A hydraulic control system for a breaking hammer and a construction machine

Abstract

This invention discloses a hydraulic control system for a hydraulic breaker and related construction machinery. The system includes: an inlet oil circuit for connecting to the inlet of the excavator's hydraulic breaker; a return oil circuit for connecting to the return port of the hydraulic breaker; and a rebound pressure relief oil circuit, with its inlet and outlet ends connected to the inlet and return oil circuits, respectively. When the pressure at the inlet meets the rebound pressure relief condition, the rebound pressure relief oil circuit is in a connected state; when the pressure at the inlet does not meet the rebound pressure relief condition, the rebound pressure relief oil circuit is in a closed state. This invention, through the rebound pressure relief oil circuit, can release abnormally high pressure generated by rebound, greatly improving the load-bearing capacity of the hydraulic system and enhancing system reliability.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery design and manufacturing technology, and in particular to a hydraulic control system for a hydraulic breaker and an engineering machine equipped with such a system. Background Technology

[0002] With the joint issuance of the "Implementation Opinions on Accelerating the Construction of Green Mines" by the Ministry of Land and Resources, the Ministry of Finance, and the Ministry of Environmental Protection, the state has become increasingly strict in its control over the use of explosives in mining. In recent years, most mining operations have undergone a revolutionary transformation, with large hydraulic excavators equipped with hydraulic breakers becoming the most economical, safest, and most popular construction solution. This market is showing a clear expansion trend. However, the following problems have emerged in the market during the application of this equipment and urgently need to be addressed:

[0003] When a hydraulic breaker encounters hard rock, the chisel is prone to rebound during hammering. This rebound causes a sharp fluctuation in pressure, resulting in short-term abnormal high pressure in the hydraulic system and affecting the lifespan of the entire hydraulic system. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a hydraulic control system for a hydraulic breaker and an engineering machine, which can release the abnormal high pressure generated by the rebound through the rebound pressure relief oil circuit, greatly improve the load condition of the hydraulic system and enhance the system reliability.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A hydraulic control system for a hydraulic breaker includes:

[0007] Oil inlet line, used to connect to the oil inlet of the excavator's breaker hammer;

[0008] The rebound pressure relief oil circuit has its inlet and outlet ends connected to the inlet oil circuit and the return oil circuit, respectively.

[0009] When the pressure at the oil inlet meets the rebound pressure relief condition, the rebound pressure relief oil circuit is in a connected state;

[0010] When the pressure at the oil inlet does not meet the rebound pressure relief condition, the rebound pressure relief oil circuit is in a closed state.

[0011] The rebound pressure relief condition refers to any judgment condition that can determine whether the hydraulic breaker has rebounded. For example, the rebound pressure relief condition can be:

[0012] The pressure at the oil inlet of the hydraulic breaker was detected to be greater than the maximum oil inlet pressure during normal operation of the hydraulic breaker.

[0013] And / or, the pressure rise rate (i.e., pressure increase rate) at the hydraulic breaker inlet is detected to be greater than a first preset value;

[0014] And / or, the pressure change curve at the hydraulic breaker inlet is detected to match the rebound curve (i.e., the pressure change curve at the hydraulic breaker inlet when a rebound occurs);

[0015] Or any other reference factor that can be used as a basis for determining that a rebound has occurred (at which point the hydraulic breaker inlet will generally experience instantaneous high pressure).

[0016] Optionally, the rebound pressure relief oil circuit is equipped with a rebound pressure relief valve;

[0017] When the valve core of the rebound pressure relief valve is in the first working position, the rebound pressure relief oil circuit is in a connected state;

[0018] When the valve core of the rebound pressure relief valve is in the second working position, the rebound pressure relief oil circuit is in a closed state.

[0019] Optionally, the rebound pressure relief valve is provided with:

[0020] The first oil port is connected to the oil inlet circuit;

[0021] The second oil port is connected to the return oil circuit;

[0022] The pilot control unit is able to control the movement of the valve core according to the pressure of the first oil port;

[0023] When the valve core moves to the first working position, the internal oil passage between the first oil port and the second oil port is connected; when the valve core moves to the second working position, the internal oil passage between the first oil port and the second oil port is closed.

[0024] Optionally, the pilot control unit includes:

[0025] The first pilot control unit is connected to the first oil port through the first pilot oil circuit and to the second oil port through the second pilot oil circuit;

[0026] The second pilot control unit is connected to the first oil port through a third pilot oil circuit and to the second oil port through a fourth pilot oil circuit. The third pilot oil circuit is equipped with a flow limiting valve.

[0027] The elastic element is capable of controlling the valve core to be in the second working position under normal conditions.

[0028] Optionally, the return oil circuit is provided with:

[0029] Back pressure valve;

[0030] An oil diffuser is connected in series at the outlet of the back pressure valve;

[0031] The peak-shaving oil circuit is connected at one end to the outlet of the oil diffuser and at the other end to the inlet of the back pressure valve.

[0032] When the internal pressure of the oil distributor or the internal pressure of the oil inlet pipe of the oil distributor meets the return oil peak reduction conditions, the peak reduction oil circuit is in a connected state.

[0033] When the internal pressure of the oil distributor or the internal pressure of the oil inlet pipe of the oil distributor does not meet the return oil peak reduction conditions, the peak reduction oil circuit is in a closed state.

[0034] The return oil peak reduction condition refers to any judgment condition that can determine whether return oil pulsation occurs in the return oil circuit. For example, the return oil peak reduction condition can be:

[0035] Within a preset time period, the number of times the internal pressure of the oil diffuser or the internal pressure of the oil inlet pipe of the oil diffuser is greater than or equal to the maximum rated oil pressure of the oil diffuser is greater than a preset number.

[0036] And / or, the internal pressure of the oil breaker or the internal pressure of the oil inlet pipe of the oil breaker is greater than or equal to the maximum internal pressure of the oil breaker when the breaker is working normally and the return oil circuit is returning oil normally, that is, the maximum rated oil pressure of the oil breaker.

[0037] And / or, the internal pressure of the oil distributor or the internal pressure of the oil distributor's inlet pipe is greater than or equal to the maximum pressure in the return oil circuit when the hydraulic breaker is working normally and the return oil circuit is returning oil normally, i.e., the maximum rated return oil pressure.

[0038] And / or, the rate of increase of the internal pressure of the oil diffuser or the rate of increase of the internal pressure of the oil diffuser's inlet pipe (i.e., the rate of pressure increase) is greater than a second preset value;

[0039] And / or, the pressure change curve of the internal pressure of the oil diffuser or the internal pressure of the oil inlet pipe of the oil diffuser conforms to the return oil pulsation curve (i.e., the pressure change curve of the return oil path, especially the location of the oil diffuser, when return oil pulsation occurs).

[0040] Or any other reference factor that can be used as the basis for determining the occurrence of return oil pulsation (at which time the oil pressure change in the return oil circuit, especially at the location of the oil diffuser, is in the form of a pulse).

[0041] Optionally, the preset time is any value within the range of 1 second to 3 seconds;

[0042] The maximum rated oil pressure of the oil diffuser is any value within the range of 1.2 MPa to 1.4 MPa;

[0043] The preset number of times is any value within the range of 4 to 6.

[0044] Optionally, an electronically controlled switching valve is provided in the peak-shaving oil circuit;

[0045] The oil dispenser is equipped with a first pressure sensor for detecting the internal pressure of the oil dispenser, and / or the oil inlet pipe of the oil dispenser is equipped with a first pressure sensor (16) for detecting the internal pressure of the oil inlet pipe.

[0046] The first pressure sensor is connected to the electronically controlled switching valve via signal connection; or, both the first pressure sensor and the electronically controlled switching valve are connected to the central controller via signal connection.

[0047] Optionally, the oil inlet circuit is provided with a first main pump and a second main pump, as well as a switching valve for controlling the alternating operation of the first main pump and the second main pump.

[0048] An engineering machine includes a hydraulic breaker and the hydraulic control system for the hydraulic breaker described above.

[0049] As can be seen from the above technical solution, the hydraulic control system for hydraulic breakers provided by the present invention has a rebound pressure relief oil circuit. When the hydraulic breaker encounters a hard rock (or other hard material) that it cannot break and rebounds, the abnormal instantaneous high pressure (or high pressure peak) formed by the rebound can be released through the rebound pressure relief oil circuit, which can greatly improve the load condition of the hydraulic system and improve the reliability of the system.

[0050] Furthermore, the hydraulic control system for the hydraulic breaker provided by the present invention is also equipped with a peak-suppression oil circuit, which can realize the peak-suppression function of the hydraulic breaker return oil pulsation, release the peak value of the hydraulic breaker return oil pulsation, and protect the oil diffuser.

[0051] Furthermore, the hydraulic control system for the hydraulic breaker provided by this invention is also equipped with dual pumps that can work alternately, and has a dual pump switching function for crushing. Under the premise of ensuring that the original single pump is used for crushing, it can also realize the switching between two single pumps (i.e., the first main pump and the second main pump), thereby balancing the life of the two main pumps, which can greatly extend the working time of the main pump and improve the overall life of the machine. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of the excavator breaker control system provided in an embodiment of the present invention;

[0054] Figure 2 for Figure 1 A magnified view of a local area.

[0055] in:

[0056] 1-Switch valve, 2-Oil tank, 3-Return oil filter, 4-Oil diffuser, 5-Back pressure valve

[0057] 6-Broken pipeline filter, 7-Low-pressure accumulator, 8-Return oil shut-off valve, 9-Rebound pressure relief valve

[0058] 10- Hydraulic breaker, 11- Oil inlet shut-off valve, 12- High-pressure accumulator.

[0059] 13- Crushing overflow valve, 14- Crushing overload valve, 15- Second pressure sensor

[0060] 16 - First pressure sensor, 17 - Third pressure sensor

[0061] 18-First main pump, 19-Second main pump, 20-Switching valve

[0062] 21-Main valve, 22-Pilot pump, 23-Control button, 24-Control foot pedal

[0063] 25 - Central controller; 26 - Crushing pilot solenoid valve;

[0064] 101 - Oil inlet, 102 - Oil outlet

[0065] 901 - First pilot oil circuit, 902 - Second pilot oil circuit

[0066] 903 - Third pilot oil circuit, 904 - Fourth pilot oil circuit

[0067] 911 - First oil port, 912 - Second oil port

[0068] 921-First pilot control unit, 922-Second pilot control unit, 931-Flow limiting valve;

[0069] L1 - Oil inlet circuit, L2 - Oil return circuit, L3 - Rebound pressure relief circuit, L4 - Peak reduction circuit. Detailed Implementation

[0070] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] Please see Figure 1 and Figure 2This invention provides a hydraulic control system for a hydraulic breaker (hereinafter referred to as the hydraulic system), which includes an inlet oil line L1, a return oil line L2, and a rebound pressure relief oil line L3. Specifically: the inlet oil line L1 is connected to the inlet port 101 of the excavator breaker 10; the return oil line L2 is connected to the return port 102 of the breaker 10; the inlet and outlet ends of the rebound pressure relief oil line L3 are connected to the inlet oil line L1 and the return oil line L2, respectively, meaning the rebound pressure relief oil line L3 is connected in parallel with the breaker 10.

[0072] When the pressure at the oil inlet 101 meets the rebound pressure relief condition, the rebound pressure relief oil circuit L3 is in a connected state, thus serving as a bypass oil circuit for the hydraulic breaker 10 to achieve pressure relief, that is, to release the instantaneous high pressure formed by the rebound.

[0073] When the pressure at the oil inlet 101 does not meet the rebound pressure relief condition, the rebound pressure relief oil circuit L3 is closed, and the hydraulic breaker 10 operates normally.

[0074] In this article, the rebound pressure relief condition refers to any condition that can determine whether the hydraulic breaker has rebounded. For example, the rebound pressure relief condition can be:

[0075] The pressure at the oil inlet 101 of the hydraulic breaker was detected to be greater than the maximum oil inlet pressure during normal operation of the hydraulic breaker.

[0076] And / or, the pressure rise rate (i.e., pressure rise rate) at the hydraulic breaker inlet 101 is detected to be greater than a first preset value;

[0077] And / or, if the pressure change curve of the hydraulic breaker inlet 101 is detected to match the rebound curve (the "rebound curve" refers to the pressure change curve formed when the pressure of the hydraulic breaker inlet 101 changes over a period of time during a rebound, which is generally preset in the controller; when the actual pressure change curve formed when the pressure of the hydraulic breaker inlet 101 changes over time is detected to be basically consistent with the rebound curve stored in the controller, it is determined that the pressure of the inlet 101 meets the rebound pressure relief condition, a rebound has occurred, and the rebound pressure relief oil circuit L3 is opened to relieve pressure).

[0078] Or any other reference factor that can be used as a basis for determining that a rebound has occurred (at which point the hydraulic breaker inlet will generally experience instantaneous high pressure).

[0079] As can be seen, the hydraulic control system for the hydraulic breaker provided in this embodiment of the invention can release the abnormal instantaneous high pressure (or high pressure peak) formed by the rebound when the hydraulic breaker 10 encounters a hard rock (or other hard material) that it cannot break and rebounds. This can greatly improve the load conditions of the hydraulic system and enhance the reliability of the system.

[0080] Specifically, the aforementioned rebound pressure relief oil circuit L3 is equipped with a rebound pressure relief valve 9. When the rebound pressure relief valve 9 is open, its valve core is in the first working position (see [reference]). Figure 2 When the right-hand connecting position is reached, the internal oil passage between the first oil port 911 and the second oil port 912 is connected, thus the rebound pressure relief oil passage L3 is in a connected state; when the rebound pressure relief valve 9 is closed, its valve core is in the second working position (see [reference]). Figure 2 When the left side of the oil port is closed, the internal oil passage between the first oil port 911 and the second oil port 912 is closed, thus the rebound pressure relief oil passage L3 is in a closed state.

[0081] For specific implementation details, please refer to [link / reference]. Figure 2 The rebound pressure relief valve 9 is equipped with a first oil port 911, a second oil port 912, and a pilot control unit. Specifically, the first oil port 911 is connected to the inlet oil circuit L1; the second oil port 912 is connected to the return oil circuit L2; and the pilot control unit can control the movement of the valve core based on the pressure at the first oil port 911. The valve core moves to the first working position (i.e.,... Figure 2 When the valve core moves to the right-hand connecting position, the internal oil passage between the first oil port 911 and the second oil port 912 is connected, the rebound pressure relief valve 9 opens, and the rebound pressure relief oil passage L3 is in a connected state; the valve core moves to the second working position (i.e., Figure 2 When the left side of the valve is closed, the internal oil passage between the first oil port 911 and the second oil port 912 is closed, the rebound pressure relief valve 9 is closed, and the rebound pressure relief oil passage L3 is in a closed state.

[0082] Specifically, the pilot control unit includes a first pilot control unit 921, a second pilot control unit 922, and an elastic element (e.g., a spring). The first pilot control unit 921 is connected to a first oil port 911 via a first pilot oil passage 901 and to a second oil port 912 via a second pilot oil passage 902. The second pilot control unit 922 is connected to the first oil port 911 via a third pilot oil passage 903 and to the second oil port 912 via a fourth pilot oil passage 904. The third pilot oil passage 903 is equipped with a flow-limiting valve 931 (or a damping valve). The elastic element controls the valve core to be in the second working position (i.e., the closed position) under normal conditions. That is, after the first pilot control unit 921 drives the valve core to move to the first working position, if the oil pressure on both sides of the valve core is equal, the restoring force of the elastic element controls the valve core to return to the second working position.

[0083] When the hydraulic breaker encounters a hard, impenetrable rock and rebounds, the pressure at the inlet 101 will inevitably meet the rebound pressure relief condition. At this time, an abnormal instantaneous high pressure appears on the upper side of the rebound pressure relief valve 9 (i.e., at the first port 911), and is simultaneously transmitted to both sides of the rebound pressure relief valve 9. At this time, the pressure at the inlet 101 is greater than the pressure at the return port 102, thus the pressure at the first port 911 is greater than the pressure at the second port 912. Although both the first pilot control unit 921 and the second pilot control unit 922 are connected to the first port 911, under the action of the flow limiting valve 931, the pressure exerted on the valve core by the first pilot control unit 921 is greater than the pressure exerted on the valve core by the second pilot control unit 922. Therefore, the first pilot control unit 921 can overcome the spring force and push the valve core to move forward (specifically, it means...). Figure 2 (The valve core in the middle moves to the left), thereby causing the valve core of the rebound relief valve 9 to move to... Figure 2 The first working position is located on the right side. At this time, the internal oil passage between the first oil port 911 and the second oil port 912 is connected, that is, the rebound pressure relief valve 9 is in the open state, so the rebound pressure relief oil passage L3 is in the connected state. The rebound pressure relief oil passage L3 serves as the bypass oil passage of the breaker 10, which can release the instantaneous high pressure formed by the rebound.

[0084] When no rebound occurs, the pressure at inlet 101 will inevitably not meet the rebound pressure relief condition. For example, after the instantaneous high pressure formed by the rebound is released, the pressure at the first port 911 will not be greater than the pressure at the second port 912. At this time, since the first pilot control unit 921 and the second pilot control unit 922 are connected to the second port 912 through the second pilot oil passage 902 and the fourth pilot oil passage 904 respectively, the pressure exerted on the valve core by the first pilot control unit 921 and the pressure exerted on the valve core by the second pilot control unit 922 are equal. Under the restoring force of the elastic element, the valve core moves in the opposite direction (specifically, it refers to...). Figure 2 (The valve core in the middle moves to the right), thereby causing the valve core of the rebound relief valve 9 to move to... Figure 2 The second working position is located on the left side. At this time, the internal oil passage between the first oil port 911 and the second oil port 912 is closed, that is, the rebound pressure relief valve 9 is in the closed state, so the rebound pressure relief oil passage L3 is in the closed state, and the breaker hammer 10 works normally.

[0085] Furthermore, taking the excavator's breaking system as an example, during the application of the equipment, due to the frequent hammering characteristic of the hydraulic breaker, the return oil pressure of the hydraulic system will generate high-pressure pulsation. This high-pressure pulsation is very likely to cause fatigue cracking failure of the radiator (such as aluminum radiator). If this pulsation peak can be eliminated, the stress condition of the oil radiator can be effectively improved, and the failure of radiator fatigue cracking failure can be reduced.

[0086] Based on this, please see Figure 1The hydraulic control system for the hydraulic breaker provided in this embodiment of the invention includes a back pressure valve 5, an oil diffuser 4, and a peak-shaving oil circuit L4 in its return oil circuit L2. Specifically, the oil diffuser 4 is connected in series at the outlet of the back pressure valve 5; one end of the peak-shaving oil circuit L4 is connected to the outlet of the oil diffuser 4, and the other end is connected to the inlet of the back pressure valve 5.

[0087] When the internal pressure of oil distributor 4 or the internal pressure of its inlet pipe meets the conditions for peak shaving in the return oil circuit, peak shaving oil circuit L4 is in a connected state. At this time, peak shaving oil circuit L4 is equivalent to a bypass pipe. When high-pressure pulsation occurs in the return oil circuit L2, the high-pressure oil flows back to the oil tank 2 through peak shaving oil circuit L4, basically bypassing oil distributor 4. This achieves the purpose of eliminating high-pressure pulsation in the return oil circuit L2, effectively improving the stress condition of oil distributor 4, protecting oil distributor 4, and avoiding fatigue cracking failure caused by high-pressure pulsation.

[0088] When the internal pressure of oil distributor 4 or the internal pressure of oil distributor 4's inlet pipe does not meet the conditions for oil return and peak reduction, peak reduction oil circuit L4 is in a closed state, and oil return oil circuit L2 resumes normal operation. The oil return flows back to oil tank 2 after passing through back pressure valve 5 and oil distributor 4.

[0089] It should be noted that the above-mentioned return oil peak-shaving conditions used to control the opening and closing of the L4 peak-shaving oil circuit refer to any judgment condition that can determine whether there is a return oil pulsation in the return oil circuit. For example, the return oil peak-shaving condition can be: within a preset time, the number of times the internal pressure of the oil diffuser or the internal pressure of the oil diffuser inlet pipe is greater than or equal to the maximum rated oil pressure of the oil diffuser is greater than a preset number.

[0090] Preferably, the preset time is any value within the range of 1 to 3 seconds (e.g., 2 seconds); the maximum rated oil pressure of the oil diffuser is any value within the range of 1.2 MPa to 1.4 MPa (e.g., 1.3 MPa); and the preset number of times is any value within the range of 4 to 6 (e.g., 5 times).

[0091] Alternatively, in other specific embodiments, the oil return peak reduction conditions can also be set as follows:

[0092] The internal pressure of oil distributor 4 or the internal pressure of oil distributor 4 in the oil inlet pipe is greater than or equal to the maximum internal pressure of oil distributor when the hydraulic breaker 10 is working normally and the oil return line L2 is returning oil normally, that is, the maximum rated oil pressure of oil distributor.

[0093] And / or, the internal pressure of the oil distributor 4 or the internal pressure of the oil inlet pipe of the oil distributor 4 is greater than or equal to the maximum pressure in the return oil circuit L2 when the breaker 10 is working normally and the return oil circuit L2 is returning oil normally, i.e. the maximum rated return oil pressure.

[0094] And / or, the rate of increase of the internal pressure of the oil diffuser 4 or the rate of increase of the internal pressure of the oil inlet pipe of the oil diffuser 4 (i.e., the rate of pressure increase) is greater than the second preset value;

[0095] And / or, the pressure change curve of the internal pressure of oil distributor 4 or the internal pressure of the oil inlet pipe of oil distributor 4 conforms to the return oil pulsation curve (the "return oil pulsation curve" refers to the pressure change curve formed when the pressure of the return oil circuit L2, especially the location of oil distributor 4, changes over a period of time during the return oil pulsation. It is generally preset in the controller. When the actual pressure change curve formed when the internal pressure of oil distributor 4 or the internal pressure of the oil inlet pipe of oil distributor 4 changes over time is basically consistent with the rebound curve stored in the controller, it is determined that the internal pressure of oil distributor 4 or the internal pressure of the oil inlet pipe of oil distributor 4 meets the return oil peak elimination condition, the return oil pulsation occurs, and the return oil peak elimination circuit L4 is opened to achieve peak elimination).

[0096] Or any other reference factor that can be used as the basis for determining the occurrence of return oil pulsation (at which time the oil pressure change in the return oil circuit L2, especially at the location of oil diffuser 4, presents a pulse form).

[0097] Specifically, an electrically controlled switching valve 1 is installed in the peak-shaving oil circuit L4; a first pressure sensor 16 for detecting the internal pressure of the oil distributor 4 is installed, and / or, a first pressure sensor 16 for detecting the internal pressure of the oil inlet pipe of the oil distributor 4 is installed. Furthermore, the first pressure sensor 16 is signal-connected to the electrically controlled switching valve 1, or both the first pressure sensor 16 and the electrically controlled switching valve 1 are signal-connected to the central controller 25. When the pressure detected by the first pressure sensor 16 meets the peak-shaving conditions for the return oil circuit, the electrically controlled switching valve 1 opens, and the peak-shaving oil circuit L4 is in a connected state, which can perform peak-shaving function for the high-pressure pulsation phenomenon in the return oil circuit L2.

[0098] In a preferred embodiment, the electronically controlled switching valve 1 is an electronically controlled high-speed switching bypass valve. Its control signal is controlled by the central controller (ECU) 25. When the first pressure sensor 16 senses an abnormal pressure pulsation (for example, when the oil diffuser pressure is greater than 1.3 MPa, a 2-second timer is triggered, and the number of times the pressure is greater than 1.3 MPa is counted. If the number is greater than 5 times within 2 seconds, it is considered that an abnormal pressure pulsation has occurred), the central controller (ECU) 25 calculates and outputs a switching command to the electronically controlled switching valve 1 according to the above-mentioned abnormal pressure conditions, so as to release the pulsating peak pressure at high speed, effectively protecting the oil diffuser 4 from pressure fatigue cracking and failure.

[0099] As can be seen, the hydraulic control system for the hydraulic breaker provided by the present invention has the function of reducing the peak of the hydraulic breaker's return oil pulsation, which can release the peak value of the hydraulic breaker's return oil pulsation and protect the oil diffuser.

[0100] During equipment application, when the working parameters of the excavator and the breaker are matched, the economic benefits of single-pump breaker operation are significantly better than those of dual-pump merging breaker operation. However, using single-pump breaker operation continuously can easily lead to a reduction in the lifespan of the single pump.

[0101] Based on this, please see Figure 1 In the hydraulic control system for the hydraulic breaker provided in this embodiment of the invention, the oil inlet circuit L1 is equipped with a first main pump 18 and a second main pump 19, as well as a switching valve 20 for controlling the alternating operation of the first main pump 18 and the second main pump 19. It can be seen that the hydraulic control system for the hydraulic breaker provided by this invention has a dual-pump switching function, ensuring that while the original single pump is used for crushing, it can also achieve the switching between two single pumps (i.e., the first main pump 18 and the second main pump 19), thereby balancing the lifespan of the two main pumps, significantly extending the working time of the main pumps, and improving the overall lifespan of the machine.

[0102] Specifically, please see Figure 1 The switching valve 20 is the switching valve core for the first main pump 18 and the second main pump 19, and mainly consists of two parts: the main valve core stage and the electro-hydraulic pilot stage. The control signal of the electro-hydraulic pilot stage is controlled by the central controller (ECU) 25, which can realize a variety of control methods according to actual needs: for example, timed switching, that is, whenever one of the pumps has accumulated a certain amount of work time (e.g., 500 hours), the controller switching condition is triggered to realize the switching between the first main pump 18 and the second main pump 19; another example is that a touch button (or any one or more combinations of touch button / control button 23 / control foot pedal 24) is set on the central display screen in the excavator cab, which can be manually triggered by the driver according to actual needs.

[0103] For specific implementation details, please refer to [link / reference]. Figure 1 In the hydraulic control system of this hydraulic breaker:

[0104] In the oil inlet circuit L1, a series of switching dual pumps (first main pump 18 and second main pump 19), switching valve 20, main valve 21, high-pressure accumulator 12, and oil inlet shut-off valve 11 are connected in series along the oil inlet direction.

[0105] In the return oil circuit L2, the return oil shut-off valve 8, low-pressure accumulator 7, crushing pipeline filter 6, back pressure valve 5, oil distributor 4, return oil filter 3, and oil tank 2 are connected in series along the return oil direction; and the return oil peak reduction switch valve 1 mentioned above is also installed; the oil distributor 4 is equipped with a first pressure sensor 16, the crushing pipeline filter 6 is equipped with a second pressure sensor 15, and the return oil filter 3 is equipped with a third pressure sensor 17.

[0106] A crushing overload valve 14, a crushing overflow valve 13 (preferably an electronically controlled proportional overflow valve), and a rebound pressure relief valve 9 are also provided between the oil inlet circuit L1 and the oil return circuit L2.

[0107] The main valve 21 is connected to the pilot pump 22 and the central controller (ECU) 25 via the crushing pilot solenoid valve 26. The central controller (ECU) 25 is equipped with control buttons 23 and a control foot pedal 24. Figure 1A, B, and C are used to control switch valve 1, crushing overflow valve 13, and switching valve 20, respectively.

[0108] This invention also provides an engineering machine, which includes a hydraulic breaker 10 and the hydraulic breaker hydraulic control system mentioned above.

[0109] In summary, the hydraulic control system and construction machinery for hydraulic breakers provided in this embodiment of the invention have functions such as dual-pump switching for breaking, pressure relief from breaking rebound, and peak reduction of oil return pulsation during breaking. These functions can significantly improve system reliability and effectively solve market pain points.

[0110] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only 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.

[0111] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0112] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydraulic control system for a breaking hammer, characterized in that, include: The oil inlet passage (L1) is used to connect the oil inlet (101) of the hydraulic breaker (10). The return oil passage (L2) is used to connect the return oil port (102) of the hydraulic breaker (10). The rebound pressure relief oil circuit (L3) has its inlet and outlet ends connected to the inlet oil circuit (L1) and the return oil circuit (L2), respectively. The rebound pressure relief oil circuit (L3) is equipped with a rebound pressure relief valve (9) for controlling the opening and closing of the oil circuit. The first port (911) and the second port (912) of the rebound pressure relief valve (9) are connected to the inlet oil circuit (L1) and the return oil circuit (L2), respectively. The pilot control unit of the rebound pressure relief valve (9) can control the valve core according to the pressure at the first port (911). Movement; the pilot control unit includes: a first pilot control unit (921) connected to the first oil port (911) via a first pilot oil passage (901), and connected to the second oil port (912) via a second pilot oil passage (902); a second pilot control unit (922) connected to the first oil port (911) via a third pilot oil passage (903), and connected to the second oil port (912) via a fourth pilot oil passage (904); the third pilot oil passage (903) is provided with a flow limiting valve (931); When the pressure at the oil inlet (101) meets the rebound pressure relief condition, the rebound pressure relief oil passage (L3) is in a connected state to serve as a bypass oil passage between the oil inlet (101) and the oil return port (102) to release the instantaneous high pressure formed by the rebound. When the pressure at the oil inlet (101) does not meet the rebound pressure relief condition, the rebound pressure relief oil passage (L3) is closed, and the hydraulic breaker (10) operates normally.

2. The breaking hammer hydraulic control system of claim 1, wherein, The rebound and pressure relief conditions include at least the following: The pressure at the oil inlet (101) is greater than the maximum oil inlet pressure of the hydraulic breaker; And / or, the pressure rise rate of the oil inlet (101) is greater than a first preset value; And / or, the pressure change curve of the oil inlet (101) conforms to the rebound curve.

3. The hydraulic control system for the hydraulic breaker according to claim 1, characterized in that, When the valve core moves to the first working position, the internal oil passage between the first oil port (911) and the second oil port (912) is connected, and the rebound pressure relief oil passage (L3) is in a connected state; When the valve core moves to the second working position, the internal oil passage between the first oil port (911) and the second oil port (912) is closed, and the rebound pressure relief oil passage (L3) is in a closed state.

4. The hydraulic control system for the hydraulic breaker according to claim 1, characterized in that, Also includes: The elastic element is capable of controlling the valve core to be in the second working position under normal conditions.

5. The hydraulic control system for the hydraulic breaker according to any one of claims 1 to 4, characterized in that, The return oil circuit (L2) is equipped with: Back pressure valve (5); Oil diffuser (4) is connected in series at the outlet of the back pressure valve (5); The peak-shaving oil circuit (L4) is connected at one end to the outlet of the oil diffuser (4) and at the other end to the inlet of the back pressure valve (5); When the internal pressure of the oil distributor (4) or the internal pressure of the oil inlet pipe of the oil distributor (4) meets the return oil peak reduction conditions, the peak reduction oil circuit (L4) is in a connected state. When the internal pressure of the oil distributor (4) or the internal pressure of the oil inlet pipe of the oil distributor (4) does not meet the return oil peak reduction conditions, the peak reduction oil circuit (L4) is in a closed state.

6. The hydraulic control system for the hydraulic breaker according to claim 5, characterized in that, The conditions for oil return and peak reduction include at least the following: Within a preset time period, the number of times the internal pressure of the oil diffuser (4) or the internal pressure of the oil inlet pipe of the oil diffuser (4) is greater than or equal to the maximum rated oil pressure of the oil diffuser (4) is greater than a preset number; And / or, the internal pressure of the oil diffuser (4) or the internal pressure of the oil inlet pipe of the oil diffuser (4) is greater than or equal to the maximum rated oil pressure of the oil diffuser; And / or, the internal pressure of the oil diffuser (4) or the internal pressure of the oil inlet pipe of the oil diffuser (4) is greater than or equal to the maximum rated return oil pressure; And / or, the rate of increase of the internal pressure of the oil diffuser (4) or the internal pressure of the oil inlet pipe of the oil diffuser (4) is greater than the second preset value; And / or, the pressure change curve of the internal pressure of the oil diffuser (4) or the internal pressure of the oil inlet pipe of the oil diffuser (4) conforms to the return oil pulsation curve.

7. The hydraulic control system for the hydraulic breaker according to claim 6, characterized in that, The preset time is any value within the range of 1 second to 3 seconds; The maximum rated oil pressure of the oil diffuser is any value within the range of 1.2 MPa to 1.4 MPa; The preset number of times is any value within the range of 4 to 6.

8. The hydraulic control system for the hydraulic breaker according to claim 5, characterized in that, An electrically controlled switching valve (1) is installed in the peak-shaving oil circuit (L4); The oil dispenser (4) is provided with a first pressure sensor (16) for detecting the internal pressure of the oil dispenser, and / or the oil inlet pipe of the oil dispenser (4) is provided with a first pressure sensor (16) for detecting the internal pressure of the oil inlet pipe. The first pressure sensor (16) is signal-connected to the electronically controlled switch valve (1); or, both the first pressure sensor (16) and the electronically controlled switch valve (1) are signal-connected to the central controller (25).

9. The hydraulic control system for the hydraulic breaker according to any one of claims 1 to 4, characterized in that, The oil inlet circuit (L1) is equipped with a first main pump (18) and a second main pump (19), as well as a switching valve (20) for controlling the alternating operation of the first main pump (18) and the second main pump (19).

10. An engineering machinery, characterized in that, It includes a hydraulic breaker (10) and a hydraulic control system for the hydraulic breaker as described in any one of claims 1 to 9.

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