Control unit and hydraulic system and working machine

Abstract

This application provides a control unit, a hydraulic system, and a working machine. The control unit has a P port, a T port, and a B port, as well as a pressure reducing valve, a sequence valve, and an unloading damper connected between the P port and the B port. The control unit is configured such that, in the initial state, pressure oil supplied from the P port is simultaneously supplied to the T port and the B port via the unloading damper; in the load state, pressure oil supplied from the P port can be supplied to the B port from the inlet side of the unloading damper, and the B port is disconnected from the unloading damper. The control unit also includes a first pilot oil circuit and a second pilot oil circuit, wherein the first pilot oil circuit controls the sequence valve to switch the control unit between the initial state and the load state, and the second pilot oil circuit controls the pressure reducing valve to control the input flow of the P port. Through the above settings, this application first reduces pressure and overflows, and then opens sequentially, enabling on-demand opening. Even with lower manufacturing precision, the pressure at the B port can be guaranteed, thereby solving the problem of winch vibration in micro-motion conditions in the winch system.

Description

Technical Field

[0001] This application relates to the field of hydraulic technology, specifically to a control unit, a hydraulic system, and a working machine. Background Technology

[0002] Currently, cartridge valves with sequential pressure reduction and overflow functions are widely used in construction machinery, particularly in winch balance valves. These valves typically open sequentially before releasing pressure and overflow. This type of cartridge valve has stringent requirements for the size of the unloading groove and the fit between the valve core and the valve sleeve. When the winch is in a micro-movement lifting condition, winch shaking often occurs, severely affecting lifting accuracy and safety.

[0003] To address the issue of winch vibration during low-motion operation, a new valve assembly needs to be developed. This assembly can reduce winch vibration during low-motion operation. Summary of the Invention

[0004] The purpose of this application is to solve the problem of winch vibration during micro-motion lifting operations. Therefore, embodiments of this application aim to provide a control unit, a hydraulic system, and a working machine, which can reduce winch vibration during micro-motion operations.

[0005] To address the aforementioned problems, in a first aspect, this application provides a control unit. The control unit has a P port leading to a pressure source, a T port leading to an oil tank, and a B port leading to an actuator. The control unit includes a pressure reducing valve, a sequence valve, and an unloading damper connected between the P port and the B port. The control unit is configured such that, in the initial state, pressure oil supplied from the P port is simultaneously supplied to both the T port and the B port via the unloading damper; in the load state, pressure oil supplied from the P port can be supplied to the B port from the inlet side of the unloading damper, and the B port is disconnected from the unloading damper. The control unit further includes a first pilot oil circuit and a second pilot oil circuit, wherein the first pilot oil circuit controls the sequence valve to switch the control unit between the initial state and the load state, and the second pilot oil circuit controls the pressure reducing valve to control the input flow rate of the P port.

[0006] In another possible embodiment, the two ends of the first pilot oil circuit are respectively connected to the control end of the sequence valve and the inlet of the unloading damper, and / or the two ends of the second pilot oil circuit are respectively connected to the control end of the pressure reducing valve and the inlet of the unloading damper.

[0007] In another possible embodiment, the housing of the pressure reducing valve and the housing of the sequence valve are an integral valve body, with the P port, T port and B port formed on the valve body.

[0008] In another possible embodiment, the valve core of the pressure reducing valve and the valve core of the sequence valve are a single integrated valve core. The unloading damping is formed on the single valve core. The valve body has a valve body cavity. The single valve core is slidably disposed in the valve body cavity. Ports P, T and B penetrate the wall of the valve body and communicate with the valve body cavity.

[0009] In another possible embodiment, the main valve core is provided with an axially extending central oil passage, and the unloading damping includes a damping hole that penetrates the wall of the main valve core and passes through the central oil passage. The main valve core is also provided with a pressure oil port that passes through the wall of the main valve core and connects to the central oil passage: In the initial state, port P connects to port T and port B simultaneously through the pressure oil port and the central oil passage and then through the damping hole.

[0010] In another possible embodiment, a pilot oil hole is formed on the main valve core, which has a wall that runs through the main valve core and connects to the central oil passage. In the load state, the damping hole is disconnected from port B, and port P and port B are connected. The pressure oil delivered from port P passes through the pressure oil port along the central oil passage to the pilot oil hole to form a first pilot oil path. Under the action of the first pilot oil path, the main valve core can move so that the pilot oil hole connects with port B, thereby realizing the switching of the control unit from the initial state to the load state.

[0011] A second aspect of this application provides a hydraulic system including the control unit and the execution unit described above, wherein port B leads to the execution unit.

[0012] In another possible embodiment, the execution unit includes a motor and a brake for the motor, with port B leading to the brake cylinder of the brake. The hydraulic system also includes a first pipeline and a second pipeline. The motor has two oil ports, one of which is connected to a second main pressure oil port through the first pipeline, and the other is connected to a first main pressure oil port through the second pipeline. Port P is connected to the high-pressure port in the first pipeline and the second pipeline.

[0013] In another possible embodiment, the hydraulic system further includes a balance valve mounted on one of the first and second pipelines, with the control end of the balance valve connected to the other.

[0014] A third aspect of this application provides a work machine that includes the aforementioned hydraulic system.

[0015] Through the above settings, this application sets an unloading damper between the pressure reducing valve and the sequence valve, and configures the pressure oil supplied from port P in the initial state to be connected to ports B and T respectively after the unloading damper, thereby achieving pressure reduction and overflow unloading. In the load state, ports B and P bypass the unloading damper and are directly connected to provide the required pressure to the execution unit. This application also controls the flow rate of port P by controlling the pressure reducing valve through the first pilot oil circuit, and controls the action of the sequence valve through the second pilot oil circuit to achieve switching between the initial state and the load state. It can achieve on-demand opening, first pressure reduction and overflow, and then sequential opening. In this way, even if the manufacturing precision of the control unit is low, the housing can ensure that the brake connected to port B works normally, thereby avoiding the abnormal opening of the brake in the hoisting system caused by the influence of the manufacturing precision of the control unit, thus completely solving the problem of vibration of the hoisting system in the micro-motion condition of the hoisting system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the working principle of a control unit provided in an embodiment of this application.

[0017] Figure 2 This is a schematic diagram of a control unit provided in an embodiment of this application.

[0018] Figure 3 for Figure 2 A schematic diagram of the main valve core.

[0019] Figure 4 This is a schematic diagram of a hydraulic system provided for an embodiment of this application. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] To better understand this application, the following description is based on specific embodiments and in conjunction with the accompanying drawings.

[0022] Firstly, see [the following] Figures 1-3 As shown, this application provides a control unit. The control unit has a P port leading to a pressure source, a T port leading to an oil tank, and a B port leading to an actuator. The control unit includes a pressure reducing valve k1 and a sequence valve k2 connected between the P port and the B port, and an unloading damper k3. The control unit is configured such that, in the initial state, the pressure oil supplied from the P port is simultaneously supplied to the T port and the B port via the unloading damper k3. Figure 1In one embodiment shown, in the initial state, the pressure oil supplied from port P is delivered to port T via unloading damper k3 and second oil passage L2, and simultaneously delivered to port B via third oil passage L3; in the load state, the pressure oil supplied from port P can be delivered to port B from the inlet side of unloading damper k3, and port B is disconnected from unloading damper k3, and the pressure oil supplied from port P flows to port B along first oil passage L1; the control unit further includes a first pilot oil passage d1 and a second pilot oil passage d2, wherein the first pilot oil passage d1 controls the sequence valve k2 to switch the control unit between the initial state and the load state, and the second pilot oil passage d2 controls the pressure reducing valve k1 to control the input flow of port P. With this configuration, this application can achieve on-demand opening, first reducing pressure and overflowing, then opening sequentially. Even if the manufacturing precision of the pressure reducing valve k1 and the sequence valve k2 is low, and there are large gaps between the valve core and shell of the pressure reducing valve k1, and between the valve core and shell of the sequence valve k2, the brake 6 connected to port B can still operate normally. This completely solves the problem of vibration caused by overflow unloading, effectively preventing hoist vibration under hoisting micro-motion conditions in the hoisting system. In this application, since the outlet of the unloading damper k3 is simultaneously connected to ports B and T in the initial state, ports B and T are also connected at this time. When the pressure at port P gradually decreases, and the sequence valve k2 resets from the load state to the initial state, port B connects to port T, enabling rapid pressure relief at the control port and avoiding action delay.

[0023] exist Figure 1 In one embodiment shown, the sequence valve k2 has two positions. When the first position k21 of the sequence valve k2 is connected, port B is connected to the outlet of the pressure reducing valve k1 from the inlet side of the unloading damper k3. When the second position k22 of the sequence valve k2 is connected, the pressure oil delivered from port P is simultaneously delivered to port T and port B through the unloading damper k3.

[0024] In another embodiment, the two ends of the first pilot oil circuit d1 are respectively connected to the control end of the sequence valve k2 and the inlet of the unloading damper k3. The sequence valve k2 drives the valve core of the sequence valve k2 to move according to the inlet side pressure of the unloading damper k3 to achieve the switching between the initial state and the load state. The pressure at the inlet of the unloading damper k3 is the same as the pressure at the outlet of the pressure reducing valve k1.

[0025] In another embodiment, the two ends of the second pilot oil circuit d2 are respectively connected to the control end of the pressure reducing valve k1 and the inlet of the unloading damper k3. Since the inlet pressure of the unloading damper k3 is the same as the outlet pressure of the pressure reducing valve k1, the second pilot oil circuit d2 of this application can adjust the inlet flow of port P according to the outlet pressure of the pressure reducing valve k1, so that the pressure required by port B can be determined by the pressure that port P can provide.

[0026] The pressure reducing valve k1 and / or the sequence valve k2 are equipped with oil drain holes, which are connected to port T. For example... Figure 1 As shown, the drain hole of pressure reducing valve k1 is directly connected to port T via the fourth oil circuit L4 and returns to the oil tank. The drain hole of sequence valve k2 is directly connected to port T via the fifth oil circuit L5 and returns to the oil tank.

[0027] In this application, the pressure reducing valve k1, the sequence valve k2, and the unloading damper k3 can be configured as multiple independent valves connected by an external pipeline, or at least two of them can be configured to share a housing to form a valve group.

[0028] For example, the housing of pressure reducing valve k1 and the housing of sequence valve k2 are integrated into a single valve body, with ports P, T, and B formed on the valve body. Of course, the valve body can also share a housing with all three.

[0029] refer to Figure 2 In one embodiment shown, the pressure reducing valve k1, the sequence valve k2, and the unloading damper k3 share the same valve body as the outer shell. The valve core of the pressure reducing valve k1 and the valve core of the sequence valve k2 are a single integrated valve core 2. The unloading damper k3 is formed on the integrated valve core 2. The valve body has a valve body cavity 10. The integrated valve core 2 is slidably disposed in the valve body cavity 10. The P port, T port, and B port penetrate the wall of the valve body and communicate with the valve body cavity 10.

[0030] The main valve core 2 is provided with an axially extending central oil passage 2a. The unloading damping k3 includes a damping hole 2b that penetrates the wall of the main valve core 2 and runs through the central oil passage 2a. The main valve core 2 is also provided with a pressure port 2c that runs through the wall of the main valve core 2 and connects to the central oil passage 2a. In the initial state, port P connects to ports T and B simultaneously through pressure port 2c, the central oil passage 2a, and the damping hole 2b. To enable the main valve core 2 to automatically reset after the pressure at port P decreases, a pressure spring 3 is provided at one end of the main valve core 2. With this configuration, in the initial state, port P is connected to ports B and T through the damping hole 2b, allowing for pressure relief. When the axial pressure acting on the main valve core 2 exceeds the opening force of the pressure spring 3, the main valve core 2 gradually moves toward the pressure spring 3 until the damping hole 2b and port B disconnect, and port B and port P are directly connected, achieving sequential opening. The pressure provided from port P is adapted to the pressure required for the main valve core 2 to open. When the main valve core 2 reaches its limit position and can no longer move towards the pressure spring 3, the P port and the pressure oil port 2c can be disconnected.

[0031] The setting of the pressure spring 3 is as follows Figure 2 As shown, a first valve seat 5 is provided in the valve body cavity 10, and the aforementioned pressure spring 3 is also installed in the valve body cavity 10. One end of the pressure spring 3 is installed on the first valve seat 5, and the other end abuts against the main valve core 2. (Refer to...) Figure 3As shown, the main valve core 2 has a mounting rod 26. The outer diameter of the mounting rod 26 is smaller than the inner diameter of the pressure spring 3. The mounting rod 26 passes through the central hole of the pressure spring 3.

[0032] In this application, the main valve core 2 is cylindrical, and multiple annular grooves and shoulders located between two adjacent annular grooves are provided on the outer periphery of the main valve core 2. The annular grooves allow the oil to be distributed 360° around the circumference of the main valve core 2, so that when controlling each oil circuit, it is only necessary to control the axial movement of the main valve core 2 within the valve body cavity 10.

[0033] like Figure 2 and Figure 3 In one embodiment shown, the central oil passage 2a is a blind hole, and the opening of the central oil passage 2a is located on the end face of the main valve core 2 away from the pressure spring 3.

[0034] In another embodiment, in the initial state, there is a gap between the end face of the main valve core 2 away from the pressure spring 3 and the valve body, so that the pressure oil leaking between the main valve core 2 and the valve body flows from the opening of the central oil passage 2a into the central oil passage 2a, and then can return to the oil tank.

[0035] In another embodiment, the valve sleeve 11 has a first annular groove c1 that opens onto the inner surface of the valve sleeve 11, as shown in the reference. Figure 2 As shown, the inner end of port B opens onto the bottom wall of the first annular groove c1, as referenced. Figure 2 and Figure 3 As shown, the main valve core 2 has a second annular groove c2 and a third annular groove c3 opening onto its outer surface. A first shoulder 21 is formed between the second annular groove c2 and the third annular groove c3. The second annular groove c2 is located on the side of the first shoulder 21 closer to the pressure spring 3. The outer end of the damping hole 2b opens onto the bottom wall of the second annular groove c2. The main valve core 2 also has a fourth annular groove c4 opening onto its outer surface. An axially extending groove channel 24a is provided on the fourth shoulder 24 between the fourth annular groove c4 and the second annular groove c2. The damping hole 2b is connected to port T through the groove channel 24a. By providing the groove channel 24a, a certain back pressure can be provided when returning oil to port T.

[0036] Figure 2 In one embodiment shown, the damping orifice 2b can be connected to the fourth annular groove c4 and thus to the T-port through the groove channel 24a in any state.

[0037] exist Figure 2In one embodiment shown, in the initial state, the second annular groove c2 and the first annular groove c1 are connected. The damping orifice 2b connects to port B and the central oil passage 2a through the second annular groove c2 and the first annular groove c1, and thus can connect to port P through the pressure oil port 2c. That is, at this time, port P is connected to the central oil passage 2a through the pressure oil port 2c, and then simultaneously connected to port B and port T through the damping orifice 2b, thereby realizing the pressure relief overflow function of this application.

[0038] In another embodiment, a pilot oil hole 2d is formed on the main valve core 2, penetrating the wall of the main valve core 2 and connecting to the central oil passage 2a. Under load, the damping hole 2b is disconnected from port B, while port P and port B are connected. The pressure oil supplied from port P passes through the pressure oil port 2c along the central oil passage 2a to the pilot oil hole 2d, forming a... Figure 1 The first pilot oil circuit d1 shown in the diagram allows the main valve core 2 to move under its action, connecting the pilot oil port 2d with port B, thus enabling the control unit to switch from the initial state to the load state. (Reference) Figure 2 As shown, a first inner shoulder 11b is formed on the side of the first annular groove c1 near the pressure spring 3. In the initial state, the first inner shoulder 11b is axially located in the middle of the second annular groove c2, so that the damping hole 2b can be connected to port B through the second annular groove c2 and the first annular groove c1. At the same time, the damping hole 2b is connected to port T through the groove channel 24a and the fourth annular groove c4, realizing pressure relief overflow. When switching from the initial state to the load state, as the pressure at port P increases, the pressure in the central oil passage 2a also gradually increases. Under the action of axial force, the main valve core 2 is pushed to move towards the pressure spring 3. The third shoulder 23 gradually approaches the first inner shoulder 11b until it abuts against the first inner shoulder 11b, so that the damping hole 2b and the first annular groove c1 are disconnected. At this time, the pilot oil hole 2d is connected to the third annular groove c3 through the fifth annular groove c5. The fifth annular groove c5 opens on the outer surface of the main valve core 2, and the outer end of the pilot oil hole 2d opens on the bottom wall of the fifth annular groove c5. The first annular groove c1 forms a second inner shoulder 1ld on the side near the pressure port 2c. In the initial state, the second inner shoulder 1ld is in contact with the first shoulder 21, and port B cannot connect to port P through the fifth annular groove c5, the pilot oil hole 2d, and the central oil passage 2a. When switching from the initial state to the load state, the first shoulder 21 moves relative to the second inner shoulder 1ld toward the pressure spring 3, and the second inner shoulder 1ld and the first shoulder 21 gradually disengage, allowing the fifth annular groove c5 and the first annular groove c1 to connect. This allows port P to connect to port B through the pressure port 2c and the central oil passage 2a, from the pilot oil hole 2d, through the fifth annular groove c5, and then through the first annular groove c1, forming a connection as shown in the image. Figure 1 and Figure 4The first oil passage L1 is connected to the third shoulder 23 and the first inner shoulder 11b, which isolate the damping orifice 2b and port B. This allows port P and port B to be directly connected from the inlet side of the damping orifice 2b. At this time, the damping orifice 2h is only connected to port T. This avoids pressure shocks caused by pressure oil converging from the side of port B closer to pressure spring 3 and the side of port B further away from pressure spring 4, which would interfere with each other.

[0039] In this application, when the main valve core 2 is under load, and the P port and B port are directly connected through the pilot oil hole 2d, if the oil pressure continues to rise, under the action of the pressure oil in the central oil passage 2a, i.e. the action of the second pilot oil passage d2, the control side LX of the fifth annular groove c5 moves relative to the port side LT of the P port, forming a throttling orifice, which can adjust the flow rate of the P port, thereby realizing how much pressure the system provides according to how much pressure the B port needs.

[0040] As the pressure at port P gradually decreases, under the restoring force of the pressure spring 3, the main valve core 2 moves toward the pressure port 2c. The first inner shoulder 11b and the third shoulder 23 gradually separate from contact, allowing port B and port T to connect. This enables rapid pressure relief in the central oil passage 2a, avoiding delays in action.

[0041] In another embodiment, a fifth shoulder 25 is formed between the fourth annular groove c4 and the mounting rod 26, and the outer wall of the fifth shoulder 25 fits against the inner wall of the valve body cavity 10. An oil drain hole 25a is provided on the fifth shoulder 25, which extends axially through the fifth shoulder 25. The oil drain hole 25a is connected to the T-port through the fourth annular groove c4 to drain oil.

[0042] In another embodiment, the valve body includes a valve sleeve 11 and a second valve seat 12, one of which has an internal thread and the other has an external thread, and the two are threaded together.

[0043] Furthermore, the externally located valve sleeve 11 and second valve seat 12 is also provided with external threads to mount the control unit of this application onto the mechanism using the control unit. For example... Figure 2 In one embodiment shown, the valve sleeve 11 has an external thread, and the second valve seat 12 has an internal thread that mates with the external thread of the valve sleeve 11. The second valve seat 12 also has an external thread to secure the control unit to other mechanisms.

[0044] Furthermore, the control unit includes a sealing ring 4 fitted around the outside of the control unit to ensure a seal between the control unit and the aforementioned mechanism. Figure 2 In the embodiment shown, the sealing ring 4 is fitted around the outer periphery of the second valve seat 12.

[0045] Secondly, this application provides a hydraulic system including the aforementioned control unit and execution unit, wherein port B leads to the execution unit. The hydraulic system possesses the technical advantages of the aforementioned control unit, which will not be elaborated further here.

[0046] In another embodiment, the execution unit includes a motor 7 and a brake 6 of the brake motor 7. Port B leads to the brake cylinder of the brake 6. The hydraulic system also includes a first pipeline g1 and a second pipeline g2. The motor 7 has two oil ports, one of which is connected to a second main pressure oil port B' through the first pipeline g1, and the other is connected to a first main pressure oil port A' through the second pipeline g2. Port P connects to the high-pressure port in the first pipeline g1 and the second pipeline g2. In the initial state, this hydraulic system pre-charges the brake 6 with a portion of the pressurized oil through port B.

[0047] Furthermore, port P is connected to the high-pressure port in the first main pressure port A' and the second main pressure port B' via a shuttle valve.

[0048] In another embodiment, the hydraulic system further includes a balance valve k5, which is installed on one of the first pipeline g1 and the second pipeline g2, and the control end of the balance valve k5 is connected to the other pipeline.

[0049] refer to Figure 4 In one embodiment shown, pressurized oil enters the motor 7 from the second main pressure port B' along the first pipeline g1. A portion of the pressurized oil overcomes the spring pressure of the balance valve k5, opening the valve stem of the balance valve k5 and causing the second working position k52 of the balance valve k5 to be engaged, thus connecting the second pipeline g2 to the motor 7 and the first main pressure port A'. The second working position k52 of the balance valve k5 is equipped with a throttle valve to provide back pressure to the motor 7.

[0050] When pressurized oil enters motor 7 from the first main pressure oil port A' along the second pipeline g2, a one-way valve is provided in the first working position k51; under the action of the one-way valve, the first working position k51 of the balance valve k5 is connected, so that motor 7 is connected to the second main pressure oil port A'.

[0051] Regardless of whether the pressurized oil is input to the motor 7 from the first main pressure port A' or the second main pressure port B', the P port of the control unit in this application is always connected to the higher pressure port of the first main pressure port A' and the second main pressure port B', and the B port is connected to the brake 6. This achieves the effect of first overflowing to reduce pressure and then sequentially opening the sequence valve k2 to pressurize the brake 6, ensuring the normal operation of the brake 6.

[0052] Specifically, when motor 7 is used to drive the hoisting mechanism, the hydraulic system of this application can effectively solve the problem of hoisting vibration during micro-motions.

[0053] To further illustrate this application, the rise and fall of the winch will be described below.

[0054] When the hoist is lifted, the main pressure oil enters the motor 7 through the second pipeline g2 from the first main pressure oil port A'. The motor 7 rotates forward. A portion of the pressure oil delivered from the first main pressure oil port A' enters the control unit of this application through the shuttle valve k4 and then through port P. The first station k21 of the sequence valve k2 is connected, and pressure oil is delivered to the brake 6 through port B. The brake 6 is opened, the motor 7 rotates forward, and the hoist is lifted.

[0055] When the winch descends, the main pressure oil enters the motor 7 through the second main pressure oil port B' and the first pipeline g1. A portion of the pressure oil overcomes the spring pressure of the balance valve k5, opens the valve stem of the balance valve k5, and connects the outlet of the motor 7 to the first main pressure oil port A' through the second pipeline g2.

[0056] Another portion of the pressure oil enters the control unit of this application through shuttle valve k4, and is depressurized by pressure reducing valve k1. After depressurization, part of the pressure oil overflows through unloading damper k3. Part of the overflowed pressure oil returns to the oil tank, and the other part is connected to brake 6 through sequence valve k2, so that a portion of pressure oil is pre-charged in the brake line.

[0057] Simultaneously, another portion of the pressurized oil, after depressurization, acts directly on the control terminal of the sequence valve k2 via the first pilot oil circuit d1, for reference. Figure 1 and Figure 4 When the pressure reaches the opening pressure of the sequence valve k2, the sequence valve k2 is opened, the first station k21 of the sequence valve k2 is connected, and pressurized oil is supplied to the brake 6 through port B, and the brake 6 is opened.

[0058] Motor 7 returns oil through the second pipeline g2 and the first main pressure oil port A', and motor 7 reverses to realize the hoisting and lowering.

[0059] A third aspect of this application provides a work-operated machine, which includes the aforementioned hydraulic system. The work-operated machine possesses the technical advantages of a hydraulic system, which will not be elaborated further here.

[0060] The operating machinery also includes a pump, which has two ports, one of which is an inlet and the other is an outlet. The pump's inlet and outlet are connected to the two ports of the motor 7 via a first main pressure port A' and a second main pressure port B', respectively.

[0061] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0062] In this application, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0063] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0064] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A control unit having a P port leading to a pressure source, a T port leading to an oil tank, and a B port leading to an actuator, characterized in that, The control unit includes a pressure reducing valve (k1) and a sequence valve (k2) connected between port P and port B, and an unloading damper (k3). The control unit is configured as follows: In the initial state, the pressurized oil delivered from port P is simultaneously delivered to port T and port B via the unloading damper (k3); Under load, the pressure oil supplied from port P can be supplied from the inlet side of the unloading damper (k3) to port B, and port B is disconnected from the unloading damper (k3); The control unit further includes a first pilot oil circuit (d1) and a second pilot oil circuit (d2), wherein the first pilot oil circuit (d1) controls the sequence valve (k2) to switch the control unit between the initial state and the load state, and the second pilot oil circuit (d2) controls the pressure reducing valve (k1) to control the input flow of the P port; The housing of the pressure reducing valve (k1) and the housing of the sequence valve (k2) are an integral valve body, and the P port, the T port and the B port are formed on the valve body; The valve core of the pressure reducing valve (k1) and the valve core of the sequence valve (k2) are a single integrated valve core (2). The unloading damper (k3) is formed on the single integrated valve core (2). The valve body has a valve body cavity (10). The single integrated valve core (2) is slidably disposed in the valve body cavity (10). The P port, the T port and the B port penetrate the wall of the valve body and communicate with the valve body cavity (10).

2. The control unit according to claim 1, characterized in that, The two ends of the first pilot oil circuit (d1) are respectively connected to the control end of the sequence valve (k2) and the inlet of the unloading damper (k3). And / or, the two ends of the second pilot oil circuit (d2) are respectively connected to the control end of the pressure reducing valve (k1) and the inlet of the unloading damper (k3).

3. The control unit according to claim 2, characterized in that, The main valve core (2) is provided with an axially extending central oil passage (2a), and the unloading damping (k3) includes a damping hole (2b) that penetrates the wall of the main valve core (2) and passes through the central oil passage (2a). The main valve core (2) is also provided with a pressure oil port (2c) that passes through the wall of the main valve core (2) and connects to the central oil passage (2a). In the initial state, the P port is connected to the T port and the B port simultaneously through the pressure oil port (2c), the central oil passage (2a), and the damping hole (2b).

4. The control unit according to claim 3, characterized in that, The main valve core (2) has a pilot oil hole (2d) that penetrates the wall of the main valve core (2) and connects to the central oil passage (2a). In the load state, the damping orifice (2b) is disconnected from the B port, and the P port is connected to the B port. The pressure oil supplied from the P port passes through the pressure oil port (2c) and along the central oil passage (2a) to the pilot oil port (2d) to form the first pilot oil passage (d1). Under the action of the first pilot oil passage (d1), the main valve core (2) can move so that the pilot oil port (2d) is connected to the B port, thereby realizing the switching of the control unit from the initial state to the load state.

5. A hydraulic system, characterized in that, It includes the control unit and the execution unit as described in any one of claims 1-4, wherein the B port is connected to the execution unit.

6. The hydraulic system according to claim 5, characterized in that, The execution unit includes a motor (7) and a brake (6) for braking the motor (7). Port B leads to the brake cylinder of the brake (6). The hydraulic system also includes a first pipeline (g1) and a second pipeline (g2). The motor (7) has two oil ports, one of which is connected to a second main pressure oil port (B') through the first pipeline (g1), and the other is connected to a first main pressure oil port (A') through the second pipeline (g2). Port P connects the high-pressure ports in the first pipeline (g1) and the second pipeline (g2).

7. The hydraulic system according to claim 6, characterized in that, The hydraulic system also includes a balance valve (k5), which is installed on one of the first pipeline (g1) and the second pipeline (g2), and the control end of the balance valve (k5) is connected to the other pipeline.

8. A type of operating machinery, characterized in that, Includes the hydraulic system described in any one of claims 5-7.

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