return oil flow regulation function.

[0040] It is understandable that the effective area of ​​the groove sidewall refers to the projected area of ​​the groove sidewall in the axial direction.

[0041] like Figure 1 and Figure 3 As shown, in this embodiment, the guide groove 21 may include an axially adjacent body groove area 211 and a throttling groove area 212. The body groove area 211 is always aligned and connected with one of the first oil port 11 and the second oil port 12 in the open valve position and the shut-off valve position. The throttling groove area 212 is at least partially located in the axial channel between the first oil port 11 and the second oil port 12. The throttling groove area 212 is used to be aligned and connected with the other of the first oil port 11 and the second oil port 12 when the valve stem 2 is in the open valve position, and is used to be offset and shut off from the other of the first oil port 11 and the second oil port 12 when the valve stem 2 is in the shut-off valve position. The throttling channel is formed between the bottom wall 21c of the throttling groove area 212 and the inner wall of the axial channel located between the first oil port 11 and the second oil port 12.

[0042] like Figure 1As shown, taking the body groove area 211 as always connected to the second oil port 12, and the throttling groove area 212 as used to be aligned and connected with the first oil port 11 when the valve stem 2 is in the open valve position, and to be misaligned and cut off from the first oil port 11 when the valve stem 2 is in the shut-off valve position, when the hydraulic oil from the second oil port 12 enters the body groove area 211, since the body groove area 211 is always connected to the second oil port 12, the oil pressure at the groove shoulder wall (right groove side wall 21a) on the side of the body groove area 211 away from the throttling groove area 212 is almost equal to the pressure of the second oil port 12. The higher pressure hydraulic oil acts on the right groove side wall 21a, generating a larger first thrust. As the hydraulic oil moves from the main body groove area 211 to the throttling groove area 212, the area of ​​the flow channel decreases, the flow rate of the hydraulic oil increases, and the pressure decreases. The lower pressure hydraulic oil acts on the left sidewall 21b of the groove, generating a smaller second thrust. Due to the difference in oil pressure at the two locations, a pressure difference is generated between the second thrust and the first thrust. By changing the diameter of the bottom wall 21c of the throttling groove area 212 (i.e., changing the radial clearance of the throttling channel), the ratio between the pressure difference and the oil pressure can be changed.

[0043] In this embodiment, a first shoulder 22 and a second shoulder 23 are formed at both ends of the axial direction of the guide groove 21. The diameter d1 of the first shoulder 22 is preferably equal to the diameter d2 of the second shoulder 23 to facilitate the sealing fit between the valve stem 2 and the axial channel.

[0044] like Figure 2 As shown, in this embodiment, the axial distance between the right-facing groove sidewall 21a and the inlet of the throttling channel can be adjusted by adjusting the length L1 of the first groove shoulder 22 or by setting the right-facing groove sidewall 21a as an inclined oblique wall. The closer to the throttling channel, the faster the hydraulic oil flows and the lower the pressure. This can further adjust the ratio between the pressure difference and the oil pressure to achieve different compensation effects.

[0045] like Figure 2 As shown, in this embodiment, the angle α of the oblique wall is preferably 30°-180°.

[0046] In this embodiment, depending on the usage requirements, the main body groove area 211 can be configured to be connected only to the second oil port 12 in the open valve position, and the throttling groove area 212 can be configured to be connected to the first oil port 11 in both the open valve position and the shut-off valve position.

[0047] To facilitate the formation of the throttling channel, the body groove area 211 and the throttling groove area 212 can be machined to different depths during part processing, such as... Figure 1 and Figure 2As shown, through processing, the radial distance from the bottom wall 21c of the body groove area 211 to the central axis of the valve stem 2 is made smaller than the radial distance from the bottom wall 21c of the throttling groove area 212 to the central axis of the valve stem 2. A throttling channel can be formed between the bottom wall of the throttling groove area 212 and the inner wall of the axial channel. By adjusting the radial distance from the bottom wall 21c of the throttling groove area 212 to the central axis of the valve stem 2, the flow area of ​​the throttling channel can be changed.

[0048] In other words, in this embodiment, the bottom wall of the throttling groove area 212 is higher than the bottom wall of the main body groove area 211. The area of ​​the flow channel formed between the bottom wall of the throttling groove area 212 and the inner wall of the axial channel will be smaller than the area of ​​the flow channel formed between the main body groove area 211 and the inner wall of the axial channel. By changing the height of the bottom wall of the throttling groove area 212, the size of the flow channel area of ​​the throttling channel can be adjusted.

[0049] In this embodiment, in the direction of hydraulic oil flowing from the body groove area 211 to the throttling groove area 212 (i.e. Figure 3 (From left to right in the middle), the radial distance from the bottom wall 21c of the throttling groove 212 to the central axis of the valve stem gradually increases. That is, in Figure 3 From left to right, the bottom wall 21c of the throttling groove 212 gradually approaches the inner wall of the axial channel, and the flow area of ​​the throttling channel gradually decreases from left to right. When the pressure of the second port 12 is low, the throttling channel with a gradually decreasing flow area restricts the flow between the first port 11 and the second port 12 to slow down the rate of increase in flow and prevent a sudden change in the flow through the pressure-compensated flow control valve caused by abrupt opening of the first port 11 and the second port 12. When the pressure of the second port 12 gradually increases, the throttling channel with a smaller flow area increases the flow velocity of the hydraulic oil at this point, making the thrust difference between the first thrust and the second thrust larger, the valve core moves faster, and the response speed of pressure compensation is improved. In addition, as the valve core moves, the throttling channel with a gradually decreasing flow area gradually reduces the throttling area between the first port 11 and the second port 12, thereby achieving the effect that the greater the oil pressure, the stronger the flow suppression capability of the throttling channel.

[0050] In this embodiment, the effective area of ​​the sidewalls of the guide groove 21 relative to the two orientations can be optimized to generate a thrust difference on both sides of the guide groove 21 in the axial direction.

[0051] Specifically, such as Figure 1 and Figure 2As shown, moving the valve stem 2 toward the shut-off valve position is defined as moving to the left, and moving the valve stem 2 toward the open valve position is defined as moving to the right. The opposite sidewalls of the guide groove 21 are the right sidewall 21a and the left sidewall 21b, respectively. Depending on the shape of the guide groove 21, the number of right sidewall 21a and left sidewall 21b is not limited to one. For example, when the guide groove 21 is a stepped groove, it can have multiple right sidewall 21a or left sidewall 21b.

[0052] Hydraulic oil acts on the right-facing sidewall 21a of the guide groove, generating a second thrust that moves the valve towards the shut-off position. Hydraulic oil acts on the left-facing sidewall 21b of the guide groove, generating a first thrust that moves the valve towards the open position. By setting the effective area of ​​all right-facing sidewalls 21a in the guide groove 21 to be larger than that of all left-facing sidewalls 21b, the hydraulic oil acting on the opposite sidewalls of the guide groove 21 can achieve the effect that the second thrust is greater than the first thrust. Alternatively, setting the effective area of ​​all left-facing sidewalls 21b in the guide groove 21 to be smaller than that of all right-facing sidewalls 21a will result in a second thrust that is less than the first thrust.

[0053] like Figure 1 and Figure 3 As shown, in this embodiment, the pressure-compensated flow control valve further includes a sealing seat 3. The sealing seat 3 is disposed within the axial channel between the first oil port 11 and the second oil port 12 and is arranged around the valve stem 2. The sealing seat 3 is used to abut against the peripheral wall of the valve stem 2 when the valve stem 2 is in the shut-off position, so as to isolate the throttling groove area 212 from the corresponding one of the first oil port 11 and the second oil port 12. When the valve stem 2 is in the open position, the sealing seat 3 is radially disposed towards the throttling groove area 212 or the body groove area 211. By providing the sealing seat 3, oil leakage of the valve stem 2 when it is in the shut-off position is prevented.

[0054] In this embodiment, the sealing seat 3 is preferably a pointed seat.

[0055] like Figure 1 and Figure 3 As shown, in this embodiment, the pressure-compensated flow control valve further includes a first valve sleeve 4. The first valve sleeve 4 is fixedly disposed within the axial channel and abuts against the end of the sealing seat 3. The first valve sleeve 4 is also slidably fitted with the valve stem 2. By providing the first valve sleeve 4, the resistance during the movement of the valve stem 2 can be reduced, and the sealing seat 3 can be axially limited to facilitate the installation of the sealing seat 3.

[0056] like Figure 1 and Figure 3As shown, in this embodiment, the valve body 1 may also be provided with a one-way channel 13 connecting the first oil port 11 and the second oil port 12. A one-way control device is provided within the one-way channel 13. The one-way control device is used to open when hydraulic oil flows from the first oil port 11 to the second oil port 12 and to close in the reverse direction. Through the one-way channel 13, hydraulic oil from the first oil port 11 can easily and without resistance enter the second oil port 12 when the load requires oil intake, and load compensation flow control can be achieved when the load requires oil discharge.

[0057] like Figure 1 and Figure 3 As shown, in this embodiment, the one-way control device can be a one-way valve and includes a second valve sleeve 51, a one-way valve core 52, and a one-way valve plug 53. The second valve sleeve 51 is disposed within the one-way channel 13, and the one-way valve plug 53 is disposed on the side of the second valve sleeve 51 facing away from the first oil port 11 and is used to limit the one-way valve plug 53. The one-way valve core 52 is disposed between the second valve sleeve 51 and the one-way valve plug 53, and the one-way valve core 52 and the one-way valve plug 53 are supported and engaged by an elastic element. When the pressure of the first oil port 11 reaches a set value, it will overcome the elastic force of the elastic element and push the one-way valve core 52 open, realizing the conduction between the first oil port 11 and the second oil port 12. When the pressure of the first oil port 11 is lower than the set value, the elastic element will drive the one-way valve core 52 to reset, realizing the cut-off between the first oil port 11 and the second oil port 12.

[0058] like Figure 1 and Figure 3 As shown, in this embodiment, one axial end of the valve body 1 is a conducting drive end, which is equipped with a conducting drive device 6. The conducting drive device 6 acts on one axial end of the valve stem 2 and drives the valve stem 2 to move toward the conducting valve position. The other axial end of the valve body 1 is a shut-off drive end, which is equipped with a reset drive device 7. The reset drive device 7 acts on the other axial end of the valve stem 2 and drives the valve stem 2 to move toward the shut-off valve position. By using the conducting drive device 6 and the shut-off drive end, the valve stem 2 is controlled to switch valve positions.

[0059] like Figure 1 and Figure 3 As shown, in this embodiment, the conduction drive device 6 includes an end cap 61 and a piston 62. The end cap 61 is disposed on the conduction drive end of the valve body 1 and forms a drive chamber 61a. The piston 62 is movably disposed in the drive chamber 61a and can move axially. The piston 62 is disposed on one axial end of the valve stem 2. When pressure oil enters the drive chamber 61a, the piston 62 will push the valve stem 2 to move toward the conduction valve position.

[0060] like Figure 1 and Figure 3As shown, in this embodiment, the reset drive device 7 includes a guide sleeve 71, a reset spring 72, and a screw 73. The guide sleeve 71 is hollow and docks with the other end of the axial channel. The reset spring 72 is located inside the guide sleeve 71 and abuts against the other end of the valve stem 2 in the axial direction. The screw 73 is used to adjust the elastic force of the reset spring 72. With the elastic force of the reset spring 72, the valve stem 2 can be pushed to move toward the shut-off valve position when no pressure oil enters the drive chamber 61a.

[0061] like Figure 1 and Figure 3 As shown, in this embodiment, the pressure-compensated flow control valve also includes an electro-proportional pressure reducing valve 8. The output end of the electro-proportional pressure reducing valve 8 is connected to the oil inlet of the drive chamber 61a to realize the supply of oil from the electro-proportional pressure reducing valve 8 to the drive chamber 61a.

[0062] To achieve the above objectives, this utility model also provides a working machine, which includes a pressure-compensated flow control valve as described above. The working machine can be an excavator, crane, or other machine with a boom that can extend. Since the working machine adopts all the technical solutions of the above embodiments, it at least possesses the beneficial effects brought by the above embodiments, and will not be repeated here.

[0063] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0064] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0065] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0066] Although embodiments of the present invention have been described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A pressure-compensated flow control valve, characterized in that, The pressure-compensated flow control valve includes: The valve body (1) is provided with an axial channel and a first oil port (11) and a second oil port (12) respectively connected to the axial channel; The valve stem (2) is movably disposed in the axial channel and has a conducting valve position and a shut-off valve position. A conducting groove (21) is provided on the peripheral wall of the valve stem (2). The conducting groove (21) is used to conduct the first oil port (11) and the second oil port (12) in the conducting valve position, and to control the second oil port (12) and the first oil port (11) to shut off in the shut-off valve position. When the hydraulic oil pressure changes as it flows from the first port (11) or the second port (12) into the guide groove (21) at the open valve position, the hydraulic oil acts on the guide groove (21) relative to the side wall of the groove, which will drive the valve stem (2) to move toward the open valve position or the shut-off valve position, so as to change the opening degree of the guide groove (21) to the first port (11) and / or the second port (12).

2. The pressure-compensated flow control valve according to claim 1, characterized in that, The first oil port (11) and the second oil port (12) are axially spaced apart. The bottom wall (21c) of the guide groove (21) is radially spaced from the inner wall of the axial channel to form a throttling channel. In the axial direction, the throttling channel is located between the first oil port (11) and the second oil port (12).

3. The pressure-compensated flow control valve according to claim 2, characterized in that, The guide groove (21) includes an axially adjacent body groove area (211) and a throttling groove area (212). The body groove area (211) is always aligned and connected with one of the first oil port (11) and the second oil port (12) in the open valve position and the close valve position. The throttling groove area (212) is at least partially located in the axial channel between the first oil port (11) and the second oil port (12). The throttling groove area (212) is used to be aligned and connected with the other of the first oil port (11) and the second oil port (12) when the valve stem (2) is in the open valve position, and is used to be offset and closed with the other of the first oil port (11) and the second oil port (12) when the valve stem (2) is in the close valve position. The throttling channel is formed between the bottom wall (21c) of the throttling groove area (212) and the inner wall of the axial channel located between the first oil port (11) and the second oil port (12).

4. The pressure-compensated flow control valve according to claim 3, characterized in that, The radial distance from the bottom wall (21c) of the main body groove (211) to the central axis of the valve stem (2) is less than the radial distance from the bottom wall (21c) of the throttling groove (212) to the central axis of the valve stem (2).

5. The pressure-compensated flow control valve according to claim 4, characterized in that, In the direction in which hydraulic oil flows from the body groove area (211) to the throttling groove area (212), the radial distance from the bottom wall (21c) of the throttling groove area (212) to the central axis of the valve stem (2) gradually increases.

6. The pressure-compensated flow control valve according to claim 3, characterized in that, The pressure-compensated flow control valve further includes a sealing seat (3), which is disposed in the axial channel between the first oil port (11) and the second oil port (12) and is arranged around the valve stem (2). The sealing seat (3) is used to seal against the peripheral wall of the valve stem (2) when the valve stem (2) is in the shut-off valve position, so as to isolate the throttling groove area (212) from one of the corresponding first oil port (11) and the second oil port (12). When the valve stem (2) is in the open valve position, the sealing seat (3) is radially opposed to the bottom wall (21c) of the groove located in the throttling groove area (212) or the body groove area (211).

7. The pressure-compensated flow control valve according to any one of claims 1 to 6, characterized in that, The axial ends of the guide groove (21) are respectively formed with a first shoulder (22) and a second shoulder (23), and the diameter of the first shoulder (22) is equal to the diameter of the second shoulder (23).

8. The pressure-compensated flow control valve according to any one of claims 1 to 6, characterized in that, The second oil port (12) is used to connect to the actuator of the hydraulic system. The valve body (1) is also provided with a one-way channel (13) connecting the first oil port (11) and the second oil port (12). The one-way channel (13) is provided with a one-way control device. The one-way control device is used to conduct when the hydraulic oil from the first oil port (11) flows to the second oil port (12) and to cut off in the reverse direction.

9. The pressure-compensated flow control valve according to any one of claims 1 to 6, characterized in that, The valve body (1) has a conduction drive device (6) at one axial end. The conduction drive device (6) acts on one axial end of the valve stem (2) and is used to drive the valve stem (2) to move toward the conduction valve position. The valve body (1) has a reset drive device (7) at the other axial end. The reset drive device (7) acts on the other axial end of the valve stem (2) and drives the valve stem (2) to move toward the shut-off valve position.

10. A type of operating machinery, characterized in that, Includes the pressure-compensated flow control valve according to any one of claims 1 to 9.

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