Static two-stage control priority valve and steering control system applying same

Abstract

The utility model relates to the technical field of engineering machinery, and provides a static two-stage control priority valve which comprises a priority valve body, a spring cavity is formed in the priority valve body, a control spring is movably arranged in the spring cavity, one end of the control spring is connected with a valve rod, the other end of the control spring is connected with a transposition piston, the valve rod is arranged in a main cavity in a sliding mode, and the main cavity is used for communicating a P oil port, a CF oil port and an EF oil port. The position changing piston is arranged in the piston cavity in a sliding mode, a piston oil way is formed in the position changing piston, the first closed cavity is communicated with the spring cavity, the second closed cavity is communicated with the first oil way, the first oil way is communicated with the second oil way, the second oil way is communicated with the sequence valve, the sequence valve is arranged in the ninth oil way, and the ninth oil way is communicated with the fourth oil way, the sixth oil way and the seventh oil way. The fourth oil way is communicated with the third oil way, the third oil way is communicated with the piston cavity, the sixth oil way is communicated with the LS oil way, the LS oil way is communicated with the CF oil port, the spring cavity and the fifth oil way, the seventh oil way is communicated with the eighth oil way, and the eighth oil way is communicated with the CF oil port. According to the utility model, vibration abnormal sound can be reduced or eliminated and energy can be saved.

Description

TECHNICAL FIELD

[0001] The utility model relates to engineering machinery technical field, concretely relates to static two -level control priority valve and its application's steering control system. BACKGROUND

[0002] The existing loader hydraulic steering system is mainly divided into coaxial flow amplification steering system and flow amplification valve system, in the coaxial flow amplification steering system, the steering system combination of static steering gear matching static priority valve is more commonly used, and it is found in the application process of the steering system of static steering gear matching static priority valve that the loader has the problems of severe steering gear vibration and obvious abnormal sound at idle speed or a certain speed.

[0003] Preliminary analysis believes that the reasons for the steering gear vibration are as follows: first, the gear pump tooth shape and the gear modulus difference cause the flow to have certain pulsation phenomenon; second, the flow is preferentially distributed to the CF port through the priority valve stem, and the remaining flow is unloaded through the EF port, and due to the back pressure of the EF port, the valve stem is in dynamic balance at all times, the pressure in the pipeline changes at all times, and vibration is generated; third, there are many bubbles in the oil, which causes the system to vibrate and make a loud noise. Further found that different vehicles using the same gear pump have the steering gear vibration problem, and some do not have the problem, combined with the current gear pump processing status, the steering gear vibration problem is not considered to be solved in this regard; the vehicles with the steering gear vibration problem have not found that the oil deteriorates prematurely, and the pump and other components have not found abnormal damage, so the possibility of too many bubbles in the oil is excluded; for the steering gear vibration vehicles, it is found that when the static priority valve with different control pressure and the same flow is replaced, the steering gear vibration phenomenon is more slight.

[0004] Therefore, in view of the above problems, a static two-level control priority valve is proposed to solve the above problems. UTILITY MODEL CONTENTS

[0005] The utility model aims at the deficiency of prior art, develops a kind of static two-level control priority valve, and the utility model can be realized when there is no steering action, the control pressure of static two-level control priority valve is lower, when steering action occurs, the control pressure of static two-level control priority valve is consistent with the control pressure of common static priority valve, to reduce or eliminate vibration abnormal sound, and energy can be saved simultaneously.

[0006] The utility model realizes the above-mentioned purposes by the following technical solutions:

[0007] The static two-stage control priority valve comprises a priority valve body, a spring cavity is formed in the priority valve body, a control spring is movably arranged in the spring cavity, one end of the control spring is connected with a valve rod, the other end of the control spring is connected with a transposition piston, the valve rod is slidably arranged in a main cavity, the main cavity is used for connecting a P oil port, a CF oil port and an EF oil port, the transposition piston is slidably arranged in a piston cavity, the transposition piston is internally provided with a piston oil way, a first closed cavity and a second closed cavity are further arranged between the transposition piston and the priority valve body, the first closed cavity is connected with the spring cavity through the piston oil way, the second closed cavity is connected with an oil way one, the oil way one is connected with an oil way two and an oil tank, the oil way two is connected with a sequence valve, the sequence valve is arranged in an oil way nine, the oil way nine is connected with an oil way four, an oil way six and an oil way seven, the oil way four is connected with an oil way three, the oil way three is connected with the piston cavity, the oil way six is connected with an LS oil way, one end of the LS oil way is connected with the CF oil port, the other end of the LS oil way is connected with the spring cavity and an oil way five, the oil way five is connected with the oil tank through an overflow valve, the oil way seven is connected with an oil way eight, and the oil way eight is connected with the CF oil port.

[0008] Preferably, a throttle one is arranged in the oil way three, a throttle two is arranged in the piston oil way, and a throttle three is arranged in the LS oil way between the oil way five and the oil way six.

[0009] Preferably, the P oil port is connected with a gear pump for oil supply, the P oil port is selectively connected with the CF oil port or the EF oil port through the sliding of the valve rod, the CF oil port is used for connecting the LS oil way, and the EF oil port is used for connecting an external oil way.

[0010] Preferably, the sequence valve comprises a valve core and a sequence spring, the valve core is slidably arranged in the oil way nine, one end of the valve core is connected with the sequence spring, the other end of the sequence spring is connected with a plug, the plug is connected with the priority valve body, and the valve core can selectively connect the oil way four with the oil way seven or connect the oil way four with the oil way two through sliding.

[0011] Preferably, a connecting plug one is arranged at one end of the piston cavity away from the spring cavity, and a connecting plug two is arranged at one end of the main cavity away from the spring cavity.

[0012] The utility model also provides a kind of steering control system, including the static two-stage control priority valve as described above, still include:

[0013] Oil tank, oil tank is used for storing hydraulic oil in;

[0014] Gear pump, the input end of gear pump is connected with oil tank, and output end is connected with P oil port;

[0015] Overflow valve, one end of overflow valve is connected with oil way five, and the other end is connected with oil tank;

[0016] Static diverter, CF oil port is connected by check valve, and it is connected with LS oil way, when steering, hydraulic oil can flow into static diverter from CF oil port, and from static diverter to LS oil way;

[0017] Turning cylinder, communicate static steering gear, be used for realizing steering.

[0018] The effect provided in the content of the utility model is only the effect of the embodiment, and is not all the effects of the utility model, and the above technical scheme has the following advantages:

[0019] The utility model discloses a static two -level control priority valve is modified to static two -level control priority valve by the ordinary static priority valve, makes the steering oil circuit exist two states, i. e. non -steering state and steering state, when being in non -steering state, the control pressure of LS oil circuit is 0, and sequence valve is closed, and the position of transposition piston is in initial position, and control spring is not forced, and is in low pressure state, when being in steering state, the control pressure of LS oil circuit rises, and overcomes the pressure of sequence spring, and sequence valve completes transposition, and CF oil port communicates piston cavity, and transposition piston completes transposition, and compresses control spring, and priority valve control pressure improves, and completes normal steering action, can save the energy when not steering, simultaneously, through changing control pressure, lightens or eliminates vibration phenomenon, avoids abnormal sound, through setting throttle mouth no. One and throttle mouth no. Two, avoid the pressure impact problem caused by the transposition action of transposition piston too fast, through setting throttle mouth no. Three, improved the stability of valve rod when working, stabilized the pressure of spring cavity. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the utility model, and constitute a part of the specification, and are used together with the embodiments of the utility model to explain the utility model, and do not constitute the limitation to the utility model.

[0021] Figure 1 It is the front view structural schematic drawing of static two -level control priority valve of the utility model embodiment;

[0022] Figure 2 It is the top view structural schematic drawing of static two -level control priority valve of the utility model embodiment;

[0023] Figure 3 It is the front view part sectional view structural schematic of static two -level control priority valve of the utility model embodiment Figure 1 ;

[0024] Figure 4 It is the sectional view structural schematic drawing of A direction in Figure 3 ;

[0025] Figure 5 It is the front view part sectional view structural schematic of static two -level control priority valve of the utility model embodiment Figure 2 ;

[0026] Figure 6 It is the sectional view structural schematic drawing of B direction in Figure 5 ;

[0027] Figure 7 Front view part cross section structure diagram of static two-level control priority valve of the embodiment of the utility model Figure 3

[0028] Figure 8 For Figure 7 The cross section structure diagram of direction C;

[0029] Figure 9 Front view part cross section structure diagram of static two-level control priority valve of the embodiment of the utility model Figure 4 ;

[0030] Figure 10 For Figure 9 The cross section structure diagram of direction D;

[0031] Figure 11 The oil circuit diagram of the steering control system of the embodiment of the utility model in non-steering state;

[0032] Figure 12 The oil circuit diagram of the steering control system of the embodiment of the utility model in steering state.

[0033] In the figure, 1, priority valve body;2, spring cavity;3, control spring;4, valve stem;5, transposition piston;6, main cavity;7, P oil port;8, CF oil port;9, EF oil port;10, piston cavity;11, piston oil circuit;12, closed cavity one;13, closed cavity two;14, oil circuit one;15, oil circuit two;16, oil circuit three;17, oil circuit four;18, oil circuit five;19, oil circuit six;20, oil circuit seven;21, oil circuit eight;22, oil circuit nine;23, oil tank;24, sequence valve;25, LS oil circuit;26, overflow valve;27, throttle one;28, throttle two;29, throttle three;30, gear pump;31, plug;32, connecting plug one;33, connecting plug two;34, static steering gear;35, steering oil cylinder;36, static two-level control priority valve;241, valve core;242, sequence spring. DETAILED DESCRIPTION

[0034] The technical scheme in the embodiments of the utility model will be described clearly and completely below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0035] Embodiment one

[0036] For example Figures 1-10 ​As shown, the static two-stage control priority valve comprises a priority valve body 1, a spring cavity 2 is formed in the priority valve body 1, a control spring 3 is movably arranged in the spring cavity 2, one end of the control spring 3 is connected with a valve rod 4, the other end of the control spring 3 is connected with a transposition piston 5, the valve rod 4 is slidably arranged in a main cavity 6, the main cavity 6 is used for connecting a P oil port 7, a CF oil port 8 and an EF oil port 9, the P oil port 7 is located on the upper side of the priority valve body 1, the CF oil port 8 is located on the lower side of the priority valve body 1, and the EF oil port 9 is located on the front side of the priority valve body 1, the transposition piston 5 is slidably arranged in a piston cavity 10, a piston oil way 11 is formed in the transposition piston 5, a closed cavity one 12 and a closed cavity two 13 are further arranged between the transposition piston 5 and the priority valve body 1, the closed cavity one 12 and the closed cavity two 13 are used to play a certain damping effect, slow down the moving speed of the transposition piston 5, the closed cavity one 12 is connected with the spring cavity 2 through the piston oil way 11, the closed cavity two 13 is connected with an oil way one 14, the oil way one 14 is connected with an oil way two 15 and an oil tank, the oil way two 15 is connected with an oil way nine 22, a sequence valve 24 is arranged in the oil way nine 22, the oil way nine 22 is connected with an oil way four 17, an oil way six 19 and an oil way seven 20, the oil way four 17 is connected with an oil way three 16, the oil way three 16 is connected with the piston cavity 10, the oil way six 19 is connected with an LS oil way 25, one end of the LS oil way 25 can be connected with the CF oil port 8, the other end of the LS oil way 25 is connected with the spring cavity 2 and an oil way five 18, the oil way five 18 is connected with the oil tank through an overflow valve, the oil way seven 20 is connected with an oil way eight 21, and the oil way eight 21 is connected with the CF oil port 8.

[0037] In the embodiment, a throttle one 27 is arranged in the oil way three 16, which is used to control the speed of the hydraulic oil in the CF oil port 8 entering the piston cavity 10, slow down the moving speed of the transposition piston 5 to the right, reduce the impact force caused by the sudden increase of the spring force of the control spring 3, a throttle two 28 is arranged in the piston oil way 11, which is used to avoid the transposition piston 5 resetting too fast, improve the continuity when the left and right directions are repeatedly turned, and a throttle three 29 is arranged in the LS oil way 25 between the oil way five 18 and the oil way six 19, which is used to improve the stability of the valve rod 4 during work, stabilize the pressure in the spring cavity 2, and improve the safety and stability.

[0038] In the embodiment, the P oil port 7 is connected with a gear pump, which is used to supply oil to the priority valve, the P oil port 7 can selectively connect with the CF oil port 8 or the EF oil port 9 through the sliding of the valve rod 4, the CF oil port 8 is used to connect with the LS oil way 25, the EF oil port 9 is used to connect with the oil way of other external systems, so that the priority valve enters the CF oil port 8 according to the required flow of the steering gear to ensure the oil of the steering gear, and the excess flow enters other systems from the EF oil port 9, the left sliding of the valve rod 4 is realized by forming an internal oil way in one end of the valve rod 4 close to the CF oil port 8, and the realization principle is the same as that of the existing priority valve.

[0039] In the embodiment, the sequence valve 24 comprises a valve core 241 and a sequence spring 242, the valve core 241 is slidingly arranged in the oil circuit nine 22, one end of the valve core 241 is connected with the sequence spring 242, the sequence spring 242 is connected with the plug 31 at the end away from the valve core 241, the plug 31 is connected on the priority valve body 1, the valve core 241 is provided with an internal oil circuit, which can selectively communicate the oil circuit four 17 with the oil circuit seven 20 or the oil circuit four 17 with the oil circuit two 15 by sliding.

[0040] In the embodiment, the piston cavity 10 is provided with the connecting plug one 32 at the end away from the spring cavity 2, the main cavity 6 is provided with the connecting plug two 33 at the end away from the spring cavity 2, the piston cavity 10 and the main cavity 6 are sealed by the connecting plug one 32 and the connecting plug two 33, which facilitates disassembly and maintenance and improves practicability.

[0041] Embodiment two

[0042] As shown in Figures 11-12 A steering control system, comprising the static two-stage control priority valve 36 as described above, further comprising:

[0043] The oil tank 23 is used for storing hydraulic oil;

[0044] The gear pump 30 is connected with the oil tank 23 at the input end and connected with the P oil port 7 at the output end, for supplying hydraulic oil to the system;

[0045] The overflow valve 26 can be arranged inside the priority valve body 1, one end of the overflow valve 26 is connected with the oil circuit five 18, the other end is connected with the oil tank 23, for improving the safety in use;

[0046] The static steering gear 34 is connected with the CF oil port 8 through the one-way valve and connected with the LS oil circuit 25, when steering, hydraulic oil can flow into the static steering gear 34 from the CF oil port 8 and flow out of the static steering gear 34 to the LS oil circuit 25, a common steering gear on the market can be selected;

[0047] The steering oil cylinder 35 is preferably provided with two, both of which are connected with the static steering gear 34, the connection oil circuit is arranged as a conventional connection, for realizing steering.

[0048] Working principle: when starting to turn, hydraulic oil from static steering gear 34 through LS oil way 25 to spring cavity 2, at the same time, hydraulic oil through LS oil way 25, oil way six 19 and oil way nine 22 to the position of sequence valve 24, and push one end of valve core 241, so that valve core 241 slides in oil way nine 22 and compresses sequence spring 242, so that oil way seven 20 is communicated with oil way four 17 at this time, hydraulic oil of CF oil port 8 enters piston cavity 10 through oil way eight 21, oil way seven 20, oil way four 17 and oil way three 16, pushes the displacement piston 5 to slide and compresses the control spring 3, at this time, the hydraulic oil in the closed cavity one 12 enters the spring cavity 2 through the piston oil way 11, and the oil in the closed cavity two 13 returns to the oil tank through oil way one 14 and oil way two 15, the control spring 3 is compressed so that the control pressure is increased to about 12.7bar, so that the steering action is carried out normally.

[0049] When not turning, the pressure of LS oil way 25 is reduced, the valve core 241 is reset under the action of the sequence spring 242, the communication of oil way seven 20 and oil way four 17 is cut off, and oil way four 17 is communicated with oil way two 15 through oil way nine 22 and the internal oil channel of valve core 241, the hydraulic oil in piston cavity 10 returns to the oil tank through oil way three 16, oil way four 17, oil way nine 22, the internal oil channel of valve core 241 and oil way two 15, the hydraulic oil in spring cavity 2 fills closed cavity one 12 through piston oil way 11, and the hydraulic oil in oil way two 15 fills closed cavity two 13 under the action of the back pressure of the oil return, at this time, the pressure of the control spring is reduced to about 3bar, so as to save energy.

[0050] The details of the utility model not described are conventional technical means known to those skilled in the art.

[0051] In the description of the utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.

[0052] In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features, so that the features with "first" and "second" can be explicitly or implicitly included one or more features, and in the description of the utility model, the meaning of "multiple" is two or more than two, unless otherwise explicitly and specifically limited.

[0053] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

[0054] Finally, it should be noted that: the above only for the preferred embodiments of the present application have, and not for limiting the present application, although the foregoing detailed description of the present application is made with reference to the foregoing embodiments, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application, should be included in the scope of protection of the present application.

Claims

1. A static two-stage priority valve, comprising a priority valve body (1), characterized in that, a spring cavity (2) is formed inside the priority valve body (1), a control spring (3) is movably arranged in the spring cavity (2), one end of the control spring (3) is connected with a valve rod (4), the other end of the control spring (3) is connected with a shift piston (5), the valve rod (4) is slidably arranged in a main cavity (6), the main cavity (6) is used for connecting a P oil port (7), a CF oil port (8) and an EF oil port (9), the shift piston (5) is slidably arranged in a piston cavity (10), the shift piston (5) is internally provided with a piston oil passage (11), the shift piston (5) and the priority valve body (1) are further provided with a closed cavity I (12) and a closed cavity II (13), the closed cavity I (12) is connected with the spring cavity (2) through the piston oil passage (11), the closed cavity II (13) is connected with an oil passage I (14), the oil passage I (14) is connected with an oil passage II (15) and an oil tank, the oil passage II (15) is connected with a sequence valve (24), the sequence valve (24) is arranged in an oil passage IX (22), the oil passage IX (22) is connected with an oil passage IV (17), an oil passage VI (19) and an oil passage VII (20), the oil passage IV (17) is connected with an oil passage III (16), the oil passage III (16) is connected with the piston cavity (10), the oil passage VI (19) is connected with an LS oil passage (25), one end of the LS oil passage (25) is connected with the CF oil port (8), the other end of the LS oil passage (25) is connected with the spring cavity (2) and an oil passage V (18), the oil passage V (18) is connected with the oil tank through an overflow valve, the oil passage VII (20) is connected with an oil passage VIII (21), the oil passage VIII (21) is connected with the CF oil port (8).

2. The static two-stage control priority valve of claim 1, wherein: A throttle I (27) is arranged in the oil passage III (16), a throttle II (28) is arranged in the piston oil passage (11), and a throttle III (29) is arranged in the LS oil passage (25) between the oil passage V (18) and the oil passage VI (19).

3. The static two-stage control priority valve of claim 2, wherein: The P oil port (7) is connected with a gear pump for oil supply, the P oil port (7) is connected with the CF oil port (8) or the EF oil port (9) through the sliding of the valve rod (4), the CF oil port (8) is used for connecting the LS oil passage (25), and the EF oil port (9) is used for connecting an external oil passage.

4. The static two-stage control priority valve of claim 3, wherein: The sequence valve (24) comprises a valve core (241) and a sequence spring (242), the valve core (241) is slidably arranged in the oil passage IX (22), one end of the valve core (241) is connected with the sequence spring (242), the other end of the sequence spring (242) is connected with a plug (31), the plug (31) is connected with the priority valve body (1), and the valve core (241) can connect the oil passage IV (17) with the oil passage VII (20) or connect the oil passage IV (17) with the oil passage II (15) through sliding.

5. The static two-stage control priority valve of claim 4, wherein: A connecting plug I (32) is arranged at one end of the piston cavity (10) away from the spring cavity (2), and a connecting plug II (33) is arranged at one end of the main cavity (6) away from the spring cavity (2).

6. A steering control system comprising the static two-stage control priority valve according to claim 5, characterized by Further comprising: an oil tank (23) for storing hydraulic oil; a gear pump (30), an input end of the gear pump (30) is connected with the oil tank (23), and an output end of the gear pump (30) is connected with the P oil port. An overflow valve (26) is connected to the oil passage five at one end and to the oil tank (23) at the other end; A static steering gear (34) is connected to the CF oil port through a one-way valve and to the LS oil passage. When steering, hydraulic oil can flow into the static steering gear (34) from the CF oil port and flow out of the static steering gear (34) to the LS oil passage; A steering oil cylinder (35) is connected to the static steering gear (34) to realize steering.

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