Damping-adjustable hydraulic lock suitable for heightening oil cylinder of coal mining machine

Abstract

The utility model relates to a damping-adjustable hydraulic lock suitable for a heightening oil cylinder of a coal mining machine, which comprises a valve block, and a first hydraulic control one-way valve, a second hydraulic control one-way valve and a one-way adjustable throttle valve which are arranged on the valve block. An inlet of the first hydraulic control one-way valve and a hydraulic control port of the second hydraulic control one-way valve are both communicated with a first inlet of the valve block, an outlet of the first hydraulic control one-way valve is communicated with an inlet of the one-way adjustable throttling valve, and an outlet of the one-way adjustable throttling valve is communicated with a first outlet of the valve block. An inlet of the second hydraulic control one-way valve and a hydraulic control port of the first hydraulic control one-way valve are communicated with a second inlet of the valve block, and an outlet of the second hydraulic control one-way valve is communicated with a second outlet of the valve block. When the rocker arm is heightened, frequent impact and vibration between the valve core and the valve seat are avoided, so that the rocker arm is long in service life, and the rocker arm can descend stably without shaking.

Description

Technical Field

[0001] This utility model relates to a hydraulic lock, particularly a hydraulic lock used in the control circuit of the height adjustment cylinder of a coal mining machine. This hydraulic lock is not easily damaged and has a long service life. Background Technology

[0002] The control circuit of the height adjustment cylinder of the coal mining machine is equipped with a hydraulic lock. During the descent of the rocker arm, the rocker arm and drum often descend at excessive speed due to their own weight. This can cause insufficient oil supply to the inlet chamber of the height adjustment cylinder, resulting in a momentary drop or even disappearance of the inlet pressure. Consequently, the hydraulic lock closes due to the loss of control oil pressure. After closing, the inlet pressure is re-established as oil supply resumes, and the hydraulic lock reopens. Due to this intermittent opening and closing, the rocker arm movement becomes intermittent, and the height adjustment oil pipe vibrates violently, generating significant impact and noise. The hydraulic lock valve core connected to the large chamber (rodless chamber) of the height adjustment cylinder is easily damaged due to frequent impacts on the valve seat. When the coal mining machine is moving and cutting coal while descending, especially in hard coal seams, the rocker arm experiences even greater impact and vibration, and the load changes of the height adjustment cylinder become more complex, increasing the probability of hydraulic lock damage. Utility Model Content

[0003] The present invention aims to provide a damping adjustable hydraulic lock suitable for the height adjustment cylinder of a coal mining machine. When the rocker arm is height adjusted, there will be no frequent impact and vibration between the valve core and the valve seat, thus resulting in a longer service life and preventing the rocker arm from shaking during descent.

[0004] The main technical solutions of this utility model are as follows:

[0005] A damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine includes a valve block and a first hydraulically controlled check valve, a second hydraulically controlled check valve, and a one-way adjustable throttle valve mounted on the valve block. Through a channel inside the valve block, the inlet of the first hydraulically controlled check valve and the hydraulic control port of the second hydraulically controlled check valve are both connected to the first inlet of the valve block. The outlet of the first hydraulically controlled check valve is connected to the inlet of the one-way adjustable throttle valve, and the outlet of the one-way adjustable throttle valve is connected to the first outlet of the valve block. The inlet of the second hydraulically controlled check valve and the hydraulic control port of the first hydraulically controlled check valve are both connected to the second inlet of the valve block, and the outlet of the second hydraulically controlled check valve is connected to the second outlet of the valve block. The first inlet, second inlet, first outlet, and second outlet of the valve block are all located on the bottom surface of the valve block. The first and second hydraulically controlled check valves are arranged horizontally in opposite directions and symmetrically, while the one-way adjustable throttle valve is arranged vertically.

[0006] The one-way adjustable throttle valve may include a valve seat, a one-way valve core, a spring, a stop block, a stud, a nut, and a plug. The valve seat is a tubular part, and several oil inlet holes are provided on the middle side wall of the valve seat along its length. These oil inlet holes serve as the inlet of the one-way adjustable throttle valve. The parts before and after the oil inlet holes are respectively the front and rear parts of the valve seat. The inner hole of the front part of the valve seat is set as a stepped cylindrical hole with a larger diameter at the front and a smaller diameter at the rear. The rear part of the one-way valve core is slidably connected in the small-diameter cylindrical hole of the stepped cylindrical hole. The front part of the one-way valve core has an outer conical surface with a larger diameter at the front and a smaller diameter at the rear. The inner edge of the stepped surface and the outer conical surface form a one-way valve sealing pair in the form of a reverse cone valve. The front and rear parts of the one-way valve core are separated by an annular groove with the groove facing outwards radially. The rear part of the one-way valve core has a flow channel that runs through the front and rear, and this flow channel communicates with the annular groove. The spring is set in the inner hole of the valve seat, in front of the one-way valve core. The spring is kept in a compressed state and abuts against the one-way valve core. The front port of the valve seat acts as the outlet of the one-way adjustable throttle valve. The one-way valve core has a hollow structure. The front end of the inner hole of the one-way valve core opens to the front port of the valve seat, and the rear end of the inner hole of the one-way valve core is set to front... The throttle valve core has a conical bore that is smaller at the front and larger at the back. The rear part of the throttle valve core is slidably connected to the inner bore of the rear part of the valve seat. A seal is provided between the rear part of the throttle valve core and the valve seat. The front part of the throttle valve core is a truncated cone, smaller at the front and larger at the back. An annular gap is formed between the outer conical surface of the front end of the truncated cone and the conical bore on the check valve core. The inner bore of the check valve core communicates with the oil inlet through this annular gap. The stop block is threaded into the valve seat and located behind the throttle valve core. The stud is threaded into the core of the stop block and passes through the stop block, abutting against the rear end of the check valve core. The rear part of the stud is connected to the nut by screwing it in. The stop block is fixed, and the screw plug is threadedly connected to the valve seat and abuts against the stop block from the rear. The rear outer cylindrical surface of the valve seat is provided with a cylindrical section, an external thread section and a polygonal prism section with progressively increasing equivalent diameter from front to back. The cylindrical section is provided with an annular first sealing groove, and a first sealing ring is provided in the first sealing groove. The valve seat is installed in the one-way adjustable throttle valve socket on the valve block. The valve seat cooperates with the valve block and seals through the cylindrical section. The valve seat is axially positioned by the stepped surface between the polygonal prism section and the external thread section against one end face of the valve block. The valve seat is fixed in the valve block through the external thread section.

[0007] The front end of the one-way valve core is preferably provided with an annular groove, and the rear end of the spring is embedded in the annular groove.

[0008] The one-way adjustable throttle valve may also include a spring seat, the front end of which abuts against the spring seat. The spring seat is fixed in the inner hole at the front of the valve seat, and a retaining ring installed in the inner hole of the valve seat restricts the forward movement of the spring seat. The spring seat is an annular structure with its axis extending back and forth, and the annular inner hole communicates with the front port of the valve seat.

[0009] A first retaining ring is also provided behind the first sealing ring in the first sealing groove.

[0010] The outer cylindrical surface at the rear of the throttle valve core is provided with an annular second sealing groove, and a second sealing ring and a second retaining ring are respectively provided in the front and rear of the second sealing groove.

[0011] The rear end face of the screw plug has multiple pin holes.

[0012] The inner hole at the rear of the valve seat can be set as a stepped hole with a smaller front and a larger rear. The rear part of the throttle valve core is slidably connected in the small-diameter cylindrical hole of the stepped hole. The stop block and the screw plug are installed in the large-diameter threaded hole of the stepped hole, and the front end face of the stop block rests on the stepped surface of the stepped hole.

[0013] The first and second hydraulically controlled check valves can be CK series check valves from Shengxu Hydraulics Co., Ltd., and are installed in the valve block using a threaded cartridge mounting method.

[0014] The cone angle of the conical hole on the one-way valve core is preferably greater than the cone angle of the front part of the throttle valve core.

[0015] The beneficial effects of this utility model are:

[0016] By installing a one-way adjustable throttle valve on the downstream oil line of one of the hydraulic control check valves, back pressure can be provided when the rocker arm descends. By limiting the descent speed of the rocker arm, the rocker arm can descend smoothly, eliminating vibration and preventing damage caused by frequent impacts of the hydraulic lock valve core on the valve seat, thereby extending the service life and operational stability of the hydraulic lock.

[0017] Because the throttle opening of the one-way adjustable throttle valve is adjustable, the throttle opening size can be changed according to the different rocker arm loads of different models, the throttle damping can be adjusted, and a reasonable return oil back pressure can be set, making the hydraulic lock more adaptable to the height adjustment cylinder control circuit of different models.

[0018] Since both hydraulic check valves and one-way adjustable throttle valves can be installed as a whole on the valve block, they have a compact structure, high integration, and are easy to disassemble and assemble. When damaged, they can be replaced as a whole, which can effectively reduce maintenance costs.

[0019] The one-way adjustable throttle valve's valve core also functions as the valve seat for the throttle valve section, greatly simplifying the valve's internal structure, reducing space requirements, and improving operational reliability. It also makes the damping adjustable hydraulic lock more compact and suitable for direct mounting on the height-adjusting cylinder. Because the rear cylindrical surface of the one-way valve core slides against the inner bore of the valve seat, a high degree of concentricity is achieved, resulting in good guiding properties. When adjusting the throttle opening, the valve core is less prone to misalignment or jamming, thus ensuring high reliability for the entire one-way adjustable throttle valve. Attached Figure Description

[0020] Figure 1The schematic diagram shows the damping adjustable hydraulic lock applicable to the height adjustment cylinder of a coal mining machine.

[0021] Figure 2 A front view of one embodiment of the damping adjustable hydraulic lock applicable to the height adjustment cylinder of a coal mining machine;

[0022] Figure 3 for Figure 2 Left view of the embodiment shown;

[0023] Figure 4 for Figure 3 BB section view;

[0024] Figure 5 for Figure 3 CC section view;

[0025] Figure 6 for Figure 2 Top view of the embodiment shown;

[0026] Figure 7 for Figure 2 K-direction view;

[0027] Figure 8 for Figure 5 AA section view;

[0028] Figure 9 This is a schematic diagram of a half-section of the valve core of the one-way valve;

[0029] Figure 10 yes Figure 9 The left view.

[0030] Figure label:

[0031] 1-Valve seat; 2-Plug; 3-Nut; 4-Stud; 5-First sealing ring; 6-First retaining ring; 7-Second sealing ring; 8-Second retaining ring; 9-Throttle valve core; 10-Check valve core; 101-Outer conical surface; 102-Annular groove; 103-Flow channel; 11-Spring; 12-Spring seat; 13-Retaining ring; 14-Stop block; 15-Valve block; D1-First hydraulically controlled check valve; D2-Second hydraulically controlled check valve; D3-One-way adjustable throttle valve. Detailed Implementation

[0032] like Figure 1-10As shown, this utility model discloses a damping adjustable hydraulic lock (hereinafter referred to as a hydraulic lock) suitable for the height adjustment cylinder of a coal mining machine, including a valve block 15 and a first hydraulically controlled check valve D1, a second hydraulically controlled check valve D2, and a one-way adjustable throttle valve D3 installed on the valve block. Through a channel set inside the valve block, the inlet K11 of the first hydraulically controlled check valve and the hydraulic control port K23 of the second hydraulically controlled check valve are both connected to the first inlet P1 of the valve block. The outlet K12 of the first hydraulically controlled check valve is connected to the inlet K31 of the one-way adjustable throttle valve, and the outlet K32 of the one-way adjustable throttle valve is connected to the first outlet A of the valve block. The inlet K21 of the second hydraulically controlled check valve and the hydraulic control port K13 of the first hydraulically controlled check valve are both connected to the second inlet P2 of the valve block, and the outlet K22 of the second hydraulically controlled check valve is connected to the second outlet B of the valve block.

[0033] The first inlet, second inlet, first outlet, and second outlet of the valve block are all located on the bottom surface of the valve block. The valve block can be directly fixed to the hydraulic lock mounting surface reserved on the height adjustment cylinder using multiple bolts. This eliminates the need for high-pressure hoses and pipe fittings, minimizes the space occupied by the hydraulic lock, and also prevents pipe bursts and reduces the risk of external leakage. The first and second hydraulically controlled check valves are arranged horizontally in opposite directions and symmetrically, controlling the two chambers of the height adjustment cylinder respectively. The one-way adjustable throttle valve is arranged vertically.

[0034] The one-way adjustable throttle valve includes a valve seat 1, a one-way valve core 10, a spring 11, a throttle valve core 9, a stop block 14, a stud 4, a nut 3, and a plug 2. The valve seat is a tubular part, and several oil inlet holes are provided on the middle side wall along the length direction of the valve seat. These oil inlet holes serve as the inlet K31 of the one-way adjustable throttle valve. The parts before and after the oil inlet holes are respectively the front and rear parts of the valve seat (corresponding to...). Figure 8 (Lower and upper viewpoints). The inner hole at the front of the valve seat is configured as a stepped cylindrical hole, larger at the front and smaller at the rear. The rear part of the one-way valve core is slidably connected in the small-diameter cylindrical hole of the stepped cylindrical hole. The front part of the one-way valve core has an outer conical surface 101, larger at the front and smaller at the rear. The inner edge of the stepped surface of the stepped cylindrical hole and the outer conical surface form a one-way valve sealing pair in the form of a reverse cone valve. The front and rear parts of the one-way valve core are separated by an annular groove 102 with the groove opening facing outward. The rear part of the one-way valve core has a flow channel 103 that runs through the front and rear, which communicates with the annular groove. The one-way valve part of the one-way adjustable throttle valve has good sealing performance due to the use of a cone valve type. The spring is set in the inner hole of the valve seat, in front of the one-way valve core, and the spring is kept in a compressed state against the one-way valve core. The front port of the valve seat serves as the outlet K32 of the one-way adjustable throttle valve. The components inside the valve seat of the one-way adjustable throttle valve are arranged axially, and the inlet and outlet channels are arranged at right angles, which facilitates combination with other components to form a composite valve.

[0035] The check valve core has a hollow structure. The front end of the inner bore of the check valve core opens to the front port of the valve seat. The rear end of the inner bore of the check valve core is designed as a conical hole, smaller at the front and larger at the rear. The rear part of the throttle valve core is slidably connected to the inner bore of the rear part of the valve seat, and a seal is provided between the rear part of the throttle valve core and the valve seat. The front part of the throttle valve core is a truncated cone, smaller at the front and larger at the rear. Most of the outer conical surface of the truncated cone is radially opposite to the oil inlet. An annular gap, i.e., the throttle orifice, is formed between the outer conical surface of the front end of the truncated cone and the conical hole on the check valve core. The inner bore of the check valve core communicates with the oil inlet through this annular gap. Since the check valve core also serves as the valve seat of the throttle valve, it greatly simplifies the internal structure of the valve, helps to reduce the space occupied by the valve and improve the working reliability of the valve. It also makes the structure of the damping adjustable hydraulic lock more compact and more suitable for direct installation on the height adjustment cylinder. Because the outer cylindrical surface of the rear part of the one-way valve core is slidably connected to the inner hole of the valve seat, it can achieve a high degree of concentricity, thus providing good guidance. When adjusting the opening of the throttle orifice, the valve core of the throttle valve is not prone to deflection or jamming.

[0036] The stop block is threaded into the valve seat and located behind the throttle valve core. The stud is threaded into the core of the stop block and passes through the stop block, abutting against the rear end of the one-way valve core to limit the backward movement of the throttle valve core. The rear part of the stud is fixed relative to the stop block by screwing on the nut. The plug is threaded into the valve seat and abuts against the stop block from the rear to prevent the stop block from moving backward. Turning the stud forward pushes the throttle valve core forward, which can close the throttle orifice. When it is necessary to increase the throttle orifice, the stud is turned backward, leaving a gap between the throttle valve core and the stud, allowing the outlet of the one-way adjustable throttle valve to be connected to pressurized oil. The pressurized oil flows through the inner hole of the one-way valve core and acts on the throttle valve core, pushing the throttle valve core backward until it is against the front end face of the stud, forming and maintaining the adjusted throttle orifice. After the throttle opening is adjusted, the stud is locked by tightening the nut, thereby fixing the front and rear positions of the throttle valve core and thus fixing the size of the throttle opening. The stud, nut, and stop that make up the throttle opening adjustment mechanism are all located inside the valve seat and protected by a screw plug on the outside, which can effectively prevent them from being crushed or collided by coal blocks. They are easy to maintain and can be well adapted to the working environment of coal mines.

[0037] The rear outer cylindrical surface of the valve seat has, from front to back, a cylindrical section, an externally threaded section, and a polygonal prism section with progressively increasing equivalent diameters. The cylindrical section has an annular first sealing groove, within which a first sealing ring 7 is installed. During installation, the valve seat is installed in the one-way adjustable throttle valve socket on the valve block. The valve seat cooperates with and seals against the valve block through the cylindrical section and its sealing structure. The valve seat is axially positioned by the stepped surface between the polygonal prism section and the externally threaded section against one end face of the valve block. The valve seat is fixed in the valve block by the externally threaded section. All other parts of the one-way adjustable throttle valve are housed in the valve seat. In the installed state, only the valve seat contacts the valve block. Only the cylindrical section and the stepped surface between the polygonal prism section and the externally threaded section on the valve seat require high machining precision. Therefore, the installation reference machining is simple, and accuracy is easily guaranteed. If the one-way adjustable throttle valve is damaged, the entire unit can be replaced, and disassembly and assembly are very convenient.

[0038] The one-way adjustable throttle valve has two working states. One is the one-way conduction state, where the medium enters the valve seat through the inlet K31, overcoming the spring force to push the one-way valve core forward, causing the one-way valve core to move away from the throttle valve core, which is equivalent to the one-way valve opening. The medium flows through the inner hole of the one-way valve core and flows out through the outlet K32. After the inlet is depressurized, the spring pushes the one-way valve core to reset. The other is the reverse throttle state, where the medium enters the valve seat through the outlet K32, flows out through the inner hole of the one-way valve core, the annular gap between the throttle valve core and the one-way valve core, and the oil inlet. The presence of the annular gap generates a certain damping, which can limit the flow rate of the medium.

[0039] When the hydraulic lock is used in the control circuit of the height adjustment cylinder of the coal mining machine, the first outlet A of the hydraulic lock is connected to the rodless chamber of the height adjustment cylinder, and the second outlet B is connected to the rod chamber of the height adjustment cylinder. When the rocker arm rises, oil enters the rodless chamber side. A small amount of oil first opens the second hydraulic control check valve D2 on the rod chamber side through the hydraulic control circuit. After the rod chamber is depressurized, the first hydraulic control check valve D1 on the rodless chamber side also opens at the same time. The oil pressure in the rodless chamber pushes the piston of the height adjustment cylinder to move towards the rod chamber. The oil returning from the rod chamber returns to the oil sump through the second hydraulic control check valve. There is no additional resistance in the system's inlet and outlet oil circuits. When the rocker arm descends, oil enters the rod chamber. A small amount of oil first opens the first hydraulic check valve D1 on the rodless chamber side through the hydraulic control circuit. After the rodless chamber is depressurized, the second hydraulic check valve D2 on the rod chamber side also opens simultaneously. The oil pressure in the rod chamber pushes the piston of the height adjustment cylinder to move towards the rodless chamber. The one-way adjustable throttle valve is in a reverse throttling state. The oil returning from the rodless chamber passes through the throttling and speed-limiting point of the one-way adjustable throttle valve and then returns to the oil sump through the first hydraulic check valve. During this period, as long as the opening of the throttle orifice of the one-way adjustable throttle valve is adjusted according to the weight of different rollers and rocker arms to form a suitable damping, a certain back pressure is formed on the rodless chamber side after the oil returning from the rodless chamber passes through the throttle orifice. This prevents the moving parts such as the rollers and rocker arms from descending at excessive speed, and the oil inlet will not lose pressure. In this way, the first hydraulic check valve is in a normally open state under the action of stable hydraulic control oil pressure, and the valve port will not experience frequent impacts and vibrations. Therefore, the problem of rocker arm descent vibration can be completely solved.

[0040] The hydraulic lock of this invention can be further optimized in one or more of the following aspects:

[0041] 1. The inlet and outlet ports of the one-way valve section of the aforementioned one-way adjustable throttle valve are arranged at right angles, with the outlet located at the front port of the tubular valve seat. By setting a valve seat of sufficient diameter and a sufficient opening height for the one-way valve core, this one-way valve section can achieve a large flow rate to adapt to high-flow-rate applications. The flow channel at the rear of the one-way valve core is preferably configured as multiple fan-shaped cross-section channels to maximize the flow cross-sectional area and reduce flow resistance, enabling the one-way valve section to be suitable for more applications and larger flow rates.

[0042] Furthermore, the fan-shaped cross-section of the channel can be configured as a radially externally open structure, and multiple channels are evenly distributed around the circumference, so that while the one-way valve part can adapt to high flow rate applications, the rear part of the one-way valve core still maintains a sliding connection with the valve seat and balanced guidance.

[0043] 2. The oil inlet holes can be evenly distributed around the axis of the valve seat.

[0044] 3. The front end of the one-way valve core may be provided with an annular groove, and the rear end of the spring is embedded in the annular groove, which saves space and makes the spring installation reliable.

[0045] Furthermore, the front end of the one-way valve core can be configured as a protruding tube structure, with the spring sleeved on the tube to prevent unnecessary lateral displacement or deformation of the spring and improve the working reliability of the spring.

[0046] 4. The one-way adjustable throttle valve may further include a spring seat 12, the spring seat fitting its outer cylindrical surface into the inner hole at the front of the valve seat, the front end of the spring abutting against the spring seat, and the spring seat being restricted from moving forward by a retaining ring 3 installed in the inner hole of the valve seat. The spring seat is an annular structure with its axis extending front and back, and its outer cylindrical surface has multiple through notches, the annular inner hole and the notches communicating with the front port of the valve seat.

[0047] 5. A first retaining ring may also be provided behind the first sealing ring in the first sealing groove to prevent the first sealing ring from being damaged due to being squeezed into the gap between the valve core and the valve seat of the throttle valve.

[0048] 6. The outer cylindrical surface at the rear of the throttle valve core is provided with an annular second sealing groove. The second sealing groove is provided with a second sealing ring and a second retaining ring at the front and rear respectively. Similarly, the second retaining ring can prevent the second sealing ring from being damaged by being squeezed into the gap between the valve seat and the valve block.

[0049] 7. The rear end face of the screw plug has multiple pin holes, which can be used to install special tools to facilitate the removal of the screw plug.

[0050] 8. The inner hole at the rear of the valve seat is set as a stepped hole with a smaller front and a larger rear. The rear part of the throttle valve core is slidably connected in the small diameter cylindrical hole of the stepped hole. The stop block and the screw plug are installed in the large diameter threaded hole of the stepped hole, and the front end face of the stop block rests on the stepped surface of the stepped hole.

[0051] 9. The first and second hydraulically controlled check valves are preferably CK series check valves from Shengxu Hydraulics, and are installed in their respective mounting holes in the valve block using a threaded cartridge mounting method (see [link]). Figure 6 , 7 ).

[0052] 10. The cone angle of the conical hole on the one-way valve core is preferably greater than the cone angle of the front part of the throttle valve core. This can increase the opening at the end edge of the throttle outlet, which is beneficial to slow down the fluid flow rate, reduce hydraulic shock, and avoid system vibration, noise, damage to hydraulic components, or valve malfunction that may occur under extreme conditions.

[0053] The first and second hydraulic control check valves and the one-way adjustable throttle valve each perform one or more hydraulic functions. Since they are independent and can be disassembled as a whole, they are not only easy to replace, but also simple to process. Only the necessary valve installation reference and a small number of hydraulic control ports and connection channels between inlets and outlets are required. While ensuring the function of the damping adjustable hydraulic lock, it also greatly facilitates use and maintenance.

[0054] The use of "before" and "after" in this article is for ease of expression and is not a limitation on absolute location.

Claims

1. A damping adjustable hydraulic lock suitable for the height adjustment cylinder of a coal mining machine, characterized in that: The valve block includes a valve block and a first hydraulically controlled check valve, a second hydraulically controlled check valve, and a one-way adjustable throttle valve mounted on the valve block. Through a channel inside the valve block, the inlet of the first hydraulically controlled check valve and the hydraulic control port of the second hydraulically controlled check valve are both connected to the first inlet of the valve block. The outlet of the first hydraulically controlled check valve is connected to the inlet of the one-way adjustable throttle valve, and the outlet of the one-way adjustable throttle valve is connected to the first outlet of the valve block. The inlet of the second hydraulically controlled check valve and the hydraulic control port of the first hydraulically controlled check valve are both connected to the second inlet of the valve block, and the outlet of the second hydraulically controlled check valve is connected to the second outlet of the valve block. The first inlet, second inlet, first outlet, and second outlet of the valve block are all located on the bottom surface of the valve block. The first and second hydraulically controlled check valves are arranged horizontally in opposite directions and symmetrically, while the one-way adjustable throttle valve is arranged vertically.

2. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as described in claim 1, characterized in that: The one-way adjustable throttle valve includes a valve seat, a one-way valve core, a spring, a stop block, a stud, a nut, and a plug. The valve seat is a tubular part, and several oil inlet holes are provided on the middle side wall of the valve seat along its length. These oil inlet holes serve as the inlet of the one-way adjustable throttle valve. The parts before and after the oil inlet holes are respectively the front and rear parts of the valve seat. The inner hole of the front part of the valve seat is set as a stepped cylindrical hole with a larger diameter at the front and a smaller diameter at the rear. The rear part of the one-way valve core is slidably connected in the small-diameter cylindrical hole of the stepped cylindrical hole. The front part of the one-way valve core has an outer conical surface with a larger diameter at the front and a smaller diameter at the rear. The inner edge of the stepped surface and the outer conical surface form a one-way valve sealing pair in the form of a reverse cone valve. The front and rear parts of the one-way valve core are separated by an annular groove with the groove facing outwards radially. The rear part of the one-way valve core has a flow channel that runs through the front and rear, and this flow channel communicates with the annular groove. The spring is set in the inner hole of the valve seat, in front of the one-way valve core. The spring is kept in a compressed state and abuts against the one-way valve core. The front port of the valve seat acts as the outlet of the one-way adjustable throttle valve. The one-way valve core has a hollow structure. The front end of the inner hole of the one-way valve core opens to the front port of the valve seat, and the rear end of the inner hole of the one-way valve core is set to be smaller at the front. The throttle valve core has a large conical bore at the rear, and its rear part is slidably connected to the inner bore at the rear of the valve seat. A seal is provided between the rear part of the throttle valve core and the valve seat. The front part of the throttle valve core is a truncated cone with a smaller front and a larger rear. An annular gap is formed between the outer conical surface of the front end of the truncated cone and the conical bore on the check valve core. The inner bore of the check valve core communicates with the oil inlet through this annular gap. The stop block is threadedly connected to the valve seat and located behind the throttle valve core. The stud is threadedly connected to the core of the stop block and passes through the stop block, abutting against the rear end of the check valve core. The rear part of the stud is connected to the nut by screwing it on. The stop block is fixed, and the screw plug is threadedly connected to the valve seat and abuts against the stop block from the rear. The rear outer cylindrical surface of the valve seat is provided with a cylindrical section, an external thread section and a polygonal prism section with progressively increasing equivalent diameter from front to back. The cylindrical section is provided with an annular first sealing groove, and a first sealing ring is provided in the first sealing groove. The valve seat is installed in the one-way adjustable throttle valve socket on the valve block. The valve seat cooperates with the valve block and seals through the cylindrical section. The valve seat is axially positioned by the stepped surface between the polygonal prism section and the external thread section against one end face of the valve block. The valve seat is fixed in the valve block through the external thread section.

3. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as described in claim 2, characterized in that: The front end of the one-way valve core is provided with an annular groove, and the rear end of the spring is embedded in the annular groove.

4. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as described in claim 2, characterized in that: The one-way adjustable throttle valve also includes a spring seat, the front end of the spring abuts against the spring seat, the spring seat is fixed in the inner hole at the front of the valve seat, and the forward movement of the spring seat is restricted by a retaining ring installed in the inner hole of the valve seat. The spring seat is an annular structure with its axis extending back and forth, and the annular inner hole communicates with the front port of the valve seat.

5. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as described in claim 2, characterized in that: A first retaining ring is also provided behind the first sealing ring in the first sealing groove.

6. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as described in claim 2, characterized in that: The outer cylindrical surface at the rear of the throttle valve core is provided with an annular second sealing groove, and a second sealing ring and a second retaining ring are respectively provided in the front and rear of the second sealing groove.

7. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as described in claim 2, characterized in that: The rear end face of the screw plug has multiple pin holes.

8. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as described in claim 2, characterized in that: The inner hole at the rear of the valve seat is set as a stepped hole with a smaller front and a larger rear. The rear part of the throttle valve core is slidably connected in the small-diameter cylindrical hole of the stepped hole. The stop block and the screw plug are installed in the large-diameter threaded hole of the stepped hole, and the front end face of the stop block rests on the stepped surface of the stepped hole.

9. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as described in claims 2, 3, 4, 5, 6, 7, or 8, characterized in that: The first and second hydraulically controlled check valves are CK series check valves from Shengxu Hydraulics, and are installed in the valve block using a threaded cartridge mounting method.

10. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as described in claims 2, 3, 4, 5, 6, 7, or 8, characterized in that: The cone angle of the conical hole on the one-way valve core is greater than the cone angle of the front part of the throttle valve core.

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