Control main valve and integrated valve group

Abstract

The utility model discloses a control main valve and an integrated valve group comprising the control main valve. The control main valve is a plate-type multi-way valve which supplies oil to two actuators at the same time, and comprises a valve body which defines a valve chamber and is provided with an oil inlet, a first working oil port, a second working oil port, an oil return port and a load-sensitive oil port; and a spool mounted in the valve chamber and axially slidable to define a neutral valve position, a first working valve position, and a second working valve position for controlling the main valve. The valve body and the valve element are configured in the mode that at the neutral valve position, the oil inlet, the first working oil port, the second working oil port and the oil return port are all cut off. At the first working valve position, the oil inlet is communicated with the first working oil port and the second working oil port, and the oil return port is cut off; and at the second working valve position, the oil inlet is cut off, and the first working oil port and the second working oil port are communicated with the oil return port. And the cost and the size of the control main valve are reduced.

Description

Technical Field

[0001] The present application relates to a control main valve (a plate-type multi-way valve) used in a hydraulic system of engineering machinery, which is capable of simultaneously supplying oil to two actuators in a single connection, and an integrated valve group using such a control main valve. Background Art

[0002] In the hydraulic systems of construction machinery, control main valves are often used to control the supply of hydraulic oil to the actuators. In some construction machinery, the movement of certain components requires the coordinated operation of two hydraulic actuators. In the prior art, for components that require the coordinated operation of two hydraulic actuators, each actuator is equipped with a corresponding control main valve to control the synchronous movement of the two actuators. For example, a forklift is equipped with two symmetrical lifting cylinders for lifting, each of which is equipped with a corresponding control main valve and hydraulic circuit. When the lifting cylinders are raised or lowered, the control main valve needs to supply oil to the two lifting cylinders synchronously. In this solution of synchronously controlling two hydraulic actuators, since each actuator uses its own control main valve and hydraulic circuit, the cost of the hydraulic system is high and the installation space is large. In addition, when supplying oil to the two hydraulic actuators synchronously through the two control main valves, it is difficult to ensure that the supplied oil pressure is the same, which may cause the two hydraulic actuators to move in an uncoordinated manner. Utility Model Content

[0003] An object of the present application is to provide an improved control main valve, which can simultaneously supply hydraulic oil to two hydraulic actuators through a single control main valve plate.

[0004] A control main valve is a plate-type multi-way valve that supplies oil to two actuators simultaneously, comprising:

[0005] a valve body defining a valve chamber and having an oil inlet port, a first operating oil port, a second operating oil port, an oil return port, and a load sensing oil port; and

[0006] a valve core installed in the valve chamber and axially slidable to define a neutral valve position, a first working valve position, and a second working valve position for controlling the main valve;

[0007] In which, the valve body and the valve core are configured so that, in the neutral valve position, the oil inlet, the first working oil port, the second working oil port and the oil return port are all cut off; in the first working valve position, the oil inlet is connected with the first working oil port and the second working oil port, and the oil return port is cut off; in the second working valve position, the oil inlet is cut off, and the first working oil port and the second working oil port are connected with the oil return port.

[0008] In one embodiment, a communication channel is formed in the valve body, connecting the first working oil port and the second working oil port.

[0009] In one embodiment, the oil return port includes a first oil return port and a second oil return port. In the second working valve position, the first working oil port is communicated with the second oil return port, and the second working oil port is communicated with the first oil return port.

[0010] In one embodiment, in the second working valve position, the first working oil port is in throttling communication with the second oil return port, and the second working oil port is in throttling communication with the first oil return port.

[0011] In one embodiment, the valve body is further formed with a load-sensitive oil port; wherein, in the neutral valve position, the load-sensitive oil port is connected to the first oil return port; in the first working valve position, the load-sensitive oil port is connected to the oil inlet, the first working oil port, and the second working oil port; in the second working valve position, the load-sensitive oil port is cut off.

[0012] In one embodiment, a first transition oil chamber and a second transition oil chamber that are connected to each other are formed in the valve body; wherein, in the first working valve position, the oil inlet is connected to the first working oil port through the first transition oil chamber and the second transition oil chamber, and is connected to the second working oil port through the first transition oil chamber.

[0013] In one embodiment, the load sensing oil port is communicated with the first transition oil chamber.

[0014] In one embodiment, in the neutral valve position, the load sensing oil port is communicated with the first oil return port via the first transition oil chamber and the load sensing channel in the valve core.

[0015] In one embodiment, in the first working valve position, the load sensing oil port is communicated with the first working oil port via the first transition oil chamber and the second transition oil chamber.

[0016] In one embodiment, in the second working valve position, the load-sensing oil port is communicated with the first oil return port via a load-sensing channel in the valve core.

[0017] In another aspect, the present application provides an integrated valve group, comprising:

[0018] Control main valve as previously described; and

[0019] The pilot valve integrated on the valve body of the main control valve is configured to control the valve position of the main control valve.

[0020] The control main valve and integrated valve assembly of this application utilizes a single integrated valve disc to synchronously supply hydraulic oil to two hydraulic actuators, eliminating the need for separate two-valve discs as in the prior art. This reduces the cost and size of the control main valve. Furthermore, it facilitates synchronized oil supply and return to the two hydraulic actuators at balanced pressures, ensuring consistent operation of the two actuators. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The foregoing and other aspects of the present application will be more fully understood and appreciated through the following detailed description made with reference to the accompanying drawings, in which:

[0022] Figure 1 is a schematic diagram of the integrated valve group of the present application;

[0023] Figure 2 It is the hydraulic symbol of the control main valve in the integrated valve group of this application;

[0024] Figure 3 is a cross-sectional view of an exemplary structure of the control main valve of the present application;

[0025] Figure 4 、 Figure 5 They are Figure 2 A cross-sectional view of the valve body and valve core of the control main valve shown;

[0026] Figure 6 、 Figure 7 yes Figure 2 The cross-sectional view of the control main valve is shown in two working valve positions. DETAILED DESCRIPTION

[0027] The present application generally relates to a control main valve in a hydraulic system for construction machinery, which is a plate-type multi-way valve for controlling the supply of hydraulic oil to two hydraulic actuators that act synchronously. An example of using the control main valve of the present application is the lifting of a forklift, which is equipped with two symmetrical lifting cylinders, and the two lifting cylinders are supplied with hydraulic oil by a common control main valve valve plate. An example of using the control main valve of the present application is the boom of an excavator, which is equipped with two symmetrical boom cylinders, and the two boom cylinders are supplied with hydraulic oil by a common control main valve. The control main valve of the present application can also be applied to other construction machinery. The control main valve valve plate can be integrated with auxiliary hydraulic components to form an integrated valve group, such as Figure 1 shown.

[0028] See Figure 1 The main control valve of this application comprises a single valve disc, or valve body, within which are formed at least the following oil circuits: a high-pressure (supply) oil circuit Lp, a return oil circuit Lt, an auxiliary return oil circuit Lt1, a load-sensing oil circuit Ls, and a pilot oil circuit Lc1 and a pilot return oil circuit Lc2. The valve body also has pressure oil ports A1 and B1 for connection to the oil inlets of two hydraulic actuators, respectively.

[0029] The control main valve (hereafter referred to as the main valve) Vm is formed within the valve body. Furthermore, pilot valves a1 and b1 are integrated into the valve body to supply control oil pressure to the control terminals on either side of the main valve Vm. Pilot valves a1 and b1 are solenoid-controlled pressure-reducing valves, connected to the pilot oil circuit Lc1 and the pilot return oil circuit Lc2, respectively. They receive pilot oil pressure from the pilot oil circuit Lc1, reduce the pressure, and supply it to the corresponding control terminals of the main valve to control the valve position and opening of the main valve Vm.

[0030] In addition, the valve body is also integrated with a selector valve (shuttle valve) c1 and a one-way valve d1.

[0031] The graphic symbol of an exemplary main valve Vm of the present application is shown in FIG. Figure 2 See Figure 2 The exemplary main valve Vm is a three-position six-way valve with three valve positions and six oil ports. The three valve positions are: neutral valve position ( Figure 2 The middle valve position in the first working valve position ( Figure 2 The left valve position in the middle), and the second working valve position ( Figure 2 The valve position of the main valve Vm and the opening degree in the first and second working valve positions are controlled by the pilot valves a1 and b1.

[0032] The six oil ports are: oil inlet port P, first working oil port A, second working oil port B, first oil return port T1, second oil return port T2, and load sensing oil port S, hereinafter referred to as P port, A port, B port, T1 port, T2 port, and S port respectively.

[0033] In the neutral valve position, ports P, A, B and T2 are all blocked, and port S is connected to port T1.

[0034] In the first working valve position, port P is connected to ports A and B, ports T1 and T2 are blocked, and port S is connected to port P in a throttling manner.

[0035] In the second working valve position, port P is cut off, port A is connected to port T2 in throttling mode, port B is connected to port T1 in throttling mode, and port S is cut off.

[0036] Back to Figure 1 The P port of the main valve Vm is connected to the high-pressure oil circuit Lp through the one-way valve d1. The one-way valve d1 is oriented to allow hydraulic oil to flow from the high-pressure oil circuit Lp to the P port only and prohibit reverse flow.

[0037] Selector valve c1 is a shuttle valve with two oil inlets and one outlet. The outlet is connected to the load-sensing oil line Ls. The first inlet is connected to the load-sensing oil line of an adjacent integrated valve block (not shown, used to control the oil supply to other hydraulic actuators), and the second inlet is connected to port S of the main valve Vm. Load-sensing oil line Ls is connected to the variable displacement mechanism of the main pump, used to adjust the main pump's displacement based on the load.

[0038] The T1 port of the main valve Vm is connected to the auxiliary return oil passage Lt1, and the T2 port is connected to the return oil passage Lt. The auxiliary return oil passage Lt1 is connected to the return oil passage Lt inside the valve body or outside the valve body.

[0039] Port A and port B of the main valve Vm lead to or constitute pressure oil ports A1 and B1 respectively.

[0040] A communication passage L1 is formed in the valve body to connect the A port and the B port.

[0041] Refer to the following Figure 3-Figure 7 An exemplary structure of the main valve Vm is described. Figure 3 、 Figure 6 、 Figure 7 The main valve Vm is shown in the neutral valve position, the first working valve position, and the second working valve position respectively.

[0042] See Figure 3 、 Figure 6 、 Figure 7 The main valve Vm includes a valve body 1 and a valve core 2. The valve body 1 is the single valve body of the integrated valve group described above. The figures only show the parts of the main valve Vm that are relevant to this application, and other parts (such as the control ends on both sides) are not shown.

[0043] See Figure 4 , an axially through valve chamber 10 is defined in the valve body 1, for axially slidably mounting the valve core 2 in the valve chamber 110 to achieve valve position switching. Oil chambers are formed in the valve body 1, which are connected to the P port, A port, B port, T1 port, T2 port, and S port respectively. For the purpose of convention in the art, these oil chambers are respectively referred to as the P chamber, A chamber, B chamber, T1 chamber, T2 chamber, and S chamber. In the following description, mentioning connection (or isolation) with a certain oil chamber means also connection (or isolation) with the corresponding oil port.

[0044] The valve body 1 also forms a first and second interconnected transition oil chambers C1 and C2, hereinafter referred to as chambers C1 and C2. The S chamber opens into one of the C1 and C2 chambers. The S chamber is connected to the second oil inlet of the selector valve (shuttle valve) C1 via an internal passage, not shown. The S chamber has a small fluid area, providing a throttling effect.

[0045] Along the first side from the axial direction ( Figure 4 left side) to the second axial side ( Figure 4 From the direction of the center right side, the T2 chamber, the A chamber, the C2 chamber, the P chamber, the C1 chamber, the B chamber, and the T1 chamber are arranged in sequence. These oil chambers are all connected to the valve chamber 10.

[0046] The communication channel L1 connects the A cavity and the B cavity at a position close to the opening ends of the A cavity and the B cavity.

[0047] In addition, secondary relief valve holes 11 and 12 are formed in the valve body 1. The valve hole 11 is connected to the A chamber and the T2 chamber, and the valve hole 12 is connected to the B chamber and the T1 chamber.

[0048] See Figure 5 , on the outer periphery of the valve core 2, along the first axial side ( Figure 5 left side) to the second axial side ( Figure 5 As viewed from the center right side, first to fifth oil grooves (undercut grooves) 21, 22, 23, 24, and 25 are formed in sequence. These oil grooves separate the main body of the valve core 2 into a first valve core segment 2a, a second valve core segment 2b, a third valve core segment 2c, a fourth valve core segment 2d, a fifth valve core segment 2e, and a sixth valve core segment 2f from the first axial side to the second axial side.

[0049] An axial hole (not shown) is formed inside the body of the valve core 2 , with both axial ends of the axial hole blocked and axially extending at least between the fourth valve core segment 2 d and the fifth valve core segment 2 e .

[0050] A first radial hole H1 is formed in the fifth valve core segment 2e, extending inward from the outer circumference and communicating with the axial hole. A second radial hole H2 is formed in the fourth valve core segment 2d, extending inward from the outer circumference and communicating with the axial hole. The first radial hole H1, the axial hole, and the second radial hole H2 form a load-sensing passage.

[0051] Back to Figure 3 In the neutral position of main valve Vm, the first oil groove 21 faces chamber T2, the second oil groove 22 faces chamber C2, the third oil groove 23 faces chamber C1, the fourth oil groove 24 faces chamber B, and the fifth oil groove 25 faces chamber T1. The second valve core segment 2b isolates chamber A from chambers T2 and C2, the third valve core segment 2c isolates chamber P from chambers C1 and C2, the fourth valve core segment 2d isolates chamber B from chamber C1, and the fifth valve core segment 2e isolates chamber B from chamber T1. Therefore, ports P, A, B, and T2 are all blocked. The first radial hole H1 communicates with chamber T1, and the second radial hole H2 communicates with chamber C1. Thus, chamber S communicates with port T1 via chamber C1 and the load-sensing channel formed by the first radial hole H1, the axial hole, and the second radial hole H2.

[0052] When the pilot valve a1 is activated and drives the valve core 2 to move toward the first axial side, the main valve Vm moves to the first working valve position, such as Figure 6As shown in the figure, in the first operating valve position, the second oil groove 22 faces chambers A and C2, the third oil groove 23 faces chambers C1 and P, and the fourth oil groove 24 faces chambers C1 and B. The second valve core segment 2b still separates chamber A from chambers T2 and C2, and the fifth valve core segment 2e still separates chamber B from chamber T1. Chamber S communicates with chamber P via chamber C1, and thus with both chambers A and B.

[0053] In this way, Figure 6 As shown by the arrows in Figure 1, high-pressure oil entering chamber P at port P flows through third oil groove 23 into chamber C1. It then flows through chamber C2 and second oil groove 22 into chamber A, where it is supplied to the first hydraulic actuator via port A. It then flows through fourth oil groove 24 into chamber B, where it is supplied to the second hydraulic actuator via port B. The connecting channel L1 ensures that the hydraulic oil pressures output from ports A and B are roughly equal, allowing the two hydraulic actuators to actuate in a substantially synchronized forward direction. For the two boom cylinders of an excavator or the two lift cylinders of a forklift, forward actuation involves cylinder extension.

[0054] When the pilot valve a2 is activated and drives the valve core 2 to move toward the second axial side, the main valve Vm moves to the first working valve position, such as Figure 7 As shown. In the second operating valve position, the first oil groove 21 faces chambers A and T2, while the fourth oil groove 24 faces chambers B and T1. The second valve core segment 2b separates chambers A from chambers C2, the third valve core segment 2c separates chambers P from chambers C1, and the fourth valve core segment 2d separates chambers B from chambers C1. The portion of the second valve core segment 2b located in chamber A has a larger axial width, leaving a smaller flow area between chamber A and the first oil groove 21, creating a throttling effect. The fifth valve core segment 2e is completely located in chamber T1, leaving a smaller flow area between the fourth oil groove 24 and chamber T1, creating a throttling effect.

[0055] In this way, the return hydraulic oil from the first hydraulic actuator enters the A chamber through the A port, and then returns to the oil tank through the first oil groove 21 and the T2 port. The return hydraulic oil from the second hydraulic actuator enters the B chamber through the B port, and then returns to the oil tank through the fourth oil groove 24 and the T1 chamber. Figure 7 As shown by the arrow in .

[0056] The communication channel L1 can make the hydraulic oil pressure returning through ports A and B roughly equal, so that the two hydraulic actuators can basically move in opposite directions synchronously. For the two boom cylinders of an excavator or the two lift cylinders of a forklift, the opposite movement is cylinder retraction.

[0057] As can be seen, the single-link integrated valve plate according to this application allows for the synchronous supply of hydraulic oil to two hydraulic actuators through a single main valve Vm, eliminating the need for separate two-link valve plates as in the prior art. This reduces the cost and size of the control main valve. Furthermore, it facilitates synchronous oil supply and return to the two hydraulic actuators at balanced pressures, ensuring consistent operation of the two hydraulic actuators.

[0058] The valve body 1 and valve core 2 of the main valve Vm of this application can be manufactured using techniques well known in the art. The pilot valves a1 and b1, as well as the selector valve (shuttle valve) c1 and the check valve d1, can also be manufactured using techniques well known in the art and assembled to the valve body 1. These techniques do not relate to the improvements made by this application to existing technologies and are therefore not described here.

[0059] Furthermore, in the example described above, the main valve Vm is a three-position, six-way valve. However, the main valve Vm of the present application can also be designed with other numbers of valve positions and other numbers of oil ports, as long as the basic dual-path oil supply function of the main valve Vm described above is achieved. For example, for some applications, the load-sensing oil circuit Ls may not be required. In this case, the load-sensing oil circuit Ls, the associated selector valve c1, and the S port in the main valve Vm can be eliminated from the integrated valve manifold of the present application. If the S port is eliminated, the T1 port of the main valve Vm is also blocked in the neutral valve position.

[0060] Furthermore, in the valve body 1 , the T1 cavity and the T2 cavity can be connected via an internal passage, thereby merging the T1 port and the T2 port into a single oil return port.

[0061] Although the present application is described herein with reference to specific exemplary embodiments, the scope of the present application is not limited to the details shown, and various modifications may be made to these details without departing from the basic principles of the present application.

Claims

1. A control main valve, which is a plate-type multi-way valve that supplies oil to two actuators simultaneously, comprising: A valve body (1) defines a valve chamber and is formed with an oil inlet (P), a first working oil port (A), a second working oil port (B), an oil return port, and a load sensing oil port (S); and A valve core (2) is installed in the valve chamber and is axially slidable to define a neutral valve position, a first working valve position, and a second working valve position of the control main valve; The invention is characterized in that the valve body (1) and the valve core (2) are configured such that, in the neutral valve position, the oil inlet (P), the first working oil port (A), the second working oil port (B) and the oil return port are all cut off; in the first working valve position, the oil inlet (P) is connected with the first working oil port (A) and the second working oil port (B), and the oil return port is cut off; in the second working valve position, the oil inlet (P) is cut off, and the first working oil port (A) and the second working oil port (B) are connected with the oil return port.

2. The control main valve according to claim 1, characterized in that: A communication passage (L1) is formed in the valve body (1) for connecting the first working oil port (A) and the second working oil port (B).

3. The control main valve according to claim 1, characterized in that: The oil return port includes a first oil return port (T1) and a second oil return port (T2). In the second working valve position, the first working oil port (A) is connected to the second oil return port (T2), and the second working oil port (B) is connected to the first oil return port (T1).

4. The control main valve according to claim 3, characterized in that: In the second working valve position, the first working oil port (A) is connected to the second oil return port (T2) in a throttling manner, and the second working oil port (B) is connected to the first oil return port (T1) in a throttling manner.

5. The control main valve according to any one of claims 1 to 4, characterized in that: The valve body (1) is also formed with a load-sensitive oil port (S); Among them, in the neutral valve position, the load-sensing oil port (S) is connected to the first oil return port (T1); in the first working valve position, the load-sensing oil port (S) is connected to the oil inlet (P), the first working oil port (A) and the second working oil port (B); in the second working valve position, the load-sensing oil port (S) is cut off.

6. The control main valve according to claim 5, characterized in that: A first transition oil chamber (C1) and a second transition oil chamber (C2) communicating with each other are formed in the valve body (1); wherein, in a first working valve position, the oil inlet (P) is communicated with the first working oil port (A) via the first transition oil chamber (C1) and the second transition oil chamber (C2), and is also communicated with the second working oil port (B) via the first transition oil chamber (C1).

7. The control main valve according to claim 6, characterized in that: The load-sensing oil port (S) is in communication with the first transition oil chamber (C1).

8. The control main valve according to claim 7, characterized in that: In the neutral valve position, the load-sensitive oil port (S) is communicated with the first oil return port (T1) via the first transition oil chamber (C1) and the load-sensitive channel in the valve core (2).

9. The control main valve according to claim 7, characterized in that: In the first working valve position, the load-sensing oil port (S) is communicated with the first working oil port (A) via the first transition oil chamber (C1) and the second transition oil chamber (C2).

10. The control main valve according to claim 7, characterized in that: In the second working valve position, the load-sensitive oil port (S) is communicated with the first oil return port (T1) via the load-sensitive channel in the valve core (2).

11. An integrated valve group, characterized in that: include: The control main valve according to any one of claims 1 to 10; as well as A pilot valve (a1, b1) integrated on the valve body (1) of the control main valve is configured to control the valve position of the control main valve.

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