A hydraulic control system for high-low impact free switching of a jumbo

Abstract

The application discloses a rock drilling jumbo high-low impact free switching hydraulic control system, and relates to the field of engineering machinery. The hydraulic control system comprises a pump assembly, an oil outlet valve group, a main reversing valve and a pressure limiting valve group. When the main reversing valve is in the first position, the pressure limiting valve group sets the standby pressure of the hydraulic control system to the relief pressure value of the third overflow valve, so that the pump assembly maintains the minimum flow output. When the main reversing valve is in the second position, the impact maximum pressure is limited to the relief pressure value of the first overflow valve, which is suitable for the open hole and soft rock working condition. When the main reversing valve is in the third position, the impact pressure is limited to the relief pressure value of the second overflow valve, which protects the impact power of the rock drilling jumbo from being over limited and is suitable for the hard rock and deep hole working condition. Through the cooperation of various control oil ports and the pressure limiting valve group, different maximum system pressures are limited under different working conditions, the high and low impact pressure segmented control can be realized, and the working efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of engineering machinery, and in particular to a hydraulic control system for a rock drilling rig that allows for free switching between high and low impact. Background Technology

[0002] Hydraulic rock drilling rigs are important hard rock drilling equipment in drill-and-blast tunnel construction. During rock drilling operations, the impact pressure requirements are different at different stages of rock drilling. Generally, the impact pressure requirements are lower in the hole opening stage or soft rock stage, and higher in the rock drilling stage or hard rock stage, with a large energy demand. Due to the high pressure and large flow of hydraulic rock drills, the system consumes a lot of energy, making it particularly important to improve the efficiency of impact hydraulic control.

[0003] The existing rock drilling rig impact hydraulic system does not have segmented control of high and low impact pressure, which is not conducive to hole drilling operation and increases the wear and tear of the rock drill. Summary of the Invention

[0004] This application provides a hydraulic control system for a rock drilling rig that allows for free switching between high and low pressure, enabling segmented control of high and low pressure to improve work efficiency.

[0005] This application provides a hydraulic control system for a rock drilling rig that allows for free switching between high and low strokes, including a pump assembly, an oil outlet valve group, a main directional valve, a speed regulating valve group, and a pressure limiting valve group. The pump assembly is connected to the oil outlet valve group. The oil outlet valve group is connected to the main directional valve, which has three working positions. The main directional valve includes a P port and three working ports. The P port is connected to the oil outlet valve group. One working port of the main directional valve is configured as a first control port, and the other two working ports are connected to the speed regulating valve group for controlling flow rate. The first output port of the speed regulating valve group is connected to the actuator of the rock drilling rig. The speed regulating valve group also includes a second control port connected to the first output port. The pressure limiting valve group includes a first pilot directional valve, a second pilot directional valve, a first relief valve, a second relief valve, and a third... The first pilot directional valve includes a first pilot port, a first inlet port, a first outlet port, and a second outlet port. The first pilot port is connected to a first control port, the first inlet port is connected to a second pilot directional valve, the first outlet port is connected to the oil tank via a second relief valve, and the second outlet port is connected to the oil tank via a first relief valve. The second pilot directional valve includes a second pilot port, a second inlet port, a third outlet port, and a fourth outlet port. The second pilot port is connected to a second control port, the second inlet port is connected to the first feedback port of the pump assembly via an outlet valve group, the third outlet port is connected to the oil tank via a third relief valve, and the fourth outlet port is connected to the first inlet port of the first pilot directional valve. The relief pressure values ​​of the first relief valve, the second relief valve, and the third relief valve increase sequentially.

[0006] Preferably, the pump assembly includes a load-sensitive pump, which includes a second output port and a first feedback port. The second output port is connected to the oil outlet valve assembly, and the first feedback port is connected to the second feedback port of the oil outlet valve assembly.

[0007] Preferably, the oil outlet valve assembly includes a check valve and a first damper. The check valve is connected to the second output port of the load-sensitive pump and the P port of the main directional valve, respectively. One end of the first damper is connected to the second output port of the load-sensitive pump, and the other end is configured as the second feedback port of the oil outlet valve assembly.

[0008] Preferably, the main directional valve's working ports include working port A, working port B, and working port C. Working ports A and B are both connected to the speed regulating valve assembly, and working port C is configured as the first control port. The main directional valve's P ports include P1 inlet and P2 inlet, both of which are connected to the outlet valve assembly. P1 inlet is used to communicate with working port A or working port B, and P2 inlet is used to communicate with the first control port.

[0009] Preferably, the P port of the main directional valve also includes a P3 inlet port, and the P3 inlet port is connected to the outlet valve group via a fourth relief valve.

[0010] Preferably, the speed regulating valve assembly includes an oil inlet P4, an oil inlet P5, a first output oil port, and a second control oil port; the working oil port A is connected to the oil inlet P4, and the oil inlet P4 and the first output oil port are connected by a second damping connection; the working oil port B is connected to the oil inlet P5, and the oil inlet P5 and the first output oil port are connected by a third damping connection; the second control oil port is connected to the first output oil port.

[0011] Preferably, the opening of the P4 oil inlet is greater than the opening of the P5 oil inlet.

[0012] Preferably, the pressure relief valve assembly is provided with a third feedback port, and the second inlet of the second pilot directional valve is connected to the second feedback port of the outlet valve assembly through the third feedback port; an electromagnetic switch valve is provided between the third feedback port and the oil tank.

[0013] Preferably, the main directional valve is configured as a three-position six-way directional valve, which is one of the multi-way valves of the rock drilling rig.

[0014] The hydraulic control system of this application has at least the following beneficial effects: The main directional valve of this application has three working positions. When the main directional valve is in the first position, no oil flows from any of the three working ports, and neither of the two pilot directional valves of the pressure relief valve assembly operates. The pressure relief valve assembly sets the standby pressure of the hydraulic control system to the relief pressure value of the third relief valve. This pressure value is indirectly fed back to the pump assembly through the oil outlet valve assembly, so that the pump assembly maintains a minimum flow output. At this time, the power of the pump assembly is relatively low. When the main directional valve is in the second position, pressurized oil flows through the first control port of the main directional valve to the first pilot directional valve of the pressure relief valve assembly. At the same time, pressurized oil flows through the second control port to the second pilot directional valve. The maximum impact pressure is limited to the overflow pressure value of the first relief valve. This is the low-impact mode, suitable for drilling and soft rock conditions. When the main directional valve is in the third position, no oil is discharged from the first control port. The pressurized oil flows to the second pilot directional valve through the second control port of the speed regulating valve group. At this time, the impact pressure is limited to the overflow pressure value of the second relief valve, protecting the impact power of the rock drilling rig from exceeding the limit. This is the high-impact mode, suitable for hard rock and deep hole conditions. This application achieves different maximum system pressure limits under different working conditions through the cooperation of each control port and the pressure limiting valve group. It can realize segmented control of high and low impact pressures and improve work efficiency. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the hydraulic control system of this application; Figure 2 yes Figure 1 Schematic diagram of the intermediate pump assembly; Figure 3 yes Figure 1 Schematic diagram of the oil outlet valve assembly; Figure 4 yes Figure 1 Schematic diagram of the main directional valve; Figure 5 yes Figure 1 Schematic diagram of a medium-speed regulating valve assembly; Figure 6 yes Figure 1 Schematic diagram of the medium pressure limiting valve assembly; The annotations in the attached figures are explained as follows: 100. Pump assembly; 200. Oil outlet valve assembly; 201. Check valve; 202. First damper; 300. Main directional valve; 301. Fourth relief valve; 400. Speed ​​regulating valve assembly; 401. Second damper; 402. Third damper; 500, Pressure relief valve assembly; 501, First pilot-operated directional valve; 502, Second pilot-operated directional valve; 503, First relief valve; 504, Second relief valve; 505, Third relief valve; 506, Solenoid switch valve; 600. Implementing agency. Detailed Implementation

[0016] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0017] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0018] This embodiment discloses a hydraulic control system and method for freely switching between high and low impact pressures on a rock drilling rig, which can realize segmented control of high and low impact pressures on the rock drilling rig. First, the hydraulic control system of this embodiment will be introduced.

[0019] like Figure 1 As shown, the hydraulic control system includes a pump assembly 100, an oil outlet valve assembly 200, a main directional valve 300, and a pressure relief valve assembly 500, as detailed below: like Figure 2 As shown, the pump assembly 100 includes a load-sensitive pump with a pressure cut-off function. This pump can provide the required flow rate and pressure according to the system's pressure and flow demands, minimizing power loss and achieving a much higher efficiency than a fixed-displacement pump. In this embodiment, the port for outputting high-pressure oil from the load-sensitive pump is configured as a second output port H, and the load-sensitive pump also has a first feedback port LS1.

[0020] like Figure 3 As shown, the outlet valve assembly 200 includes a check valve 201 and a first damper 202. The inlet end of the check valve 201 is connected to the second output port H of the load-sensitive pump, and the outlet end of the check valve 201 is connected to the P port of the main directional valve 300. One end of the first damper 202 is connected to the second output port H of the load-sensitive pump, and the other end of the first damper 202 is configured as the second feedback port LS2 of the outlet valve assembly 200. The first feedback port LS1 of the load-sensitive pump is connected to the second feedback port LS2. In this embodiment, the outlet valve assembly 200 has a built-in check valve 201 to prevent hydraulic oil backflow, and a built-in first damper 202 to suppress pressure fluctuations, avoid shocks and vibrations caused by sudden load changes, and make the flow more stable.

[0021] like Figure 4 As shown, the main directional valve 300 is configured as a three-position six-way directional valve. In other embodiments, the main directional valve 300 is configured as one of the multi-way valves of a rock drilling rig.

[0022] like Figure 4 As shown, the main directional valve 300 is a three-position six-way directional valve with six ports. The three ports on the first side are configured as P ports, and the three ports on the second side are configured as working ports. The P port on the first side is connected to the check valve 201 of the outlet valve group 200. Of the three ports on the second side, one port is configured as the first control port X1, which is connected to the pressure relief valve group 500. The other two ports are connected to the speed regulating valve group 400.

[0023] like Figure 4 As shown, in this embodiment, the working ports on the second side include working port A, working port B, and working port C. Working ports A and B are both connected to the speed regulating valve group 400, and working port C is configured as the first control port X1. The P ports on the first side include P1 inlet, P2 inlet, and P3 inlet, all of which are connected to the outlet end of the one-way valve 201.

[0024] like Figure 4 As shown, when the main directional valve 300 is in the first position, the P1 oil inlet is not connected to the working oil port B, the P2 oil inlet is not connected to the working oil port C, and the P3 oil inlet is connected to the working oil port A. However, in this embodiment, a fourth relief valve 301 is provided between the P3 oil inlet and the outlet end of the check valve 201. The relief pressure value of the fourth relief valve 301 is set according to actual needs. Preferably, when in the first position, the hydraulic oil of the check valve 201 cannot flow to the P3 oil inlet.

[0025] like Figure 4As shown, when the main directional valve 300 is in the second position, the P1 oil inlet is connected to the working oil port B, the P2 oil inlet is connected to the working oil port C, and the P3 oil inlet is not connected to the working oil port A. At this time, the high-pressure oil is divided into two paths. One path is delivered to the actuator 600 of the rock drilling rig through the working oil port B and the speed regulating valve group 400. The high-pressure oil in the speed regulating valve group 400 is fed back to the second pilot directional valve 502 through the second control oil port X2. The other path flows through the working oil port C (i.e. the first control oil port X1) to the first pilot directional valve 501. The pilot oil ports of the first pilot directional valve 501 and the second pilot directional valve 502 switch direction after oil is introduced.

[0026] like Figure 4 As shown, when the main directional valve 300 is in the third position, the P1 oil inlet is connected to the working oil port A, the P2 oil inlet is not connected to the working oil port C, and the P3 oil inlet is not connected to the working oil port A. At this time, high-pressure oil is delivered to the actuator 600 of the rock drilling rig through the working oil port A and the speed regulating valve group 400. The high-pressure oil in the speed regulating valve group 400 is fed back to the second pilot directional valve 502 through the second control oil port X2.

[0027] like Figure 5 As shown, the speed regulating valve assembly 400 includes an oil inlet P4, an oil inlet P5, a first output oil port MH, a second control oil port X2, a second damper 401, and a third damper 402. The oil inlet P4 is connected to the working oil port A, the oil inlet P5 is connected to the working oil port B, the first output oil port MH is connected to the actuator 600 of the rock drilling rig, and the second control oil port X2 is connected to the first output oil port MH. The second damper 401 is located between the oil inlet P4 and the first output oil port MH, allowing high-pressure oil from the oil inlet P4 to flow to the first output oil port MH. The third damper 402 is located between the oil inlet P5 and the first output oil port MH, allowing high-pressure oil from the oil inlet P5 to flow to the first output oil port MH. The second control oil port X2 is located between the first output oil port MH and the oil inlets P4 and P5, and is connected to the pressure relief valve assembly 500.

[0028] In this embodiment, preferably, the opening degree of the P4 inlet of the speed regulating valve group 400 is greater than the opening degree of the P5 inlet, so that the flow rate of hydraulic oil through the P4 inlet is greater than that through the P5 inlet.

[0029] The speed regulating valve group 400 in this embodiment can control the flow rate. The second damper 401 and the third damper 402 can be manually adjusted on-site according to the impact conditions, thereby controlling the impact frequency.

[0030] like Figure 6As shown, the pressure relief valve group 500 includes a first pilot directional valve 501, a second pilot directional valve 502, a first relief valve 503, a second relief valve 504, and a third relief valve 505. The first pilot directional valve 501 and the second pilot directional valve 502 have the same structure, and both are selected as two-position three-way valves that can be controlled by the pilot oil circuit.

[0031] like Figure 6 As shown, the first pilot directional valve 501 has a first pilot port X3, a first inlet port PM1, a first outlet port TM1, and a second outlet port TM2. The first pilot port X3 is connected to the working port C (i.e., the first control port X1) of the main directional valve 300. The first inlet port PM1 is connected to the second pilot directional valve 502. The first outlet port TM1 is connected to the oil tank through the second relief valve 504, and the second outlet port TM2 is connected to the oil tank through the first relief valve 503. When no oil enters the first pilot port X3, the first inlet port PM1 is connected to the first outlet port TM1. After oil enters the first pilot port X3, the first inlet port PM1 is connected to the second outlet port TM2.

[0032] like Figure 6 As shown, the second pilot directional valve 502 has a second pilot port X4, a second inlet port PM2, a third outlet port TM3, and a fourth outlet port TM4. The second pilot port X4 is connected to the second control port X2 of the speed regulating valve group 400. The pressure limiting valve group 500 is also provided with a third feedback port LS3. The second inlet port PM2 of the second pilot directional valve 502 is connected to the third feedback port LS3. The third feedback port LS3 is connected to the second feedback port LS2 of the outlet valve group 200. The second feedback port LS2 is connected to the first feedback port LS1 of the load-sensitive pump. The third outlet port TM3 of the second pilot directional valve 502 is connected to the oil tank through the third relief valve 505. The fourth outlet port TM4 of the second pilot directional valve 502 is connected to the first inlet port PM1 of the first pilot directional valve 501, realizing the two pilot directional valves connected in series. When no oil enters the second pilot port X4, the second oil inlet PM2 is connected to the third oil outlet TM3. After oil enters the second pilot port X4, the first oil inlet PM1 is connected to the fourth oil outlet TM4.

[0033] like Figure 6As shown, the overflow pressure values ​​of the first overflow valve 503, the second overflow valve 504, and the third overflow valve 505 increase sequentially. The pressure of the first overflow valve 503 is the low-stroke limit pressure, the pressure of the second overflow valve 504 is the high-stroke limit pressure, and the pressure of the third overflow valve 505 is the system limit pressure. Specifically, the overflow pressure value of the first overflow valve 503 is less than that of the second overflow valve 504, and the overflow pressure value of the second overflow valve 504 is less than that of the third overflow valve 505. The specific overflow values ​​are selected according to the actual situation. In this embodiment, the first overflow valve 503, the second overflow valve 504, and the third overflow valve 505 can all be manually adjusted. The pressure can be manually adjusted according to the actual drilling situation to ensure drilling efficiency.

[0034] In this embodiment, when the main directional valve 300 is in the first position, neither working port A nor B is supplied with oil, and the actuator 600 of the rock drilling rig is not working. In the second position, working port B supplies oil to the actuator 600, and both the first pilot port X3 and the second pilot port X4 of the pressure limiting valve assembly 500 are supplied with oil, thereby achieving the switching of the pilot directional valve and limiting the pressure to the set value of the first relief valve 503. At this time, it is in low-impact mode or open-hole mode. In the third position, working port A supplies oil to the actuator 600, and the second pilot port X4 of the pressure limiting valve assembly 500 is supplied with oil, limiting the pressure to the set value of the second relief valve 504. At this time, it is in high-impact mode or rock drilling mode.

[0035] In some preferred embodiments, the pressure relief valve assembly 500 further includes a solenoid valve 506, specifically a two-position, two-way valve. One end of the solenoid valve 506 is connected to the third feedback port LS3 of the pressure relief valve assembly 500, and the other end is connected to the oil tank. The pressure relief valve assembly 500, through the built-in solenoid valve 506, controls the start and stop of the pump assembly 100 and can also act as an emergency stop for the pump assembly 100, thereby protecting the safety and reliability of the hydraulic control system.

[0036] This embodiment also discloses a hydraulic control method for freely switching between high and low thrust on a rock drilling rig. The method utilizes the aforementioned hydraulic control system for freely switching between high and low thrust on the rock drilling rig. The hydraulic control method includes switching the working position of the main directional valve 300 according to the working conditions. like Figure 1As shown, when the main directional valve 300 switches to the first position, the P1 inlet of the main directional valve 300 is not connected to the working port B, and the P2 inlet is not connected to the working port C (i.e., the first control port X1). Because of the presence of the fourth relief valve 301, the high-pressure oil will not flow into the P3 inlet under normal circumstances. At this time, the first pilot directional valve 501 and the second pilot directional valve 502 inside the pressure relief valve group 500 do not operate. The second inlet PM2 of the second pilot directional valve 502 is connected to the third outlet TM3. The third outlet TM3 is connected to the oil tank through the third relief valve 505, thereby setting the standby pressure of the system to the pressure value of the third relief valve 505. This pressure value is indirectly fed back to the first feedback port LS1 of the pump assembly 100 through the third feedback port LS3 of the pressure relief valve group 500, so that the pump assembly 100 maintains the minimum flow output.

[0037] like Figure 1 As shown, when the main directional valve 300 switches to the second position, the P1 oil inlet is connected to the working oil port B, the P2 oil inlet is connected to the working oil port C (i.e., the first control oil port X1), and the P3 oil inlet is not connected to the working oil port A. The high-pressure oil from the main directional valve 300 is divided into two paths. One path passes through the working oil port B and the speed regulating valve group 400 and is delivered to the actuator 600 of the rock drilling rig for rock drilling. The high-pressure oil flowing through the speed regulating valve group 400 flows through the second control oil port X2 of the speed regulating valve group 400 into the second pilot oil port X4 of the pressure limiting valve group 500 to control the second pilot directional valve 502 to switch. The other path passes through the working oil port C (i.e., the first control oil port X1). The flow to the first pilot port X3 controls the switching of the first pilot directional valve 501. After the two pilot directional valves switch, the second inlet PM2 of the second pilot directional valve 502 is connected to the fourth outlet TM4. The fourth outlet TM4 of the second pilot directional valve 502 is connected to the first inlet PM1 of the first pilot directional valve 501. The first inlet PM1 of the first pilot directional valve 501 is connected to the second outlet TM2. The second outlet TM2 of the first pilot directional valve 501 is connected to the oil tank through the first relief valve 503, thereby setting the impact pressure to the pressure value of the first relief valve 503. At this time, it is a low-impact mode, which is suitable for drilling and soft rock conditions.

[0038] like Figure 1As shown, when the main directional valve 300 switches to the third position, the P1 oil inlet is connected to the working oil port A, the P2 oil inlet is not connected to the working oil port C (i.e., the first control oil port X1), and the P3 oil inlet is not connected to the working oil port A. The high-pressure oil from the main directional valve 300 is transported to the actuator 600 of the rock drilling rig through the working oil port A and the speed regulating valve group 400 for rock drilling. The high-pressure oil flowing through the speed regulating valve group 400 flows into the second pilot oil port X4 of the pressure limiting valve group 500 through the second control oil port X2 of the speed regulating valve group 400 to control the second pilot directional valve 502 to switch. Rearward, the second inlet PM2 of the second pilot directional valve 502 is connected to the fourth outlet TM4, the fourth outlet TM4 of the second pilot directional valve 502 is connected to the first inlet PM1 of the first pilot directional valve 501, the first inlet PM1 of the first pilot directional valve 501 is connected to the first outlet TM1, and the first outlet TM1 of the first pilot directional valve 501 is connected to the oil tank through the second relief valve 504, thereby limiting the impact pressure to the set value of the second relief valve 504 and protecting the impact power from exceeding the limit. This is the high-impact mode, which is suitable for hard rock and deep hole working conditions.

[0039] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A hydraulic control system for a rock drilling rig that allows free switching between high and low thrust, characterized in that, include: The pump assembly (100) is connected to the outlet valve assembly (200); The oil outlet valve assembly (200) is connected to the main directional valve (300) having three working positions; The main directional valve (300) includes a P port and three working ports. The P port is connected to the outlet valve assembly (200). One working port of the main directional valve (300) is configured as the first control port (X1), and the other two working ports are connected to the speed regulating valve assembly (400) for controlling the flow rate. The speed regulating valve assembly (400) has a first output port (MH) connected to the actuator (600) of the rock drilling rig. The speed regulating valve assembly (400) also includes a second control port (X2) connected to the first output port (MH). The pressure relief valve assembly (500) includes a first pilot directional valve (501), a second pilot directional valve (502), a first relief valve (503), a second relief valve (504), and a third relief valve (505). The first pilot directional valve (501) includes a first pilot port (X3), a first inlet port (PM1), a first outlet port (TM1), and a second outlet port (TM2). The first pilot port (X3) is connected to the first control port (X1), the first inlet port (PM1) is connected to the second pilot directional valve (502), the first outlet port (TM1) is connected to the oil tank through the second relief valve (504), and the second outlet port (TM2) is connected to the oil tank through the first relief valve (503). The second pilot directional valve (502) includes a second pilot port (X4), a second inlet port (PM2), a third outlet port (TM3), and a fourth outlet port (TM4). The second pilot port (X4) is connected to the second control port (X2). The second inlet port (PM2) is connected to the first feedback port (LS1) of the pump assembly (100) through the outlet valve group (200). The third outlet port (TM3) is connected to the oil tank through the third relief valve (505). The fourth outlet port (TM4) is connected to the first inlet port (PM1) of the first pilot directional valve (501). The relief pressure values ​​of the first relief valve (503), the second relief valve (504), and the third relief valve (505) increase sequentially.

2. The hydraulic control system according to claim 1, characterized in that, The pump assembly (100) includes a load-sensitive pump, which includes a second output port (H) and a first feedback port (LS1). The second output port (H) is connected to the outlet valve assembly (200), and the first feedback port (LS1) is connected to the second feedback port (LS2) of the outlet valve assembly (200).

3. The hydraulic control system according to claim 2, characterized in that, The oil outlet valve assembly (200) includes a check valve (201) and a first damper (202). The check valve (201) is connected to the second output port (H) of the load-sensitive pump and the P port of the main directional valve (300). One end of the first damper (202) is connected to the second output port (H) of the load-sensitive pump, and the other end is configured as the second feedback port (LS2) of the oil outlet valve assembly (200).

4. The hydraulic control system according to any one of claims 1 to 3, characterized in that, The working ports of the main directional valve (300) include working port A, working port B and working port C. Working ports A and B are both connected to the speed regulating valve group (400). Working port C is configured as the first control port (X1). The P ports of the main directional valve (300) include P1 inlet port and P2 inlet port, both of which are connected to the outlet valve group (200). P1 inlet port is used to communicate with working port A or working port B. P2 inlet port is used to communicate with the first control port (X1).

5. The hydraulic control system according to claim 4, characterized in that, The P port of the main directional valve (300) also includes the P3 inlet port, which is connected to the outlet valve group (200) via a fourth relief valve (301).

6. The hydraulic control system according to claim 4, characterized in that, The speed regulating valve assembly (400) includes an oil inlet P4, an oil inlet P5, a first output oil port (MH), and a second control oil port (X2); Working port A is connected to P4 inlet port, and P4 inlet port is connected to the first output port (MH) via a second damper (401); working port B is connected to P5 inlet port, and P5 inlet port is connected to the first output port (MH) via a third damper (402); second control port (X2) is connected to the first output port (MH).

7. The hydraulic control system according to claim 6, characterized in that, The opening of the P4 oil inlet is greater than that of the P5 oil inlet.

8. The hydraulic control system according to claim 1, characterized in that, The pressure relief valve assembly (500) is provided with a third feedback port (LS3). The second inlet (PM2) of the second pilot directional valve (502) is connected to the second feedback port (LS2) of the outlet valve assembly (200) through the third feedback port (LS3). An electromagnetic switch valve (506) is provided between the third feedback port (LS3) and the oil tank.

9. The hydraulic control system according to claim 1, characterized in that, The main directional valve (300) is configured as a three-position six-way directional valve, and the main directional valve (300) is one of the multi-way valves of the rock drilling rig.

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