Hydraulic breaking hammer and engineering machine

Abstract

The present application belongs to the field of engineering machinery, and discloses a hydraulic breaking hammer and engineering machinery, wherein the hydraulic breaking hammer comprises: a middle cylinder body; a piston rod arranged in the middle cylinder body; a continuous reversing circuit arranged between a breaking hammer oil inlet, a breaking hammer oil outlet and the middle cylinder body and capable of controlling the piston rod to reciprocate at a preset stroke; and a variable frequency trigger oil path arranged between the continuous reversing circuit and the middle cylinder body, the variable frequency trigger oil path being capable of triggering the reversing time of a master control hydraulic reversing valve in the continuous reversing circuit to change so as to adjust the piston rod to reciprocate at a non-pre-set stroke. The hydraulic breaking hammer of the present application can adjust the reciprocating stroke of the piston rod in a wide range, automatically adjust the striking frequency or striking force, thereby being capable of improving the breaking work amount and work efficiency, being suitable for different breaking working conditions, and avoiding causing resource waste without the need of re-matching and selecting the hydraulic breaking hammer.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically to a hydraulic breaker and engineering machinery. Background Technology

[0002] A hydraulic breaker is a device that uses hydraulic energy as its power source, converting it into mechanical impact kinetic energy during operation. This causes the piston rod to continuously strike the chisel rod to perform breaking operations. Hydraulic breakers are typically mounted on excavators, utilizing the hydraulic energy provided by the excavator. The efficiency of a breaker depends on the kinetic energy and frequency of the chisel rod's impact on the object. Under fixed pressure and flow rate, the impact force is inversely proportional to the impact frequency, which in turn is inversely proportional to the piston rod stroke. For traditional hydraulic breakers, the piston rod stroke is fixed. Adjusting the impact frequency requires manually regulating the return oil back pressure using a valve.

[0003] However, the above-mentioned methods for adjusting the striking frequency have a narrow adjustment range. If a larger range of adjustment of the hydraulic breaker's striking frequency and striking force is required, the hydraulic breaker must be re-matched and selected, resulting in a certain waste of resources.

[0004] Furthermore, due to the significant differences in hardness among different types of stone, the impact frequency of the hydraulic breaker needs to be frequently adjusted manually under various crushing conditions to improve its impact force. When encountering hard stone, it often requires several judgments and manual adjustments to match the appropriate impact frequency and speed, thus affecting work efficiency. Summary of the Invention

[0005] In view of at least one of the above-mentioned defects or deficiencies in the prior art, the present invention provides a hydraulic breaker and engineering machinery that can adjust the reciprocating stroke of the piston rod over a wide range and automatically adjust the striking frequency, so as to achieve the purpose of increasing the crushing workload, improving work efficiency, and avoiding resource waste.

[0006] To achieve the above objectives, a first aspect of the present invention provides a hydraulic breaker, comprising:

[0007] Middle cylinder block;

[0008] The piston rod is disposed within the middle cylinder body;

[0009] A continuous reversing circuit is installed between the breaker's oil inlet, oil return, and the intermediate cylinder, and is capable of controlling the piston rod to reciprocate at an initial stroke; and

[0010] A variable frequency triggering oil circuit is provided between the continuous reversing circuit and the middle cylinder block. The variable frequency triggering oil circuit can trigger the main control hydraulic reversing valve in the continuous reversing circuit to change the reversing timing so as to adjust the piston rod to reciprocate with a non-initial stroke.

[0011] Optionally, the middle cylinder body forms an upper chamber and a lower chamber, which are separated by an annular flange on the peripheral wall of the piston rod and can generate a pressure difference under the action of the continuous reversing circuit. The main control hydraulic reversing valve includes an upward working valve position and a downward working valve position. The peripheral wall of the middle cylinder body forms a preliminary stroke port and at least one variable stroke port arranged vertically and connected to the lower chamber of the middle cylinder body. The continuous reversing circuit includes a preliminary stroke triggering oil circuit, which is located between the preliminary stroke port and the hydraulic control end of the downward working valve position. The variable frequency triggering oil circuit is located between the variable stroke port and the hydraulic control end of the downward working valve position. During the upward movement of the piston rod, the lower chamber of the middle cylinder body can be connected to the hydraulic control end of the downward working valve position through one of the stroke ports and the corresponding triggering oil circuit.

[0012] Optionally, the variable stroke port includes a first variable stroke port and a second variable stroke port, and the frequency conversion triggering oil circuit includes a three-position four-way directional valve with O-type neutral position function, a first oil inlet branch, a second oil inlet branch, and an oil outlet branch. The first variable stroke port is connected to the hydraulic control terminal of the downward working valve position in sequence through the first oil inlet branch, the three-position four-way directional valve, and the oil outlet branch. The second variable stroke port is connected to the hydraulic control terminal of the downward working valve position in sequence through the second oil inlet branch, the three-position four-way directional valve, and the oil outlet branch.

[0013] Optionally, the initial stroke port, the first variable stroke port, and the second variable stroke port are arranged sequentially from top to bottom.

[0014] Optionally, the initial stroke triggering oil circuit is provided with a check valve, and one end of the oil discharge branch is connected to the three-position four-way directional valve and the other end is connected to the portion of the initial stroke triggering oil circuit located between the check valve and the hydraulic control end of the downward working valve position.

[0015] Optionally, the three-position four-way directional valve is a hydraulic pilot directional valve and is provided with a control port for controlling the pilot pressure.

[0016] Optionally, the hydraulic breaker includes a transition valve block, the hydraulic pilot directional valve is integrated in the transition valve block, and the control port is located on the outer wall of the transition valve block.

[0017] Optionally, the peripheral wall of the middle cylinder is formed with a lower chamber oil return port, and the continuous reversing circuit includes a downward oil return circuit with both ends connected to the lower chamber oil return port and the hydraulic breaker oil return port, respectively. When the lower chamber of the middle cylinder is connected to the hydraulic control end of the downward working valve position through one of the stroke oil ports and the corresponding trigger oil circuit, the lower chamber oil return port is connected to the lower chamber of the middle cylinder.

[0018] Optionally, the peripheral wall of the middle cylinder body is formed with an upper cavity inlet / outlet switching oil port communicating with the upper cavity of the middle cylinder body and a lower cavity inlet oil port communicating with the lower cavity of the middle cylinder body. The lower cavity inlet oil port is kept in communication with the breaker inlet oil port, and the upper cavity inlet / outlet switching oil port can be selectively connected to one of the breaker inlet oil port and the breaker return oil port through the main control hydraulic directional valve.

[0019] Optionally, the hydraulic breaker further includes an upper cylinder connected to the upper end of the middle cylinder, wherein a nitrogen chamber is formed in the upper cylinder, and the top end of the piston rod extends into the nitrogen chamber.

[0020] Optionally, the hydraulic breaker further includes a lower cylinder connected to the lower end of the middle cylinder and a chisel inserted into the lower cylinder, wherein the bottom end of the piston rod extends into the lower cylinder and can strike the top of the chisel.

[0021] A second aspect of the present invention provides an engineering machine comprising the aforementioned hydraulic breaker.

[0022] Through the above technical solution, the hydraulic breaker of the present invention can control the piston rod to reciprocate along an initial stroke under the action of a continuous reversing circuit. When it is necessary to adjust the impact frequency, the switching timing of the main control hydraulic reversing valve in the continuous reversing circuit is changed by triggering the frequency conversion trigger oil circuit. The piston rod can switch to downward movement when it moves upward but has not reached the initial critical position for switching between upward and downward movement, or when it has exceeded the initial critical position for switching between upward and downward movement. Overall, the piston rod reciprocates along a non-initial stroke, thereby achieving automatic adjustment of the impact frequency. Compared with the traditional method of adjusting the impact frequency by changing the return oil back pressure of the breaker using a manual regulating valve, the hydraulic breaker of the present invention has a much wider adjustment range, making it suitable for different crushing conditions. It eliminates the need for re-matching and selecting the hydraulic breaker, avoiding resource waste, increasing crushing workload, and improving work efficiency.

[0023] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0025] Figure 1 This is a schematic diagram illustrating the working principle of a hydraulic breaker according to a specific embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of a hydraulic breaker according to a specific embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the middle cylinder of a hydraulic breaker according to a specific embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of a transition valve block of a hydraulic breaker and a three-position four-way directional valve integrated on the transition valve block, according to a specific embodiment of the present invention.

[0029] Figure 5 for Figure 4 A schematic diagram of the valve core of a three-position four-way directional valve.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Cylinder block 2. Piston rod

[0032] 3. Main control hydraulic directional valve; 4. Three-position four-way directional valve

[0033] 5. One-way valve; 6. Transition valve block

[0034] 7 upper cylinder block 8 lower cylinder block

[0035] 9-pin

[0036] 11. Upper cavity of cylinder block; 12. Lower cavity of cylinder block

[0037] 13 Upper chamber inlet / outlet switching port; 14 Lower chamber return port.

[0038] 15 Initial design of the stroke oil inlet 16 First variable stroke oil inlet

[0039] 17 Second variable stroke oil port 18 Lower chamber oil inlet

[0040] L1 is initially designed as the stroke trigger oil circuit, and L2 is the first oil inlet branch.

[0041] L3 Second Inlet Branch, L4 Drain Branch

[0042] L5 Downward Return Oil Circuit

[0043] P hydraulic breaker inlet, T hydraulic breaker outlet.

[0044] K1 First Control Port K2 Second Control Port Detailed Implementation

[0045] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0047] In the embodiments of the present invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used to describe the relative positional relationships of the components in relation to the directions shown in the accompanying drawings or in relation to the vertical, perpendicular, or gravitational directions.

[0048] The present invention will now be described in detail with reference to the accompanying drawings and exemplary embodiments.

[0049] Reference Figures 1 to 5 The first exemplary embodiment of the present invention provides a hydraulic breaker, which includes a central cylinder 1, a piston rod 2, a continuous reversing circuit and a frequency conversion triggering oil circuit.

[0050] Specifically, the piston rod 2 is located inside the middle cylinder 1.

[0051] A continuous reversing circuit is installed between the hydraulic breaker's inlet P, return port T, and the intermediate cylinder 1. External hydraulic oil can enter the intermediate cylinder 1 through the hydraulic breaker's inlet P and the continuous reversing circuit. Hydraulic oil inside the intermediate cylinder 1 can be discharged from the hydraulic breaker through the continuous reversing circuit and the hydraulic breaker's return port T. Under the action of the continuous reversing circuit, a pressure difference can be formed between the upper and lower parts of the piston rod 2 to control the piston rod 2 to move upward or downward. When the piston rod 2 moves upward to the initially set critical position for switching between upward and downward movement, the oil circuit in the continuous reversing circuit introduces the hydraulic oil in the intermediate cylinder 1 into the hydraulic control end of the main control hydraulic reversing valve 3, causing the main control hydraulic reversing valve 3 to switch its working valve position, thereby causing the piston rod 2 to change from upward to downward movement. Overall, the piston rod 2 reciprocates with the initially set stroke. The initially set stroke is the stroke of the piston rod 2 when the frequency converter trigger oil circuit is not connected to the intermediate cylinder 1 and the continuous reversing circuit, and is preset manually.

[0052] The variable frequency triggering oil circuit is set between the continuous reversing circuit and the middle cylinder 1. It can introduce the hydraulic oil in the middle cylinder 1 into the hydraulic control end of the main control hydraulic reversing valve 3 of the continuous reversing circuit in advance or in advance, so that the main control hydraulic reversing valve 3 switches the working valve position in advance or in advance, thereby causing the piston rod 2 to change from upward to downward. Overall, the piston rod 2 reciprocates with a non-initial stroke.

[0053] For example, if the stroke of piston rod 2 is to be shortened (i.e., the striking frequency is to be increased), the frequency conversion triggering oil circuit can connect the hydraulic control end of the middle cylinder 1 and the main control hydraulic directional valve 3 before the piston rod 2 moves up to the initially set critical position for switching between upward and downward movement. This will trigger the main control hydraulic directional valve 3 to switch the working valve position in advance, so that the piston rod 2 changes from upward to downward movement in advance. Overall, the piston rod 2 will reciprocate with a stroke shorter than the initially set stroke.

[0054] To increase the stroke of piston rod 2 (i.e., reduce the striking frequency), when piston rod 2 moves upward to the initially set critical position for switching between upward and downward movement, the oil circuit in the continuous reversing circuit can be de-connected to the hydraulic control terminal of the main hydraulic directional valve 3. At this time, the main hydraulic directional valve 3 cannot be triggered to switch its working position temporarily, and piston rod 2 can continue to move upward. When piston rod 2 continues to move upward to a position exceeding the initially set critical position for switching between upward and downward movement, the middle cylinder 1 is then connected to the hydraulic control terminal of the main hydraulic directional valve 3 through the frequency conversion trigger oil circuit, that is, the triggering of the main hydraulic directional valve 3 to switch its working position is delayed, so that piston rod 2 changes from upward to downward movement delayed. Overall, piston rod 2 reciprocates with a stroke greater than the initially set stroke.

[0055] It can be seen that the variable frequency triggering oil circuit is used to trigger the change of the switching timing of the main control hydraulic directional valve 3 in the continuous switching circuit, that is, the switching timing is advanced or delayed, so as to adjust the piston rod 2 to reciprocate with a non-initial stroke and realize the adjustment of the striking frequency.

[0056] It is understandable that by adjusting the position of the piston rod 2 to activate the hydraulic control end of the variable frequency trigger oil circuit, the switching timing of the main hydraulic directional valve 3 can be directly determined by how much it should be advanced or delayed. This allows for a wide range of adjustment of the piston rod 2's stroke, which is equivalent to a wide range of adjustment of the striking frequency.

[0057] Compared to the traditional method of manually adjusting the back pressure of the hydraulic breaker to change the impact frequency, the hydraulic breaker of this exemplary embodiment has a much wider adjustment range, making it suitable for different crushing conditions. It eliminates the need for re-matching and selecting the hydraulic breaker, avoids resource waste, increases crushing workload, and improves work efficiency.

[0058] In one embodiment, the cylinder body 1 has an upper cavity 11 and a lower cavity 12 formed within it, separated by an annular flange on the peripheral wall of the piston rod 2, and capable of generating a pressure difference under the action of a continuous reversing circuit. Under the pressure difference between the upper cavity 11 and the lower cavity 12, the piston rod 2 is pushed upwards or downwards. The main control hydraulic reversing valve 3 includes an upward working valve position and a downward working valve position, for example... Figure 1The main hydraulic directional valve 3 has two working positions, the upper working position and the lower working position, respectively. The peripheral wall of the cylinder 1 has a vertically arranged initial stroke port 15 and at least one variable stroke port that connect to the lower chamber 12 of the cylinder. With only one variable stroke port, the impact frequency of the hydraulic breaker can be adjusted in two stages; with multiple variable stroke ports, the impact frequency can be adjusted in multiple stages. Furthermore, the continuous directional control circuit includes an initial stroke triggering circuit L1. The initial stroke triggering circuit L1 is located between the initial stroke port 15 and the hydraulic control end of the lower working position, while the variable stroke triggering circuit is located between the variable stroke port and the hydraulic control end of the lower working position. During the upward movement of the piston rod 2, the lower chamber 12 of the cylinder can be connected to the hydraulic control end of the lower working position of the main hydraulic directional valve 3 through one of the stroke ports and the corresponding triggering circuit, thereby causing the piston rod 2 to reciprocate with a corresponding stroke.

[0059] For example, when the piston rod 2 moves upward to the point where the lower chamber 12 of the middle cylinder is connected to the initial stroke port 15, the hydraulic oil in the lower chamber 12 of the middle cylinder can be introduced into the hydraulic control end of the downward working valve position of the main control hydraulic directional valve 3 through the initial stroke port 15 and the initial stroke trigger oil circuit L1, thereby triggering the main control hydraulic directional valve 3 to switch from the upward working valve position to the downward working valve position, so that the piston rod 2 changes from upward to downward. Overall, the piston rod 2 reciprocates with the initial stroke.

[0060] When the piston rod 2 moves upward to the point where the lower chamber 12 of the middle cylinder is connected to any one of the variable stroke ports, the hydraulic oil in the lower chamber 12 of the middle cylinder can be introduced into the hydraulic control end of the downward working valve position of the main control hydraulic directional valve 3 through the variable stroke port and the frequency conversion trigger oil circuit. This triggers the main control hydraulic directional valve 3 to switch from the upward working valve position to the downward working valve position, causing the piston rod 2 to change from upward to downward. Overall, the piston rod 2 reciprocates with the corresponding stroke (not the initial stroke).

[0061] In one embodiment, the variable stroke port includes a first variable stroke port 16 and a second variable stroke port 17. For example, initially, the stroke port 15, the first variable stroke port 16, and the second variable stroke port 17 can be arranged sequentially from top to bottom. The frequency conversion triggering oil circuit includes a three-position four-way directional valve 4 with O-type neutral position function, a first oil inlet branch L2, a second oil inlet branch L3, and an oil outlet branch L4. The first variable stroke port 16 is connected sequentially to the hydraulic control terminal of the downward working position of the main control hydraulic directional valve 3 through the first oil inlet branch L2, the three-position four-way directional valve 4, and the oil outlet branch L4. The second variable stroke port 17 is connected sequentially to the hydraulic control terminal of the downward working position of the main control hydraulic directional valve 3 through the second oil inlet branch L3, the three-position four-way directional valve 4, and the oil outlet branch L4. That is, the connection between the first variable stroke port 16 and the second variable stroke port 17 and the hydraulic control end of the downward working valve position of the main control hydraulic directional valve 3 is achieved through the same oil discharge branch L4.

[0062] For example, refer to Figure 1 When the three-position four-way directional valve 4 is in the middle position, even if the first variable stroke port 16 or the second variable stroke port 17 is connected to the lower chamber 12 of the cylinder block, the hydraulic oil in the lower chamber 12 of the cylinder block cannot be introduced into the hydraulic control terminal of the downward working position of the main control hydraulic directional valve 3 through the three-position four-way directional valve 4 and the drain branch L4. When the three-position four-way directional valve 4 is in the left position, the hydraulic oil in the lower chamber 12 of the cylinder block can be introduced into the hydraulic control terminal of the downward working position of the main control hydraulic directional valve 3 through the first variable stroke port 16, the first inlet branch L2, the three-position four-way directional valve 4, and the drain branch L4. When the three-position four-way directional valve 4 is in the right position, the hydraulic oil in the lower chamber 12 of the cylinder block can be introduced into the hydraulic control terminal of the downward working position of the main control hydraulic directional valve 3 through the second variable stroke port 17, the second inlet branch L3, the three-position four-way directional valve 4, and the drain branch L4.

[0063] In this embodiment, the striking frequency of the hydraulic breaker can be adjusted in three levels.

[0064] In one embodiment, a check valve 5 is provided in the initial stroke triggering oil circuit L1. When the piston rod 2 moves upward to the point where the lower chamber 12 of the middle cylinder is connected to the initial stroke oil port 15, the hydraulic oil in the lower chamber 12 of the middle cylinder can enter the initial stroke triggering oil circuit L1 through the initial stroke oil port 15 and open the check valve 5, allowing the hydraulic oil to be introduced into the hydraulic control terminal of the downward working valve position of the main control hydraulic directional valve 3 through the initial stroke triggering oil circuit L1. Further, one end of the oil discharge branch L4 is connected to the three-position four-way directional valve 4 and the other end is connected to the portion of the initial stroke triggering oil circuit L1 located between the check valve 5 and the hydraulic control terminal of the downward working valve position.

[0065] In one embodiment, the three-position four-way directional valve 4 is a hydraulic pilot directional valve and is provided with control ports K1 and K2 for controlling the pilot pressure.

[0066] Reference Figure 1 Hydraulic oil is input through K1, and the three-position four-way directional valve 4 can be switched to the left valve position. When the piston rod 2 moves upward to make the lower chamber 12 of the middle cylinder connect with the first variable stroke oil port 16, the hydraulic oil in the lower chamber 12 of the middle cylinder can be introduced into the hydraulic control end of the downward working valve position of the main control hydraulic directional valve 3 through the first variable stroke oil port 16, the first oil inlet branch L2, the three-position four-way directional valve 4 and the oil outlet branch L4.

[0067] Hydraulic oil is input through K2, and the three-position four-way directional valve 4 can be switched to the right valve position. When the piston rod 2 moves upward to make the lower chamber 12 of the middle cylinder connect with the second variable stroke port 17, the hydraulic oil in the lower chamber 12 of the middle cylinder can be introduced into the hydraulic control end of the downward working valve position of the main control hydraulic directional valve 3 through the second variable stroke port 17, the second oil inlet branch L3, the three-position four-way directional valve 4 and the oil outlet branch L4.

[0068] In one embodiment, the hydraulic breaker includes a transition valve block 6, and a hydraulic pilot directional valve can be integrated in the transition valve block 6. Accordingly, control ports K1 and K2 are opened on the outer wall of the transition valve block 6 to simplify the structural arrangement of the hydraulic breaker.

[0069] In one embodiment, the peripheral wall of the cylinder block 1 has a lower chamber return port 14, and the continuous reversing circuit includes a downward return oil passage L5 with its two ends connected to the lower chamber return port 14 and the breaker return oil passage T, respectively. When the lower chamber 12 of the cylinder block is connected to the hydraulic control end of the downward working valve position through one of the stroke oil ports and the corresponding trigger oil passage, the lower chamber return port 14 is connected to the lower chamber 12 of the cylinder block, so that during the downward movement of the piston rod 2, the lower chamber 12 of the cylinder block can be depressurized through the lower chamber return port 14, the downward return oil passage L5, and the breaker return oil passage T.

[0070] In one embodiment, the peripheral wall of the middle cylinder 1 is formed with an upper cavity inlet / outlet switching oil port 13 communicating with the upper cavity 11 of the middle cylinder and a lower cavity inlet 18 communicating with the lower cavity 12 of the middle cylinder. The lower cavity inlet 18 is kept in communication with the breaker inlet P. The upper cavity inlet / outlet switching oil port 13 can be selectively connected to one of the breaker inlet P and the breaker return port T through the main control hydraulic directional valve 3.

[0071] During the upward movement of piston rod 2, the upper chamber inlet / outlet switching port 13 is connected to the breaker return port T through the main control hydraulic directional valve 3, so that the upper chamber 11 of the middle cylinder can be depressurized through the upper chamber inlet / outlet switching port 13, the main control hydraulic directional valve 3 and the breaker return port T.

[0072] When the upper chamber inlet / outlet switching port 13 is connected to the hydraulic breaker inlet port P through the main control hydraulic directional valve 3, hydraulic oil is introduced from the upper chamber inlet / outlet switching port 13 into the upper chamber 11 of the middle cylinder, making the pressure in the upper chamber 11 of the middle cylinder greater than the pressure in the lower chamber 12 of the middle cylinder, thereby pushing the piston rod 2 downward.

[0073] In one embodiment, the hydraulic breaker further includes an upper cylinder 7 connected to the upper end of the middle cylinder 1. A nitrogen chamber is formed inside the upper cylinder 7, and the tip of the piston rod 2 extends into the nitrogen chamber. During the upward movement of the piston rod 2, its tip compresses the nitrogen gas in the nitrogen chamber, causing the nitrogen chamber to store energy. During the downward movement of the piston rod 2, the high-pressure nitrogen gas in the nitrogen chamber can exert a downward thrust on the piston rod 2.

[0074] In one embodiment, the hydraulic breaker also includes a lower cylinder 8 connected to the lower end of the middle cylinder 1 and a chisel 9 inserted into the lower cylinder 8. The bottom end of the piston rod 2 extends into the lower cylinder 8 and can strike the top of the chisel 9 when the piston rod 2 moves downward. Through the reciprocating motion of the piston rod 2, the chisel 9 can continuously impact the stone, thereby achieving the crushing function.

[0075] A second exemplary embodiment of the present invention provides an engineering machine that includes the aforementioned hydraulic breaker. For example, the engineering machine may be an excavator, and its internal hydraulic system is capable of providing hydraulic energy to the hydraulic breaker. Clearly, the engineering machine of this exemplary embodiment possesses all the technical effects brought about by the aforementioned hydraulic breaker, and therefore will not be elaborated further here.

[0076] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0077] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the embodiments of the present invention will not describe the various possible combinations separately.

[0078] Furthermore, various different implementations of the present invention can be combined arbitrarily, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed in the present invention.

Claims

1. A hydraulic breaker, characterized in that, The hydraulic breaker includes: Cylinder block (1); Piston rod (2) is disposed inside the middle cylinder body (1); A continuous reversing circuit is provided between the breaker's oil inlet (P), the breaker's oil return port (T), and the middle cylinder (1), and is capable of controlling the piston rod (2) to reciprocate at an initial stroke; and The variable frequency triggering oil circuit is set between the continuous reversing circuit and the middle cylinder (1). The variable frequency triggering oil circuit can trigger the main control hydraulic reversing valve (3) in the continuous reversing circuit to change the reversing timing so as to adjust the piston rod (2) to reciprocate with a non-initial stroke. The middle cylinder (1) has an upper cavity (11) and a lower cavity (12) that are separated by the annular flange of the piston rod (2) and can generate a pressure difference under the action of the continuous reversing circuit. The main control hydraulic reversing valve (3) includes an upward working valve position and a downward working valve position. The peripheral wall of the middle cylinder (1) has a preliminary stroke oil port (15) and at least one variable stroke oil port that are arranged vertically and can connect to the lower cavity (12). The continuous reversing circuit includes a preliminary stroke trigger oil circuit (L1). The initial stroke triggering oil circuit (L1) is located between the initial stroke oil port (15) and the hydraulic control end of the downward working valve position, and the variable frequency triggering oil circuit is located between the variable stroke oil port and the hydraulic control end of the downward working valve position. During the upward movement of the piston rod (2), the lower chamber (12) of the middle cylinder can be connected to the hydraulic control end of the downward working valve position through one of the stroke oil ports and the corresponding triggering oil circuit. The hydraulic breaker also includes an upper cylinder (7) connected to the upper end of the middle cylinder (1), and a nitrogen chamber is formed inside the upper cylinder (7), with the top end of the piston rod (2) extending into the nitrogen chamber.

2. The hydraulic breaker according to claim 1, characterized in that, The variable stroke port includes a first variable stroke port (16) and a second variable stroke port (17). The frequency conversion triggering oil circuit includes a three-position four-way directional valve (4) with O-type neutral position function, a first oil inlet branch (L2), a second oil inlet branch (L3), and an oil outlet branch (L4). The first variable stroke port (16) is connected to the hydraulic control end of the downward working valve position in sequence through the first oil inlet branch (L2), the three-position four-way directional valve (4), and the oil outlet branch (L4). The second variable stroke port (17) is connected to the hydraulic control end of the downward working valve position in sequence through the second oil inlet branch (L3), the three-position four-way directional valve (4), and the oil outlet branch (L4).

3. The hydraulic breaker according to claim 2, characterized in that, The initial stroke port (15), the first variable stroke port (16), and the second variable stroke port (17) are arranged sequentially from top to bottom.

4. The hydraulic breaker according to claim 3, characterized in that, The initial stroke triggering oil circuit (L1) is equipped with a check valve (5). One end of the oil discharge branch (L4) is connected to the three-position four-way directional valve (4), and the other end is connected to the part of the initial stroke triggering oil circuit (L1) located between the check valve (5) and the hydraulic control end of the downward working valve position.

5. The hydraulic breaker according to claim 2, characterized in that, The three-position four-way directional valve (4) is a hydraulic pilot directional valve and is provided with control ports (K1, K2) for controlling the pilot pressure.

6. The hydraulic breaker according to claim 5, characterized in that, The hydraulic breaker includes a transition valve block (6), the hydraulic pilot directional valve is integrated in the transition valve block (6), and the control ports (K1, K2) are opened on the outer wall of the transition valve block (6).

7. The hydraulic breaker according to claim 1, characterized in that, The peripheral wall of the middle cylinder (1) is formed with a lower cavity return port (14). The continuous reversing circuit includes a downward return oil passage (L5) with both ends connected to the lower cavity return port (14) and the breaker return port (T). When the lower cavity (12) of the middle cylinder is connected to the hydraulic control end of the downward working valve position through one of the stroke oil ports and the corresponding trigger oil passage, the lower cavity return port (14) is connected to the lower cavity (12) of the middle cylinder.

8. The hydraulic breaker according to claim 1, characterized in that, The peripheral wall of the middle cylinder (1) has an upper cavity inlet / outlet switching oil port (13) that communicates with the upper cavity (11) of the middle cylinder and a lower cavity inlet (18) that communicates with the lower cavity (12) of the middle cylinder. The lower cavity inlet (18) is connected to the breaker inlet (P). The upper cavity inlet / outlet switching oil port (13) can be selectively connected to one of the breaker inlet (P) and the breaker return port (T) through the main control hydraulic directional valve (3).

9. The hydraulic breaker according to claim 1, characterized in that, The hydraulic breaker also includes a lower cylinder (8) connected to the lower end of the middle cylinder (1) and a chisel (9) inserted into the lower cylinder (8). The bottom end of the piston rod (2) extends into the lower cylinder (8) and can strike the top of the chisel (9).

10. An engineering machinery, characterized in that, The engineering machinery includes a hydraulic breaker as described in any one of claims 1 to 9.

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