Vibration absorption device and rock drill

Abstract

The vibration absorption device comprises a shell and a buffer piston which are coaxially arranged, the buffer piston is sleeved with the shell, and the vibration absorption device further comprises at least two buffer cavities, an oil inlet way and a balance valve which are distributed on the periphery of the buffer piston at intervals in the axial direction; the oil inlet path is arranged on the shell and is communicated with at least one buffer cavity; the buffer cavities are communicated through the balance valves, the balance valves are used for changing the communication relation between the buffer cavities according to the pressure difference between the buffer cavities, the buffer cavities can be communicated in time, the buffer cavities needing oil supplementing are subjected to oil supplementing, sudden pressure drop of the cavities is avoided, and the phenomena of negative pressure and cavitation are avoided. Damage to parts in the rock drill is reduced, and the vibration absorption effect is improved. The second aspect provides a rock drill comprising the vibration absorption device in the first aspect, an impact piston coaxially arranged in the buffer piston in a sliding mode, a bit shank coaxially arranged on the front side of the impact piston, and a plug buffer spacer bush arranged on the impact piston in a sleeving mode and located between the buffer piston and the bit shank.

Description

Technical Field

[0001] This application relates to the field of rock drill technology, specifically to a vibration absorption device and a rock drill. Background Technology

[0002] Rock drilling rigs are widely used in various working conditions such as rock mining and tunnel excavation. As a key core component of the rig, hydraulic rock drills have become the preferred choice for rock drilling equipment due to their high efficiency and environmental friendliness, which also places higher demands on the design of rock drills. During rock drilling operations, energy rebound is inevitable. This rebound force is transmitted to the inside of the rock drill in the form of waves through the drill bit, which can easily cause damage to the internal components of the rock drill and increase the consumption of drill bit components.

[0003] In existing technology, vibration damping devices are installed inside rock drills to absorb rebound energy. However, if there are multiple buffer chambers in the vibration damping device, the pressure in each buffer chamber will change accordingly because the buffer piston in the vibration damping device will move axially. In most existing vibration damping devices, only one oil inlet is set up, connecting only one buffer chamber. The other buffer chambers are connected to each other through the gap between the buffer piston and the housing. During the buffer piston reset phase, the oil replenishment of the other buffer chambers that are not directly connected to the oil inlet will be delayed, causing a sudden drop in chamber pressure, or even negative pressure. This can easily lead to cavitation of the oil, damaging the components and affecting the service life and operating cost of the rock drill.

[0004] Therefore, there is room for further improvement in the vibration absorption devices of existing rock drills. Utility Model Content

[0005] In view of this, and addressing the technical problem in the prior art where the oil replenishment in the buffer chamber of the vibration damping device of the rock drill is not timely, leading to a sudden drop in pressure within the chamber, or even negative pressure, which easily causes cavitation of the oil and damages the components, this application provides a vibration damping device and a rock drill. The vibration damping device is equipped with a balance valve between the buffer chambers, which can replenish the oil in the buffer chamber in a timely manner, avoid a sudden drop in pressure within the chamber, avoid negative pressure and cavitation, and reduce damage to the components inside the rock drill.

[0006] In a first aspect, this application provides a vibration-absorbing device for use in a rock drill, comprising a housing and a buffer piston arranged coaxially, wherein the housing is sleeved outside the buffer piston, and further comprising:

[0007] At least two buffer chambers are spaced apart along the outer periphery of the buffer piston in the axial direction;

[0008] An oil inlet passage is located on the housing and is connected to at least one buffer chamber;

[0009] A balancing valve is provided, through which the buffer chambers are connected. The balancing valve is used to change the connection relationship between the buffer chambers according to the pressure difference between them.

[0010] The balance valve is provided with at least two balance oil chambers, and each buffer chamber is connected to one balance oil chamber.

[0011] Compared with the prior art, the vibration absorption device of this application is equipped with a balance valve. All buffer chambers are connected through the balance valve. The balance valve can open and close accordingly according to the pressure changes between the buffer chambers, changing the connection between the buffer chambers. This allows the buffer chambers to be connected in a timely manner, and oil can be replenished to the buffer chambers that need oil replenishment. This avoids a sudden drop in chamber pressure, avoids negative pressure and cavitation, reduces damage to the internal parts of the rock drill, and improves the vibration absorption, buffering, and braking effects.

[0012] Preferably, the balancing valve includes a valve body and a movable valve, and the valve body is provided with a balancing chamber;

[0013] The movable valve is slidably disposed in the balance chamber along the first direction to divide the balance chamber into a primary balance oil chamber and a secondary balance oil chamber. The movable valve is used to adjust the connection between the primary balance oil chamber and the secondary balance oil chamber.

[0014] The buffer chamber is configured as two chambers, namely a primary buffer chamber and a secondary buffer chamber. The primary buffer chamber is connected to the oil inlet circuit; the primary buffer chamber is connected to the primary balancing oil chamber; and the secondary buffer chamber is connected to the secondary balancing oil chamber.

[0015] In this embodiment, by setting two buffer chambers, two-stage braking can be achieved, improving the vibration absorption and buffer braking effect of the vibration absorption device; the movable valve is set in the balance chamber, dividing the balance chamber into a primary balance oil chamber and a secondary balance oil chamber. It can move in the balance chamber along the first reverse direction, thereby changing the area of ​​the primary balance oil chamber and the secondary balance oil chamber, and also changing the connection relationship between the buffer chambers, so as to replenish the oil in time.

[0016] Preferably, the valve body is provided with a signal oil passage, and the primary balance oil chamber and the secondary balance oil chamber are connected through the signal oil passage, and the secondary balance oil chamber and the signal oil passage are normally connected;

[0017] The movable valve is used to adjust the connection between the primary balance oil chamber and the signal oil passage.

[0018] In this embodiment, the signal oil passage works in conjunction with the movable valve to respond promptly, thereby changing the connection between the primary and secondary balance oil chambers and ensuring the accuracy of the balance valve control.

[0019] Preferably, the housing is provided with a primary balance oil passage and a secondary balance oil passage, the primary buffer chamber is connected to the primary balance oil passage, and the secondary buffer chamber is connected to the secondary balance oil passage;

[0020] The valve body is provided with a first channel and a second channel. The first-stage balance oil passage is connected to the first-stage balance oil chamber through the first channel, and the second-stage balance oil passage is connected to the signal oil passage through the second channel.

[0021] In this embodiment, the balancing oil passage can be independently connected to the buffer chamber and the corresponding balancing chamber, ensuring the accuracy of the balancing valve control.

[0022] Preferably, the balancing cavity includes a first sidewall and a second sidewall perpendicular to the first direction, and a third sidewall and a fourth sidewall parallel to the first direction, wherein the first sidewall is adjacent to the third sidewall, and the third sidewall is disposed close to the housing;

[0023] The first channel opens on the first sidewall of the balancing cavity;

[0024] The signal oil passage includes a first oil port, a second oil port, and a third oil port. The first oil port opens on the third side wall, the second oil port is connected to the secondary balance oil passage, and the third oil port opens on the second side wall.

[0025] In this embodiment, this configuration can shorten the flow path of the oil between the housing and the balance valve, and ensure that the balance valve can achieve oil balance between the buffer chambers.

[0026] Preferably, the length of the movable valve in the first direction is b, the length of the third sidewall is s, and the distance between the first oil port and the first sidewall is b;

[0027] Where, sa > b.

[0028] In this embodiment, the balancing valve can function normally.

[0029] Preferably, the valve housing is further provided with an activation chamber, which is distributed on both sides of the balance chamber along the first direction, and the activation chamber is in communication with the balance chamber;

[0030] In the first direction, the length of the starting cavity is less than that of the balancing cavity, so as to form a limiting step on the first sidewall and the second sidewall.

[0031] In this embodiment, the starting chamber ensures that the balance valve still has sufficient oil contact area at both the opening and closing positions, guaranteeing normal operation during opening and closing.

[0032] Preferably, the active valve includes a first valve body and a second valve body, the first valve body and the second valve body being distributed along a first direction;

[0033] In the direction perpendicular to the first direction, the width of the first valve body is smaller than the width of the second valve body and smaller than the width of the starting chamber;

[0034] The width of the second valve body is less than or equal to the width of the balance chamber, and greater than the length of the start chamber.

[0035] In this embodiment, this configuration satisfies the requirement for the formation of the difference in opening and closing forces of the balancing valve.

[0036] Preferably, the valve housing is provided with a movable cavity, the movable cavity is connected to the balance cavity, the first valve body is slidably disposed in the movable cavity along the first direction, and the width of the movable cavity perpendicular to the first direction is smaller than that of the balance cavity;

[0037] In the direction perpendicular to the first direction, the width of the active cavity is smaller than that of the balance cavity, and the width of the first valve body is less than or equal to the width of the active cavity;

[0038] In the first direction, the length of the first valve body is c, and the length of the movable cavity is d, where c > d + sb.

[0039] In this embodiment, this configuration ensures the normal operation of the balancing valve.

[0040] Secondly, this application provides a rock drill, including the vibration absorption device described in any embodiment of the first aspect, and further comprising:

[0041] The impact piston is coaxially and slidingly disposed within the buffer piston.

[0042] The drill bit is coaxially positioned on the front side of the impact piston.

[0043] The buffer sleeve is fitted onto the impact piston and is located between the buffer piston and the drill bit.

[0044] In this embodiment, the rock drill can replenish the oil in the buffer chamber in a timely manner through the vibration absorption device, so as to avoid a sudden drop in pressure in the chamber, avoid negative pressure and cavitation, and reduce damage to the internal components of the rock drill. Attached Figure Description

[0045] Figure 1 This is a cross-sectional structural schematic diagram of a vibration absorption device provided in an embodiment of this application;

[0046] Figure 2 This is a cross-sectional structural schematic diagram of a balance valve provided in an embodiment of this application;

[0047] Figure 3 This is a schematic diagram of the partial motion state of the vibration absorption device provided in one embodiment of this application. Figure 1 ;

[0048] Figure 4 This is a schematic diagram of the partial motion state of the vibration absorption device provided in one embodiment of this application. Figure 2 .

[0049] Reference numerals: 1. Housing; 2. Buffer piston; 3. Balance valve; 4. Rod tail; 5. Buffer sleeve; 6. Impact piston; 7. Primary buffer chamber; 8. Secondary buffer chamber;

[0050] 11. Oil inlet passage; 12. Primary balance oil passage; 13. Secondary balance oil passage;

[0051] 31. Valve housing; 32. Moving valve;

[0052] 31.0 Primary Balance Oil Chamber; 31.1 Secondary Balance Oil Chamber; 31.2 Signal Oil Passage; 31.3 Starting Chamber; 31.4 Movable Chamber; 31.5 First Channel; 31.6 Second Channel; 31.7 First Side Wall; 31.8 Second Side Wall; 31.9 Third Side Wall; 31.10 Fourth Side Wall; 31.11 First Oil Port; 31.12 Second Oil Port; 31.13 Third Oil Port;

[0053] 32.0 First valve body; 32.1 Second valve body. Detailed Implementation

[0054] To enable those skilled in the art to better understand the technical solutions of this disclosure, the following detailed, clear, and complete description of this disclosure is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this disclosure and are not intended to limit it.

[0055] In the description of this application, the use of "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0056] Those skilled in the art should understand that in the disclosure of this application, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this application.

[0057] The present application will now be described in further detail with reference to the accompanying drawings, see below. Figures 1 to 4 illustrate.

[0058] First aspect

[0059] This application provides a vibration-absorbing device that is used in the impact structure of a rock drill to absorb and buffer the vibration of the rock drill's impact structure. The vibration-absorbing device can absorb the rebound force generated by the drill bit, thereby reducing the damage to the inside of the rock drill caused by the rebound force and improving the service life of the rock drill and drill bit.

[0060] Specifically, such as Figures 1 to 2 As shown, the vibration damping device includes a housing 1, a buffer piston 2, and a balance valve 3. The housing 1 is sleeved outside the buffer piston 2, which is axially displaceable within the housing 1. The buffer piston 2 and the housing 1 are coaxially arranged, forming at least two buffer chambers capable of containing oil between the buffer piston 2 and the housing 1. The buffer chambers are axially spaced on the outer periphery of the buffer piston 2. The housing 1 is provided with an oil inlet passage 11, which is radially arranged and has openings on the inner and outer walls of the housing 1. The oil inlet passage 11 is normally connected to one of the buffer chambers for supplying oil to the buffer chamber. The balance valve 3... Externally mounted on the housing 1, the balance valve 3 has at least two balance oil chambers. Each buffer chamber is connected to a corresponding balance oil chamber, meaning that all buffer chambers are connected through the balance valve 3. The balance valve 3 can change the connection relationship between the balance oil chambers according to the pressure difference between the connected buffer chambers, thereby opening or closing accordingly. This allows for timely replenishment of oil to buffer chambers that are not directly connected to the oil inlet circuit 11, thus balancing the pressure difference between the buffer chambers in a timely manner, preventing a sudden drop in pressure within the chambers, avoiding negative pressure and cavitation, and reducing damage to the internal components of the rock drill.

[0061] Among them, the oil inlet passage 11 is connected to the buffer cavity closest to the drill bit 4.

[0062] Furthermore, the balancing valve 3 is described in more detail; such as Figures 1 to 2 As shown, the balance valve 3 includes a valve housing 31 and a movable valve 32. The valve housing 31 has a balance chamber. The movable valve 32 is slidably disposed in the balance chamber along a first direction, which is parallel to the axial displacement direction of the buffer piston 2. The movable valve 32 is used to divide the balance chamber into a primary balance oil chamber 31.0 and a secondary balance oil chamber 31.1. The primary balance oil chamber 31.0 and the secondary balance oil chamber 31.1 are located on the left and right sides of the movable valve 32, respectively. When the movable valve 32 moves along the first direction, it can change the volume of the primary balance oil chamber 31.0 and the secondary balance oil chamber 31.1, but the total volume of the primary balance oil chamber 31.0 and the secondary balance oil chamber 31.1 remains unchanged.

[0063] like Figure 1As shown, there are two buffer chambers: a primary buffer chamber 7 and a secondary buffer chamber 8. The primary buffer chamber 7 is located axially in front of the secondary buffer chamber 8 and is connected to the oil inlet passage 11. The primary buffer chamber 7 is connected to the primary balancing oil chamber 31.0, and the secondary buffer chamber 8 is connected to the secondary balancing oil chamber 31.1. When the movable valve 32 moves in the first direction, it can change the connection between the primary balancing oil chamber 31.0 and the secondary balancing oil chamber 31.1, thereby changing the connection between the primary buffer chamber 7 and the secondary buffer chamber 8. This allows the oil in the primary buffer chamber 7 to be promptly transferred to the secondary buffer chamber 8 to replenish the oil in the secondary buffer chamber 8 and prevent a sudden drop in pressure in the secondary buffer chamber 8, which could lead to low-pressure cavitation.

[0064] It should be noted that the buffer piston 2 has two corresponding working surfaces, which are respectively matched with the primary buffer chamber 7 and the secondary buffer chamber 8.

[0065] Furthermore, such as Figure 1 , Figure 2 As shown, the valve housing 31 is provided with a signal oil passage 31.2. The primary balance oil chamber 31.0 and the secondary balance oil chamber 31.1 are connected through the signal oil passage 31.2, and the secondary balance oil chamber 31.1 and the signal oil passage 31.2 are normally open. When the movable valve 32 moves along the first direction, when the movable valve 32 moves to the corresponding position, it can open the connection between the signal oil passage 31.2 and the primary balance oil chamber 31.0, thereby realizing the connection between the primary balance oil chamber 31.0 and the secondary balance oil chamber 31.1. Through the signal oil passage 31.2, the oil in the primary buffer chamber 7 can be guided to the secondary buffer chamber 8. This allows the movable valve 32 to move in a timely manner, with the cooperation of the signal oil passage 31.2, to open or close the connection between the primary balance oil chamber 31.0 and the secondary balance oil chamber 31.1. This means that the connection between the primary and secondary buffer oil chambers can be opened or closed in a timely manner, thereby replenishing the secondary buffer chamber 8 with oil in a timely manner and preventing a sudden drop in pressure in the secondary buffer chamber 8 that could lead to low-pressure cavitation.

[0066] Among them, such as Figures 1 to 2 As shown, the housing 1 is provided with a primary balance oil passage 12 and a secondary balance oil passage 13. The primary balance oil passage 12 and the secondary balance oil passage 13 are distributed axially at intervals and extend almost radially. One end of the primary balance oil passage 12 is open on the outer wall of the housing 1, and the other end is open on the inner wall of the cavity of the housing 1. The primary balance oil passage 12 is connected to the primary buffer cavity 7. One end of the secondary balance oil passage 13 is open on the outer wall of the housing 1, and the other end is open on the inner wall of the cavity of the housing 1. The secondary balance oil passage 13 is connected to the secondary buffer cavity 8.

[0067] Correspondingly, the valve housing 31 is provided with a first channel 31.5 and a second channel 31.6. Both the first channel 31.5 and the second channel 31.6 are open on the outer wall of the valve housing 31. One end of the first channel 31.5 is connected to the first-stage balance oil chamber 31.0, and the other end of the first channel 31.5 is connected to the first-stage balance oil passage 12, so that the first-stage balance oil passage 12 is connected to the first-stage balance oil chamber 31.0 through the first channel 31.5. One end of the second channel 31.6 is connected to the signal oil passage 31.2, and the other end of the second channel 31.6 is connected to the second-stage balance oil passage 13, so that the second-stage balance oil passage 13 is connected to the signal oil passage 31.2 through the second channel 31.6.

[0068] And such Figure 2 As shown, the signal oil passage 31.2 includes three ports: a first port 31.11, a second port 31.12, and a third port 31.13. The first port 31.11 is connected to the primary balancing oil chamber 31.0, the second port 31.12 is connected to the second channel 31.6, and the third port 31.13 is normally connected to the secondary balancing oil chamber 31.1. This allows the oil in the primary buffer chamber 7 to enter the primary balancing oil chamber 31.0 when the oil pressure is too high, and then, under the influence of hydraulic pressure... The valve 32 is pushed down and moved backward until it opens the connection between the first oil port 31.11 and the first-stage balance oil chamber 31.0. Then, the oil in the first-stage balance oil chamber 31.0 can flow into the first oil port 31.11, and then flow to the second oil port 31.12 and the third oil port 31.13 respectively, which are connected to the second-stage buffer chamber 8 and the second-stage balance oil chamber 31.1 respectively. This allows the oil in the second-stage buffer chamber 8 to be replenished in time, achieving oil balance between the buffer chambers and preventing low-pressure cavitation in the second-stage buffer chamber 8.

[0069] Based on any of the above embodiments, the balance valve 3 will be further described; such as Figure 2 As shown, the balancing cavity includes a first sidewall 31.7, a second sidewall 31.8, a third sidewall 31.9, and a fourth sidewall 31.10. The first sidewall 31.7 and the second sidewall 31.8 are arranged parallel to each other and spaced apart. The first sidewall 31.7 and the second sidewall 31.8 are arranged perpendicular to the first direction, and the first sidewall 31.7 is located in front of the second sidewall 31.8. The third sidewall 31.9 and the fourth sidewall 31.10 are arranged parallel to each other and spaced apart. The third sidewall 31.9 and the fourth sidewall 31.10 are arranged parallel to the first direction, and the third sidewall 31.9 is located above the fourth sidewall 31.10. The first sidewall 31.7 and the third sidewall 31.9 are adjacent to each other. The first sidewall 31.7 is located near the drill bit 4, and the third sidewall 31.9 is located near the housing 1.

[0070] The first channel 31.5 opens on the first side wall 31.7, the first oil port 31.11 opens on the third side wall 31.9, the third oil port 31.13 opens on the second side wall 31.8, the second oil port 31.12 is located between the first oil port 31.11 and the third oil port 31.13, and the third oil port 31.13 is connected to the second channel 31.6.

[0071] Furthermore, such as Figure 2 As shown, in the first direction, the length of the movable valve 32 is b, the length of the third sidewall 31.9 is s, and the distance between the first oil port 31.11 and the first sidewall 31.7 is b; where s > a, s > b, b > a, and sa > b. That is, when the movable valve 32 slides in the balance chamber, the length of the third sidewall 31.9 is large enough, and the position of the signal valve allows the movable valve 32 to block the signal valve when the displacement is no greater than a. At this time, the first-stage balance oil chamber 31.0 and the second-stage balance oil chamber 31.1 are always disconnected. When the movable valve 32 moves beyond a, the balance chamber has enough space to place the movable valve 32 to ensure the normal operation of the balance valve 3.

[0072] Based on the above embodiments, the balance valve 3 is further improved; such as... Figure 2 As shown, the valve housing 31 is also provided with an activation chamber 31.3. Two activation chambers 31.3 are provided, distributed along the first direction on both sides of the balance chamber, and connected to the balance chamber. The length of the activation chamber 31.3 is less than that of the balance chamber along the direction perpendicular to the first direction. The presence of the activation chamber 31.3 causes the first sidewall 31.7 and the second sidewall 31.8 to be disconnected in the middle, while their two ends remain connected to the third sidewall 31.9 and the fourth sidewall 31.10. This forms limiting steps at the upper and lower ends of the first sidewall 31.7 and the second sidewall 31.8, limiting the movement of the movable valve 32 and preventing it from moving into the activation chamber 31.3. Furthermore, the front and... The two rear starting chambers 31.3 correspond to the closed and open positions of the balance valve 3, respectively. When the movable valve 32 is close to the front starting chamber 31.3, the movable valve 32 blocks the first oil port 31.11 of the signal oil passage 31.2, and the balance valve 3 is in the closed state. When the movable valve 32 is close to the rear starting chamber 31.3, the movable valve 32 does not block the first oil port 31.11 of the signal oil passage 31.2, and the balance valve 3 is in the open state. The oil can be temporarily stored through the front and rear starting chambers 31.3, thereby providing the pressure value for the movable valve 32 to move and start, ensuring that the balance valve 3 still has sufficient oil contact area in the open and closed positions, and ensuring that the opening and closing can be carried out normally.

[0073] In this embodiment, the first channel 31.5 is connected to the front start chamber 31.3, and the third oil port 31.13 of the signal oil passage 31.2 is connected to the rear start chamber 31.3, so as to avoid the first channel 31.5 and the third oil port 31.13 being blocked by the movable valve 32.

[0074] Furthermore, such as Figure 2 As shown, the active valve 32 includes a first valve body 32.0 and a second valve body 32.1. The first valve body 32.0 and the second valve body 32.1 are distributed along a first direction. The second valve body 32.1 is connected to the rear end of the first valve body 32.0. The first valve body 32.0 and the second valve body 32.1 are coaxially arranged. In the direction perpendicular to the first direction, the width of the first valve body 32.0 is smaller than the width of the second valve body 32.1, and the width of the first valve body 32.0 is smaller than the width of the starting chamber 31.3. The width of the second valve body 32.1 is less than or equal to the width of the balance chamber, and greater than the length of the starting chamber 31.3.

[0075] Correspondingly, the valve housing 31 is provided with a movable cavity 31.4, which is connected to the balance cavity and located in front of the balance cavity. The movable cavity 31.4 is connected to the front starting cavity 31.3, which is located between the movable cavity 31.4 and the first-stage balance oil cavity 31.0. The first valve body 32.0 is slidably disposed in the movable cavity 31.4 along the first direction. The width of the movable cavity 31.4 perpendicular to the first direction is smaller than that of the balance cavity. In the first direction, the width of the movable cavity 31.4 is smaller than that of the balance cavity, and the width of the first valve body 32.0 is less than or equal to the width of the movable cavity 31.4, thereby enabling the first valve body 32.0 to slide along the movable cavity 31.4. In the first direction, the length of the first valve body 32.0 is c, and the length of the movable cavity 31.4 is d, where c > d + sb, thus ensuring that the first valve body 32.0 will not detach from the movable cavity 31.4.

[0076] In actual operation, when the vibration damping device is applied to the impact structure of a rock drill, it includes the retraction stage and the forward stage of the buffer piston 2. The coordination of the balance valve 3 in the two stages is as follows:

[0077] like Figure 3 As shown, during the retraction phase of the buffer piston 2: In this phase, the buffer piston 2 moves backward, and the primary buffer chamber 7 and the secondary buffer chamber 8 are compressed, resulting in a rapid increase in pressure in the two buffer chambers. The speed of the buffer piston 2 gradually decreases to 0 and then moves in the opposite direction.

[0078] like Figure 4As shown, during the forward movement of the buffer piston 2: In this stage, the buffer piston 2 moves forward, but because the primary buffer chamber 7 is directly connected to the oil inlet passage 11, the pressure change in the primary buffer chamber 7 is relatively small. However, since the secondary buffer chamber 8 is connected to the primary buffer chamber 7 by a gap, the oil replenishment in the secondary buffer chamber 8 is not timely, resulting in a pressure drop. At this time, the pressure in the secondary balance oil chamber 31.1 also decreases accordingly. The oil in the primary buffer chamber 7 enters the primary balance oil chamber 31.0, pushing the movable valve 32 to move backward to open the balance valve 3. When the movable valve 32 moves to the signal oil passage 31.2 and connects with the primary balance oil chamber 31.0, the oil in the primary buffer chamber 7 is replenished to the secondary buffer chamber 8 via the primary buffer chamber 7—primary balance oil passage 12—primary balance oil chamber 31.0—signal oil passage 31.2—secondary balance oil chamber 31.1—secondary balance oil passage 13—secondary buffer chamber 8, thereby reducing the pressure in the secondary buffer chamber 8 and balancing the pressure in the secondary buffer chamber 8.

[0079] Second aspect

[0080] This application provides a rock drill, including the vibration-absorbing device in any embodiment provided in the first aspect. The rock drill further includes an impact piston 6, a drill bit 4, and a buffer sleeve 5, as shown below. Figure 1 As shown, the impact piston 6 is coaxially slidably disposed inside the buffer piston 2; the drill bit 4 is coaxially disposed on the front side of the impact piston 6; the buffer sleeve 5 is disposed on the outside of the impact piston 6. The drill bit 4, the impact piston 6, the buffer sleeve 5 and the housing 1 are coaxially disposed. The buffer sleeve 5 is located between the buffer piston 2 and the drill bit 4. The buffer sleeve 5 plays a buffering role between the drill bit 4 and the buffer piston 2, avoiding direct dry friction between the drill bit 4 and the buffer piston 2.

[0081] In the impact structure of the rock drill of this application, the vibration absorption device can buffer the rebound force in the impact structure of the rock drill, reduce the impact on the internal parts of the rock drill, and effectively improve the service life of the rock drill.

[0082] It should be noted that the various embodiments of this application can be arbitrarily combined into new embodiments, provided that the solutions do not conflict and the technical solutions can coexist.

[0083] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the embodiments above are only for the purpose of helping to understand the present application and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A vibration absorbing device applied to a rock drill, characterized in that, The system includes a housing (1) and a buffer piston (2) arranged coaxially, wherein the housing (1) is sleeved over the buffer piston (2), and further includes: At least two buffer chambers are spaced apart along the axial direction on the outer periphery of the buffer piston (2); An oil inlet passage (11) is provided on the housing (1) and is connected to at least one buffer chamber; A balance valve (3) is used to connect the buffer chambers, and the balance valve (3) is used to change the connection relationship between the buffer chambers according to the pressure difference between them. The balance valve (3) is provided with at least two balance oil chambers, and each buffer chamber is connected to a balance oil chamber.

2. The vibration-absorbing device according to claim 1, characterized in that, The balancing valve (3) includes a valve body (31) and a movable valve (32), and the valve body (31) is provided with a balancing chamber; The movable valve (32) is slidably disposed in the balance chamber along the first direction to divide the balance chamber into a primary balance oil chamber (31.0) and a secondary balance oil chamber (31.1). The movable valve (32) is used to adjust the connection between the primary balance oil chamber (31.0) and the secondary balance oil chamber (31.1). The buffer chamber is configured as two chambers, namely a primary buffer chamber (7) and a secondary buffer chamber (8). The primary buffer chamber (7) is connected to the oil inlet circuit (11); the primary buffer chamber (7) is connected to the primary balance oil chamber (31.0); and the secondary buffer chamber (8) is connected to the secondary balance oil chamber (31.1).

3. The vibration-absorbing device according to claim 2, characterized in that, The valve body (31) is provided with a signal oil passage (31.2). The primary balance oil chamber (31.0) and the secondary balance oil chamber (31.1) are connected through the signal oil passage (31.2). The secondary balance oil chamber (31.1) and the signal oil passage (31.2) are normally connected. The active valve (32) is used to adjust the connection between the primary balance oil chamber (31.0) and the signal oil passage (31.2).

4. The vibration-absorbing device according to claim 3, characterized in that, The housing (1) is provided with a primary balance oil passage (12) and a secondary balance oil passage (13). The primary buffer chamber (7) is connected to the primary balance oil passage (12), and the secondary buffer chamber (8) is connected to the secondary balance oil passage (13). The valve housing (31) is provided with a first channel (31.5) and a second channel (31.6). The first-stage balance oil passage (12) is connected to the first-stage balance oil chamber (31.0) through the first channel (31.5), and the second-stage balance oil passage (13) is connected to the signal oil passage (31.2) through the second channel (31.6).

5. The vibration-absorbing device according to claim 4, characterized in that, The balancing cavity includes a first sidewall (31.7) and a second sidewall (31.8) perpendicular to the first direction, and a third sidewall (31.9) and a fourth sidewall (31.10) parallel to the first direction. The first sidewall (31.7) is adjacent to the third sidewall (31.9), and the third sidewall (31.9) is disposed close to the housing (1). The first channel (31.5) opens on the first sidewall (31.7) of the balancing cavity; The signal oil passage (31.2) includes a first oil port (31.11), a second oil port (31.12), and a third oil port (31.13). The first oil port (31.11) opens on the third side wall (31.9), the second oil port (31.12) is connected to the secondary balance oil passage (13), and the third oil port (31.13) opens on the second side wall (31.8).

6. The vibration-absorbing device according to claim 5, characterized in that, The length of the movable valve (32) in the first direction is b, the length of the third sidewall (31.9) is s, and the distance between the first oil port (31.11) and the first sidewall (31.7) is b; Where, sa > b.

7. The vibration-absorbing device according to claim 5, characterized in that, The valve housing (31) is also provided with an activation chamber (31.3), which is distributed on both sides of the balance chamber along the first direction and is connected to the balance chamber; In the first direction, the length of the starting cavity (31.3) is less than that of the balancing cavity, so as to form a limiting step on the first sidewall (31.7) and the second sidewall (31.8).

8. The vibration-absorbing device according to claim 7, characterized in that, The movable valve (32) includes a first valve body (32.0) and a second valve body (32.1), wherein the first valve body (32.0) and the second valve body (32.1) are distributed along a first direction; In the direction perpendicular to the first direction, the width of the first valve body (32.0) is smaller than the width of the second valve body (32.1) and smaller than the width of the starting chamber (31.3); The width of the second valve body (32.1) is less than or equal to the width of the balance chamber and greater than the length of the start chamber (31.3).

9. The vibration-absorbing device according to claim 8, characterized in that, The valve housing (31) is provided with a movable cavity (31.4), which is connected to the balance cavity. The first valve body (32.0) is slidably disposed in the movable cavity (31.4) along the first direction. The width of the movable cavity (31.4) perpendicular to the first direction is smaller than that of the balance cavity. In the direction perpendicular to the first direction, the width of the active cavity (31.4) is smaller than that of the balance cavity, and the width of the first valve body (32.0) is less than or equal to the width of the active cavity (31.4). In the first direction, the length of the first valve body (32.0) is c, and the length of the movable cavity (31.4) is d, where c > d + sb.

10. A rock drill, characterized in that The device includes the vibration-absorbing device as described in any one of claims 1 to 9, and further includes: The impact piston (6) is coaxially slidably disposed inside the buffer piston (2); The drill bit (4) is coaxially located on the front side of the impact piston (6); The buffer sleeve (5) is fitted on the impact piston (6) and is located between the buffer piston (2) and the drill bit (4).

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