Combined control valve with optimized structure

Abstract

The utility model relates to the technical field of hydraulic plunger pumps, and discloses a combined control valve with an optimized structure, which comprises a plunger pump, a control system, a flow control valve module and a power control module, the control system is connected with the plunger pump, the control system comprises an LS pressure feedback port, an oil outlet of the plunger pump is connected with the flow control valve module, and the power control module is connected with the flow control valve module. The flow control valve module is connected with the power control module, and the power control module is connected with an LS pressure feedback port of the control system. The power control pressure is the LS pressure of the system and is different from the outlet oil pressure of the traditional plunger pump as the control pressure, but the realized control functions are completely the same, a constant power control module in the traditional control valve is cancelled, the flow control valve module is directly connected with the power control module, and the power control module is directly connected with the flow control valve module. And the flow control module not only realizes a flow control function, but also realizes power control together with the power control module.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic piston pump technology, and specifically to a combined control valve with optimized structure. Background Technology

[0002] Traditional plunger pumps use two separate control modules for flow control and power control. The flow control valve module only controls the flow output characteristics of the plunger pump, while the constant power control module only controls the power characteristics. Figure 1 The image shows an integrated valve comprising a flow control module and a portion of a constant power control module. Figure 2 For power control module, it is related to Figure 1 The constant power control module in the middle works synchronously to achieve constant power characteristic control. Figure 3 Hydraulic schematic diagram for flow control and power control of traditional plunger pumps;

[0003] like Figure 1 , 3 As shown, the hydraulic oil at the outlet of the plunger pump passes through oil passage P and acts on the right end of the flow control valve stem 2. The left end connector 4 of the valve stem is connected to the system LS feedback port. When the pressure at port P exerts a leftward force on the flow control valve stem 2 greater than the sum of the rightward pressure exerted by the system LS feedback pressure on the flow control valve stem 2 and the spring force, the flow control valve stem 2 moves to the left. The pressure oil at port P enters the servo plunger chamber through the control oil port A, and the output flow of the plunger pump decreases. When the leftward force of the pressure at port P exerts a leftward force on the flow control valve stem 2 less than the sum of the rightward pressure exerted by the LS feedback pressure on the flow control valve stem 2 and the spring force, the flow control valve stem 2 moves to the right. The pressure oil at port P cannot enter the servo plunger chamber through the control oil port A. The hydraulic oil in the servo plunger chamber returns through port T under the action of the plunger pump reset spring, and the output flow of the plunger pump increases. This is the control logic of the flow control valve module 9 for the output flow of the plunger pump.

[0004] like Figure 2 and Figure 3As shown, the hydraulic oil from the plunger pump outlet enters the right end of valve stem 1 through oil passage P, and simultaneously enters the left side of valve stem 1 through the throttle orifice inside valve stem 1. The constant power control connector 3 is connected to the upper connector 5 of the power control module through an external steel pipe. The hydraulic oil from the plunger pump outlet enters the sealed space formed by valve core 6 and valve sleeve 7 of the power control module. When the force exerted by the plunger pump outlet oil pressure P on the difference in area between the left and right shoulders of valve core 6 is less than the right spring force, valve core 6 does not move, and the pressure on the left and right sides of valve stem 1 is equal. Due to the presence of the spring force on the left side of valve stem 1, valve stem 1 moves to the right, and the plunger pump outlet oil pressure P cannot enter the control oil port A to reach the servo plunger cavity. Under the action of the reset spring, the output flow of the plunger pump remains at its maximum and does not enter constant power control. When the outlet oil pressure P continues to increase, and the force acting on the area difference of valve core 6 is greater than the set value of the right spring, valve core 6 moves to the right, and the crescent groove on valve core 6 connects with port T. The oil pressure in the sealed space formed by valve core 6 and valve sleeve 7 drops instantaneously, and the oil pressure on the left side of valve stem 1 also drops at any time. Due to the throttling orifice on valve stem 1, the oil pressure on the right side of valve stem 1 does not drop instantaneously. Therefore, for valve stem 1, when the sum of the hydraulic pressure on the left side and the spring force is less than the hydraulic pressure on the right side, valve stem 1 moves to the left, and oil pressure P connects with control port A and enters the servo plunger chamber. The plunger pump displacement decreases, and the constant power control stage is entered. It can be seen that the constant power control is achieved by two modules.

[0005] As can be seen from the above, the flow and constant power control structure of the plunger pump is complex, involves many types of parts, and has high manufacturing costs. Therefore, the control valve designed in this way has great limitations in terms of processing difficulty and cost control. Utility Model Content

[0006] The technical problem this invention aims to solve is that existing plunger pumps have two independent control modules for flow control and power control, resulting in complex structures, numerous parts, high manufacturing costs, and significant processing difficulties.

[0007] To solve the above-mentioned technical problems, the technical solution of this utility model is to provide a structurally optimized combined control valve, including a plunger pump, a control system, a flow control valve module, and a power control module. The control system is connected to the plunger pump and includes an LS pressure feedback port. The oil outlet of the plunger pump is connected to the flow control valve module, the flow control valve module is connected to the power control module, and the power control module is connected to the LS pressure feedback port of the control system.

[0008] Optionally, the flow control valve module includes a flow control valve stem, a T-type return port, an A-type port, and a P-type port. The left end of the flow control valve stem is provided with a spring and a left end connector of the valve stem. The right end of the flow control valve stem is provided with a groove connecting the A-type port and the P-type port. The P-type port is connected to the outlet of the plunger pump, and the A-type port is connected to the servo plunger chamber of the plunger pump.

[0009] Optionally, the power control module is provided with an upper connector and a throttling plug. The upper connector is connected to the left end connector of the valve stem via an external steel pipe, and the throttling plug is connected to the LS pressure feedback port of the control system.

[0010] Optionally, the throttling plug is threadedly connected to the power control module, and the throttling plug has a throttling hole inside.

[0011] Optionally, the power control module is provided with a valve core and a valve sleeve. The valve core is located inside the valve sleeve. A spring is provided on the right side of the valve core and the valve sleeve. The valve sleeve is provided with an annular groove. The valve core is provided with a crescent groove that can communicate with the T return oil port.

[0012] In summary, the power control pressure of this invention is the system LS pressure, which differs from the traditional method of using the outlet oil pressure of a plunger pump as the control pressure. However, the control function achieved is exactly the same. Furthermore, this invention eliminates the constant power control module in the traditional control valve and directly connects the flow control valve module and the power control module, greatly simplifying the structure of the power control module and reducing the complexity of control. The flow control module not only realizes the function of flow control but also achieves power control together with the power control module. The control structure is simple, the number of parts is small, and the manufacturing cost is low. Attached Figure Description

[0013] Figure 1 A schematic diagram of a valve structure integrating a traditional flow control module and a partial power control module;

[0014] Figure 2 This is a schematic diagram of a traditional power control module.

[0015] Figure 3 Hydraulic schematic diagram for flow control and power control of traditional plunger pumps;

[0016] Figure 4 A schematic diagram of the flow control module in a combined control valve with optimized structure provided by this utility model;

[0017] Figure 5 A schematic diagram of the power control module structure in a combined control valve with optimized structure provided by this utility model;

[0018] Figure 6 A hydraulic schematic diagram of a combined control valve with optimized structure provided by this utility model;

[0019] In the diagram: 1. Valve stem; 2. Flow control valve stem; 3. Constant power control connector; 4. Left end connector of valve stem; 5. Upper end connector of power control module; 6. Valve core; 7. Valve sleeve; 8. Throttling plug; 9. Flow control valve module; 10. Power control module. Detailed Implementation

[0020] The following combination Figure 1-6 The present invention will be described in further detail below.

[0021] This utility model discloses a structurally optimized combined control valve, referring to... Figure 4 and Figure 5 It includes a plunger pump, a control system, a flow control valve module 9, and a power control module 10. The control system is connected to the plunger pump and includes an LS pressure feedback port. The plunger pump outlet is connected to the flow control valve module 9, the flow control valve module 9 is connected to the power control module 10, and the power control module 10 is connected to the LS pressure feedback port of the control system.

[0022] In a further embodiment, the flow control valve module 9 includes a flow control valve stem 2, a T-type return port, an A-type port, and a P-type port. The left end of the flow control valve stem 2 is equipped with a spring and a left-end connector 4. The right end of the flow control valve stem 2 is equipped with a groove connecting the A-type port and the P-type port. The P-type port is connected to the outlet of the plunger pump, and the A-type port is connected to the servo plunger chamber of the plunger pump. The power control module 10 is equipped with an upper connector 5 and a throttling plug 8. The upper connector 5 of the power control module... The external steel pipe is connected to the left end connector 4 of the valve stem, and the throttling plug 8 is connected to the LS pressure feedback port of the control system. The throttling plug 8 is threadedly connected to the power control module 10, and the throttling plug 8 has a throttling hole. The internal structure of the power control module 10 is the same as that of a traditional power control module. It has a valve core 6 and a valve sleeve 7 inside. The valve core 6 is located inside the valve sleeve 7. A spring is provided on the right side of the valve core 6 and the valve sleeve 7. The valve sleeve 7 has an annular groove. The valve core 6 has a crescent groove that can communicate with the T return oil port.

[0023] Reference Figures 4 to 6 The principles of flow control and power control of this utility model are as follows:

[0024] The flow control principle is as follows: the oil pressure at the outlet of the plunger pump enters the flow control valve module 9 through the P port and acts on the right end of the flow control valve stem 2. The valve stem left end connector 4 of the flow control valve stem 2 is the same as the upper end connector 5 of the power control module on the power control module 10. The two are connected through an external steel pipe. Since the throttling plug 8 is connected to the system LS pressure feedback signal port, and the outer cylindrical surface of the valve sleeve 7 is provided with an annular groove, the pressure of the system LS pressure feedback signal port is connected through the throttling plug 8, the circular groove on the outer cylindrical surface of the valve sleeve 7, the upper end connector 5 of the power control module, and the left side of the flow control valve stem 2. Since the system LS port pressure is too low at this time, the hydraulic pressure of the LS port pressure on the valve core 6 to the right is less than the set spring force. Therefore, the valve core 6 is in the left position and does not release pressure.

[0025] At this time, if the force exerted by the pressure at port P on the flow control valve stem 2 to the left is greater than the sum of the pressure exerted by the feedback pressure at port LS on the flow control valve stem 2 to the right and the spring force, the flow control valve stem 2 moves to the left, and the pressure oil at port P enters the servo piston chamber of the piston pump through the control port A, reducing the output flow of the piston pump. When the force exerted by the pressure at port P on the flow control valve stem 2 to the left is less than the sum of the pressure exerted by the feedback pressure at port LS on the flow control valve stem 2 to the right and the spring force, the flow control valve stem 2 moves to the right, and the pressure oil at port P cannot enter the servo piston chamber from the control port A. Under the action of the piston pump reset spring, the hydraulic oil in the servo piston chamber returns from the return port T, increasing the output flow of the piston pump and realizing the flow control function.

[0026] The constant power control principle is as follows: When the load pressure continues to rise, the system LS feedback pressure increases. When the force acting on the difference in surface area between the left and right cylindrical surfaces of the valve core 6 is greater than the spring force on the right side of the valve core 6, the valve core 6 moves to the right, and the crescent groove on the valve core 6 connects with the T return oil port. The system LS oil pressure in the sealed space formed by the valve core 6 and the valve sleeve 7 drops instantaneously. Due to the presence of the throttle plug 8 and the connection between the upper connector 5 of the power control module and the left connector 4 of the valve stem through an external steel pipe, the oil pressure on the left side of the flow control valve stem 2 also drops instantaneously. The oil pressure on the right side of the flow control valve stem 2 is kept constant by the hydraulic pressure of the plunger pump outlet oil. Therefore, for the flow control valve stem 2, when the sum of the system LS feedback pressure on the left and the spring force is less than the hydraulic pressure on the right, the P oil port of the flow control valve stem 2 connects with the control A oil port, the plunger pump outlet oil enters the servo plunger chamber, the plunger pump displacement decreases, and constant power control is achieved.

[0027] It can be seen that the power control pressure of the traditional power control module is taken from the pump outlet oil pressure, while the power control pressure of this utility model is taken from the system LS pressure. Although the pressures are different, the control functions are exactly the same. In addition, this utility model eliminates the constant power control module, which greatly simplifies the structure of the power control module and reduces the complexity of control. The flow control module not only realizes the function of flow control, but also realizes power control together with the power control module.

[0028] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A structurally optimized combined control valve, characterized in that, It includes a plunger pump, a control system, a flow control valve module (9) and a power control module (10). The control system is connected to the plunger pump and includes an LS pressure feedback port. The oil outlet of the plunger pump is connected to the flow control valve module (9). The flow control valve module (9) is connected to the power control module (10). The power control module (10) is connected to the LS pressure feedback port of the control system.

2. The structurally optimized combined control valve according to claim 1, characterized in that, The flow control valve module (9) includes a flow control valve stem (2), a T return port, an A port, and a P port. The left end of the flow control valve stem (2) is provided with a spring and a valve stem left end connector (4). The right end of the flow control valve stem (2) is provided with a groove for connecting the A port and the P port. The P port is connected to the oil outlet of the plunger pump, and the A port is connected to the servo plunger cavity of the plunger pump.

3. The structurally optimized combined control valve according to claim 2, characterized in that, The power control module (10) is provided with an upper connector (5) and a throttling plug (8). The upper connector (5) is connected to the left connector (4) of the valve stem through an external steel pipe. The throttling plug (8) is connected to the LS pressure feedback port of the control system.

4. The structurally optimized combined control valve according to claim 3, characterized in that, The throttling plug (8) is threadedly connected to the power control module (10), and the throttling plug (8) has a throttling hole inside.

5. The structurally optimized combined control valve according to claim 3, characterized in that, The power control module (10) is provided with a valve core (6) and a valve sleeve (7). The valve core (6) is located inside the valve sleeve (7). A spring is provided on the right side of the valve core (6) and the valve sleeve (7). The valve sleeve (7) is provided with an annular groove. The valve core (6) is provided with a crescent groove that can communicate with the T return oil port.

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