Hydraulic control system and method for free switching of high impact and low impact of drill jumbo

Abstract

The invention discloses a hydraulic control system and method for free switching of high impact and low impact of a drill jumbo and relates to the field of engineering machine.The hydraulic control system comprises a pump assembly, an oil outlet valve set, a main reversing valve and a pressure limiting valve set. When the main reversing valve is located at the first station, the pressure limiting valve set sets the standby pressure of the hydraulic control system to the overflow pressure value of the third overflow valve, the pump assembly maintains the minimum flow output, when the main reversing valve is located at the second station, the highest impact pressure is limited to the overflow pressure value of the first overflow valve, and the pump assembly is suitable for tapping and soft rock working conditions, and when the main reversing valve is located at the third station, the highest impact pressure is limited to the overflow pressure value of the second overflow valve. The impact pressure is limited to the overflow pressure value of the second overflow valve, the impact power of the drill jumbo is prevented from exceeding the limit, the drill jumbo is suitable for hard rock and deep hole working conditions, through cooperation of the control oil ports and the pressure limiting valve set, different highest system pressures are limited under different working conditions, segmented control over the high impact pressure and the low impact pressure can be achieved, and the working efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engineering machinery, in particular to a hydraulic control system and method for freely switching high and low impacts of a rock drilling jumbo. BACKGROUND

[0002] The hydraulic rock drilling jumbo is an important hard rock drilling equipment for tunnel construction by the drill and blast method. During rock drilling, the impact pressure requirements are different in different rock drilling stages. The impact pressure is generally low in the opening stage or soft rock stage, and the impact pressure is high in the rock drilling stage or hard rock stage, and the energy demand is large. Since the hydraulic rock drilling machine has high pressure and large flow, the system energy consumption is large, and it is particularly important to improve the impact hydraulic control efficiency.

[0003] The impact hydraulic system of the rock drilling jumbo in the prior art does not have segmented control of high and low impact pressures, which is not conducive to the control of opening rock drilling and increases the loss of the rock drilling machine. SUMMARY

[0004] The present application provides a hydraulic control system and method for freely switching high and low impacts of a rock drilling jumbo, which is used to realize segmented control of high and low impact pressures and improve work efficiency.

[0005] In a first aspect, the present application provides a hydraulic control system for freely switching high and low impacts of a rock drilling jumbo, comprising a pump assembly, an oil outlet valve group, a main reversing valve, a speed regulating valve group, and a pressure limiting valve group; the pump assembly is connected with the oil outlet valve group; the oil outlet valve group is connected with the main reversing valve having three working positions; the main reversing valve comprises a P oil port and three working oil ports, the P oil port is connected with the oil outlet valve group, one of the working oil ports of the main reversing valve is configured as a first control oil port, and the other two working oil ports are connected with the speed regulating valve group for controlling flow; a first output oil port of the speed regulating valve group is connected with an actuator of the rock drilling jumbo, and the speed regulating valve group further comprises a second control oil port in communication with the first output oil port; the pressure limiting valve group comprises a first pilot reversing valve, a second pilot reversing valve, a first overflow valve, a second overflow valve, and a third overflow valve; the first pilot reversing valve comprises a first pilot oil port, a first inlet oil port, a first outlet oil port, and a second outlet oil port, the first pilot oil port is connected with the first control oil port, the first inlet oil port is connected with the second pilot reversing valve, the first outlet oil port is connected with an oil tank through the second overflow valve, and the second outlet oil port is connected with the oil tank through the first overflow valve; the second pilot reversing valve comprises a second pilot oil port, a second inlet oil port, a third outlet oil port, and a fourth outlet oil port, the second pilot oil port is connected with the second control oil port, the second inlet oil port is connected with a first feedback oil port of the pump assembly through the oil outlet valve group; the third outlet oil port is connected with the oil tank through the third overflow valve, and the fourth outlet oil port is connected with the first inlet oil port of the first pilot reversing valve; the overflow pressure values of the first overflow valve, the second overflow valve, and the third overflow valve increase in turn.

[0006] Preferably, the pump assembly comprises a load sensing pump, the load sensing pump comprises a second output oil port connected with the oil outlet valve group and a first feedback oil port connected with the second feedback oil port of the oil outlet valve group.

[0007] Preferably, the oil outlet valve group comprises a one-way valve connected with the second output oil port of the load sensing pump and the P oil port of the main directional valve respectively and a first damper having one end connected with the second output oil port of the load sensing pump and the other end configured as the second feedback oil port of the oil outlet valve group.

[0008] Preferably, the working oil port of the main directional valve comprises a working oil port A, a working oil port B and a working oil port C, the working oil port A and the working oil port B are connected with the speed regulating valve group, and the working oil port C is configured as the first control oil port; the P oil port of the main directional valve comprises a P1 inlet oil port and a P2 inlet oil port both connected with the oil outlet valve group, the P1 inlet oil port is used for communicating with the working oil port A or the working oil port B, and the P2 inlet oil port is used for communicating with the first control oil port.

[0009] Preferably, the P oil port of the main directional valve further comprises a P3 inlet oil port, and the P3 inlet oil port is connected with the oil outlet valve group through a fourth overflow valve.

[0010] Preferably, the speed regulating valve group comprises a P4 inlet oil port, a P5 inlet oil port, a first output oil port and a second control oil port; the working oil port A is connected with the P4 inlet oil port, the P4 inlet oil port is connected with the first output oil port through a second damper; the working oil port B is connected with the P5 inlet oil port, the P5 inlet oil port is connected with the first output oil port through a third damper; and the second control oil port is connected with the first output oil port.

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

[0012] Preferably, the pressure limiting valve group is provided with a third feedback oil port, the second inlet oil port of the second pilot directional valve is connected with the second feedback oil port of the oil outlet valve group through the third feedback oil port, and an electromagnetic on-off valve is arranged between the third feedback oil port and the oil tank.

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

[0014] In a second aspect, the application provides a hydraulic control method for switching a high-low impact of a rock drilling rig freely, the hydraulic control method uses the hydraulic control system, and the control method comprises the following steps. When the main directional valve is in the first working position, none of the working oil ports of the main directional valve discharges oil, neither the first pilot directional valve nor the second pilot directional valve of the pressure limiting valve group acts, and the pressure limiting valve group sets the standby pressure of the hydraulic control system as the overflow pressure value of the third overflow valve. When the main directional valve is in the second position, the working port B of the main directional valve is connected to the actuator of the rock drilling rig through the speed regulating valve group; the pressure oil flows to the first pilot directional valve through the first control port of the main directional valve, and the hydraulic oil in the speed regulating valve group flows to the second pilot directional valve through the second control port. Both the first pilot directional valve and the second pilot directional valve are activated to set the impact pressure of the hydraulic control system to the overflow pressure value of the first relief valve. When the main directional valve is in the third position, the working port A of the main directional valve is connected to the actuator of the rock drilling rig through the speed regulating valve group; the hydraulic oil in the speed regulating valve group flows to the second pilot directional valve through the second control port; the second pilot directional valve is activated, setting the impact pressure of the hydraulic control system to the overflow pressure value of the second relief valve.

[0015] The hydraulic control system and method of this application have 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

[0016] 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 is Figure 1 a schematic diagram of an oil outlet valve group in the embodiment; Figure 4 is Figure 1 a schematic diagram of a main reversing valve in the embodiment; Figure 5 is Figure 1 a schematic diagram of a speed regulating valve group in the embodiment; Figure 6 is Figure 1 a schematic diagram of a pressure limiting valve group in the embodiment; The description of the reference signs is as follows: 100, pump assembly; 200, oil outlet valve group; 201, one-way valve; 202, first damper; 300, main reversing valve; 301, fourth overflow valve; 400, speed regulating valve group; 401, second damper; 402, third damper; 500, pressure limiting valve group; 501, first pilot reversing valve; 502, second pilot reversing valve; 503, first overflow valve; 504, second overflow valve; 505, third overflow valve; 506, electromagnetic on-off valve; 600, actuator. DETAILED DESCRIPTION

[0017] The features and exemplary embodiments of the various aspects of the present application will be described in detail below with reference to the drawings. To make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, but not to limit the present application. The present application can be implemented without some of the specific details by those skilled in the art. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application.

[0018] It should be noted that, in this document, relational terms such as first and second and the like can only be used to distinguish one entity or action from another entity or action, and do not necessarily require or imply that these entities or actions exist in any such actual relationship or order. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a list of elements does not only include those elements, but also includes other elements not expressly listed or other elements inherent in such process, method, article or apparatus. Without more limitations, an element defined by the statement "comprising" does not exclude the presence of additional identical elements in the process, method, article or apparatus that includes the element.

[0019] The embodiment discloses a hydraulic control system and method for freely switching high and low impacts of a rock drilling jumbo, which can realize segmented control of high impact pressure and low impact pressure of the rock drilling jumbo, and first introduces the hydraulic control system.

[0020] As shown in Figure 1 , the hydraulic control system comprises a pump assembly 100, an oil outlet valve group 200, a main reversing valve 300 and a pressure limiting valve group 500, and specifically as follows: As shown in Figure 2 , the pump assembly 100 comprises a load-sensitive pump, the load-sensitive pump has a pressure cut-off function, can provide required flow and pressure according to system pressure and flow demand, power loss is controlled to be minimum, and efficiency is much higher than that of a constant-displacement pump. In the embodiment, an oil outlet for outputting high-pressure oil of the load-sensitive pump is configured as a second output oil port H, and the load-sensitive pump also has a first feedback oil port LS1.

[0021] As shown in Figure 3 , the oil outlet valve group 200 comprises a one-way valve 201 and a first damper 202, an inlet end of the one-way valve 201 is communicated with the second output oil port H of the load-sensitive pump, an outlet end of the one-way valve 201 is communicated with a P oil port of the main reversing valve 300, one end of the first damper 202 is communicated with the second output oil port H of the load-sensitive pump, the other end of the first damper 202 is configured as a second feedback oil port LS2 of the oil outlet valve group 200, and the first feedback oil port LS1 of the load-sensitive pump is communicated to the second feedback oil port LS2. The one-way valve 201 is built in the oil outlet valve group 200 of the embodiment, which avoids backflow of hydraulic oil, and the first damper 202 is built in, which can suppress pressure fluctuation, avoid impact and vibration caused by load mutation, and make flow more stable.

[0022] As shown in Figure 4 , the main reversing valve 300 is configured as a three-position six-way reversing valve, and in other embodiments, the main reversing valve 300 is configured as one connection of a multi-way valve of the rock drilling jumbo.

[0023] As shown in Figure 4 , the main reversing valve 300 is a three-position six-way reversing valve and has six oil ports, three oil ports on a first side are configured as P oil ports, and three oil ports on a second side are configured as working oil ports, wherein the P oil ports on the first side are communicated with the one-way valve 201 of the oil outlet valve group 200, and among the three oil ports on the second side, one oil port is configured as a first control oil port X1, the first control oil port X1 is communicated with the pressure limiting valve group 500, and the other two oil ports are both communicated with the speed regulating valve group 400.

[0024] As shown in Figure 4As shown, in the present embodiment, the working oil ports located at the second side include working oil port A, working oil port B and working oil port C, working oil port A and working oil port B are both communicated with the speed regulating valve group 400, and working oil port C is configured as the first control oil port X1. The P oil ports located at the first side include P1 inlet port, P2 inlet port and P3 inlet port, and the P1 inlet port, the P2 inlet port and the P3 inlet port are all communicated with the outlet end of the one-way valve 201.

[0025] As shown, when the main reversing valve 300 is in the first position, the P1 inlet port is not communicated with the working oil port B, the P2 inlet port is not communicated with the working oil port C, and the P3 inlet port is communicated with the working oil port A. However, in the present embodiment, the fourth overflow valve 301 is arranged between the P3 inlet port and the outlet end of the one-way valve 201, and the overflow pressure value of the fourth overflow valve 301 is set according to actual requirements. Preferably, when in the first position, the hydraulic oil of the one-way valve 201 cannot flow to the P3 inlet port. Figure 4 As shown, when the main reversing valve 300 is in the second position, the P1 inlet port is communicated with the working oil port B, the P2 inlet port is communicated with the working oil port C, and the P3 inlet port is not communicated with 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 jumbo through the working oil port B and the speed regulating valve group 400, and the high-pressure oil in the speed regulating valve group 400 is fed back to the second pilot reversing valve 502 through the second control oil port X2, and the other path is communicated to the first pilot reversing valve 501 through the working oil port C (i.e. the first control oil port X1). Wherein, the pilot oil ports of the first pilot reversing valve 501 and the second pilot reversing valve 502 are switched after oil inlet.

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

[0027] As shown, when the main reversing valve 300 is in the third position, the P1 inlet port is communicated with the working oil port A, the P2 inlet port is not communicated with the working oil port C, and the P3 inlet port is not communicated with the working oil port A. At this time, the high-pressure oil is delivered to the actuator 600 of the rock drilling jumbo through the working oil port A and the speed regulating valve group 400, and the high-pressure oil in the speed regulating valve group 400 is fed back to the second pilot reversing valve 502 through the second control oil port X2. Figure 4 As shown, when the main reversing valve 300 is in the third position, the P1 inlet port is communicated with the working oil port A, the P2 inlet port is not communicated with the working oil port C, and the P3 inlet port is not communicated with the working oil port A. At this time, the high-pressure oil is delivered to the actuator 600 of the rock drilling jumbo through the working oil port A and the speed regulating valve group 400, and the high-pressure oil in the speed regulating valve group 400 is fed back to the second pilot reversing valve 502 through the second control oil port X2.

[0028] Figure 5 ​​As shown, the speed regulating valve group 400 includes a P4 inlet, a P5 inlet, a first output oil port MH, a second control oil port X2, a second damping 401, and a third damping 402. The P4 inlet is in communication with the working oil port A, the P5 inlet is in communication with the working oil port B, the first output oil port MH is in communication with the actuator 600 of the drill jumbo, and the second control oil port X2 is in communication with the first output oil port MH. The second damping 401 is arranged between the P4 inlet and the first output oil port MH, and the high-pressure oil of the P4 inlet flows to the first output oil port MH through the second damping 401. The third damping 402 is arranged between the P5 inlet and the first output oil port MH, and the high-pressure oil of the P5 inlet flows to the first output oil port MH through the third damping 402. The second control oil port X2 is arranged between the first output oil port MH and the P4 inlet and the P5 inlet, and is in communication with the pressure limiting valve group 500.

[0029] In the embodiment, the opening degree of the P4 inlet of the speed regulating valve group 400 is greater than that of the P5 inlet, so that the flow rate of the hydraulic oil passing through the P4 inlet is greater than that of the P5 inlet.

[0030] The speed regulating valve group 400 of the embodiment can control the flow rate, and the second damping 401 and the third damping 402 can be manually adjusted according to the impact situation to control the impact frequency.

[0031] As shown in FIG. 4, Figure 6 As shown, the pressure limiting valve group 500 includes a first pilot reversing valve 501, a second pilot reversing valve 502, a first overflow valve 503, a second overflow valve 504, and a third overflow valve 505. The first pilot reversing valve 501 and the second pilot reversing valve 502 have the same structure and are both two-position three-way valves that can be controlled by a pilot oil line.

[0032] As shown in FIG. 5, Figure 6 As shown, the first pilot reversing valve 501 has a first pilot oil port X3, a first inlet PM1, a first outlet TM1, and a second outlet TM2. The first pilot oil port X3 is in communication with the working oil port C (i.e., the first control oil port X1) of the main reversing valve 300. The first inlet PM1 is in communication with the second pilot reversing valve 502. The first outlet TM1 is in communication with the oil tank through the second overflow valve 504, and the second outlet TM2 is in communication with the oil tank through the first overflow valve 503. When the first pilot oil port X3 has no oil, the first inlet PM1 is in communication with the first outlet TM1. After the first pilot oil port X3 is supplied with oil, the first inlet PM1 is in communication with the second outlet TM2.

[0033] As shown in FIG. 6, Figure 6As shown, the second pilot directional control valve 502 has a second pilot oil port X4, a second inlet oil port PM2, a third outlet oil port TM3 and a fourth outlet oil port TM4, the second pilot oil port X4 communicates with the second control oil port X2 of the speed regulating valve group 400, the pressure limiting valve group 500 is further provided with a third feedback oil port LS3, the second inlet oil port PM2 of the second pilot directional control valve 502 communicates with the third feedback oil port LS3, the third feedback oil port LS3 communicates with the second feedback oil port LS2 of the outlet valve group 200, and the second feedback oil port LS2 communicates with the first feedback oil port LS1 of the load sensing pump; the third outlet oil port TM3 of the second pilot directional control valve 502 communicates with the oil tank through the third overflow valve 505, and the fourth outlet oil port TM4 of the second pilot directional control valve 502 communicates with the first inlet oil port PM1 of the first pilot directional control valve 501, realizing the series connection of the two pilot directional control valves. When the second pilot oil port X4 has no oil inlet, the second inlet oil port PM2 communicates with the third outlet oil port TM3, and after the second pilot oil port X4 is filled with oil, the first inlet oil port PM1 communicates with the fourth outlet oil port TM4.

[0034] As shown in the figure, Figure 6 The overflow pressure values of the first overflow valve 503, the second overflow valve 504 and the third overflow valve 505 increase in turn, the pressure of the first overflow valve 503 is the low impact limiting pressure, the pressure of the second overflow valve 504 is the high impact limiting pressure, and the pressure of the third overflow valve 505 is the system limiting 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 value is 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 be manually adjusted, and the pressure can be manually adjusted according to the actual situation of drilling to ensure the efficiency of drilling.

[0035] In this embodiment, when the main directional control valve 300 is in the first position, neither of the working oil ports A and B is filled with oil, and the actuator 600 of the rock drilling jumbo does not work. When in the second position, the working oil port B supplies oil to the actuator 600, the first pilot oil port X3 and the second pilot oil port X4 of the pressure limiting valve group 500 are filled with oil, thereby realizing the directional control of the pilot directional control valve and limiting the pressure to the set value of the first overflow valve 503, at this time, the low impact mode or the opening mode is realized. When in the third position, the working oil port A supplies oil to the actuator 600, the second pilot oil port X4 of the pressure limiting valve group 500 is filled with oil, limiting the pressure to the set value of the second overflow valve 504, at this time, the high impact mode or the rock drilling mode is realized.

[0036] In some preferred embodiments, the pressure limiting valve group 500 further comprises an electromagnetic on-off valve 506, specifically a two-position two-way on-off valve, one end of the electromagnetic on-off valve 506 being in communication with the third feedback oil port LS3 of the pressure limiting valve group 500, and the other end of the electromagnetic on-off valve 506 being in communication with the oil tank. The pressure limiting valve group 500 controls the start and stop of the pump assembly 100 through the built-in electromagnetic on-off valve 506, and can also serve as an emergency stop of the pump assembly 100, thereby protecting the safety and reliability of the hydraulic control system.

[0037] The embodiment also discloses a hydraulic control method for free switching of high and low impacts of a rock drilling jumbo, which uses the hydraulic control system for free switching of high and low impacts of the rock drilling jumbo, and the hydraulic control method comprises switching the working position of the main reversing valve 300 according to the working condition: As shown in Figure 1 The main reversing valve 300 is switched to the first working position, the P1 inlet of the main reversing valve 300 is not in communication with the working oil port B, and the P2 inlet is not in communication with the working oil port C (i.e. the first control oil port X1). Because of the existence of the fourth overflow valve 301, high-pressure oil will not generally flow into the P3 inlet. At this time, the first pilot reversing valve 501 and the second pilot reversing valve 502 in the pressure limiting valve group 500 are not actuated, the second inlet PM2 of the second pilot reversing valve 502 is in communication with the third outlet TM3, the third outlet TM3 is in communication with the oil tank through the third overflow valve 505, thereby setting the standby pressure of the system to the pressure value of the third overflow valve 505. This pressure value is indirectly fed back to the first feedback oil port LS1 of the pump assembly 100 through the third feedback oil port LS3 of the pressure limiting valve group 500, so that the pump assembly 100 maintains the minimum flow output.

[0038] As shown in Figure 1As shown, the main reversing valve 300 is switched to the second position, the P1 inlet communicates with the working oil port B, the P2 inlet communicates with the working oil port C (i.e. the first control oil port X1), and the P3 inlet does not communicate with the working oil port A. The high-pressure oil of the main reversing valve 300 is divided into two paths. One path passes through the working oil port B, the speed regulating valve group 400, and is delivered to the actuator 600 of the rock drilling jumbo to perform rock drilling construction. 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 reversing valve 502 to reverse. The other path passes through the working oil port C (i.e. the first control oil port X1) to the first pilot oil port X3 to control the first pilot reversing valve 501 to reverse. After the two pilot reversing valves reverse, the second inlet PM2 of the second pilot reversing valve 502 communicates with the fourth outlet TM4, the fourth outlet TM4 of the second pilot reversing valve 502 communicates with the first inlet PM1 of the first pilot reversing valve 501, the first inlet PM1 of the first pilot reversing valve 501 communicates with the second outlet TM2, and the second outlet TM2 of the first pilot reversing valve 501 communicates with the oil tank through the first overflow valve 503, so as to set the impact pressure to the pressure value of the first overflow valve 503. At this time, it is a low-impact mode, which is suitable for opening hole and soft rock working conditions.

[0039] As shown, Figure 1 As shown, the main reversing valve 300 is switched to the third position, the P1 inlet communicates with the working oil port A, the P2 inlet does not communicate with the working oil port C (i.e. the first control oil port X1), and the P3 inlet does not communicate with the working oil port A. The high-pressure oil of the main reversing valve 300 passes through the working oil port A and the speed regulating valve group 400 to be delivered to the actuator 600 of the rock drilling jumbo to perform rock drilling construction. 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 reversing valve 502 to reverse. After reversing, the second inlet PM2 of the second pilot reversing valve 502 communicates with the fourth outlet TM4, the fourth outlet TM4 of the second pilot reversing valve 502 communicates with the first inlet PM1 of the first pilot reversing valve 501, the first inlet PM1 of the first pilot reversing valve 501 communicates with the first outlet TM1, and the first outlet TM1 of the first pilot reversing valve 501 communicates with the oil tank through the second overflow valve 504, so as to limit the impact pressure to the set value of the second overflow valve 504, and protect the impact power from exceeding the limit. At this time, it is a high-impact mode, which is suitable for hard rock and deep hole working conditions.

[0040] The above merely describes a specific implementation of the present application. Those skilled in the art can clearly understand the specific working processes of the system, modules and units described above for the convenience and brevity of description, and can refer to the corresponding processes in the foregoing method embodiments, which will not be described herein again. It should be understood that the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application.

Claims

1. A hydraulic control system for a drill jumbo with free switching between high and low percussion, characterized in that, The application relates to a pump assembly (100) connected with an oil outlet valve group (200), the oil outlet valve group (200) is connected with a main reversing valve (300) having three working positions, the main reversing valve (300) comprises a P oil port and three working oil ports, the P oil port is connected with the oil outlet valve group (200), one working oil port of the main reversing valve (300) is configured as a first control oil port (X1), and the other two working oil ports are connected with a speed regulating valve group (400) used for controlling flow, the speed regulating valve group (400) comprises a first output oil port (MH) connected with an actuator (600) of a rock drilling jumbo, and the speed regulating valve group (400) further comprises a second control oil port (X2) in communication with the first output oil port (MH), the speed regulating valve group (400) further comprises a pressure limiting valve group (500) comprising a first pilot reversing valve (501), a second pilot reversing valve (502), a first overflow valve (503), a second overflow valve (504) and a third overflow valve (505), the first pilot reversing valve (501) comprises a first pilot oil port (X3), a first inlet oil port (PM1), a first outlet oil port (TM1) and a second outlet oil port (TM2), the first pilot oil port (X3) is connected with the first control oil port (X1), the first inlet oil port (PM1) is connected with the second pilot reversing valve (502), the first outlet oil port (TM1) is connected with an oil tank through the second overflow valve (504), and the second outlet oil port (TM2) is connected with the oil tank through the first overflow valve (503), the second pilot reversing valve (502) comprises a second pilot oil port (X4), a second inlet oil port (PM2), a third outlet oil port (TM3) and a fourth outlet oil port (TM4), the second pilot oil port (X4) is connected with the second control oil port (X2), the second inlet oil port (PM2) is connected with a first feedback oil port (LS1) of the pump assembly (100) through the oil outlet valve group (200), the third outlet oil port (TM3) is connected with the oil tank through the third overflow valve (505), and the fourth outlet oil port (TM4) is connected with the first inlet oil port (PM1) of the first pilot reversing valve (501), the overflow pressure values of the first overflow valve (503), the second overflow valve (504) and the third overflow valve (505) increase in sequence. The pump assembly (100) comprises a load-sensitive pump, the load-sensitive pump comprises a second output oil port (H) and a first feedback oil port (LS1), the second output oil port (H) is connected with the oil outlet valve group (200), and the first feedback oil port (LS1) is connected with a second feedback oil port (LS2) of the oil outlet valve group (200). The oil outlet valve group (200) comprises a one-way valve (201) and a first damper (202), the one-way valve (201) is connected with the second output oil port (H) of the load-sensitive pump and the P oil port of the main reversing valve (300) respectively, one end of the first damper (202) is connected with the second output oil port (H) of the load-sensitive pump, and the other end is configured as the second feedback oil port (LS2) of the oil outlet valve group (200). ​ ​ ​ ​ ​ 2. The hydraulic control system of claim 1, wherein, ​ 3. The hydraulic control system of claim 2, wherein, ​ 4. The hydraulic control system according to any one of claims 1 to 3, characterized by The working oil ports of the main directional valve (300) include working oil port A, working oil port B and working oil port C, the working oil port A and the working oil port B are connected with the speed regulating valve group (400), and the working oil port C is configured as a first control oil port (X1); the P oil ports of the main directional valve (300) include P1 and P2 inlet ports connected with the oil outlet valve group (200), the P1 inlet port is used for communicating with the working oil port A or the working oil port B, and the P2 inlet port is used for communicating with the first control oil port (X1).

5. The hydraulic control system of claim 4, wherein, The P oil ports of the main directional valve (300) further include a P3 inlet port, and the P3 inlet port is connected with the oil outlet valve group (200) through the fourth overflow valve (301).

6. The hydraulic control system of claim 4, wherein, The speed regulating valve group (400) includes a P4 inlet port, a P5 inlet port, a first output oil port (MH) and a second control oil port (X2); The working oil port A is connected with the P4 inlet port, the P4 inlet port is connected with the first output oil port (MH) through a second damper (401), the working oil port B is connected with the P5 inlet port, the P5 inlet port is connected with the first output oil port (MH) through a third damper (402), and the second control oil port (X2) is connected with the first output oil port (MH).

7. The hydraulic control system of claim 6, wherein, The opening degree of the P4 inlet port is greater than that of the P5 inlet port.

8. The hydraulic control system of claim 1, wherein, The pressure limiting valve group (500) is provided with a third feedback oil port (LS3), a second inlet port (PM2) of the second pilot directional valve (502) is connected with a second feedback oil port (LS2) of the oil outlet valve group (200) through the third feedback oil port (LS3), and an electromagnetic on-off valve (506) is arranged between the third feedback oil port (LS3) and an oil tank.

9. The hydraulic control system of claim 1, wherein, 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 multiple valves of the rock drilling jumbo.

10. A hydraulic control method for a drill jumbo high-low impact free switching, characterized by, The hydraulic control system of any one of claims 1 to 9, the control method comprising: When the main directional valve (300) is in the first working position, none of the working oil ports of the main directional valve (300) discharges oil, the first pilot directional valve (501) and the second pilot directional valve (502) of the pressure limiting valve group (500) are not actuated, and the pressure limiting valve group (500) sets the standby pressure of the hydraulic control system as the overflow pressure value of the third overflow valve (505); When the main directional valve (300) is in the second working position, the working oil port B of the main directional valve (300) is connected to the actuator (600) of the rock drilling jumbo through the speed regulating valve group (400); the pressure oil flows to the first pilot directional valve (501) through the first control oil port (X1) of the main directional valve (300), the hydraulic oil in the speed regulating valve group (400) flows to the second pilot directional valve (502) through the second control oil port (X2), and the first pilot directional valve (501) and the second pilot directional valve (502) are actuated to set the impact pressure of the hydraulic control system as the overflow pressure value of the first overflow valve (503); When the main directional valve (300) is in the third position, the working oil port A of the main directional valve (300) is connected to the actuator (600) of the rock drilling jumbo through the speed regulating valve group (400); the hydraulic oil in the speed regulating valve group (400) flows to the second pilot directional valve (502) through the second control oil port (X2); the second pilot directional valve (502) acts to set the impact pressure of the hydraulic control system as the relief pressure value of the second relief valve (504).

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