Hydraulic control system and tunnel construction equipment

Abstract

The utility model belongs to the technical field of hydraulic working systems, and particularly provides a hydraulic control system and tunnel construction equipment. The hydraulic control system comprises a main valve and a variable-amplitude oil cylinder, a balance valve is arranged on an oil way between a rodless cavity of the variable-amplitude oil cylinder and the main valve, the balance valve comprises a main valve port, and a first throttling valve is further arranged on an oil way between the main valve port and the rodless cavity. The tunnel construction equipment comprises the hydraulic control system. The throttle valve for controlling the oil pressure is arranged on the oil way connected with the main valve port (connected with the variable-amplitude oil cylinder) of the balance valve, when the piston rod of the variable-amplitude oil cylinder retracts, namely when the rodless cavity returns oil to the main valve, the opening degree of the throttle hole of the throttle valve can be actively adjusted, and then the oil pressure in the rodless cavity is controlled to be kept in a stable state; and the stability of the working arm during movement can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of hydraulic working systems, in particular to a hydraulic control system and tunnel construction equipment. Background Art

[0002] With the continuous development of underground space, the supporting tunnel construction equipment is also constantly developing, such as rock drilling trolleys for drilling blastholes, arch frame trolleys for assembling arch frames, wet spraying trolleys for spraying concrete, etc. The common point of each construction equipment is that they are all equipped with a working arm that can swing up and down, and the up and down swing of the working arm is driven by a variable-length oil cylinder. The variable-length oil cylinder is generally a double-acting cylinder, which includes a piston rod and a cylinder barrel. The piston rod divides the inside of the cylinder barrel into a rod chamber and a rodless chamber. Oil enters the rodless chamber, oil returns to the rod chamber, the piston rod extends, and the working arm swings upward; oil enters the rod chamber, oil returns to the rodless chamber, the piston rod is retracted, and the working arm swings downward.

[0003] During the downward swing of the working arm, the piston rod of the luffing cylinder retracts, and the gravity of the working arm will act on the luffing cylinder, which may easily cause the luffing cylinder to overspeed. In order to solve the overspeed problem, the prior art generally sets a balancing valve in the oil circuit connected to the rodless chamber, and the opening and closing of the balancing valve as well as the opening size are jointly controlled by the pilot oil pressure and the rodless chamber oil pressure. However, when the working arm is downward swinging, the angle between the luffing cylinder and the working arm is constantly changing, and the load acting on the luffing cylinder is also constantly changing. Affected by the load change, the pilot oil pressure and the oil pressure of the rodless chamber are constantly changing, and the balancing valve is prone to alternate opening and closing, resulting in shaking during the descent of the working arm and insufficient movement stability.

[0004] After searching and analyzing, the patent document with application publication number CN107934807A discloses a control system for a variable-length oil cylinder. The system is equipped with an external pilot oil source for controlling the pilot oil pressure of a balancing valve. A pressure control valve is connected between the pilot oil source and the pilot port of the balancing valve. The pressure control valve can control the pressure of the pilot oil pressure according to the valve core displacement of the main valve, thereby stabilizing the pressure of the pilot oil pressure and the valve port opening of the balancing valve.

[0005] Although the control system of the above-mentioned variable-luffing oil cylinder can maintain the stability of the pilot oil pressure, the fluctuation of the oil pressure in the rodless chamber will also affect the opening and closing of the balance valve and the opening size of the balance valve. In actual use, the above-mentioned control system still has the problem of frequent opening and closing of the balance valve due to the fluctuation of the oil pressure in the rodless chamber caused by the load change. In addition, the pilot oil pressure is controlled by an external oil source. If the working arm descends at an excessive speed during use, in addition to closing the main valve, it is necessary to control and close the external oil circuit. The control system is complex and there are safety hazards. Utility Model Content

[0006] The purpose of the utility model is to provide a hydraulic control system to solve the technical problem that the balance valve in the hydraulic control system of the variable-luff cylinder in the prior art is prone to frequent opening and closing due to the oil pressure fluctuation of the rodless chamber. The purpose of the utility model is also to provide a tunnel construction equipment to solve the same technical problem.

[0007] In order to achieve the above-mentioned purpose, the technical solution of the hydraulic control system provided by the utility model is:

[0008] The hydraulic control system includes a main valve and a variable-length oil cylinder. The oil circuit between the rodless chamber of the variable-length oil cylinder and the main valve is provided with a balancing valve. The balancing valve includes a main valve port. A first throttle valve is also provided on the oil circuit between the main valve port and the rodless chamber.

[0009] As a further improvement, the first throttle valve is a first proportional throttle valve.

[0010] As a further improvement, the hydraulic control system also includes a displacement sensor for detecting the valve core displacement of the main valve, and the displacement sensor is communicatively connected to the controller of the first proportional throttle valve to control the throttle hole opening of the first proportional throttle valve according to the displacement signal of the main valve.

[0011] As a further improvement, the hydraulic control system also includes a pressure sensor for detecting the oil pressure of the rodless chamber, and the pressure sensor is communicatively connected to the controller of the first proportional throttle valve to control the throttle hole opening of the first proportional throttle valve according to the oil pressure of the rodless chamber.

[0012] As a further improvement, the balancing valve includes a pilot port, and a pilot oil circuit is connected between the pilot port and the main valve.

[0013] As a further improvement, a second proportional throttle valve is arranged on the pilot oil circuit.

[0014] As a further improvement, the hydraulic control system also includes a displacement sensor for detecting the valve core displacement of the main valve, and the displacement sensor is communicatively connected to the controller of the second proportional throttle valve to control the throttle hole opening of the second proportional throttle valve according to the displacement signal of the main valve.

[0015] As a further improvement, a hydraulically controlled one-way valve is arranged on the oil circuit between the rod chamber of the boom cylinder and the main valve, and the hydraulic control port of the hydraulically controlled one-way valve is connected to the oil circuit between the rodless chamber of the boom cylinder and the main valve.

[0016] As a further improvement, the oil circuit between the rod chamber of the variable-length oil cylinder and the main valve is further provided with an overflow valve, and the overflow valve and the hydraulically controlled one-way valve are connected in parallel.

[0017] The beneficial effect is that the utility model belongs to an improved invention. Specifically, when the piston rod of the variable-length oil cylinder retracts, the hydraulic oil in the rodless chamber can return to the main valve through the first throttle valve. In this process, the opening of the throttle hole of the first throttle valve can be controlled to stabilize the oil pressure in the rodless chamber. Therefore, in actual operation, the oil pressure in the rodless chamber can be maintained in a relatively stable state, thereby solving the problem of frequent opening and closing of the balance valve caused by the fluctuation of the oil pressure in the rodless chamber, which is conducive to improving the stability of the swing of the working arm.

[0018] To achieve the above purpose, the technical solution of the tunnel construction equipment provided by the utility model is:

[0019] Tunnel construction equipment includes a working arm, which is equipped with a hydraulic control system for driving the working arm to swing. The hydraulic control system includes a main valve and a boom cylinder. The oil circuit between the rodless chamber of the boom cylinder and the main valve is equipped with a balancing valve. The balancing valve includes a main valve port. A first throttle valve is also arranged on the oil circuit between the main valve port and the rodless chamber.

[0020] As a further improvement, the first throttle valve is a first proportional throttle valve.

[0021] As a further improvement, the hydraulic control system also includes a displacement sensor for detecting the valve core displacement of the main valve, and the displacement sensor is communicatively connected to the controller of the first proportional throttle valve to control the throttle hole opening of the first proportional throttle valve according to the displacement signal of the main valve.

[0022] As a further improvement, the hydraulic control system also includes a pressure sensor for detecting the oil pressure of the rodless chamber, and the pressure sensor is communicatively connected to the controller of the first proportional throttle valve to control the throttle hole opening of the first proportional throttle valve according to the oil pressure of the rodless chamber.

[0023] As a further improvement, the balancing valve includes a pilot port, and a pilot oil circuit is connected between the pilot port and the main valve.

[0024] As a further improvement, a second proportional throttle valve is arranged on the pilot oil circuit.

[0025] As a further improvement, the hydraulic control system also includes a displacement sensor for detecting the valve core displacement of the main valve, and the displacement sensor is communicatively connected to the controller of the second proportional throttle valve to control the throttle hole opening of the second proportional throttle valve according to the displacement signal of the main valve.

[0026] As a further improvement, a hydraulically controlled one-way valve is arranged on the oil circuit between the rod chamber of the boom cylinder and the main valve, and the hydraulic control port of the hydraulically controlled one-way valve is connected to the oil circuit between the rodless chamber of the boom cylinder and the main valve.

[0027] As a further improvement, the oil circuit between the rod chamber of the variable-length oil cylinder and the main valve is further provided with an overflow valve, and the overflow valve and the hydraulically controlled one-way valve are connected in parallel.

[0028] The beneficial effect is that the utility model belongs to an improved invention. Specifically, when the piston rod of the variable-length oil cylinder retracts, the hydraulic oil in the rodless chamber can return to the main valve through the first throttle valve. In this process, the opening of the throttle hole of the first throttle valve can be controlled to stabilize the oil pressure in the rodless chamber. Therefore, in actual operation, the oil pressure in the rodless chamber can be maintained in a relatively stable state, thereby solving the problem of frequent opening and closing of the balance valve caused by the fluctuation of the oil pressure in the rodless chamber, which is conducive to improving the stability of the swing of the working arm. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the principle of an embodiment of the hydraulic control system in the utility model.

[0030] Description of reference numerals:

[0031] 1. Displacement sensor; 2. Main valve group; 3. Balance valve; 4. Pressure sensor; 5. First proportional throttle valve; 6. First variable-length oil cylinder; 7. Second proportional throttle valve; 8. Hydraulic-controlled one-way valve; 9. Overflow valve; 10. Second variable-length oil cylinder. DETAILED DESCRIPTION

[0032] In order to solve the problem of frequent opening and closing of the balancing valve caused by oil pressure fluctuations in the rodless chamber of the boom cylinder, the basic technical concept of the utility model is to arrange a throttle valve for controlling the oil pressure in the oil circuit connected to the main valve port of the balancing valve (connected to the boom cylinder). When the piston rod of the boom cylinder retracts, that is, when the rodless chamber returns oil to the main valve, the throttle hole opening of the throttle valve can be actively adjusted, thereby controlling the oil pressure in the rodless chamber to maintain a stable state, which is beneficial to improving the stability of the working arm during movement.

[0033] The present invention is further described in detail below in conjunction with the embodiments and drawings.

[0034] The specific embodiment of the hydraulic control system provided by the utility model is as follows:

[0035] The hydraulic control system provided in this embodiment is as follows: Figure 1 As shown in FIG. 1 , it is a control system of a double-linked luffing cylinder. For the same working arm, it is articulated with two luffing cylinders arranged in parallel to drive its swing, namely, a first luffing cylinder 6 and a second luffing cylinder 10. Specifically, the hydraulic control system includes a main valve group 2. Figure 1 What is shown is a double-linked variable-luffing oil cylinder, and the main valve group 2 includes two main valves that respectively control the oil inlet direction of the two variable-luffing oil cylinders. The structure of the variable-luffing oil cylinder is consistent with the prior art, and it includes a rod chamber and a rodless chamber. Naturally, in addition to the oil inlet and return ports, the main valve also includes two working oil ports (port A and port B). Preferably, the main valve is a three-position four-way reversing valve.

[0036] like Figure 1As shown, one of the working oil ports (port A) of the main valve is connected to the rodless chamber of the luffing oil cylinder, and the other working oil port (port B) of the main valve is connected to the rod chamber of the luffing oil cylinder. The oil circuit between the rodless chamber of the luffing oil cylinder and the main valve is provided with a balancing valve 3. The balancing valve 3 is a balancing valve 3 in the prior art, specifically, it can be regarded as a one-way valve and a pilot relief valve 9 in parallel, and naturally, it has a main valve port and a pilot port.

[0037] A first throttle valve is arranged on the oil circuit between the main valve port of the balancing valve 3 and the rodless chamber of the boom cylinder. Preferably, the first throttle valve is a one-way throttle valve (the one-way valve and the throttle valve are connected in parallel), wherein the flow direction of the one-way valve is from the main valve to the rodless chamber. In this way, when the piston rod of the boom cylinder needs to be extended, the main valve works in the right position, and the hydraulic oil flows out from the A port of the main valve, and flows to the rodless chamber through the one-way valve of the first throttle valve, and the hydraulic oil in the rod chamber of the boom cylinder can flow to the B port of the main valve through the return oil circuit. When the piston rod of the luffing cylinder needs to retract, the main valve works in the left position, and the hydraulic oil flows from the B port of the main valve into the rod chamber of the luffing cylinder. The hydraulic oil in the rodless chamber of the luffing cylinder flows to the main valve port of the balancing valve 3 through the throttle valve of the first throttle valve. In this process, the throttle hole opening of the first throttle valve can be adjusted according to the oil pressure change in the rodless chamber, so as to stabilize the oil pressure in the rodless chamber and avoid frequent opening and closing of the balancing valve due to oil pressure fluctuation in the rodless chamber.

[0038] It should be noted that in the preferred embodiment, the first throttle valve is a one-way throttle valve, which is considered that when oil is fed into the rodless chamber, the hydraulic oil can pass through the one-way valve oil path to ensure smooth oil feeding. However, in other embodiments, the first throttle valve can also be a common two-way throttle valve, which ensures that the first throttle valve is at the maximum opening when oil is fed into the rodless chamber.

[0039] In order to facilitate the precise control of the throttle opening of the first throttle valve, as a preferred embodiment, the first throttle valve is an electrically controlled proportional throttle valve (solenoid valve), that is, the first proportional throttle valve 5, which is equipped with a controller to control the current of the proportional throttle valve, thereby controlling the displacement of the valve core and further controlling the opening of the throttle hole. Of course, it can be understood that in other embodiments, the first throttle valve can also use a one-way throttle valve controlled manually (handle). Before the equipment leaves the factory, the technician can calibrate the appropriate throttle opening range in advance according to the movement conditions of the working arm, and the construction operator can manually adjust the opening of the throttle hole of the first throttle valve according to the movement of the working arm. Of course, in other embodiments, the first throttle valve can also use a hydraulically controlled one-way throttle valve. By controlling the oil circuit and related logic valves, the main valve action can be associated with the throttle opening.

[0040] The hydraulic control system can also be equipped with a displacement sensor 1, which can detect the displacement of the valve core of the main valve. The displacement sensor 1 is connected to the controller of the first proportional throttle valve 5 in communication, and the opening of the throttle hole can be controlled according to the data of the displacement sensor 1. The larger the displacement (absolute value) detected by the displacement sensor 1, the more hydraulic oil (large oil volume) enters the rod cavity, and the opening of the throttle hole of the first proportional throttle can be increased.

[0041] When the main valve adopts a manually controlled manual control valve, the displacement sensor 1 can accurately obtain the displacement of the valve core, which is convenient and efficient, and has low control difficulty. Of course, in other implementations, the main valve can also adopt an electrically controlled proportional valve, which can control the input current of the main valve and control the displacement of the valve core of the main valve. In this case, the displacement sensor 1 may not be configured.

[0042] In addition to the above-mentioned method of controlling the throttle hole opening of the first proportional throttle valve 5 by the displacement of the main valve, in other embodiments, a pressure sensor 4 can be added. The pressure sensor 4 is used to detect the oil pressure in the rodless chamber of the variable-length cylinder. The pressure sensor 4 is communicatively connected to the controller of the first proportional throttle valve 5, and the throttle hole opening of the first proportional throttle valve 5 can be directly controlled according to the oil pressure in the rodless chamber. When it is detected that the oil pressure in the rodless chamber is greater than the set value, the opening of the throttle hole can be increased.

[0043] In addition, for the pilot oil circuit connected to the pilot port of the balancing valve, in this embodiment, one end of the pilot oil circuit is connected to the pilot port, and the other end is connected to the main valve. Different from the prior art, the pilot oil circuit does not use an external oil circuit, so when the luffing cylinder stalls, the pilot oil circuit can be cut off synchronously when the main valve is cut off, thereby closing the balancing valve 3, maintaining the pressure of the luffing cylinder, and making it easier to control.

[0044] In order to facilitate the control of the oil pressure of the pilot oil circuit, the pilot oil circuit is equipped with a proportional throttle valve, that is, Figure 1 The second proportional throttle valve 7 can also control the oil pressure of the pilot oil circuit by adjusting the opening size of the throttle hole of the second proportional throttle valve 7. It is easy to understand that the proportional throttle valve used here also has the function of facilitating accurate control of the oil pressure.

[0045] Furthermore, if the hydraulic control system is equipped with a displacement sensor 1 for detecting the main valve core, the displacement sensor 1 can be connected to the controller of the second proportional throttle valve 7 for communication, and the controller can accurately control the throttle opening of the second proportional throttle valve 7 according to the data of the displacement sensor 1. Similarly, when it is detected that the spool displacement of the main valve is large, it means that more hydraulic oil is flowing out of the main valve. In order to avoid the pressure build-up in the pilot oil circuit, the throttle opening of the second proportional throttle valve 7 can be increased to maintain the stability of the pilot oil pressure. Of course, in other embodiments, if the main valve is an electrically controlled proportional valve, the displacement sensor 1 may not be configured.

[0046] It should be noted that, as a preferred solution, Figure 1 As shown, the second proportional throttle valve 7 is also a one-way throttle valve, which has a better cut-off effect. In this way, when oil enters the rodless chamber, it can prevent the hydraulic oil from passing through the pilot oil circuit.

[0047] In order to further improve the safety of the luffing cylinder, in this embodiment, the oil circuit between the rod chamber of the luffing cylinder and the main valve is further provided with a hydraulically controlled one-way valve 8, and the hydraulically controlled port of the hydraulically controlled one-way valve 8 is connected with the rodless chamber of the luffing cylinder and the oil circuit of the main valve. Figure 1 As shown, when the piston rod of the luffing oil cylinder needs to be extended, the hydraulic oil enters the rodless chamber of the luffing oil cylinder from the A port of the main valve. During this process, the hydraulic oil can simultaneously enter the hydraulic control port of the hydraulic control check valve 8. The hydraulic control check valve 8 opens in the reverse direction, and the hydraulic oil in the rod chamber can flow back to the B port of the main valve through the hydraulic control check valve 8. This design can prevent the hydraulic oil in the rod chamber from accidentally flowing back to the main valve, thereby improving the safety of the luffing oil cylinder during operation.

[0048] Furthermore, if Figure 1 As shown, the oil circuit between the rod chamber of the luffing oil cylinder and the main valve is also equipped with a relief valve 9, and the relief valve 9 is connected in parallel with the hydraulic control check valve 8. In actual work, when the oil pressure inside the luffing oil cylinder rises due to temperature rise and other reasons, the hydraulic oil can flow out from the relief valve 9 to avoid damage to the luffing oil cylinder and the hydraulic pipeline caused by high oil pressure.

[0049] It should be noted that the hydraulically controlled one-way valve 8 and the relief valve 9 are mainly used as safety valves for the circuit connected to the rod chamber of the variable-length oil cylinder. In other embodiments, the oil circuit between the main valve and the rod chamber may not be equipped with a safety valve.

[0050] in addition, Figure 1 The principle of the hydraulic control system of the double-linked luffing cylinder is shown. In actual engineering, the two luffing cylinders work together to drive the working arm to move. It can be understood by those skilled in the art that in actual engineering, the working arm of some equipment is only equipped with one luffing cylinder, and the luffing cylinder can also adopt the hydraulic control system of this embodiment.

[0051] Specific embodiments of the tunnel construction equipment in the utility model:

[0052] The tunnel construction equipment includes a working arm, and the working arm is equipped with the hydraulic control system described in the embodiment of the hydraulic control system. Specifically, the tunnel construction equipment can be a wet spraying trolley, a rock drilling trolley, an arch trolley, a charging trolley, etc., which is not specifically limited in this embodiment.

[0053] Finally, it should be noted that the above is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments without creative work, or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A hydraulic control system, comprising a main valve and a variable-luff cylinder, wherein a balancing valve is arranged on the oil path between the rodless chamber of the variable-luff cylinder and the main valve, and the balancing valve comprises a main valve port, wherein the balancing valve comprises: A first throttle valve is also arranged on the oil path between the main valve port and the rodless chamber.

2. The hydraulic control system according to claim 1, characterized in that: The first throttle valve is a first proportional throttle valve.

3. The hydraulic control system according to claim 2, characterized in that: The hydraulic control system also includes a displacement sensor for detecting the displacement of the valve core of the main valve. The displacement sensor is communicatively connected with the controller of the first proportional throttle valve to control the throttle hole opening of the first proportional throttle valve according to the displacement signal of the main valve.

4. The hydraulic control system according to claim 2, characterized in that: The hydraulic control system also includes a pressure sensor for detecting the oil pressure of the rodless chamber. The pressure sensor is communicatively connected to the controller of the first proportional throttle valve to control the throttle hole opening of the first proportional throttle valve according to the oil pressure of the rodless chamber.

5. The hydraulic control system according to claim 1, 2 or 4, characterized in that: The balancing valve comprises a pilot port, and a pilot oil circuit is connected between the pilot port and the main valve.

6. The hydraulic control system according to claim 5, characterized in that: A second proportional throttle valve is arranged on the pilot oil circuit.

7. The hydraulic control system according to claim 6, characterized in that: The hydraulic control system also includes a displacement sensor for detecting the displacement of the valve core of the main valve. The displacement sensor is communicatively connected with the controller of the second proportional throttle valve to control the throttle hole opening of the second proportional throttle valve according to the displacement signal of the main valve.

8. The hydraulic control system according to any one of claims 1 to 4, characterized in that: A hydraulically controlled one-way valve is arranged on the oil circuit between the rod chamber of the variable-length oil cylinder and the main valve, and the hydraulic control port of the hydraulically controlled one-way valve is communicated with the oil circuit between the rodless chamber of the variable-length oil cylinder and the main valve.

9. The hydraulic control system according to claim 8, characterized in that: The oil circuit between the rod chamber of the luffing oil cylinder and the main valve is also provided with a relief valve, and the relief valve and the hydraulically controlled one-way valve are connected in parallel.

10. Tunnel construction equipment, comprising a working arm, the working arm being provided with a hydraulic control system for driving the working arm to swing, characterized in that: The hydraulic control system is the hydraulic control system described in any one of claims 1-9.

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