A hydraulic system for preventing rock drill jamming

Abstract

This invention discloses a hydraulic system for preventing rock drill jamming, comprising: a propulsion cylinder; a rod chamber oil circuit connected to the rod chamber; a rodless chamber oil circuit connected to the rodless chamber; a pressure reducing valve located in the rodless chamber oil circuit; a one-way throttle valve located in the rod chamber oil circuit; a first hydraulically controlled directional valve connected to the rod chamber oil circuit, positioned between the rod chamber and the one-way throttle valve, the control oil circuit of the first hydraulically controlled directional valve being connected to the rock drill impact pressure signal; and a first hydraulically controlled proportional relief valve, the control port of which is connected to the outlet of the first hydraulically controlled directional valve, the inlet of which is connected to the control oil circuit of the pressure reducing valve, and the outlet of which is connected to an oil tank. The impact pressure signal causes the first hydraulically controlled directional valve to open. When encountering a cavern, the one-way throttle valve generates back pressure, causing the first hydraulically controlled proportional relief valve to open. The propulsion pressure passes through the pressure reducing valve, and a portion of the propulsion pressure is unloaded through the first hydraulically controlled proportional relief valve, reducing the propulsion pressure and preventing the drill from jamming in a cavern.

Description

Technical Field

[0001] This invention relates to the field of hydraulic systems for rock drills, and more specifically, to a hydraulic system for preventing rock drill jamming. Background Technology

[0002] In the field of rock drilling rig technology, current anti-jamming hydraulic systems are mainly designed for gradual jamming and crack jamming. However, for the most complex karst cave jamming, most anti-jamming hydraulic systems do not have the function of preventing karst cave jamming.

[0003] Existing systems that can prevent pins from getting stuck in caves require repeatedly pushing the push handle back and forth to prevent pins from getting stuck when encountering caves. This is cumbersome and the reversing valve core is prone to damage.

[0004] Therefore, how to provide a hydraulic system for preventing rock drills from getting stuck in karst caves and avoid switching the push handle back and forth is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a hydraulic system for preventing rock drill jamming, which can prevent the drill from getting stuck in a cave and avoid switching the rock drill's push handle back and forth.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A hydraulic system for preventing rock drill bit jamming, comprising:

[0008] Propulsion cylinder;

[0009] The rod chamber oil passage is connected to the rod chamber of the propulsion cylinder;

[0010] The rodless chamber oil passage is connected to the rodless chamber of the propulsion cylinder;

[0011] A pressure reducing valve is located in the oil circuit of the rodless chamber;

[0012] A one-way throttle valve is located in the rod chamber oil passage;

[0013] The first hydraulically controlled directional valve is connected to the rod chamber oil circuit, and the connection position is located between the rod chamber and the one-way throttle valve. The control oil circuit of the first hydraulically controlled directional valve is connected to the impact pressure signal of the rock drill.

[0014] The first hydraulically controlled proportional relief valve has its control port connected to the outlet port of the first hydraulically controlled directional valve, its inlet port connected to the control oil circuit of the pressure reducing valve, and its outlet port connected to the oil tank.

[0015] Optionally, it also includes a second hydraulically controlled proportional relief valve, the control port of which is connected to the rotation pressure signal of the rock drill, the inlet of the second hydraulically controlled proportional relief valve is connected to the control oil circuit of the pressure reducing valve, and the outlet of the second hydraulically controlled proportional relief valve is connected to the oil tank.

[0016] Optionally, it also includes:

[0017] The second hydraulic control directional valve is connected to the rod chamber oil circuit and the rodless chamber oil circuit respectively, and is used to switch the hydraulic flow direction. The second hydraulic control directional valve is also connected to the first oil circuit and the second oil circuit. When the rock drill's push handle is turned to the forward position, the first oil circuit is connected to the pressure oil source, and the second oil circuit is connected to the oil tank.

[0018] The third hydraulic directional valve has its control oil circuit connected to the rotation pressure signal of the rock drill. The oil inlet of the third hydraulic directional valve is connected to the first oil circuit, and the oil outlet of the third hydraulic directional valve is connected to the pilot control oil port of the non-spring end of the second hydraulic directional valve.

[0019] Optionally, the pilot control port at the spring end of the second hydraulic directional valve is connected to the second oil circuit.

[0020] Optionally, it also includes:

[0021] The fourth hydraulically controlled directional valve is connected to the rod chamber oil circuit and the rodless chamber oil circuit respectively, and is used to switch the hydraulic flow direction. The fourth hydraulically controlled directional valve is also connected to the third oil circuit and the fourth oil circuit. One of the third oil circuit and the fourth oil circuit is connected to the pressure oil source, and the other is connected to the oil tank.

[0022] The sequence valve has its inlet connected to the rotation pressure signal of the rock drill, and its outlet is connected to the pilot control port of the non-spring end of the fourth hydraulic directional valve.

[0023] Optionally, it also includes a first check valve connected between the rodless chamber oil circuit and the third oil circuit, with the inlet of the first check valve connected to the rodless chamber oil circuit; when the rock drill's push handle is in the forward position, the third oil circuit is connected to the pressure oil source, and the fourth oil circuit is connected to the oil tank; when the push handle is in the reverse position, the third oil circuit is connected to the oil tank, and the fourth oil circuit is connected to the pressure oil source.

[0024] Optionally, it also includes a second check valve connected between the rod chamber oil circuit and the fourth oil circuit, with the oil inlet of the second check valve connected to the fourth oil circuit; when the rock drill's push handle is in the forward position, the third oil circuit is connected to the pressure oil source, and the fourth oil circuit is connected to the oil tank; when the push handle is in the reverse position, the third oil circuit is connected to the oil tank, and the fourth oil circuit is connected to the pressure oil source.

[0025] The rock drill anti-jamming hydraulic system provided by this invention allows the hydraulic oil in the rodless chamber to flow into the rodless chamber after being depressurized by a pressure reducing valve during rock drill propulsion, causing the piston rod of the propulsion cylinder to extend and achieve propulsion. During this process, the hydraulic oil in the rod chamber flows through a one-way throttle valve and then flows from the rod chamber oil circuit to the oil tank to achieve oil return. When a rock drill encounters a karst cave, the drill bit's propulsion load suddenly decreases and the propulsion speed increases the instant it enters the cave. At this moment, back pressure is generated at the one-way throttle valve. Under the action of the impact pressure signal, the first hydraulically controlled directional valve remains open. The back pressure generated at the one-way throttle valve serves as the pilot control pressure, which acts on the first hydraulically controlled proportional relief valve through the first hydraulically controlled directional valve, causing the first hydraulically controlled proportional relief valve to open. Thus, when the propulsion pressure in the rodless chamber oil circuit passes through the pressure reducing valve, part of the propulsion pressure is unloaded to the oil tank through the first hydraulically controlled proportional relief valve, thereby reducing the outlet pressure of the pressure reducing valve, i.e., the propulsion pressure. This reduces the propulsion speed of the rock drill, achieving the function of preventing the drill bit from getting stuck in a karst cave.

[0026] Moreover, it can be seen that in the above process, there is no need to frequently control the rock drill's push handle to move back and forth, avoiding cumbersome operations and making it less likely to damage the reversing valve core. While preventing the drill bit from getting stuck in the karst cave, it also improves the reliability of the rock drill's anti-jamming hydraulic system. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0028] Figure 1 A hydraulic schematic diagram of a rock drill anti-jamming hydraulic system provided in a specific embodiment of the present invention;

[0029] Figure 2 A hydraulic schematic diagram of the anti-jamming hydraulic system for a rock drill, provided in another specific embodiment of the present invention;

[0030] Figure 3 The hydraulic schematic diagram of the anti-jamming hydraulic system for a rock drill is provided in another specific embodiment of the present invention.

[0031] Figures 1 to 3 The accompanying figure labels are as follows:

[0032] 1 is the propulsion cylinder, 2 is the rod chamber oil circuit, 3 is the rodless chamber oil circuit, 4 is the pressure reducing valve, 5 is the one-way throttle valve, 6 is the first hydraulically controlled directional valve, 7 is the first hydraulically controlled proportional relief valve, 8 is the second hydraulically controlled proportional relief valve, 9 is the second hydraulically controlled directional valve, 10 is the first oil circuit, 11 is the second oil circuit, 12 is the third hydraulically controlled directional valve, 13 is the fourth hydraulically controlled directional valve, 14 is the third oil circuit, 15 is the fourth oil circuit, 16 is the sequence valve, 17 is the first check valve, 18 is the second check valve, 19 is the impact pressure signal, and 20 is the rotation pressure signal. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The core of this invention is to provide a hydraulic system for preventing rock drill jamming, which can prevent the drill from getting stuck in karst caves and avoid switching the rock drill's push handle back and forth, thus ensuring high reliability.

[0035] Please refer to Figures 1-3 , Figure 1 A hydraulic schematic diagram of a rock drill anti-jamming hydraulic system provided in a specific embodiment of the present invention; Figure 2 A hydraulic schematic diagram of the anti-jamming hydraulic system for a rock drill, provided in another specific embodiment of the present invention; Figure 3 This is a hydraulic schematic diagram of a rock drill anti-jamming hydraulic system provided in another specific embodiment of the present invention. It should be noted that... Figure 2 and 3 Zhongyu Figure 1 The relevant structure of the same anti-cavity clamp is not shown.

[0036] Please refer to Figure 1This invention provides a hydraulic system for preventing rock drill jamming, including a propulsion cylinder 1, a rod chamber oil circuit 2, a rodless chamber oil circuit 3, a pressure reducing valve 4, a one-way throttle valve 5, a first hydraulically controlled directional valve 6, and a first hydraulically controlled proportional relief valve 7. Specifically, the rod chamber oil passage 2 is connected to the rod chamber of the propulsion cylinder 1; the rodless chamber oil passage 3 is connected to the rodless chamber of the propulsion cylinder 1; the pressure reducing valve 4 is located in the rodless chamber oil passage 3; the one-way throttle valve 5 is located in the rod chamber oil passage 2; the first hydraulically controlled directional valve 6 is connected to the rod chamber oil passage 2, and the connection position between the first hydraulically controlled directional valve 6 and the rod chamber oil passage 2 is located between the rod chamber and the one-way throttle valve 5; the control oil passage of the first hydraulically controlled directional valve 6 is connected to the impact pressure signal 19 of the rock drill; the oil outlet of the first hydraulically controlled directional valve 6 is connected to the control oil port of the first hydraulically controlled proportional relief valve 7; the oil inlet of the first hydraulically controlled proportional relief valve 7 is connected to the control oil passage of the pressure reducing valve 4; and the oil outlet of the first hydraulically controlled proportional relief valve 7 is connected to the oil tank.

[0037] Understandably, when the rock drill is pushed forward, the hydraulic oil in the rodless chamber oil circuit 3 is depressurized by the pressure reducing valve 4 and flows into the rodless chamber, causing the piston rod of the push cylinder 1 to extend and achieve propulsion; during this process, the hydraulic oil in the rod chamber flows through the one-way throttle valve 5 and then flows from the rod chamber oil circuit 2 to the oil tank to achieve oil return. When the rock drill encounters a karst cave, the drilling load suddenly decreases and the drilling speed increases the instant the drill bit enters the cave. At this moment, back pressure is generated at the one-way throttle valve 5. Under the action of the impact pressure signal, the first hydraulic control directional valve remains open. The back pressure generated at the one-way throttle valve 5 serves as the pilot control pressure. It acts on the first hydraulic control proportional relief valve 7 through the first hydraulic control directional valve 6, causing the first hydraulic control proportional relief valve 7 to open. Thus, when the drilling pressure in the rodless chamber oil circuit 3 passes through the pressure reducing valve 4, part of the drilling pressure is unloaded to the oil tank through the first hydraulic control proportional relief valve 7. This reduces the outlet pressure of the pressure reducing valve 4, i.e., the drilling pressure, thereby reducing the drilling speed and achieving the function of preventing the drill bit from getting stuck in the karst cave.

[0038] Moreover, it can be seen that in the above process, there is no need to frequently control the rock drill's push handle to move back and forth, avoiding cumbersome operations and making it less likely to damage the reversing valve core. While preventing the drill bit from getting stuck in the karst cave, it also improves the reliability of the rock drill's anti-jamming hydraulic system.

[0039] For the sake of structural simplicity, in some embodiments, the first hydraulic control directional valve 6 is a two-position three-way hydraulic control directional valve.

[0040] Additionally, it's understandable that as the rock drill advances, its rotational pressure continuously increases. If the rotational pressure doesn't reach the anti-jamming setting, the anti-jamming function won't trigger. In this case, gradual jamming may occur. To prevent gradual jamming, please refer to [further details needed]. Figure 1In some embodiments, the anti-jamming hydraulic system of the rock drill also includes a second hydraulically controlled proportional relief valve 8. The control port of the second hydraulically controlled proportional relief valve 8 is connected to the rotation pressure signal 20 of the rock drill. The inlet of the second hydraulically controlled proportional relief valve 8 is connected to the control oil circuit of the pressure reducing valve 4. The outlet of the second hydraulically controlled proportional relief valve 8 is connected to the oil tank.

[0041] In other words, during the rock drill's propulsion process, when the rotational pressure does not reach the anti-jamming setting value, i.e., when the anti-jamming function is not triggered, the rotational pressure signal 20 will act on the second hydraulically controlled proportional relief valve 8, causing the second hydraulically controlled proportional relief valve 8 to open. At this time, the propulsion pressure in the rodless chamber oil circuit 3 passes through the pressure reducing valve 4, and part of the propulsion pressure will be unloaded to the oil tank through the second hydraulically controlled proportional relief valve 8, thereby reducing the outlet pressure of the pressure reducing valve 4, i.e., the propulsion pressure. This allows the propulsion pressure to change with the rotational pressure. In other words, this embodiment achieves automatic matching of propulsion pressure and rotational pressure by adding the second hydraulically controlled proportional relief valve 8 and connecting the rock drill's rotational pressure signal 20 to the second hydraulically controlled proportional relief valve 8, thus achieving the function of preventing gradual jamming.

[0042] Additionally, during the rock drill's advance, when the rotational pressure increases and reaches the anti-jamming setting value, the anti-jamming function is triggered, requiring the advance cylinder 1 to retract quickly. To achieve rapid retraction of the advance cylinder 1, please refer to [link / reference needed]. Figure 1 In some embodiments, the system also includes a second hydraulic directional valve 9 and a third hydraulic directional valve 12. The second hydraulic directional valve 9 is connected to the rod-side oil passage 2 and the rodless-side oil passage 3, respectively, for switching the hydraulic flow direction. The second hydraulic directional valve 9 is also connected to the first oil passage 10 and the second oil passage 11. When the rock drill's push handle is in the forward position, the first oil passage 10 is connected to the pressure oil source, and the second oil passage 11 is connected to the oil tank. The control oil passage of the third hydraulic directional valve 12 is connected to the rock drill's rotation pressure signal 20. The inlet of the third hydraulic directional valve 12 is connected to the first oil passage 10, and the outlet of the third hydraulic directional valve 12 is connected to the pilot control port of the non-spring end of the second hydraulic directional valve 9.

[0043] Understandably, during the normal advance of the rock drill, when the advance handle is in the forward position, the first oil circuit 10 is connected to the pressure oil source, and the second oil circuit 11 is connected to the oil tank. The pressure oil in the first oil circuit 10 enters the rodless chamber oil circuit 3 after passing through the second hydraulic control directional valve 9, and then enters the rodless chamber through the rodless chamber oil circuit 3, pushing the piston rod of the advance cylinder 1 to extend. At this time, the oil in the rod chamber passes through the rod chamber oil circuit 2 and the second hydraulic control directional valve 9, and finally returns to the oil tank through the second oil circuit 11.

[0044] During the rock drill's propulsion process, the rotational pressure increases. When the rotational pressure reaches the anti-jamming setting value, the anti-jamming function is triggered. At this time, the rotational pressure signal 20 acts on the third hydraulic control directional valve 12, causing the third hydraulic control directional valve 12 to open. This allows the pressure oil in the first oil circuit 10 to pass through the third hydraulic control directional valve 12 and act on the second hydraulic control directional valve 9, causing the second hydraulic control directional valve 9 to switch positions and realize the high-pressure oil circuit reversal. This allows the pressure oil in the first oil circuit 10 to enter the rod chamber oil circuit 2 after passing through the second hydraulic control directional valve 9, and then enter the rod chamber through the rod chamber oil circuit 2, realizing the rapid retraction of the piston rod of the propulsion cylinder 1. During this process, the oil in the rodless chamber passes through the rodless chamber oil circuit 3 and the second hydraulic control directional valve 9, and finally returns to the oil tank through the second oil circuit 11.

[0045] As can be seen from this embodiment, during the rock drill's propulsion process, when the rotation pressure reaches the anti-jamming setting value, the rotation pressure signal 20 acts as pilot control oil, opening the third hydraulic control directional valve 12 to realize the high-pressure oil circuit reversal, thereby enabling the drill bit to automatically retract and effectively preventing jamming.

[0046] Furthermore, in practical applications, when the drill bit gets stuck, the operator may unconsciously move the rock drill's push handle to the reverse position. When the push handle is in the reverse position, the first oil circuit 10 is connected to the oil tank, and the second oil circuit 11 is connected to the pressure oil source. At this time, because the second hydraulic control directional valve 9 has switched positions and the high-pressure oil circuit has been reversed, if the push handle is moved to the reverse position, the pressure oil in the second oil circuit 11 will enter the rodless chamber oil circuit 3 through the second hydraulic control directional valve 9, causing abnormal forward movement. Therefore, to prevent the operator from moving the push handle to the reverse position when the anti-jamming function is triggered, causing abnormal forward movement, please continue to refer to... Figure 1 Based on the above embodiment, the pilot control port of the spring end of the second hydraulic directional valve 9 is connected to the second oil circuit 11.

[0047] In other words, when the anti-jamming function is triggered and the operator moves the push handle to the retracted position, the second oil circuit 11 is connected to the pressure oil source. The pressure oil in the second oil circuit 11 acts on the second hydraulic control directional valve 9, causing the second hydraulic control directional valve 9 to switch positions and realize the high pressure oil circuit reversal again. That is, the pressure oil in the second oil circuit 11 enters the rod chamber oil circuit 2 after passing through the second hydraulic control directional valve 9, and enters the rod chamber through the rod chamber oil circuit 2, realizing the rapid retraction of the piston rod of the push cylinder 1. During this process, the oil in the rodless chamber passes through the rodless chamber oil circuit 3 and the second hydraulic control directional valve 9, and finally returns to the oil tank through the first oil circuit 10.

[0048] It can be seen that this embodiment can not only automatically trigger the anti-jamming function when the rotation pressure reaches the anti-jamming set value, but also prevent abnormal forward misoperation when the anti-jamming function is triggered and the push handle is moved to the retracted position. Moreover, the oil circuit connection is simple and easy to implement.

[0049] In addition, to achieve the automatic anti-jamming function, the following solutions are also possible: Figure 2 and 3 As shown, in some embodiments, the anti-jamming hydraulic system of the rock drill also includes a fourth hydraulically controlled directional valve 13 and a sequence valve 16. The fourth hydraulically controlled directional valve 13 is connected to the rod-side oil circuit 2 and the rodless-side oil circuit 3, respectively, for switching the hydraulic flow direction. The fourth hydraulically controlled directional valve 13 is also connected to the third oil circuit 14 and the fourth oil circuit 15. One of the three oil circuits and the fourth oil circuit 15 is connected to the pressure oil source, and the other is connected to the oil tank. The oil inlet of the sequence valve 16 is connected to the rotation pressure signal 20 of the rock drill, and the oil outlet of the sequence valve 16 is connected to the pilot control oil port of the non-spring end of the fourth hydraulically controlled directional valve 13.

[0050] In other words, this embodiment uses a sequence valve 16 to replace the third hydraulic directional valve 12 in the above technical solution. The rotation pressure signal 20 of the rock drill is used as the opening control pressure of the sequence valve 16. When the drill bit gets stuck, that is, when the rotation pressure reaches the anti-jamming setting value, the sequence valve 16 opens. The rotation pressure is used as the control pressure for switching the fourth hydraulic directional valve 13, which switches the fourth hydraulic directional valve 13 to realize the high-pressure oil circuit switching. The pressure oil provided by the pressure oil source enters the fourth hydraulic directional valve 13 through one of the third oil circuit 14 and the fourth oil circuit 15, and then enters the rod chamber oil circuit 2. It then enters the rod chamber through the rod chamber oil circuit 2, realizing the rapid retraction of the piston rod of the propulsion cylinder 1. During this process, the oil in the rodless chamber passes through the rodless chamber oil circuit 3 and the fourth hydraulic directional valve 13, and finally returns to the oil tank through the other of the third oil circuit 14 and the fourth oil circuit 15, realizing the function of automatic retraction of the stuck drill bit.

[0051] Please refer to Figure 2 Based on the above embodiments, in order to prevent the operator from turning the push handle to the retracted position when the rock drill automatically retracts, causing abnormal forward movement, in some embodiments, the rock drill anti-jamming hydraulic system also includes a first check valve 17. The first check valve 17 is connected between the rodless chamber oil circuit 3 and the third oil circuit 14, and the oil inlet of the first check valve 17 is connected to the rodless chamber oil circuit 3. When the rock drill's push handle is turned to the forward position, the third oil circuit 14 is connected to the pressure oil source, and the fourth oil circuit 15 is connected to the oil tank. When the push handle is turned to the retracted position, the third oil circuit 14 is connected to the oil tank, and the fourth oil circuit 15 is connected to the pressure oil source.

[0052] In other words, when the rock drill is advancing normally, the push handle is turned to the forward position. At this time, the third oil circuit 14 is connected to the pressure oil source, and the fourth oil circuit 15 is connected to the oil tank. The pressure oil in the third oil circuit 14 enters the rodless chamber oil circuit 3 after passing through the fourth hydraulic control directional valve 13, and then enters the rodless chamber through the rodless chamber oil circuit 3, pushing the piston rod of the push cylinder 1 to extend. At this time, the oil in the rod chamber passes through the rod chamber oil circuit 2 and the fourth hydraulic control directional valve 13, and finally returns to the oil tank through the fourth oil circuit 15.

[0053] During the rock drill's propulsion process, the rotary pressure increases. When the rotary pressure reaches the anti-jamming setting value, the anti-jamming function is triggered. At this time, the rotary pressure signal 20 acts on the sequence valve 16, causing the sequence valve 16 to open. The rotary pressure signal 20 then acts on the fourth hydraulic control directional valve 13 through the sequence valve 16, causing the fourth hydraulic control directional valve 13 to switch positions and realize the high-pressure oil circuit reversal. This allows the pressure oil supplied by the pressure oil source to enter the fourth hydraulic control directional valve 13 through the third oil circuit 14, and then enter the rod chamber oil circuit 2. It then enters the rod chamber through the rod chamber oil circuit 2, realizing the rapid retraction of the piston rod of the propulsion cylinder 1. During this process, the oil in the rodless chamber passes through the rodless chamber oil circuit 3 and the fourth hydraulic control directional valve 13, and finally returns to the oil tank through the fourth oil circuit 15, realizing the automatic retraction function of the jammed drill.

[0054] During the above process, when the operator moves the push handle to the reverse position, the third oil circuit 14 is connected to the oil tank, and the fourth oil circuit 15 is connected to the pressure oil source. At this time, the pressure oil in the fourth oil circuit 15 passes through the fourth hydraulic control directional valve 13, enters the rodless chamber oil circuit 3, and then flows through the first check valve 17 to the third oil circuit 14, returning to the oil tank, thus preventing abnormal forward misoperation. It can be seen that by adding the first check valve 17 between the rodless chamber oil circuit 3 and the third oil circuit 14, abnormal forward misoperation can also be prevented when the push handle is moved to the reverse position during automatic anti-jamming operation.

[0055] Please refer to Figure 3 Similar to the above principle, in some other embodiments, the rock drill anti-jamming hydraulic system also includes a second check valve 18, which is connected between the rod chamber oil passage 2 and the fourth oil passage 15. The oil inlet of the second check valve 18 is connected to the fourth oil passage 15. When the rock drill's push handle is in the forward position, the third oil passage 14 is connected to the pressure oil source, and the fourth oil passage 15 is connected to the oil tank. When the push handle is in the reverse position, the third oil passage 14 is connected to the oil tank, and the fourth oil passage 15 is connected to the pressure oil source.

[0056] Understandably, during the automatic anti-jamming process, when the operator moves the push handle to the reverse position, the third oil circuit 14 is connected to the oil tank, and the fourth oil circuit 15 is connected to the pressure oil source. At this time, the pressure oil in the fourth oil circuit 15 enters the rod chamber oil circuit 2 through the second check valve 18, and then enters the rod chamber through the rod chamber oil circuit 2, realizing the retraction of the push cylinder 1. During this process, the oil in the rodless chamber enters the fourth hydraulic control directional valve 13 through the rodless chamber oil circuit 3, and flows into the third oil circuit 14, and finally flows back to the oil tank, avoiding abnormal forward misoperation.

[0057] It can be seen that by adding a second check valve 18 between the rod chamber oil circuit 2 and the fourth oil circuit 15, abnormal forward misoperation can be prevented when the push handle is moved to the retracted position during automatic anti-jamming.

[0058] It should be noted that the above embodiments do not limit the specific structure of the second hydraulic directional valve 9, the third hydraulic directional valve 12, and the fourth hydraulic directional valve 13.

[0059] In some embodiments, the second hydraulic control directional valve 9 and the fourth hydraulic control directional valve 13 may be two-position four-way hydraulic control directional valves, respectively.

[0060] In some embodiments, the third hydraulic control directional valve 12 is a two-position three-way hydraulic control directional valve.

[0061] It should also be noted that, in this specification, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0062] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0063] The rock drill anti-jamming hydraulic system provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A hydraulic system for preventing drill jamming in a rock drill, characterized in that Comprise: A push cylinder (1); A rod cavity oil circuit (2) connected with the rod cavity of the push cylinder (1); A rodless cavity oil circuit (3) connected with the rodless cavity of the push cylinder (1); A pressure reducing valve (4) arranged in the rodless cavity oil circuit (3); A one-way throttle valve (5) arranged in the rod cavity oil circuit (2); A first hydraulic control reversing valve (6) connected with the rod cavity oil circuit (2), and the connection position is between the rod cavity and the one-way throttle valve (5), and the control oil circuit of the first hydraulic control reversing valve (6) is connected with the percussion pressure signal (19) of the rock drill; A first hydraulic control proportional relief valve (7), the control oil port of which is connected with the oil outlet of the first hydraulic control reversing valve (6), the oil inlet of the first hydraulic control proportional relief valve (7) is connected with the control oil circuit of the pressure reducing valve (4), and the oil outlet of the first hydraulic control proportional relief valve (7) is connected with the oil tank; A second hydraulic control reversing valve (9) connected with the rod cavity oil circuit (2) and the rodless cavity oil circuit (3) respectively, used for switching the hydraulic flow direction, the second hydraulic control reversing valve (9) is also connected with a first oil circuit (10) and a second oil circuit (11), when the push handle of the rock drill hits the forward position, the first oil circuit (10) is connected with the pressure oil source, and the second oil circuit (11) is connected with the oil tank; A third hydraulic control reversing valve (12), the control oil circuit of which is connected with the rotation pressure signal (20) of the rock drill, the oil inlet of the third hydraulic control reversing valve (12) is connected with the first oil circuit (10), and the oil outlet of the third hydraulic control reversing valve (12) is connected with the pilot control oil port of the non-spring end of the second hydraulic control reversing valve (9).

2. The hydraulic system for preventing drill jamming of a rock drill according to claim 1, characterized by Further comprising a second hydraulic control proportional relief valve (8), the control oil port of which is connected with the rotation pressure signal (20) of the rock drill, the oil inlet of the second hydraulic control proportional relief valve (8) is connected with the control oil circuit of the pressure reducing valve (4), and the oil outlet of the second hydraulic control proportional relief valve (8) is connected with the oil tank.

3. A jamming prevention hydraulic system for a rock drill according to claim 1 or 2, characterized in that, The pilot control oil port of the spring end of the second hydraulic control reversing valve (9) is connected with the second oil circuit (11).

4. A jamming prevention hydraulic system for a rock drill according to claim 1 or 2, characterized in that, Further comprise: A fourth hydraulic control reversing valve (13) connected with the rod cavity oil circuit (2) and the rodless cavity oil circuit (3) respectively, used for switching the hydraulic flow direction, the fourth hydraulic control reversing valve (13) is also connected with a third oil circuit (14) and a fourth oil circuit (15), one of the third oil circuit (14) and the fourth oil circuit (15) is connected with the pressure oil source, and the other is connected with the oil tank; A sequence valve (16), the oil inlet of which is connected with the rotation pressure signal (20) of the rock drill, and the oil outlet of the sequence valve (16) is connected with the pilot control oil port of the non-spring end of the fourth hydraulic control reversing valve (13).

5. The hydraulic system for preventing drill jamming of a rock drill according to claim 4, characterized in that, Also include a first one-way valve (17) is connected between the rodless cavity oil path (3) and the third oil path (14), the oil inlet of the first one-way valve (17) is connected with the rodless cavity oil path (3); when the advancing handle of the rock drill hits the forward position, the third oil path (14) is connected with the pressure oil source, and the fourth oil path (15) is connected with the oil tank; when the advancing handle hits the retreat position, the third oil path (14) is connected with the oil tank, and the fourth oil path (15) is connected with the pressure oil source.

6. The hydraulic system for preventing drill jamming of a rock drill according to Claim 4, wherein Also include a second one-way valve (18) is connected between the rod cavity oil path (2) and the fourth oil path (15), the oil inlet of the second one-way valve (18) is connected with the fourth oil path (15); when the advancing handle of the rock drill hits the forward position, the third oil path (14) is connected with the pressure oil source, and the fourth oil path (15) is connected with the oil tank; when the advancing handle hits the retreat position, the third oil path (14) is connected with the oil tank, and the fourth oil path (15) is connected with the pressure oil source.

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