Quartering hammer hydraulic system and excavator

Abstract

The utility model relates to the technical field of engineering machinery, and discloses a breaking hammer hydraulic system and an excavator. The breaking hammer hydraulic system comprises a breaking hammer control valve and an oil return switch valve of a main valve, wherein the breaking hammer control valve comprises a valve body; a control end is formed at one end of the valve rod assembly; the reset piece is arranged in the valve cavity; the pilot valve is communicated with the main pump, one end, corresponding to the control end, of the valve cavity and a control oil port of the oil return switch valve, the pilot valve is provided with a working position and a normal position, and when the pilot valve is located at the working position, the pilot valve controls the valve rod assembly to be switched to the working position and controls the oil return switch valve to be switched to a closed state; when the pilot valve is in the normal position, the valve rod assembly is reset to the normal position under the action of the reset piece, and the oil return switch valve is reset to the open state. High-pressure oil of the main pump directly flows into the breaking hammer through the breaking hammer control valve, and the breaking hammer control valve is simple in oil duct, short in oil duct length, low in pressure loss and small in energy loss. The pilot valve controls the oil return switch valve while controlling the valve rod assembly, and control is simple.

Description

Technical Field

[0001] The utility model relates to the technical field of construction machinery, in particular to a hydraulic system for a breaker and an excavator. Background Art

[0002] The main working conditions of an excavator are shoveling, hoisting, leveling operations, etc. After installing a breaker, it can perform breaking operations.

[0003] At present, some breakers installed on excavators are supplied with oil by a single pump, and some are supplied with oil by a double pump. If the breaker is supplied with oil by a single pump, due to the limitations of single-pump oil supply, only a breaker with a smaller drill rod can be configured on the excavator or a larger drill rod can be configured for low-power operation.

[0004] To solve the above problems, some breakers are supplied with oil by a double pump. Two main pumps supply oil to the breaker through the main valve respectively. In this way, the oil supply is increased, and the excavator can be equipped with a breaker with a larger drill rod size. However, in the current double-pump oil supply system, two main pumps supply oil to the breaker through the main valve respectively. When the oil flows through the main valve, due to the complex internal pipeline of the main valve, the pressure loss of the oil flowing in the internal pipeline of the main valve is large, the heat generation is large, and more energy is wasted. Summary of the Utility Model

[0005] In view of this, the utility model provides a hydraulic system for a breaker and an excavator to solve the problem of large pressure loss of oil when the main pump supplies oil to the breaker through the main valve.

[0006] In a first aspect, the utility model provides a hydraulic system for a breaker, including: an oil tank, a main pump, a pilot pump, a breaker control valve and an oil return switch valve of the main valve. The main pump and the pilot pump are communicated with the oil tank. The breaker control valve includes: a valve body having a valve cavity, a main oil inlet and a main oil outlet. The main oil inlet and the main oil outlet are both communicated with the valve cavity. The main oil inlet is communicated with the main pump, and the main oil outlet is communicated with the oil inlet of the breaker. A valve stem assembly is arranged in the valve cavity. The valve stem assembly has a working position for communicating the main oil inlet and the main oil outlet and a normal position for closing the main oil inlet. One end of the valve stem assembly forms a control end. A reset member is arranged in the valve cavity. A pilot valve is communicated with the main pump, one end of the valve cavity corresponding to the control end, and the control oil port of the oil return switch valve. The pilot valve has a working position and a normal position. When the pilot valve is in the working position, the pilot valve controls the valve stem assembly to switch to the working position and controls the oil return switch valve to switch to the closed state. When the pilot valve is in the normal position, the valve stem assembly is reset to the normal position under the action of the reset member, and the oil return switch valve is reset to the open state.

[0007] Beneficial effects: When the control pilot valve is in the normal position, the valve stem assembly is also in the normal position under the action of the reset member. The high-pressure oil of the main pump reaches the main oil inlet and is intercepted by the valve stem assembly. The high-pressure oil of the main pump cannot pass through the breaker control valve, and the breaker does not work at this time. When the control pilot valve is in the working position, after the pilot oil of the pilot pump passes through the pilot valve, part of the pilot oil flows into one end of the valve cavity corresponding to the control end, pushing the valve stem assembly to move. The valve stem assembly switches from the normal position to the working position. The main oil inlet and the main oil outlet are connected. After the high-pressure oil of the main pump reaches the main oil inlet position, it passes through the valve stem assembly to the main oil outlet, and then through the pipeline to the oil inlet of the breaker, controlling the breaker to perform crushing operations. At the same time, part of the pilot oil flows to the control oil port on the oil return switch valve of the main valve, pushing the oil return switch valve to switch from the open state to the closed state, cutting off the oil return of the main valve, so that the high-pressure oil only supplies oil to the breaker, improving the working efficiency of the breaker. The high-pressure oil of the main pump directly flows into the breaker through the breaker control valve. The oil passage of the breaker control valve is simple, the oil passage length is short, the pressure loss is low, and the energy loss is small, effectively solving the problem of large oil pressure loss when the main pump supplies oil to the breaker through the main valve. The pilot valve can control the oil return switch valve while controlling the valve stem assembly, and the control is simple.

[0008] In an alternative embodiment, the pilot valve includes a pilot valve body, a spool, an elastic member, and a driving structure. The pilot valve body has a pilot valve cavity, a pilot oil inlet, a first pilot oil outlet, and a first oil return port. The pilot oil inlet is connected to the pilot pump. The first pilot oil outlet is connected to one end of the valve cavity corresponding to the control end and the control oil port of the oil return switch valve. The spool is arranged in the pilot valve cavity. The spool has a closed position for closing the pilot oil inlet and a working position for connecting the pilot oil inlet and the first pilot oil outlet. The driving structure drives the spool to switch to the working position, and the spool resets to the closed position under the action of the elastic member.

[0009] Beneficial effects: The structure of the pilot valve is simple and the cost is low.

[0010] In an alternative embodiment, the driving structure is an electromagnetic structure. When the electromagnetic structure is energized, the spool is in the working position; when the electromagnetic structure is de-energized, the spool is in the closed position.

[0011] Beneficial effects: The pilot valve is a pilot solenoid valve. By energizing or de-energizing, the position of the spool is controlled, and the control is simple and can respond quickly.

[0012] In an alternative embodiment, the valve cavity includes a first valve cavity and a second valve cavity. The main oil inlet and the main oil outlet are connected to the first valve cavity. One end of the second valve cavity away from the first valve cavity is connected to the first pilot oil outlet. The valve stem assembly includes a first valve stem and a second valve stem connected to each other. The first valve stem is arranged in the first valve cavity, the second valve stem is arranged in the second valve cavity, the reset member is sleeved on the second valve stem, and one end of the reset member away from the first valve stem cooperates with the control end.

[0013] Beneficial effects: By assembling two valve stems to form a valve stem assembly, it is convenient to assemble the reset part on the valve stem assembly, and the assembly is simpler.

[0014] In an alternative embodiment, the pilot valve body is fixed to one end of the valve body corresponding to the control end, and a second pilot oil outlet communicating with the second valve cavity is opened on the valve body.

[0015] Beneficial effects: The pilot valve is directly fixed on the valve body, and the first pilot oil outlet is directly communicated with the second valve cavity, eliminating the need to set up pipelines and simplifying the pipeline layout.

[0016] In an alternative embodiment, communication grooves and oil return grooves are arranged at intervals on the outer peripheral surface of the first valve stem. The communication grooves are used to communicate the main oil inlet and the main oil outlet. The oil return grooves are located on the outer peripheral surface of the first valve stem between the communication grooves and the second valve stem. The first valve stem is provided with an oil return passage communicating with the oil return groove, and one end of the oil return passage extends to the end face of the first valve stem far from the second valve stem.

[0017] Beneficial effects: When high-pressure oil leaks back to the side where the oil return groove is located through the gap between the valve stem assembly and the valve body, the leaked oil flows into the oil return groove, then enters the oil return passage, and flows out of the breaker control valve through the oil return passage. The settings of the oil return groove and the oil return passage ensure that the high-pressure oil will not affect the pilot oil area on one side of the valve stem assembly, thereby improving the reliability of the breaker control valve.

[0018] In an alternative embodiment, the breaker control valve further includes an oil return pressing plate. The oil return pressing plate covers one end of the valve body corresponding to the oil return passage. The oil return pressing plate has a second oil return port communicating with the oil return passage, and the second oil return port is used to communicate with the fuel tank.

[0019] Beneficial effects: The hydraulic oil flowing out from the return passage on the valve stem assembly flows back to the fuel tank through the second oil return port of the oil return pressing plate. The second oil return port of the oil return pressing plate can be directly connected to the oil return pipeline, facilitating the connection between the breaker control valve and the oil return pipeline.

[0020] In an alternative embodiment, the breaker control valve further includes a protective sleeve. The protective sleeve is sleeved on the second valve stem, and the reset part is sleeved on the protective sleeve to separate the reset part from the first valve stem and the second valve stem.

[0021] Beneficial effects: The valve stem assembly is protected by the protective sleeve, so that the reset part does not contact the valve stem assembly, avoiding the situation that the movement of the reset part frictions the valve stem assembly and causes damage to the valve stem assembly.

[0022] In an alternative embodiment, the pilot valve further includes a valve sleeve fixed in the pilot valve cavity. The spool is arranged inside the valve sleeve. The valve sleeve has a pilot inlet corresponding to and communicating with the pilot oil inlet and a pilot return port corresponding to and communicating with the first oil return port. A pilot groove is provided on the outer peripheral surface of the spool, and a pilot passage communicating the pilot groove and the first pilot oil outlet is provided on the spool. When the spool is in the closed position, the spool closes the pilot inlet and opens the pilot return port. When the spool is in the working position, the spool opens the pilot inlet and closes the pilot return port.

[0023] In an alternative embodiment, the hydraulic system of the breaker further includes a relief valve. The oil inlet of the relief valve is connected to the main pump, and the oil outlet of the relief valve is connected to the fuel tank. The main valve and the breaker control valve share the relief valve, and the relief pressure of the relief valve is adjustable.

[0024] Advantageous effects: The working pressures of the main valve and the breaker are controlled by the relief valve. When the breaker is working, the relief pressure of the relief valve is small. When the breaker is not working, the relief pressure of the relief valve is large. By adjusting the relief pressure of the relief valve, different working conditions can be adapted to meet the usage requirements of different working conditions.

[0025] In a second aspect, the present utility model further provides an excavator, including: a breaker; the above-mentioned hydraulic system of the breaker, which is connected to the breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is a cross-sectional view of the pilot valve and valve stem assembly of a breaker control valve in the normal position according to an embodiment of the present utility model;

[0028] Figure 2 For Figure 1 It is a schematic structural diagram of the right part of the breaker control valve shown;

[0029] Figure 3 For Figure 1 It is a top view of the pilot valve and valve stem assembly of the breaker control valve in the working position shown;

[0030] Figure 4 For Figure 3 It is a schematic structural diagram of the right part of the breaker control valve shown;

[0031] Figure 5Schematic diagram of the principle of a hydraulic system for a breaker according to an embodiment of the present utility model;

[0032] Figure 6 is Figure 5 a partially enlarged schematic view of A in

[0033] Figure 7 is Figure 5 a partially enlarged schematic view of B in

[0034] Explanation of reference numerals:

[0035] 1. Breaker control valve; 101. Valve body; 1011. Main oil inlet; 1012. Main oil outlet; 1013. Second pilot oil outlet; 102. Pilot valve; 1021. Pilot oil inlet; 1022. First oil return port; 1023. First pilot oil outlet; 1024. Pilot valve body; 1025. Spool; 1026. Driving structure; 1027. Valve sleeve; 103. Valve rod assembly; 1031. Connecting groove; 1032. Oil return groove; 1033. Oil return passage; 1034. First valve rod; 1035. Second valve rod; 105. Reset part; 106. Oil return pressing plate; 1061. Second oil return port; 107. First sleeve; 108. Second sleeve;

[0036] 2. Main pump;

[0037] 3. Pilot pump;

[0038] 4. Main valve; 401. Oil return switch valve;

[0039] 5. Breaker

[0040] 6. Oil tank;

[0041] 7. Relief valve;

[0042] 8. Controller;

[0043] 9. Solenoid valve group; 901. First solenoid valve; 902. Second solenoid valve. Detailed implementation manners

[0044] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0045] Next, in combination with Figures 1 to 7 , the embodiments of the present utility model will be described.

[0046] According to an embodiment of the present utility model, on the one hand, a hydraulic system for a breaker is provided, including: an oil tank 6, a main pump 2, a pilot pump 3, a breaker control valve 1, and an oil return switch valve 401 of a main valve 4. The main pump 2 and the pilot pump 3 are communicated with the oil tank 6. The breaker control valve 1 includes: a valve body 101, a valve stem assembly 103, a reset member 105, and a pilot valve 102.

[0047] Specifically, the valve body 101 has a valve cavity, a main oil inlet 1011, and a main oil outlet 1012. The main oil inlet 1011 and the main oil outlet 1012 are both communicated with the valve cavity. The main oil inlet 1011 is communicated with the main pump 2, and the main oil outlet 1012 is communicated with the oil inlet of the breaker 5. The valve stem assembly 103 is arranged in the valve cavity. The valve stem assembly 103 has a working position for communicating the main oil inlet 1011 and the main oil outlet 1012 and a normal position for closing the main oil inlet 1011. One end of the valve stem assembly 103 forms a control end. The reset member 105 is arranged in the valve cavity. The pilot valve 102 is communicated with the main pump 2, one end of the valve cavity corresponding to the control end, and the control oil port of the oil return switch valve 401. The pilot valve 102 has a working position and a normal position. When the pilot valve 102 is in the working position, the pilot valve 102 controls the valve stem assembly 103 to switch to the working position and controls the oil return switch valve 401 to switch to the closed state. When the pilot valve 102 is in the normal position, the valve stem assembly 103 is reset to the normal position under the action of the reset member 105, and the oil return switch valve 401 is reset to the open state.

[0048] When the pilot valve 102 of the hydraulic system of the breaker in this embodiment is controlled to be in the normal position, the valve stem assembly 103 is also in the normal position under the action of the reset member 105. The high-pressure oil of the main pump 2 reaches the main oil inlet 1011 and is intercepted by the valve stem assembly 103. The high-pressure oil of the main pump 2 cannot pass through the breaker control valve 1, and at this time, the breaker 5 does not work; when the pilot valve 102 is controlled to be in the working position, after the pilot oil of the pilot pump 3 passes through the pilot valve 102, part of the pilot oil flows into one end of the valve cavity corresponding to the control end, pushing the valve stem assembly 103 to move. The valve stem assembly 103 switches from the normal position to the working position. The main oil inlet 1011 and the main oil outlet 1012 are communicated. After the high-pressure oil of the main pump 2 reaches the main oil inlet 1011, it passes through the valve stem assembly 103 to reach the main oil outlet 1012, and then reaches the oil inlet of the breaker 5 through the pipeline to control the breaker 5 to perform the breaking operation; at the same time, part of the pilot oil flows to the control oil port on the oil return switch valve 401 of the main valve 4, pushing the oil return switch valve 401 to switch from the open state to the closed state, cutting off the oil return of the main valve 4, so that the high-pressure oil only supplies oil to the breaker 5, improving the working efficiency of the breaker 5. The high-pressure oil of the main pump 2 directly flows into the breaker 5 through the breaker control valve 1. The oil passage of the breaker control valve 1 is simple, the oil passage length is short, the pressure loss is low, and the energy loss is small, effectively solving the problem of large oil pressure loss when the main pump supplies oil to the breaker through the main valve. The pilot valve 102 can control the oil return switch valve 401 while controlling the valve stem assembly 103, and the control is simple.

[0049] Further, the oil inlet of the main valve 4 is communicated with the oil outlet of the main pump 2, and the oil outlet of the oil return switch valve 401 is communicated with the fuel tank 6. When the breaker 5 is working, the oil return switch valve 401 is in the closed state, cutting off the oil return of the main valve 4, so that the high-pressure oil only supplies oil to the breaker 5, improving the working efficiency of the breaker 5; when the breaker 5 is not working, the oil return switch valve 401 is in the open state, and the main pump 2 supplies oil to other actuators to ensure the normal operation of other actions.

[0050] In one embodiment, the pilot valve 102 includes a pilot valve body 1024, a spool 1025, an elastic member, and a driving structure 1026. The pilot valve body 1024 has a pilot valve chamber, a pilot oil inlet 1021, a first pilot oil outlet 1023, and a first oil return port 1022. The pilot oil inlet 1021 is communicated with the pilot pump 3. The first pilot oil outlet 1023 is communicated with one end of the corresponding control end of the valve chamber and the control oil port of the oil return switch valve 401. The spool 1025 is arranged in the pilot valve chamber. The spool 1025 has a closed position for closing the pilot oil inlet 1021 and a working position for communicating the pilot oil inlet 1021 and the first pilot oil outlet 1023. The driving structure 1026 drives the spool 1025 to switch to the working position, and the spool 1025 is reset to the closed position under the action of the elastic member. When the pilot valve 102 is in the working position, the driving structure 1026 drives the spool 1025 to switch to the working position; when the pilot valve 102 is in the normal position, the spool 1025 is reset to the closed position under the action of the elastic member. The structure of the pilot valve 102 is simple and the cost is low.

[0051] In one embodiment, the driving structure 1026 is an electromagnetic structure. When the electromagnetic structure is energized, the spool 1025 is in the working position; when the electromagnetic structure is de-energized, the spool 1025 is in the closed position. The pilot valve 102 is a pilot solenoid valve. By energizing or de-energizing, the position of the spool 1042 is controlled, and the control is simple and can respond quickly.

[0052] It can be understood that in another embodiment, the pilot valve 102 is a pilot pressure valve or a pilot mechanical valve.

[0053] In one embodiment, as Figure 3 shown, the valve chamber includes a first valve chamber and a second valve chamber. The main oil inlet 1011 and the main oil outlet 1012 are communicated with the first valve chamber. One end of the second valve chamber far from the first valve chamber is communicated with the first pilot oil outlet 1023. The valve stem assembly 103 includes a connected first valve stem 1034 and a second valve stem 1035. The first valve stem 1034 is arranged in the first valve chamber, and the second valve stem 1035 is arranged in the second valve chamber. The reset member 105 is sleeved on the second valve stem 1035, and one end of the reset member 105 far from the first valve stem 1034 is matched with the control end. By assembling two valve stems to form the valve stem assembly 103, it is convenient to assemble the reset member 105 on the valve stem assembly 103, and the assembly is more convenient.

[0054] In one embodiment, the pilot valve body 1024 is fixed to one end of the valve body 101 corresponding to the control end, and a second pilot oil outlet 1013 communicating with the second valve cavity is formed on the valve body 101. During assembly, first assemble the valve stem assembly 103 and the reset member 105 in the valve cavity, and then fix the pilot valve body 1024 of the assembled pilot valve 102 to the valve body 101, which is convenient for assembly. Moreover, by directly fixing the pilot valve 102 to the valve body 101, the first pilot oil outlet 1023 is directly communicated with the second valve cavity, eliminating the need for pipelines and simplifying the pipeline layout.

[0055] It should be noted that the pilot valve body 1024 has a through hole penetrating both ends thereof. One end of the through hole forms the first pilot oil outlet 1023, and the remaining part of the through hole forms the pilot valve cavity.

[0056] It can be understood that in another embodiment, the second pilot oil outlet 1013 is not provided on the valve body 101. The first pilot oil outlet 1023 is communicated with one end of the second valve cavity far from the first valve cavity through a pilot pipeline, and the pilot pipeline is communicated with the control oil port of the oil return switch valve 401 through a pilot branch pipeline.

[0057] In one embodiment, as Figure 1 shown, communication grooves 1031 and oil return grooves 1032 are arranged at intervals on the outer peripheral surface of the first valve stem 1034. The communication grooves 1031 are used to communicate the main oil inlet 1011 and the main oil outlet 1012. The oil return grooves 1032 are located on the outer peripheral surface of the first valve stem 1034 between the communication grooves 1031 and the second valve stem 1035. An oil return channel 1033 communicating with the oil return grooves 1032 is provided on the first valve stem 1034, and one end of the oil return channel 1033 extends to the end face of the first valve stem 1034 far from the second valve stem 1035. When high-pressure oil leaks through the gap between the valve stem assembly 103 and the valve body 101 to the side where the oil return grooves 1032 are located, the leaked oil flows into the oil return grooves 1032, then enters the oil return channel 1033, and flows out of the breaker control valve 1 through the oil return channel 1033. The arrangement of the oil return grooves 1032 and the oil return channel 1033 ensures that the high-pressure oil will not affect the pilot oil area on one side of the valve stem assembly 103, thereby improving the reliability of the breaker control valve.

[0058] Furthermore, the oil return channel 1033 includes an axial channel section and at least one radial channel section. The axial channel section is communicated with at least one radial channel section, and the oil return grooves 1032 are communicated with all the radial channel sections.

[0059] Specifically, the oil return grooves 1032 are annular grooves, and all the leaked oil can flow into the annular grooves and then flow back to the fuel tank 6 through the oil return channel 1033, so as to recover the permeated oil.

[0060] Furthermore, the communication groove 1031 is an annular groove. When the valve stem assembly 103 is in the working position, the area of the oil passage cavity formed by the valve body 101 and the valve stem assembly 103 is large, and the pressure loss is low, so the energy loss is small.

[0061] It can be understood that in other embodiments, the oil return groove 1032 includes a plurality of arc-shaped grooves arranged at intervals in the circumferential direction around the valve stem assembly 103.

[0062] In one embodiment, as Figure 1 and Figure 3 shown, the breaker control valve 1 further includes an oil return pressing plate 106. The oil return pressing plate 106 is covered at one end of the valve body 101 corresponding to the oil return passage 1033. The oil return pressing plate 106 has a second oil return port 1061 communicating with the oil return passage 1033. The second oil return port 1061 is used to communicate with the fuel tank 6. The hydraulic oil flowing out from the return passage on the valve stem assembly 103 flows back to the fuel tank 6 through the second oil return port 1061 of the oil return pressing plate 106. The second oil return port 1061 of the oil return pressing plate 106 can be directly connected to the oil return pipeline, which is convenient for connecting the breaker control valve 1 with the oil return pipeline.

[0063] Furthermore, the oil return pressing plate 106 is fixed to one end face of the valve body 101 by fasteners such as screws, and the fixing method of the oil return pressing plate 106 is simple.

[0064] It can be understood that in another embodiment, the oil return pressing plate 106 may not be provided, and the oil return pipeline may be directly connected to one end of the valve cavity.

[0065] In one embodiment, the breaker control valve 1 further includes a protective sleeve. The protective sleeve is sleeved on the second valve stem 1035, and the reset member 105 is sleeved on the protective sleeve to separate the reset member 105 from the first valve stem 1034 and the second valve stem 1035. The valve stem assembly 103 is protected by the protective sleeve, so that the reset member 105 does not contact the valve stem assembly 103, avoiding the situation that the valve stem assembly 103 is damaged due to the movement friction of the reset member 105 on the valve stem assembly 103.

[0066] Furthermore, as Figure 3 shown, the protective sleeve includes a first sleeve 107 and a second sleeve 108 which are oppositely arranged and spaced apart. The radially outward extending ends of the first sleeve 107 and the second sleeve 108 form radial convex parts. The radial convex parts are abutted against the reset member 105. Under the action of the reset member 105, the radial convex part of the first sleeve 107 abuts against the step surface. The end of the second valve stem 1035 extends radially outward to form a limiting convex part, and the limiting convex part abuts against the radial convex part of the second sleeve 108. The two radial convex parts of the sleeve make both ends of the reset member 105 not contact the valve body 101 and the second valve stem 1035, not only protecting the valve stem assembly 103, but also protecting the step surface of the valve body 101.

[0067] It is understandable that in other embodiments, only one sleeve may be provided. One end of the sleeve extending radially outward away from the first valve stem 1034 forms a radial protrusion, and the radial protrusion abuts against the limiting protrusion of the second valve stem 1035. The end of the sleeve close to the first valve stem 1034 is spaced from the step surface. One end of the reset member 105 abuts against the step surface and the other end abuts against the radial protrusion.

[0068] It should be noted that both the elastic member and the reset member 105 are springs, which are convenient to use and have low cost.

[0069] In one embodiment, the pilot valve 102 further includes a valve sleeve 1027. The valve sleeve 1027 is fixed in the pilot valve cavity. The valve core 1025 is arranged in the valve sleeve 1027. The valve sleeve 1027 has a pilot inlet corresponding to and communicating with the pilot oil inlet 1021 and a pilot return port corresponding to and communicating with the first oil return port 1022. A pilot groove is provided on the outer peripheral surface of the valve core 1025, and a pilot channel communicating the pilot groove and the first pilot oil outlet 1023 is provided on the valve core 1025. When the valve core 1025 is in the closed position, the valve core 1025 closes the pilot inlet and opens the pilot return port. When the valve core 1025 is in the working position, the valve core 1025 opens the pilot inlet and closes the pilot return port.

[0070] Further, when the electromagnetic structure is not powered on, the position of the valve stem assembly 103 is as Figure 1 shown. After the oil supply of the main pump 2 reaches the position of the main oil inlet 1011, it is intercepted by the valve stem assembly 103. After the electromagnetic structure is powered on, the pilot oil of the pilot pump 3 passes through the main oil inlet 1011, the pilot inlet, the pilot groove, the pilot channel, and the first pilot oil outlet 1023, and then pushes the valve stem assembly 103 to move leftward, as Figure 3 shown. At this time, after the oil supply of the main pump 2 reaches the position of the main oil inlet 1011, it passes through the oil passage cavity formed by the valve stem assembly 103 and the valve body 101 to reach the main oil outlet 1012, and then passes through the pipeline to reach the breaker 5, controlling the breaker 5 to perform the breaking operation. The oil passage cavity formed by the valve body 101 and the valve stem assembly 103 has a large area, a simple oil passage, a short oil passage length, and low pressure loss, so the energy loss is small.

[0071] Specifically, one end of the valve sleeve 1027 close to the valve body 101 extends radially inward to form a limiting protrusion, and the valve core 1025 is limited by the limiting protrusion. Pilot inlet grooves and pilot return grooves are provided at intervals on the outer peripheral surface of the valve sleeve 1027. The pilot inlet is opened at the bottom of the pilot inlet groove, and the pilot inlet groove communicates with the pilot oil inlet 1021. The pilot return port is provided at the bottom of the pilot return groove, and the pilot return groove communicates with the pilot oil return port 1022.

[0072] It should be noted that when the main oil inlet 1011 and the main oil outlet 1012 are connected through the communication groove 1031, the main oil inlet 1011, the communication groove 1031 and the main oil outlet 1012 form a main oil flow path, the oil return groove 1032 and the oil return passage 1033 form a leakage oil return flow path, and the pilot oil inlet 1021, the pilot inlet, the pilot groove, the pilot passage, the first pilot oil outlet 1023, the end of the valve cavity close to the pilot valve 102, and the second pilot oil outlet 1013 form a pilot flow path. The main oil flow path is completely separated from the leakage oil return flow path and the pilot flow path. Even if the high-pressure oil leaks to the right along the gap between the valve stem assembly 103 and the valve body 101, there is an oil return groove 1032 on the right side of the valve stem. After the leaked oil passes through the oil return groove 1032, it enters the valve stem oil return passage 1033 and flows through the oil return passage 1033 to the oil return area at the position of the second oil return port 1061, thus ensuring that the high-pressure oil will not affect the pilot oil area on the right side of the valve stem assembly 103, thereby improving the reliability of the breaker control valve 1.

[0073] It is worth noting that the left and right of the indicated direction are Figure 1 the "left and right" directions indicated by the arrows in Figure 6 In, r1 refers to the second oil return port 1061, Pi1 refers to the first pilot oil outlet 1023, Pp1 refers to the pilot oil inlet 1021, and Dr1 refers to the first oil return port 1022. Figures 1 to 4 The dotted line with an arrow in

[0074] It can be understood that in other embodiments, the valve sleeve 1027 may not be provided either.

[0075] In one embodiment, as Figure 5 shown, the breaker hydraulic system further includes an overflow valve 7. The oil inlet of the overflow valve 7 is connected to the main pump 2, and the oil outlet of the overflow valve 7 is connected to the fuel tank 6. The main valve 4 and the breaker control valve 1 share the overflow valve 7, and the overflow pressure of the overflow valve 7 is adjustable. The working pressures of the main valve 4 and the breaker 5 are controlled by the overflow valve 7. When the breaker 5 is working, the overflow pressure of the overflow valve 7 is small. When the breaker 5 is not working, the overflow pressure of the overflow valve 7 is large. By adjusting the overflow pressure of the overflow valve 7, different working conditions can be applied to meet the usage requirements of different working conditions. For example, when the breaker 5 is working, the overflow pressure of the overflow valve 7 is 30 MPa, and when the breaker 5 is not working, the overflow pressure of the overflow valve 7 is 35 MPa.

[0076] It should be noted that the specific value of the overflow pressure is not limited to this and needs to be set according to specific requirements.

[0077] Furthermore, as Figure 5As shown, the hydraulic system of the breaker further includes a solenoid valve group 9 and a controller 8. The controller 8 is electrically connected to the breaker control valve 1 and the solenoid valve group 9. The solenoid valve group 9 and the breaker control valve 1 are powered on and off through the controller 8, which makes the control simple and convenient.

[0078] Specifically, as Figure 7 shown, the solenoid valve group 9 includes a first solenoid valve 901, a second solenoid valve 902, etc. The oil inlet of the first solenoid valve 901 is communicated with the oil outlet of the pilot pump 3. The oil outlet of the first solenoid valve 901 is communicated with the pilot oil inlet 1021 of the breaker control valve 1. The oil return port of the first solenoid valve 901 is communicated with the fuel tank 6. The oil inlet of the second solenoid valve 902 is communicated with the oil outlet of the first solenoid valve 901. The oil outlet of the second solenoid valve 902 is communicated with the overflow control port of the overflow valve 7. The oil return port of the second solenoid valve 902 is communicated with the fuel tank 6. When the first solenoid valve 901 is powered on, the oil inlet and the oil outlet of the first solenoid valve 901 are communicated. When the first solenoid valve 901 is powered off, the oil outlet and the oil return port of the first solenoid valve 901 are communicated. The second solenoid valve 902 has the same structure as the first solenoid valve 901. When the breaker 5 works, the first solenoid valve 901 and the breaker control valve 1 are powered on, and the second solenoid valve 902 is powered off. When the breaker 5 does not work, the first solenoid valve 901 and the second solenoid valve 902 are powered on, and the breaker control valve 1 is powered off. By controlling the power on or off of the second solenoid valve 902, the valve stem of the overflow valve 7 is controlled at different positions, thereby adjusting the overflow pressure of the overflow valve 7.

[0079] In one embodiment, the number of main pumps 2 is two. At this time, the number of breaker control valves 1 is also two. The two main pumps 2 and the two breaker control valves 1 are connected in one-to-one correspondence. Two breaker control valves 1 are used to control the flow distribution of two different main pumps 2 respectively. When the electromagnetic structures of the two breaker control valves 1 are not powered on, the two main pumps 2 supply the main valve 4, so as to ensure the normal operation of other actions of the excavator except the breaker 5. When the electromagnetic structures of the two breaker control valves 1 are powered on at the same time, the valve stem assembly 103 changes direction. The high-pressure oil of the two main pumps 2 passes through the two breaker control valves 1 and reaches the breaker 5. At the same time, the pilot oil outlet 1013 of the breaker control valve 1 reaches the control oil port position of the oil return switch valve 401 through the pilot pipeline, pushing the valve stem of the oil return switch valve 401 to change direction, cutting off the oil return after the main pumps 2 pass through the main valve 4, and realizing the simultaneous oil supply of the two main pumps 2 to the breaker 5, improving the working efficiency.

[0080] It should be noted that the main valve 4 can adopt the structure in the prior art, and will not be elaborated in detail here.

[0081] It can be understood that in other embodiments, the number of main pumps 2 is more than three, and the same number of breaker control valves 1 and oil return switch valves 401 are configured at the same time.

[0082] According to an embodiment of the present utility model, on the other hand, an excavator is further provided, including: a breaker 5 and the above-mentioned breaker hydraulic system, and the breaker hydraulic system is communicated with the breaker 5. The breaker control valve 1 and the breaker hydraulic system have low cost and high reliability.

[0083] Although the embodiments of the present utility model are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present utility model, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A hydraulic system for a breaker hammer, characterized in that: include: An oil tank (6), a main pump (2), a pilot pump (3), a breaker hammer control valve (1) and an oil return switch valve (401) of a main valve (4), wherein the main pump (2) and the pilot pump (3) are in communication with the oil tank (6), and the breaker hammer control valve (1) comprises: The valve body (101) comprises a valve cavity, a main oil inlet (1011) and a main oil outlet (1012), wherein the main oil inlet (1011) is connected to the main pump (2), and the main oil outlet (1012) is connected to the oil inlet of the breaker (5); A valve stem assembly (103) is arranged in the valve cavity, the valve stem assembly (103) having a working position for connecting the main oil inlet (1011) and the main oil outlet (1012) and a normal position for closing the main oil inlet (1011), and one end of the valve stem assembly (103) forms a control end; A reset member (105) is arranged in the valve cavity; The pilot valve (102) is connected to the main pump (2), one end of the valve chamber corresponding to the control end, and the control oil port of the return oil switch valve (401). The pilot valve (102) has a working position and a normal position. When the pilot valve (102) is in the working position, the pilot valve (102) controls the valve stem assembly (103) to switch to the working position and controls the return oil switch valve (401) to switch to a closed state; when the pilot valve (102) is in the normal position, the valve stem assembly (103) is reset to the normal position under the action of the reset member (105), and the return oil switch valve (401) is reset to an open state.

2. The hydraulic system of a breaker hammer according to claim 1, characterized in that: The pilot valve (102) comprises a pilot valve body (1024), a valve core (1025), an elastic member and a driving structure (1026); the pilot valve body (1024) has a pilot valve cavity, a pilot oil inlet (1021), a first pilot oil outlet (1023) and a first oil return port (1022); the pilot oil inlet (1021) is in communication with the pilot pump (3); the first pilot oil outlet (1023) is in communication with an end of the valve cavity corresponding to the control end; the oil return switch valve (1022) is in communication with the pilot pump (3); The control oil ports of the pilot valve (401) are connected, the valve core (1025) is arranged in the pilot valve chamber, the valve core (1025) has a closing position for sealing the pilot oil inlet (1021) and a working position for connecting the pilot oil inlet (1021) and the first pilot oil outlet (1023), the driving structure (1026) drives the valve core (1025) to switch to the working position, and the valve core (1025) is reset to the closing position under the action of the elastic member.

3. The hydraulic system of a breaker hammer according to claim 2, characterized in that: The driving structure (1026) is an electromagnetic structure. When the electromagnetic structure is powered on, the valve core (1025) is in the working position; when the electromagnetic structure is powered off, the valve core (1025) is in the closed position.

4. The hydraulic system of a breaker hammer according to claim 2 or 3, characterized in that: The valve cavity includes a first valve cavity and a second valve cavity, the main oil inlet (1011) and the main oil outlet (1012) are connected to the first valve cavity, and the end of the second valve cavity away from the first valve cavity is connected to the first pilot oil outlet (1023), the valve stem assembly (103) includes a first valve stem (1034) and a second valve stem (1035) connected to each other, the first valve stem (1034) is arranged in the first valve cavity, and the second valve stem (1035) is arranged in the second valve cavity, the reset member (105) is sleeved on the second valve stem (1035), and the end of the reset member (105) away from the first valve stem (1034) cooperates with the control end.

5. The hydraulic system of a breaker hammer according to claim 4, characterized in that: The pilot valve body (1024) is fixed to an end of the valve body (101) corresponding to the control end, and a second pilot oil outlet (1013) communicating with the second valve chamber is provided on the valve body (101).

6. The hydraulic system for a breaker hammer according to claim 4, characterized in that: A connecting groove (1031) and an oil return groove (1032) are provided on the outer peripheral surface of the first valve stem (1034) at intervals. The connecting groove (1031) is used to connect the main oil inlet (1011) and the main oil outlet (1012). The oil return groove (1032) is located on the outer peripheral surface of the first valve stem (1034) between the connecting groove (1031) and the second valve stem (1035). The first valve stem (1034) is provided with an oil return channel (1033) connected to the oil return groove (1032). One end of the oil return channel (1033) extends to the end surface of the first valve stem (1034) away from the second valve stem (1035).

7. The hydraulic system for a breaker hammer according to claim 6, characterized in that: The breaker hammer control valve (1) further comprises an oil return pressure plate (106), wherein the oil return pressure plate (106) is disposed on one end of the valve body (101) corresponding to the oil return passage (1033), and the oil return pressure plate (106) has a second oil return port (1061) connected to the oil return passage (1033), and the second oil return port (1061) is used to be connected to an oil tank (6).

8. The hydraulic system for a breaker hammer according to claim 4, characterized in that: The breaker hammer control valve (1) further comprises a protective sleeve, wherein the protective sleeve is sleeved on the second valve stem (1035), and the reset member (105) is sleeved on the protective sleeve to separate the reset member (105) from the first valve stem (1034) and the second valve stem (1035).

9. The hydraulic system for a breaker hammer according to claim 2 or 3, characterized in that: The pilot valve (102) further comprises a valve sleeve (1027), wherein the valve sleeve (1027) is fixed in the pilot valve cavity, and the valve core (1025) is arranged in the valve sleeve (1027). The valve sleeve (1027) has a pilot inlet correspondingly connected to the pilot oil inlet (1021) and a pilot return port correspondingly connected to the first oil return port (1022). A pilot groove is arranged on the outer peripheral surface of the valve core (1025), and a pilot channel connecting the pilot groove and the first pilot oil outlet (1023) is arranged on the valve core (1025). When the valve core (1025) is in the closed position, the valve core (1025) closes the pilot inlet and opens the pilot return port. When the valve core (1025) is in the working position, the valve core (1025) opens the pilot inlet and closes the pilot return port.

10. The hydraulic system for a breaker hammer according to any one of claims 1 to 3, characterized in that: The breaker hammer hydraulic system further comprises a relief valve (7), the oil inlet of the relief valve (7) being connected to the main pump (2), the oil outlet of the relief valve (7) being connected to the oil tank (6), the main valve (4) and the breaker hammer control valve (1) sharing the relief valve (7), and the relief pressure of the relief valve (7) being adjustable.

11. An excavator, characterized in that: include: Breaker (5); The breaker hammer hydraulic system according to any one of claims 1 to 10 is connected to the breaker hammer (5).

Images