Lifting valve of mining truck

Abstract

A mining truck lifting valve comprises a three-position three-way reversing valve, and a shuttle valve, a pressure reducing valve, two sequence valves and an electromagnetic valve are arranged on the reversing valve. Oil inlets P and P1, oil return ports T and L, control interfaces K1 and K2 and a working port A are formed; an oil inlet P is respectively communicated with a first sequence valve, a pressure reducing valve and one end of a shuttle valve, an oil inlet P1 and an outlet of the first sequence valve are both communicated with a port P of a reversing valve, a pressure reducing outlet of the pressure reducing valve is respectively communicated with inlets of two electromagnetic valves, an overflow port of the pressure reducing valve and an oil drainage port of each electromagnetic valve are respectively communicated with an oil return port L, and an outlet of the first electromagnetic valve is communicated with a control interface K1. The outlet of the second solenoid valve communicates with one end of the reversing valve; the other end of the reversing valve is communicated with a control interface K2; a small valve element is arranged in the valve cover at one end, the working port A is communicated with the port A of the reversing valve and the other end of the shuttle valve, and an outlet of the shuttle valve is communicated with an inner cavity of the small valve element through a second sequence valve. The valve is compact in structure, large in flow of the valve body, stable in system and capable of avoiding the pressure building fault of the system.

Description

Technical Field

[0001] The utility model relates to a hydraulic valve, in particular to a lifting valve for a mining truck. Background Art

[0002] Mining trucks are heavy-duty dump trucks used in open-pit mines to complete rock and earth stripping and ore transportation tasks. They have the characteristics of short travel distance and heavy load. Large electric shovels or hydraulic shovels are often used for loading, and they travel back and forth between the mining point and the dumping point. They are currently common large-scale transportation equipment. With the gradual improvement of national standards and regulations on mining trucks in recent years, the outline of the standard system has gradually become clear, and the requirements for mining trucks have also been increasingly improved. Strict requirements have been imposed on safety, environmental protection, ergonomics, etc. Therefore, the demand for the development of new mining truck lifting valves has become more urgent.

[0003] The lifting valve of mining trucks needs to adjust the hydraulic components according to the working conditions to respond quickly. Considering the safety operation requirements and high-intensity work needs, the lifting valve of mining trucks needs to meet the requirements of simple valve operation, sensitive response, strong stability, and high work efficiency. The existing lifting valve has the following problems:

[0004] 1. The oil port diameter is small and the valve body flow is small, which can easily cause system pressure buildup, making the hydraulic system unstable during operation, resulting in phenomena such as slow lifting speed and inaccurate intermediate stops, which reduces work efficiency. The system is prone to heat up when it is pressurized, affecting the service life of the lifting valve and reducing its service life, requiring regular maintenance or replacement.

[0005] 2. There is no safety protection device on the telescopic cylinder. When the box is under force, the compressed piston rod of the telescopic cylinder retreats to discharge oil, and the oil pressure increases. However, the working port in the valve body is blocked, and the oil can only be retained inside the system, causing excessive oil pressure in the system, which can easily lead to system pressure holding failure and affect the service life of the lifting valve. Summary of the invention

[0006] The technical problem to be solved by the utility model is to provide a mining truck lifting valve which has a compact structure, a large valve body flow rate, a stable system and can avoid system pressure holding failure.

[0007] The technical solution of the utility model is as follows:

[0008] A lifting valve for a mining truck includes a three-position three-way reversing valve, on which a shuttle valve, a pressure reducing valve, two sequence valves and two two-position three-way solenoid valves are respectively installed; the reversing valve is provided with an oil inlet P, an oil inlet P1, an oil return port T, an oil return port L, a control interface K1, a control interface K2 and a working port A;

[0009] The oil inlet P is communicated with the inlets of the first sequence valve, the pressure reducing valve and one end of the shuttle valve respectively through the oil passage provided in the valve body, the oil inlet P1 and the outlet of the first sequence valve are both communicated with the P port of the reversing valve, the pressure reducing outlet of the pressure reducing valve is respectively communicated with the inlets of the two solenoid valves, the overflow port of the pressure reducing valve and the oil drain ports of the two solenoid valves are respectively communicated with the oil return port L, wherein the outlet of the first solenoid valve is communicated with the control interface K1, and the outlet of the second solenoid valve is communicated with the inner cavity of the valve cover at one end of the reversing valve, for controlling the reversing of the reversing valve;

[0010] The inner cavity of the valve cover at the other end of the reversing valve is communicated with the control interface K2. The control interface K1 and the control interface K2 are used to externally connect a pilot limit valve, thereby controlling the reversing of the reversing valve.

[0011] A small valve core is provided in the valve cover at one end of the reversing valve, and the working port A is respectively connected with the A port of the reversing valve and the inlet of the other end of the shuttle valve, and the outlet of the shuttle valve is connected with the inner cavity of the valve cover at the outer end of the small valve core through the second sequence valve, so as to push the small valve core to move, thereby pushing the reversing valve to reversal.

[0012] As a further preference, a one-way valve is provided at the outlet of the first sequence valve and in the inlet of the oil inlet P1 respectively, for controlling the flow direction of the oil.

[0013] As a further preferred embodiment, when the reversing valve is in the middle position, its P port is connected to the T port, and is connected to the oil return port T through the T port, and the A port is blocked; when the reversing valve is in the left position, its P port is throttled and connected to the A port, and the T port is blocked; when the reversing valve is in the right position, its P port is connected to the T port, and the A port is throttled and connected to the T port.

[0014] As a further preference, the limiting pressure of the first sequence valve is 1.5 MPa, and the limiting pressure of the second sequence valve is 22 MPa.

[0015] As a further preference, the limiting pressure of the pressure reducing valve is 3.5 MPa, and the limiting pressure of the two solenoid valves is 2.5 MPa.

[0016] As a further preference, the valve stem of the reversing valve is formed by a long axis and a short axis being coaxially connected, and the shuttle valve is installed between the inner holes of the long axis and the short axis.

[0017] The beneficial effects of the utility model are:

[0018] 1. Since the shuttle valve, pressure reducing valve, two sequence valves and two two-position three-way solenoid valves are arranged on the reversing valve, the oil inlet P is connected with the P port of the reversing valve through the first sequence valve. The system can be pressurized through the first sequence valve, so that the oil first flows to the pressure reducing valve and then flows to the two solenoid valves through the pressure reducing valve. By controlling the power supply of the two solenoid valves and the pilot limit valve connected to the control interface K1 and K2, the reversing of the reversing valve can be controlled, and the extension and contraction of the telescopic cylinder connected to the working port A can be controlled, thereby controlling the lifting and lowering of the box of the mining truck; the structure is compact, the valve body flow is large, the system is stable, the control is simple and sensitive, and it is suitable for most working environments.

[0019] 2. Since a shuttle valve is installed on the reversing valve, the inlets at both ends of the shuttle valve are connected with the oil inlet P and the working port A respectively, and the outlet of the shuttle valve is connected with the inner cavity at the outer end of the small valve core in the valve cover at one end of the reversing valve through the second sequence valve. Therefore, during operation, the oil pressure of the working port A and the oil inlet P can be compared through the shuttle valve, and the high-pressure oil circuit is selected to enter the second sequence valve. When the limited pressure of the second sequence valve is reached, the oil can enter the valve cover at one end of the reversing valve through the second sequence valve, push the small valve core to drive the second reversing valve to change direction, thereby avoiding system pressure build-up, protecting the lifting valve, oil pump and telescopic cylinder, and extending the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a hydraulic principle diagram of the utility model.

[0021] Figure 2 It is a structural schematic diagram of the utility model.

[0022] Figure 3 yes Figure 2 Top view of the .

[0023] Figure 4 yes Figure 2 Bottom view of .

[0024] Figure 5 yes Figure 2 Rear view of.

[0025] Figure 6 yes Figure 3 AA section view.

[0026] In the figure: reversing valve 1, valve body 101, valve cover 102, valve stem 103, pressure spring 104, first sequence valve 2, shuttle valve 3, pressure reducing valve 4, first solenoid valve 5, second solenoid valve 6, second sequence valve 7, small valve core 8, check valve 9, check valve 10, oil inlet P, oil inlet P1, oil return port T, oil return port L, control interface K1, control interface K2, working port A. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] like Figure 1-Figure 6 As shown, the utility model relates to a mining truck lifting valve, comprising a three-position three-way reversing valve 1, the reversing valve 1 comprising a valve body 101 and a valve cover 102 connected to both ends of the valve body, a valve stem 103 is arranged in the valve body 101 and pressure springs 104 are arranged in the valve covers 102 at both ends for assisting the resetting of the valve stem 103.

[0029] The valve body of the reversing valve 1 is respectively equipped with a shuttle valve 3, a pressure reducing valve 4, and two sequence valves, the two sequence valves are respectively a first sequence valve 2 and a second sequence valve 7, and the valve covers at both ends of the reversing valve 1 are equipped with two two-position three-way solenoid valves, which are respectively a first solenoid valve 5 and a second solenoid valve 6, for controlling the reversing of the reversing valve 1; the reversing valve 1 is provided with an oil inlet P, an oil inlet P1, an oil return port T, an oil return port L, a control interface K1, a control interface K2, and a working port A; the oil inlet P is arranged on the front end face of the valve body, the oil inlet P1, the oil return port T and the oil return port L are arranged on the rear end face of the valve body, the working port A and the two sequence valves are arranged on the top face of the valve body, and the control interface K1 and the control interface K2 are respectively arranged on the bottom face and the top face of the valve cover at the left end of the valve body. The pressure reducing valve 4 is installed on the left end face of the valve body.

[0030] When the reversing valve 1 is in the middle position, its P port is connected to the T port, and is connected to the oil return port T through the T port, and the A port is blocked; when the reversing valve 1 is in the left position, its P port is throttled and connected to the A port, and the T port is blocked; when the reversing valve 1 is in the right position, its P port is connected to the T port, and the A port is throttled and connected to the T port.

[0031] The oil inlet P is communicated with the inlets of the first sequence valve 2, the pressure reducing valve 4 and one end of the shuttle valve 3 respectively through the oil passages provided in the valve body, the oil inlet P1 and the outlet of the first sequence valve 2 are communicated with the P port of the reversing valve 1 through the oil passages in the valve body, the pressure reducing outlet of the pressure reducing valve 4 is communicated with the inlets of the two solenoid valves respectively through the oil passages provided in the valve body and the valve cover, the overflow port of the pressure reducing valve 4 and the oil drain ports of the two solenoid valves are communicated with the oil return port L respectively through the oil passages provided in the valve body and the valve cover, wherein the outlet of the first solenoid valve 5 is communicated with the control interface K1, and the outlet of the second solenoid valve 6 is communicated with the inner cavity of the valve cover at the right end of the reversing valve 1, so as to control the reversing of the reversing valve 1 to the left; a one-way valve 9 and a one-way valve 10 are respectively installed at the outlet of the first sequence valve 2 and in the inlet of the oil inlet P1, so as to control the flow direction of the oil.

[0032] The inner cavity of the valve cover at the left end of the reversing valve 1 is communicated with the control interface K2. The control interface K1 and the control interface K2 are used to externally connect a pilot limit valve, thereby controlling the reversing of the reversing valve 1.

[0033] A small valve core 8 is installed in the valve cover at the right end of the reversing valve 1 through sliding fit, and the working port A is connected with the A port of the reversing valve 1 and the inlet of the other end of the shuttle valve 3 respectively. The outlet of the shuttle valve 3 is connected with the inner cavity of the valve cover located at the outer end of the small valve core 8 through the second sequence valve 7, which is used to push the small valve core 8 to move, thereby pushing the reversing valve 1 to change direction.

[0034] The valve stem of the reversing valve 1 is formed by a long axis and a short axis coaxially connected, and the shuttle valve 3 is installed between the inner holes of the long axis and the short axis. The limit pressure of the first sequence valve 2 is 1.5 MPa, and the limit pressure of the second sequence valve 7 is 22 MPa. The limit pressure of the pressure reducing valve 4 is 3.5 MPa, and the limit pressure of the two solenoid valves is 2.5 MPa.

[0035] When in use, the oil inlets P and P1 are connected to the main pump and auxiliary pump of the mining truck through the oil circuit, the oil return ports T and L are connected to the oil tank through the oil circuit, the control interfaces K1 and K2 are connected to the pilot limit valve through the oil circuit, and the working port A is connected to the telescopic cylinder of the mining truck. The sizes of each working port are: K1 (G1 / 4), K2 (G1 / 4), MP (G1 / 4), P1 (G1), L (G1 / 4), X (G1 / 4).

[0036] When the valve body is in the middle position, the oil inlets P and P1 are connected to the oil return port T, and the system is idling. Since the first sequence valve 2 is provided between the oil inlet P and the P port of the reversing valve 1, and the limiting pressure of the first sequence valve 2 is 1.5Mpa, the oil is ensured to enter the first solenoid valve 5 and the second solenoid valve 6 on both sides through the pressure reducing valve 4 when the oil is idling, so as to supply oil to the solenoid valve; when the oil pressure entering the oil inlet P is higher than 1.5Mpa, the oil will enter the reversing valve 1 through the first sequence valve 2 and the one-way valve 4, and be connected to the oil return port T through the reversing valve 1 to achieve oil leakage.

[0037] When the box needs to be flipped up, the first solenoid valve 5 on the left side is controlled to be energized, and the oil entering the oil inlet P enters the inner cavity of the valve cover at the left end of the reversing valve 1 through the pressure reducing valve 4, the first solenoid valve and the pilot limit valve connected to the control interface K1, K2, pushing the valve stem to the right, so that the reversing valve 1 is in the left position; at this time, the oil inlets P, P1 are connected with the working port A through the reversing valve 1, and the oil entering the main pump and the auxiliary pump enters the telescopic cylinder through the reversing valve 1, so that the piston rod in the telescopic cylinder extends, pushing the box of the mining truck to flip up; when the oil pressure entering the pressure reducing valve 4 is greater than 3.5Mpa, the excess oil returns to the oil tank separately through the overflow port and the return oil port L of the pressure reducing valve 4. When the telescopic cylinder is extended to the maximum stroke, the oil entering from the oil inlet P enters the second sequence valve 7 through the shuttle valve 3, and enters the inner cavity of the valve cover at the outer end of the small valve core 8 through the sequence valve 7, pushing the small valve core 8 to drive the valve stem to move left, so that the valve stem is in the transition position between the left position and the middle position. At this time, part of the oil entering from the oil inlets P and P1 is supplied to the A port, and the other part is connected with the oil return port T through the reversing valve 1 to realize oil return, thereby avoiding pressure holding to protect the valve body. At this time, the two solenoid valves are controlled to lose power, so that the reversing valve returns to the middle position, so that the truck box body keeps flipping up to the maximum angle.

[0038] When the box body is flipped up to the maximum angle, if the box body is suddenly subjected to external pressure, the oil pressure of the working port A will suddenly increase. At this time, the working port A is greater than the pressure of the oil inlet P. The oil pressure of the working port A enters the second sequence valve through the shuttle valve 3, and enters the valve cover inner cavity at the outer end of the small valve core 8 through the second sequence valve, pushing the small valve core 8 to drive the valve stem to move left, so that the reversing valve 1 is in the right position. At this time, the oil in the working port A is throttled and connected with the oil return port T through the reversing valve 1, so that the telescopic cylinder slowly unloads oil through the reversing valve 1, and the box body automatically falls slowly, thereby buffering the external pressure and protecting the valve body and the telescopic cylinder.

[0039] When the box needs to be reset, the second solenoid valve 6 on the right side is controlled to be energized, and the oil entering the oil inlet P enters the valve cover at the right end of the valve body through the pressure reducing valve 4 and the second solenoid valve 6, pushing the valve stem to the left, so that the reversing valve 1 is in the right position. At this time, the oil inlets P and P1 are connected with the oil return port T, and the working port A is connected with the oil return port T through the throttling channel in the valve body, so that the oil in the telescopic cylinder can be throttled and unloaded through the oil return port T. At this time, the rod in the telescopic cylinder retracts and the box slowly descends.

[0040] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation modes. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A lifting valve for a mining truck, comprising a three-position three-way reversing valve, characterized in that: The reversing valve is respectively equipped with a shuttle valve, a pressure reducing valve, two sequence valves and two two-position three-way solenoid valves; the reversing valve is provided with an oil inlet P, an oil inlet P1, an oil return port T, an oil return port L, a control interface K1, a control interface K2 and a working port A; The oil inlet P is communicated with the inlets of the first sequence valve, the pressure reducing valve and one end of the shuttle valve respectively through the oil passage provided in the valve body, the oil inlet P1 and the outlet of the first sequence valve are both communicated with the P port of the reversing valve, the pressure reducing outlet of the pressure reducing valve is respectively communicated with the inlets of the two solenoid valves, the overflow port of the pressure reducing valve and the oil drain ports of the two solenoid valves are respectively communicated with the oil return port L, wherein the outlet of the first solenoid valve is communicated with the control interface K1, and the outlet of the second solenoid valve is communicated with the inner cavity of the valve cover at one end of the reversing valve, for controlling the reversing of the reversing valve; The inner cavity of the valve cover at the other end of the reversing valve is communicated with the control interface K2. The control interface K1 and the control interface K2 are used to externally connect a pilot limit valve, thereby controlling the reversing of the reversing valve. A small valve core is provided in the valve cover at one end of the reversing valve, and the working port A is respectively connected with the A port of the reversing valve and the inlet of the other end of the shuttle valve, and the outlet of the shuttle valve is connected with the inner cavity of the valve cover at the outer end of the small valve core through the second sequence valve, so as to push the small valve core to move, thereby pushing the reversing valve to reversal.

2. The mining truck lifting valve according to claim 1 is characterized in that: One-way valves are respectively provided at the outlet of the first sequence valve and in the inlet of the oil inlet P1 to control the flow direction of the oil.

3. The mining truck lifting valve according to claim 1 is characterized in that: When the reversing valve is in the middle position, its P port is connected to the T port, and is connected to the oil return port T through the T port, and the A port is blocked; when the reversing valve is in the left position, its P port is throttled and connected to the A port, and the T port is blocked; when the reversing valve is in the right position, its P port is connected to the T port, and the A port is throttled and connected to the T port.

4. The mining truck lifting valve according to claim 1 or 2, characterized in that: The limiting pressure of the first sequence valve is 1.5 MPa, and the limiting pressure of the second sequence valve is 22 MPa.

5. The lifting valve for mining trucks according to claim 4 is characterized in that: The limiting pressure of the pressure reducing valve is 3.5 MPa, and the limiting pressure of the two solenoid valves is 2.5 MPa.

6. The mining truck lifting valve according to claim 1 or 3, characterized in that: The valve stem of the reversing valve is formed by coaxially connecting a long axis and a short axis, and the shuttle valve is installed between the inner holes of the long axis and the short axis.

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