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

Abstract

The invention 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 element 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] The invention relates to a hydraulic lock, in particular to a hydraulic lock used for controlling an oil circuit of a height adjustment oil cylinder of a coal mining machine. The hydraulic lock is not easily damaged and has a long service life. Background Art

[0002] A hydraulic lock is installed on the control oil circuit of the coal mining machine's height adjustment cylinder. During the descent of the coal mining machine's rocker arm, the rocker arm and the drum often descend at an overspeed due to their own weight, which will cause insufficient oil supply to the oil inlet chamber of the height adjustment cylinder, and the oil inlet pressure will drop instantly or even disappear, causing the hydraulic lock to close due to the loss of control oil pressure. After closing, the hydraulic lock opens again as the oil supply continues and the oil inlet pressure is re-established. Due to the occasional opening and closing, the rocker arm movement is intermittent, and the height adjustment oil pipe shakes violently, generating greater impact and noise. The hydraulic lock valve core connected to the large chamber (i.e., 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 on the working surface of a hard coal seam, the rocker arm is subjected to greater impact and vibration, the load change of the height adjustment cylinder is more complicated, and the probability of damage to the hydraulic lock is higher. Summary of the invention

[0003] The present invention aims to provide a damping adjustable hydraulic lock suitable for a coal mining machine height adjustment cylinder. When the rocker arm is raised, there will be no frequent impact and vibration between the valve core and the valve seat, so the service life is longer and the rocker arm can be prevented from shaking when it descends.

[0004] The main technical solutions of the present invention are:

[0005] A damping-adjustable hydraulic lock suitable for a coal mining machine height adjustment cylinder comprises a valve block and a first hydraulically controlled one-way valve, a second hydraulically controlled one-way valve and an adjustable one-way throttle valve installed on the valve block. Through a channel arranged inside the valve block, the inlet of the first hydraulically controlled one-way valve and the hydraulically controlled port of the second hydraulically controlled one-way valve are both connected to the first inlet of the valve block, the outlet of the first hydraulically controlled one-way valve is connected to the inlet of the adjustable one-way throttle valve, the outlet of the adjustable one-way throttle valve is connected to the first outlet of the valve block, the inlet of the second hydraulically controlled one-way valve and the hydraulically controlled port of the first hydraulically controlled one-way valve are both connected to the second inlet of the valve block, and the outlet of the second hydraulically controlled one-way valve is connected to the second outlet of the valve block.

[0006] The one-way adjustable throttle valve may include a valve seat, a one-way valve core, a spring, a throttle valve core, a stopper, a stud, a nut and a screw plug. The valve seat is a tubular part. A plurality of oil inlet holes are arranged on the middle side wall in the length direction of the valve seat. The oil inlet holes serve as the inlet of the one-way adjustable throttle valve. The parts before and after the oil inlet holes are the front and rear parts of the valve seat respectively. The inner hole in the front part of the valve seat is arranged as a stepped cylindrical hole with a larger front part and a smaller rear part. 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 is provided with an outer conical surface with a larger front part and a smaller rear part. The inner edge of the step surface and the outer conical surface form a one-way valve sealing pair in the form of an inverted cone valve. The front and rear parts of the one-way valve core are separated by an annular groove with the notch radially facing outward. The rear part of the one-way valve core is provided with a flow channel that passes through the front and back, and the flow channel is connected to the annular groove. The spring is arranged in the inner hole of the valve seat and in front of the one-way valve core. The spring is kept in a compressed state and pressed against the one-way valve core. The front port of the valve seat serves as the outlet of the one-way adjustable throttle valve. The one-way valve core is a hollow structure. The front end of the inner hole of the one-way valve core leads to the front port of the valve seat, and the rear end of the inner hole of the one-way valve core is arranged as a front The throttle valve core is a conical hole that is small at the front and large at the back. The rear of the throttle valve core is slidably connected to the inner hole at the rear of the valve seat. A seal is arranged between the rear of the throttle valve core and the valve seat. The front of the throttle valve core is a frustum that is small at the front and large at the back. An annular gap is formed between the outer cone surface of the front end of the frustum and the conical hole on the one-way valve core. The inner hole of the one-way valve core is connected to the oil inlet hole through the annular gap. The stopper is threadedly connected to the valve seat and is located at the rear of the throttle valve core. The stud is threadedly connected to the core of the stopper and passes through the stopper to abut against the rear end of the one-way valve core. The rear of the stud is connected to the nut by screwing To fix the stopper, the screw plug is threadedly connected in the valve seat and resists the stopper from the rear; a cylindrical section, an external thread section and a polygonal column section with equivalent diameters increasing successively are provided on the rear outer cylindrical surface of the valve seat from front to rear; a first annular sealing groove is provided on the cylindrical section; a first sealing ring is provided in the first sealing groove; the valve seat is installed in a one-way adjustable throttle valve socket on the valve block; the valve seat cooperates and seals with the valve block through the cylindrical section; the valve seat is against one end face of the valve block through the step surface between the polygonal column section and the external thread section to realize axial positioning of the valve seat; the valve seat is fixed in the valve block through the external thread section.

[0007] The oil inlet holes are preferably evenly distributed around the circumference of the valve seat with the axis of the valve seat as the axis.

[0008] 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.

[0009] The one-way adjustable throttle valve may also include a spring seat, the front end of the spring rests on the spring seat, the spring seat is fixed in the inner hole in the front part of the valve seat, and the forward movement of the spring seat is limited by a retaining ring installed in the inner hole of the valve seat. The spring seat is an annular structure extending forward and backward with an axis, and the annular inner hole is connected to the front port of the valve seat.

[0010] A first retaining ring is also provided behind the first sealing ring in the first sealing groove.

[0011] An annular second sealing groove is arranged on the outer cylindrical surface of the rear part of the throttle valve core, and a second sealing ring and a second retaining ring are arranged in the front and rear of the second sealing groove respectively.

[0012] A plurality of pin holes are arranged on the rear end surface of the screw plug.

[0013] The inner hole at the rear of the valve seat can be set as a stepped hole with a small front and a large rear. The rear of the throttle valve core is slidably connected in the small-diameter cylindrical hole of the stepped hole. The stopper and the screw plug are installed in the large-diameter threaded hole of the stepped hole, and the front end face of the stopper rests on the step surface of the stepped hole.

[0014] The first hydraulically controlled non-return valve and the second hydraulically controlled non-return valve can be CK series non-return valves produced by Shengxu Hydraulics Co., Ltd., and can be installed in the valve block by threaded insertion.

[0015] The cone angle of the conical hole on the one-way valve core is preferably greater than the cone angle of the front portion of the throttle valve core.

[0016] The beneficial effects of the present invention are:

[0017] By setting a one-way adjustable throttle valve on the downstream oil line of one of the hydraulically controlled one-way valves, back pressure can be provided when the rocker arm descends. By limiting the descending speed of the rocker arm, the rocker arm can be smoothly lowered, jitter can be eliminated, and damage caused by frequent impact of the hydraulic lock valve core on the valve seat can be avoided, thereby extending the service life and working stability of the hydraulic lock.

[0018] Since 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, so that the hydraulic lock can be better adapted to the height adjustment cylinder control circuit of different models.

[0019] Since the hydraulically controlled one-way valve and the one-way adjustable throttle valve can be installed on the valve block as a whole, they have a compact structure, high integration, and are easy to disassemble and assemble. They can be replaced as a whole when damaged, which can effectively reduce maintenance costs.

[0020] The one-way valve core of the one-way adjustable throttle valve also serves as the valve seat of the throttle valve part, which can greatly simplify the internal structure of the valve, help reduce the space occupied by the valve and improve the working reliability of the valve, and also make the structure of the damping adjustable hydraulic lock more compact and more suitable for direct installation on the height adjustment cylinder. Since the outer cylindrical surface of the rear of the one-way valve core is slidably connected with the inner hole of the valve seat, a high concentricity can be achieved, so the guiding property is good. When adjusting the throttle opening, the throttle valve core is not easy to deflect or get stuck, so the whole one-way adjustable throttle valve has high working reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The schematic diagram of the damping adjustable hydraulic lock suitable for the height adjustment cylinder of the coal mining machine;

[0022] Figure 2 It is a front view of an embodiment of the damping adjustable hydraulic lock applicable to the height adjustment cylinder of the coal mining machine;

[0023] Figure 3 for Figure 2 a left side view of the illustrated embodiment;

[0024] Figure 4 for Figure 3 BB cross-sectional view;

[0025] Figure 5 for Figure 3 CC section view;

[0026] Figure 6 for Figure 2 A cross-sectional view of the embodiment shown in the top view;

[0027] Figure 7 for Figure 2 K-direction view;

[0028] Figure 8 for Figure 5 AA section view;

[0029] Fig. 9 is a schematic diagram of a half-section structure of the one-way valve core;

[0030] Fig.10 yes Fig. 9 Left view of .

[0031] Reference numerals:

[0032] 1-valve seat; 2-screw 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 cone; 102-annular groove; 103-flow channel; 11-spring; 12-spring seat; 13-retaining ring; 14-block; 15-valve block; D1-first hydraulically controlled check valve; D2-second hydraulically controlled check valve; D3-one-way adjustable throttle valve. DETAILED DESCRIPTION

[0033] like Figure 1-10As shown, the present invention discloses a damping adjustable hydraulic lock (referred to as a hydraulic lock) suitable for the height adjustment cylinder of a coal mining machine, comprising a valve block 15 and a first hydraulically controlled one-way valve D1, a second hydraulically controlled one-way valve D2 and a one-way adjustable throttle valve D3 installed on the valve block. Through a channel arranged inside the valve block, the inlet K11 of the first hydraulically controlled one-way valve and the hydraulically controlled port K23 of the second hydraulically controlled one-way valve are both connected to the first inlet P1 of the valve block, the outlet K12 of the first hydraulically controlled one-way valve is connected to the inlet K31 of the one-way adjustable throttle valve, 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 one-way valve and the hydraulically controlled port K13 of the first hydraulically controlled one-way valve are both connected to the second inlet P2 of the valve block, and the outlet K22 of the second hydraulically controlled one-way valve is connected to the second outlet B of the valve block.

[0034] The first inlet, second inlet, first outlet and second outlet of the valve block are all arranged on the bottom surface of the valve block. The valve block can be directly fixed on the hydraulic lock installation surface reserved on the height adjustment cylinder by multiple bolts. No high-pressure hoses and pipe joints are required, the hydraulic lock takes up little space, and can also avoid pipe bursts and reduce the risk of external leakage. The first and second hydraulically controlled one-way valves are arranged horizontally and symmetrically, respectively controlling the two chambers of the height adjustment cylinder. The one-way adjustable throttle valve is arranged vertically.

[0035] The one-way adjustable throttle valve comprises a valve seat 1, a one-way valve core 10, a spring 11, a throttle valve core 9, a stopper 14, a stud 4, a nut 3 and a screw plug 2. The valve seat is a tubular part, and a plurality of oil inlet holes are arranged on the middle side wall of the valve seat in the longitudinal direction, and the 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 The inner hole in the front of the valve seat is set as a stepped cylindrical hole with a larger front and a smaller rear. The rear of the one-way valve core is slidably connected in the small-diameter cylindrical hole of the stepped cylindrical hole. The front of the one-way valve core is provided with an outer conical surface 101 with a larger front and a smaller rear. The inner edge of the step surface of the stepped cylindrical hole and the outer conical surface form a one-way valve sealing pair in the form of an inverted cone valve. The front and rear parts of the one-way valve core are separated by an annular groove 102 with the notch radially facing outward. The rear of the one-way valve core is provided with a flow channel 103 that passes through the front and back, and the flow channel is connected to the annular groove. The one-way valve part of the one-way adjustable throttle valve adopts a cone valve type, so the closing sealing performance is good. The spring is arranged in the inner hole of the valve seat and 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 in 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 is convenient for combination with other components to form a composite valve.

[0036] The one-way valve core is a hollow structure, the front end of the inner hole of the one-way valve core leads to the front port of the valve seat, the rear end of the inner hole of the one-way valve core is set as a conical hole with a small front and a large rear, the rear part of the throttle valve core is slidably connected to the inner hole of the rear part of the valve seat, and a seal is set between the rear part of the throttle valve core and the valve seat. The front part of the throttle valve core is a frustum with a small front and a large rear, most of the outer cone surface of the frustum is opposite to the oil inlet hole in the radial direction, and an annular gap, i.e., a throttle port, is formed between the outer cone surface of the front end of the frustum and the conical hole on the one-way valve core, and the inner hole of the one-way valve core is connected to the oil inlet hole through the annular gap. Since the one-way valve core also serves as the valve seat of the throttle valve part, the internal structure of the valve can be greatly simplified, which helps to reduce the space occupied by the valve and improve the working reliability of the valve, and can also make 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 with the inner hole of the valve seat, a higher concentricity can be achieved, so the guiding property is good. When adjusting the throttle opening, the throttle valve core is not easy to deflect or get stuck.

[0037] The block is threadedly connected in the valve seat and is located behind the throttle valve core. The stud is threadedly connected to the core of the block and passes through the block to abut against the rear end of the one-way valve core, which is used to limit the backward movement of the throttle valve core. The rear of the stud is fixed relative to the block by screwing the nut. The screw plug is threadedly connected in the valve seat and abuts against the block from the rear to prevent the block from moving backward. The throttle valve core can be pushed forward by screwing the stud forward to close the throttle port. When the throttle port needs to be increased, the stud is screwed out backward to leave a gap between the throttle valve core and the stud, so that the outlet of the one-way adjustable throttle valve is connected to the pressure oil. The oil with a certain pressure flows through the inner hole of the one-way valve core and acts on the throttle valve core, pushing the throttle valve core backward to the front end face of the stud to form and maintain the adjusted throttle port. After the throttle opening is adjusted, the stud is locked by tightening the nut to fix the front and rear position of the throttle valve core, thereby fixing the size of the throttle opening. The stud, nut and block that make up the throttle opening adjustment mechanism are all set inside the valve seat, and the outside is protected by a screw plug, which can effectively avoid being squeezed and collided by coal blocks, is easy to maintain, and can adapt well to the working environment of coal mines.

[0038] The rear outer cylindrical surface of the valve seat is provided with a cylindrical section, an external thread section and a multi-prism section with increasing equivalent diameters from front to back. The cylindrical section is provided with a first annular sealing groove, and a first sealing ring 7 is provided in the first sealing groove. During installation, the valve seat is installed in the one-way adjustable throttle valve jack on the valve block. The valve seat cooperates and seals with the valve block through the cylindrical section and the sealing structure thereon. The valve seat is pressed against one end face of the valve block through the step surface between the multi-prism section and the external thread section to realize the axial positioning of the valve seat. The valve seat is fixed in the valve block through the external thread section. All other parts of the one-way adjustable throttle valve are arranged in the valve seat. In the installed state, only the valve seat is in contact with the valve block, and only the cylindrical section and the step surface between the multi-prism section and the external thread section on the valve seat have high processing accuracy requirements. Therefore, the installation base processing is simple, and the accuracy is easy to ensure. Once the one-way adjustable throttle valve is damaged, it can be replaced as a whole, and it is very convenient to disassemble and assemble.

[0039] The one-way adjustable throttle valve has two working states, one is a one-way conduction state, in which the medium enters the valve seat from the inlet K31, overcomes the elastic force of the spring to push the one-way valve core forward, and makes the one-way valve core move away from the throttle valve core, which is equivalent to the one-way valve opening, and the medium flows through the inner hole of the one-way valve core and flows out from the outlet K32. After the inlet pressure is relieved, the spring pushes the one-way valve core to reset; the other is a reverse throttling state, in which the medium enters the valve seat from 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 hole, and the existence of the annular gap produces a certain damping, which can limit the flow rate of the medium.

[0040] 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, and 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 is also opened at the same time, and the oil pressure in the rodless chamber pushes the piston of the height adjustment cylinder to move toward the rod chamber. The return oil from the rod chamber returns to the oil pool through the second hydraulic control check valve, and there is no additional resistance in the inlet and outlet oil circuits of the system. When the rocker arm descends, oil enters the rod chamber side, and a small amount of oil first opens the first hydraulically controlled one-way valve D1 on the rodless chamber side through the hydraulic control circuit. After the rodless chamber is depressurized, the second hydraulically controlled one-way valve D2 on the rod chamber side is also opened at the same time. The oil pressure in the rod chamber pushes the piston of the height adjustment cylinder to move toward the rodless chamber, and the one-way adjustable throttle valve is in a reverse throttling state. The return oil from the rodless chamber passes through the throttle speed limiter at the one-way adjustable throttle valve and then returns to the oil pool through the first hydraulically controlled one-way valve. During this period, as long as the throttle opening of the one-way adjustable throttle valve is adjusted according to the weight of different rollers and rocker arms to form a suitable damping, when the return oil from the rodless chamber passes through the throttle port, a certain back pressure is formed on the rodless chamber side, so that the moving parts such as the roller and rocker arm will not descend at an excessive speed, and the oil inlet will not lose pressure. In this way, the first hydraulically controlled one-way valve is in a normally open state under the action of stable hydraulic control oil pressure, and the valve port will not experience frequent impact and vibration, so the problem of rocker arm descending and shaking can be completely solved.

[0041] The hydraulic lock of the present invention can also be optimized in one or more of the following aspects:

[0042] 1. The oil inlet and outlet of the one-way valve part of the one-way adjustable throttle valve are arranged at right angles, and the outlet is at the front port of the tubular valve seat. By setting a valve seat with a sufficient diameter and a sufficient opening height of the one-way valve core, the one-way valve part can have a large flow rate to adapt to large flow occasions. The flow channel at the rear of the one-way valve core is preferably arranged as a plurality of fan-shaped cross-section channels to maximize the flow cross-sectional area and reduce the flow resistance, so that the one-way valve part can be applied to more occasions and larger flow rates.

[0043] Furthermore, the channel of the fan-shaped cross-section can be set as a radial external opening structure, and multiple channels are evenly distributed around the circumference, so that the one-way valve part can adapt to large flow situations while the rear of the one-way valve core still maintains a sliding connection with the valve seat and balanced guidance.

[0044] 2. The oil inlet holes can be evenly distributed around the circumference of the valve seat axis.

[0045] 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.

[0046] Furthermore, the front end middle portion of the one-way valve core can also be configured as a forward-convex tube structure, and the spring is sleeved on the tube, which can prevent unnecessary lateral displacement or deformation of the spring and improve the working reliability of the spring.

[0047] 4. The one-way adjustable throttle valve may also include a spring seat 12, the outer cylindrical surface of the spring seat fits in the inner hole in front of the valve seat, the front end of the spring abuts against the spring seat, and the spring seat uses a retaining ring 3 installed in the inner hole of the valve seat to limit the forward movement of the spring seat. The spring seat is an annular structure with an axis extending forward and backward, and a plurality of notches are provided on its outer cylindrical surface, and the annular inner hole and the notch are both connected to the front port of the valve seat.

[0048] 5. A first retaining ring may be further 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 throttle valve core and the valve seat.

[0049] 6. An annular second sealing groove is provided on the outer cylindrical surface of the rear part of the throttle valve core, and a second sealing ring and a second retaining ring are respectively provided in the front and rear of the second sealing groove. 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.

[0050] 7. There are multiple pin holes on the rear end surface of the screw plug, which can be used to install special tools to facilitate the removal of the screw plug.

[0051] 8. The inner hole at the rear of the valve seat is set as a stepped hole with a small front and a large rear. The rear of the throttle valve core is slidably connected in the small-diameter cylindrical hole of the stepped hole. The stopper and the screw plug are installed in the large-diameter threaded hole of the stepped hole, and the front end face of the stopper rests on the step surface of the stepped hole.

[0052] 9. The first hydraulically controlled one-way valve and the second hydraulically controlled one-way valve are preferably CK series one-way valves of Shengxu Hydraulic Co., Ltd., and are installed in their respective mounting holes in the valve block by threaded insertion (see Figure 6 , 7 ).

[0053] 10. The cone angle of the conical hole on the one-way valve core is preferably larger than the cone angle of the front part of the throttle valve core, which can expand the opening on the end edge at the throttle outlet, which is beneficial to slow down the liquid flow speed, reduce hydraulic shock, and avoid system vibration, noise, hydraulic component damage or valve malfunction that may be caused under extreme conditions.

[0054] The first and second hydraulically controlled one-way valves and the one-way adjustable throttle valve each bear one or more hydraulic functions. Since they are independent and can be disassembled and assembled as a whole, they are not only convenient to disassemble and replace, but also simple to process the valve block. Only the necessary valve installation reference and a small number of connecting channels between the hydraulic control port and the inlet and outlet need to be set. This greatly facilitates use and maintenance while ensuring the function of the damping adjustable hydraulic lock.

[0055] The terms "front and back" in this article are for the convenience of expression and are not a limitation of absolute positions.

Claims

1. A damping adjustable hydraulic lock suitable for the height adjustment cylinder of a coal mining machine, characterized by: It includes a valve block and a first hydraulically controlled one-way valve, a second hydraulically controlled one-way valve and a one-way adjustable throttle valve installed on the valve block. Through a channel arranged inside the valve block, the inlet of the first hydraulically controlled one-way valve and the hydraulically controlled port of the second hydraulically controlled one-way valve are both connected to the first inlet of the valve block, the outlet of the first hydraulically controlled one-way valve is connected to the inlet of the one-way adjustable throttle valve, 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 one-way valve and the hydraulically controlled port of the first hydraulically controlled one-way valve are both connected to the second inlet of the valve block, and the outlet of the second hydraulically controlled one-way valve is connected to the second outlet of the valve block.

2. The damping adjustable hydraulic lock suitable for the height adjustment cylinder of a coal mining machine as claimed in claim 1, characterized in that: The one-way adjustable throttle valve comprises a valve seat, a one-way valve core, a spring, a throttle valve core, a stopper, a stud, a nut and a screw plug. The valve seat is a tubular part. A plurality of oil inlet holes are arranged on the middle side wall in the length direction of the valve seat. The oil inlet holes serve as the inlet of the one-way adjustable throttle valve. The parts before and after the oil inlet holes are the front and rear parts of the valve seat respectively. The inner hole in the front part of the valve seat is arranged as a stepped cylindrical hole with a larger front part and a smaller rear part. 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 is provided with an outer conical surface with a larger front part and a smaller rear part. The stepped cylindrical hole has a The inner edge of the step surface and the outer conical surface form a one-way valve sealing pair in the form of an inverted cone valve. The front and rear parts of the one-way valve core are separated by an annular groove with the notch radially facing outward. The rear part of the one-way valve core is provided with a flow channel that passes through the front and back, and the flow channel is connected to the annular groove. The spring is arranged in the inner hole of the valve seat and in front of the one-way valve core. The spring is kept in a compressed state and pressed against the one-way valve core. The front port of the valve seat serves as the outlet of the one-way adjustable throttle valve. The one-way valve core is a hollow structure. The front end of the inner hole of the one-way valve core leads to the front port of the valve seat, and the rear end of the inner hole of the one-way valve core is arranged as a front small The rear part of the throttle valve core is slidably connected to the inner hole at the rear part of the valve seat, a seal is arranged between the rear part of the throttle valve core and the valve seat, the front part of the throttle valve core is a frustum of cone with a small front and a large rear, an annular gap is formed between the outer cone surface of the front end of the frustum of cone and the conical hole on the one-way valve core, the inner hole of the one-way valve core is communicated with the oil inlet hole through the annular gap, the stopper is threadedly connected to the valve seat and is located at the rear of the throttle valve core, the stud is threadedly connected to the core of the stopper and passes through the stopper to abut against the rear end of the one-way valve core, the rear part of the stud is screwed to the nut To fix the stopper, the screw plug is threadedly connected in the valve seat and resists the stopper from the rear; a cylindrical section, an external thread section and a polygonal column section with equivalent diameters increasing successively are provided on the rear outer cylindrical surface of the valve seat from front to rear; a first annular sealing groove is provided on the cylindrical section; a first sealing ring is provided in the first sealing groove; the valve seat is installed in a one-way adjustable throttle valve socket on the valve block; the valve seat cooperates and seals with the valve block through the cylindrical section; the valve seat is against one end face of the valve block through the step surface between the polygonal column section and the external thread section to realize axial positioning of the valve seat; the valve seat is fixed in the valve block through the external thread section.

3. The damping adjustable hydraulic lock suitable for the height adjustment cylinder of a coal mining machine as claimed in claim 2, characterized in that: The oil inlet holes are evenly distributed around the circumference of the valve seat with the axis of the valve seat as the axis.

4. The damping adjustable hydraulic lock suitable for the height adjustment cylinder of a coal mining machine as claimed 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.

5. The damping adjustable hydraulic lock suitable for the height adjustment cylinder of a coal mining machine as claimed in claim 2, characterized in that: The one-way adjustable throttle valve also includes a spring seat, the front end of the spring rests on the spring seat, the spring seat is fixed in the inner hole in the front part of the valve seat, and the forward movement of the spring seat is limited by a retaining ring installed in the inner hole of the valve seat. The spring seat is an annular structure extending forward and backward with an axis, and the annular inner hole is communicated with the front port of the valve seat.

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

7. The damping adjustable hydraulic lock suitable for the height adjustment cylinder of a coal mining machine as claimed in claim 2, characterized in that: An annular second sealing groove is arranged on the outer cylindrical surface of the rear part of the throttle valve core, and a second sealing ring and a second retaining ring are arranged in the front and rear of the second sealing groove respectively.

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

9. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as claimed in claim 2, 3, 4, 5, 6, 7 or 8, characterized in that: The first hydraulically controlled non-return valve and the second hydraulically controlled non-return valve are CK series non-return valves produced by Shengxu Hydraulic Co., Ltd., and are installed in the valve block by threaded insertion.

10. The damping adjustable hydraulic lock for the height adjustment cylinder of a coal mining machine as claimed in claim 2, 3, 4, 5, 6, 7, 8 or 9, 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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