A slow propulsion hydraulic system for a shield machine and a shield machine

Abstract

The present invention provides a slow propulsion hydraulic system for a shield machine and a shield machine. A variable pump system, a filter, a speed control valve, and a reversing valve I are connected in sequence. The reversing valve I is connected to an oil cylinder. An oil return oil path I is led out from the rodless cavity of the oil cylinder and connected to an oil path. A cartridge valve II is connected to the oil return oil path I. The reversing valve II is connected to the valve front oil path and the control oil path of the cartridge valve II and controls the opening and closing of the cartridge valve II. The reversing valve I controls the oil inlet and outlet directions of the rodless cavity and the rod cavity of the oil cylinder. The reversing valve I is connected to a fuel tank. A slow propulsion pump is connected in parallel with the variable pump system, and a flow control valve, a cartridge valve I, and a relief valve I are connected between their oil outlets. The relief valve I controls the opening and closing of the cartridge valve I. It effectively reduces the power consumption of the shield machine, reduces the unnecessary losses of the shield machine, increases the service life of the system, and at the same time effectively protects the cutter head body due to the existence of the new system, reduces the operation difficulty of the shield operator, and improves the tunneling efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of shield machines, and particularly relates to a slow propulsion hydraulic system and a shield machine. Background Art

[0002] The propulsion hydraulic system of a shield machine plays an extremely important role during the tunneling process of the shield machine. Its continuity and stability have a crucial impact on the tunneling speed and efficiency of the shield machine, and it is the key for the shield machine to accurately advance along the set route. The propulsion system of a shield machine has characteristics such as high power, variable load, and small installation space. When the shield machine is tunneling, the geological conditions are often complex, and the resistance of the shield body of the shield machine from the formation is different, which easily causes the tunneling direction of the shield machine to deviate. At the same time, when performing curve propulsion, it is necessary for the shield body of the shield machine to achieve attitude adjustments such as forward inclination, backward inclination, left and right swing, or compound direction. It may not be able to advance along the specified route. At this time, it is necessary to precisely control the propulsion cylinders to correct the deviation. During the tunneling process of the shield machine, the functions of the propulsion hydraulic system are as follows: 1) In the propulsion mode, it provides the power for the shield machine to move forward and the torque for the attitude adjustment of the shield machine. In shield construction, the deviation between the tunnel axis and the designed axis is an important standard to measure the quality of shield construction. Therefore, to meet the construction requirements, the propulsion hydraulic system adopts sectional control. By reasonably adjusting the propulsion pressure of each section of the propulsion hydraulic system, the required torque can be obtained, thereby completing the attitude adjustment of the shield machine; 2) In the assembly mode, after the shield machine completes a section of tunneling, the segments are assembled into a ring. At this time, the propulsion cylinders can keep the segments in position, prevent the segments from falling, and at the same time overcome the water and soil pressure on the propulsion surface to prevent the shield machine from retreating.

[0003] In the existing soft soil cutterhead EPB shield machine, the propulsion hydraulic system consists of a hydraulic pump station, a speed regulation and pressure regulation mechanism, a reversing control valve group, and propulsion cylinders. The 32 cylinders it is equipped with are evenly distributed in 16 groups on the inner circular wall of the shield middle body, and are divided into four regions where the hydraulic pressure can be adjusted, namely up, down, left, and right, to provide the propulsion force and propulsion speed for the shield machine to move forward. The turning and deviation correction functions of the shield machine are achieved by adjusting the pressure difference between the four regions. Among them, the hydraulic pump station of the propulsion system consists of a constant pressure variable pump with a power of 75KW. The constant pressure variable pump provides constant power for the shield machine to move forward. The pressure of the constant pressure pump can be adjusted by the electro-hydraulic proportional relief valve on the oil pump. When the flow rate varies within the range of 0 - qmax, the adjusted pump supply pressure remains constant. The constant pressure type variable pump is commonly used in the constant pressure oil source of valve control systems to avoid overflow losses. The high-pressure oil output by the constant pressure variable pump is respectively sent to four groups of parallel propulsion direction control valve groups, namely A, B, C, and D. After the flow rate and pressure of the valve group are adjusted and reversed, it is used to control the propulsion cylinders, so that the propulsion speed, thrust magnitude, and direction of the propulsion cylinders can be controlled to a certain extent.

[0004] However, this design method is not easy to control the tunneling speed and attitude of the shield machine when there are fixed piles or rocks all over the front. Because the power unit equipped in its propulsion system is a variable pump, when the shield machine is under construction and cutting fixed piles or rocks, the forward thrust of the cutter head of the shield machine mainly depends on this variable pump. Due to the instability of the output flow of the variable pump, the pile-grinding speed of the cutter head advancing forward is also unstable. If the pile-grinding speed of the shield machine is too fast, it will cause damage to the cutter head of the shield machine and reduce the service life of the cutter head. Therefore, it greatly increases the operation difficulty of the shield driver. For the above reasons, it is necessary to invent a slow-advancing hydraulic system with a pile-grinding function that can solve the above problems, so as to enable the shield machine to achieve a controllable tunneling speed when grinding piles, and at the same time, it can also protect the cutter head body from wear or the wear amount is at a controllable level. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a slow-advancing hydraulic system and a shield machine for a shield machine, which can effectively reduce the damage of the cutter head caused by too fast advancing speed of the shield machine.

[0006] The present invention is implemented as follows: A slow-advancing hydraulic system for a shield machine includes a variable pump system, a filter, a speed control valve, a reversing valve I, an oil cylinder, a slow-advancing pump, a flow control valve, a check valve I, a cartridge valve I, a cartridge valve II, a relief valve I, and a reversing valve II;

[0007] The variable pump system, the filter, the speed control valve, and the reversing valve I are connected in sequence. The reversing valve I is connected to the oil cylinder. An oil return oil circuit I is led out from the rodless cavity of the oil cylinder and connected to the oil circuit. The cartridge valve II is connected to the oil return oil circuit I. The reversing valve II is connected to the valve front oil circuit and the control oil circuit of the cartridge valve II and controls the opening and closing of the cartridge valve II;

[0008] The reversing valve I controls the oil inlet and outlet directions of the rodless cavity and the rod cavity of the oil cylinder; the reversing valve I is connected to the fuel tank;

[0009] The slow-advancing pump is connected in parallel with the variable pump system, and a flow control valve, a cartridge valve I, and a relief valve I are connected between the oil outlets of the two. The relief valve I controls the opening and closing of the cartridge valve I.

[0010] Further, the variable pump system includes a variable pump, a swash plate oil cylinder, a reversing valve III, and a relief valve II; the swash plate oil cylinder is connected to the variable pump and controls the swash plate inclination of the variable pump. The reversing valve III is connected to the swash plate oil cylinder and controls the oil inlet and outlet directions of the rodless cavity and the rod cavity of the swash plate oil cylinder. The relief valve II is connected to the reversing valve III.

[0011] Further, it further includes a one-way valve I, and the one-way valve I is connected to the oil path between the reversing valve I and the rodless cavity of the oil cylinder.

[0012] Further, it further includes a unloading valve and an overflow valve III, and the unloading valve and the overflow valve III are connected in parallel to the oil path between the rodless cavity of the oil cylinder and the fuel tank.

[0013] Further, it further includes a one-way valve II, and the one-way valve II is connected to the oil path between the slow propulsion pump and the filter.

[0014] Further, it further includes an overflow valve IV, a reversing valve IV and a cartridge valve III; the cartridge valve III is connected in parallel to the oil path between the filter and the speed control valve, a return oil path II is led out from the oil path behind the speed control valve and connected to the fuel tank, the overflow valve IV is connected in the return oil path II, and the reversing valve IV is connected to the oil path in front of the filter, the return oil path II and the control oil path of the cartridge valve III.

[0015] The present invention also provides a shield machine, including a hydraulic control system, and the hydraulic control system is the above-mentioned slow propulsion hydraulic system.

[0016] The beneficial effects brought by the present invention are as follows: it can effectively reduce the damage of the cutter head caused by the too fast propulsion speed of the shield machine, and at the same time, it can distinguish the control system for normal tunneling from the control system required for grinding piles. When the shield machine is grinding piles, the original working mode can be suspended and the slow propulsion module can be used instead; in this way, the power consumption of the shield machine can be effectively reduced, the unnecessary loss of the shield machine can be reduced, the service life of the system can be increased, and at the same time, the cutter head body can be effectively protected due to the existence of the new system, the operation difficulty of the shield driver can be reduced, and the tunneling efficiency can be improved. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of a preferred embodiment in the present invention. Detailed Embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "back end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "equipped with", "connected", etc. shall be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] As Figure 1 shown, this embodiment provides a slow propulsion hydraulic system for a shield machine, which includes a variable pump system, check valve I17, check valve II23, filter 9, speed control valve 10, directional control valve I12, cylinder I15, cylinder II16, slow propulsion pump 1, flow control valve 8, check valve I24, cartridge valve I3, cartridge valve II11, relief valve I2, relief valve II6, directional control valve II18, unloading valve 14, relief valve III13, relief valve IV19, directional control valve III7, directional control valve IV20, and cartridge valve III21.

[0022] The variable pump system, filter 9, speed control valve 10, and directional control valve I12 are connected in sequence. The directional control valve I12 is respectively connected to the cylinder I15 and the cylinder II16. A return oil circuit I is led out from the rodless chambers of the cylinder I15 and the cylinder II16 and connected to the oil circuit. The cartridge valve II11 is connected to the return oil circuit I. The directional control valve II18 is connected to the valve front oil circuit and the control oil circuit of the cartridge valve II11 and controls the opening and closing of the cartridge valve II11. The directional control valve I12 controls the oil inlet and outlet directions of the rodless chambers and the rod chambers of the cylinder I15 and the cylinder II16; the directional control valve I12 is connected to the fuel tank. The unloading valve 14 and the relief valve III13 are connected in parallel on the oil circuit between the rodless chambers of the cylinder I15 and the cylinder II16 and the fuel tank.

[0023] The slow propulsion pump 1 is connected in parallel with the variable pump system. A flow control valve 8, a cartridge valve I3, and a relief valve I2 are connected between the oil outlets of the two. The relief valve I2 controls the opening and closing of the cartridge valve I3. A check valve I17 is connected to the oil path between the directional valve I12 and the rodless chambers of the cylinder I15 and the cylinder II16.

[0024] The variable pump system includes a variable pump 4, a swash plate cylinder 5, a directional valve III7, and a relief valve II6. The swash plate cylinder 5 is connected to the variable pump 4 and controls the swash plate angle of the variable pump 4. The directional valve III7 is a servo directional valve, which is connected to the swash plate cylinder 5 and controls the oil inlet and outlet directions of the rodless chamber and the rod chamber of the swash plate cylinder 5, so as to realize the telescoping of the swash plate cylinder 5. The relief valve II6 is connected to the directional valve III7. A check valve II23 is connected to the oil path between the slow propulsion pump 1 and the filter 9.

[0025] The cartridge valve III21 is connected in parallel to the oil path between the filter 9 and the speed control valve 10. A return oil path II is led out from the oil path behind the speed control valve 10 and connected to the fuel tank. The relief valve IV19 is connected in the return oil path II. The directional valve IV20 is connected to the oil path in front of the filter 9, the return oil path II, and the control oil path of the cartridge valve III21.

[0026] The slow propulsion pump 1 is a fixed displacement pump. Both the relief valve II6 and the relief valve IV19 are proportional relief valves. The flow control valve 8 is a proportional flow control valve. The directional valve I12 is a three-position four-way directional valve. The directional valves II18, III7, and IV20 are all two-position three-way directional valves.

[0027] The rodless chamber diameters of the cylinder I15 and the cylinder II16 are 220 mm, the rod diameters of the rod chambers are 180 mm, and the cylinder stroke is 2200 mm. When grinding the pile, it is required that the shield machine advances at a speed of about 5 - 10 mm. Therefore, the propulsion speed of the shield machine during pile grinding is set to 5 - 10 mm.

[0028] The specific selection of the corresponding components is determined according to the following flow calculation process:

[0029] Rodless chamber area:

[0030] A1 = = = 0.038 ,

[0031] In the formula, A1 is the rodless chamber area, and the unit is ; D is the rodless chamber diameter, and the unit is mm.

[0032] Rod chamber area:

[0033] A2 = = = 0.01257 ,

[0034] Where A2 is the area of the rodless chamber, with the unit of ; D is the diameter of the rodless chamber, with the unit of mm; d is the diameter of the rod chamber, with the unit of mm.

[0035] Therefore, in the propulsion mode:

[0036] When the propulsion speed is 5 mm / min, the required flow rate is .

[0037] =n =32 × 5 × 0.038 = 6.08 L;

[0038] Where, is the flow rate provided by the slow propulsion pump 1, with the unit of L / min; n is the number of working cylinders in the propulsion mode.

[0039] is the propulsion speed, with the unit of mm / min; is the area of the rodless chamber, with the unit of .

[0040] When the propulsion speed is 10 mm / min, the required flow rate is .

[0041] =n =32 × 10 × 0.038 = 12.16 L;

[0042] Where, is the flow rate provided by the slow propulsion pump, with the unit of L / min; n is the number of working cylinders in the propulsion mode.

[0043] is the propulsion speed, with the unit of mm / min; is the area of the rodless chamber, with the unit of .

[0044] Through calculation, it is known that in the tunneling mode, when the propulsion speed is 5 mm / min, the system needs to provide a flow rate of 6.08 L, and when the propulsion speed is 10 mm / min, the system needs to provide a flow rate of 12.16 L. At the same time, in the tunneling mode, the pressure of the system can reach 350 Bar. Therefore, the required power N of the system is as follows:

[0045] N = = = 8.6928 KW;

[0046] Where N is the power required for the slow propulsion system, in KW; P is the working pressure in the propulsion mode, in Bar; Q is the system flow rate in the propulsion mode, in L / min.

[0047] After calculation, when the tunneling speed of the shield machine is 5 - 10 mm / min, the rated power required by the system is 8.6928 KW, and the maximum power is 1.2 times its rated power. Therefore, the maximum power is 10.43136 KW. According to this situation, an 11 KW motor should be selected for the system of the present invention. As an efficient asynchronous motor, it can ensure the operation reliability and safety of the slow propulsion pump 1.

[0048] Referring to the sample materials of the current mainstream hydraulic product supplier Bosch Rexroth, an internal gear pump with fixed displacement is selected for the slow propulsion pump 1 as the power unit of the present invention. The model of this pump is PGH3 - 2X / 011RE07VU2. Its main features are fixed displacement, low working noise, and low flow pulsation. Due to the seal clearance compensation of this pump, it has high efficiency even at low rotational speeds and low-viscosity oil. At the same time, this pump is applicable to a wide range of viscosities and rotational speeds, can bear a working pressure of 350 Bar, and output a flow rate of 15 L / min.

[0049] At the same time, a flow control valve 8 needs to be equipped on the pipeline. Also referring to the sample materials of Bosch Rexroth, a proportional flow control valve of 2FRE10 - 4X16LBK4M is selected. This proportional flow control valve has a two-way function and can output a corresponding flow rate with a great degree of compensation for pressure and temperature according to the provided electrical signal value. The flow rate can be adjusted through a potentiometer. In the system of the present invention, setting its maximum passing flow rate to 16 L / min can meet the design requirements. During operation, set its maximum passing flow rate to 16 L / min.

[0050] The present invention also provides a shield machine, including the above-mentioned slow propulsion hydraulic system.

[0051] Working principle and process:

[0052] In the normal tunneling mode of the shield machine, the reversing valve II18 is energized, and the cartridge valve II11 is in the conducting state. At this time, under the action of the variable pump 4, the hydraulic oil sequentially passes through the filter 9 and the speed control valve 10 and then reaches the reversing valve I12. When the left side of the reversing valve I12 is energized and in the left position, the hydraulic oil enters the rod chambers of the cylinder I15 and the cylinder II16 respectively, driving the piston rods of both to contract. The hydraulic oil in the rodless chambers of the cylinder I15 and the cylinder II16 returns to the fuel tank through the cartridge valve II11. When the reversing valve II18 is de-energized and the cartridge valve II11 is in the closed state, and the right side of the reversing valve I12 is energized and in the right position, the hydraulic oil enters the rodless chambers of the cylinder I15 and the cylinder II16 respectively, driving the piston rods of both to extend. The hydraulic oil in the rodless chambers of the cylinder I15 and the cylinder II16 returns to the fuel tank through the reversing valve I12.

[0053] In the assembly mode of the shield machine, the reversing valve IV20 is energized, the cartridge valve III21 is in the conducting state, the reversing valve II18 is energized, and the cartridge valve II11 is in the conducting state. At this time, under the action of the variable pump 4, the hydraulic oil sequentially passes through the cartridge valve III21 and reaches the reversing valve I12. When the left side of the reversing valve I12 is energized and in the left position, the hydraulic oil enters the rod chambers of the cylinder I15 and the cylinder II16 respectively, driving the piston rods of both to contract. The hydraulic oil in the rodless chambers of the cylinder I15 and the cylinder II16 returns to the fuel tank through the cartridge valve II11. When the reversing valve II18 is de-energized and the cartridge valve II11 is in the closed state, and the right side of the reversing valve I12 is energized and in the right position, the hydraulic oil enters the rodless chambers of the cylinder I15 and the cylinder II16 respectively, driving the piston rods of both to extend. The hydraulic oil in the rodless chambers of the cylinder I15 and the cylinder II16 returns to the fuel tank through the reversing valve I12.

[0054] In the slow propulsion mode of the shield machine, under the action of the slow propulsion pump 1, the hydraulic oil sequentially passes through the check valve II23, the filter 9 and the speed control valve 10 and then reaches the reversing valve I12, and then reaches the cylinder I15 and the cylinder II16. In this mode, the shield machine can smoothly enter the pile grinding mode, greatly reducing the operation difficulty of the shield driver, so that the shield machine can tunnel more smoothly.

[0055] The above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified and equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A slow propulsion hydraulic system for a shield machine, characterized in that, It includes a variable pump system, a filter (9), a speed control valve (10), a reversing valve I (12), an oil cylinder, a slow propulsion pump (1), a flow control valve (8), a check valve I (17), a cartridge valve I (3), a cartridge valve II (11), a relief valve I (2), and a reversing valve II (18); The variable pump system, the filter (9), the speed control valve (10), and the reversing valve I (12) are connected in sequence. The reversing valve I (12) is connected to the oil cylinder. An oil return circuit I is led out from the rodless cavity of the oil cylinder and connected to an oil circuit. The cartridge valve II (11) is connected to the oil return circuit I. The reversing valve II (18) is connected to the valve front oil circuit and the control oil circuit of the cartridge valve II (11) and controls the opening and closing of the cartridge valve II (11); The reversing valve I (12) controls the oil inlet and outlet directions of the rodless cavity and the rod cavity of the oil cylinder. The reversing valve I (12) is connected to the fuel tank; The slow propulsion pump (1) is connected in parallel with the variable pump system. A flow control valve (8), a cartridge valve I (3), and a relief valve I (2) are connected between their oil outlets. The relief valve I (2) controls the opening and closing of the cartridge valve I (3).

2. The slow propulsion hydraulic system for a shield machine according to claim 1, characterized in that, The variable pump system includes a variable pump (4), a swash plate oil cylinder (5), a reversing valve III (7), and a relief valve II (6). The swash plate oil cylinder (5) is connected to the variable pump (4) and controls the swash plate slope of the variable pump (4). The reversing valve III (7) is connected to the swash plate oil cylinder (5) and controls the oil inlet and outlet directions of the rod cavity and the rodless cavity of the swash plate oil cylinder (5). The relief valve II (6) is connected to the reversing valve III (7).

3. The slow propulsion hydraulic system for a shield machine according to claim 2, characterized in that, It also includes a check valve I (17). The check valve I (17) is connected to the oil circuit between the reversing valve I (12) and the rodless cavity of the oil cylinder.

4. The slow propulsion hydraulic system for a shield machine according to claim 3, characterized in that, It also includes a unloading valve (14) and a relief valve III (13). The unloading valve (14) and the relief valve III (13) are connected in parallel to the oil circuit between the rodless cavity of the oil cylinder and the fuel tank.

5. The slow propulsion hydraulic system for a shield machine according to claim 4, characterized in that, It also includes a check valve II (23). The check valve II (23) is connected to the oil circuit between the slow propulsion pump (1) and the filter (9).

6. The slow propulsion hydraulic system for a shield machine according to claim 5, characterized in that, It also includes a relief valve IV (19), a reversing valve IV (20), and a cartridge valve III (21). The cartridge valve III (21) is connected in parallel to the oil circuit between the filter (9) and the speed control valve (10). A branch oil return circuit II is led out from the valve rear oil circuit of the speed control valve (10) and connected to the fuel tank. The relief valve IV (19) is connected to the oil return circuit II. The reversing valve IV (20) is connected to the valve front oil circuit of the filter (9), the oil return circuit II, and the control oil circuit of the cartridge valve III (21).

7. A shield machine, including a hydraulic control system, is characterized in that, The hydraulic control system is a slow propulsion hydraulic system as described in Claim 1.

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