Control valve, wet brake steering system of engineering machinery and engineering machinery

Abstract

The invention discloses a control valve, a wet brake steering system of engineering machinery and the engineering machinery. The control valve comprises a valve body, a hydraulic reversing valve, a one-way valve, a shuttle valve and an electromagnetic reversing valve, the valve body is provided with an oil inlet, an oil return port, a working oil port, a first control valve LS oil port, a second control valve LS oil port and a third control valve LS oil port of the control valve; an oil inlet and an oil return port of the hydraulic reversing valve are respectively connected with an oil inlet and an oil return port of the control valve, a first control end is communicated with a working oil port of the control valve and a working oil port of the hydraulic reversing valve, and a second control end is communicated with a working oil port of the hydraulic reversing valve; an oil inlet and an oil outlet of the one-way valve are connected with an oil inlet and a working oil port of the control valve; a first oil port, a second oil port and a third oil port of the shuttle valve are respectively connected with an LS oil port of the first control valve, an LS oil port of the second control valve and a working oil port of the electromagnetic reversing valve; an oil inlet of the electromagnetic reversing valve is connected with an LS oil port of the third control valve, and an oil return port of the electromagnetic reversing valve is connected with an oil return port of the hydraulic reversing valve. According to the invention, oil source sharing of working, steering and braking can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering machinery, and in particular relates to a control valve, an engineering machinery wet brake steering system and engineering machinery. Background Art

[0002] More and more construction machinery vehicles use full hydraulic brake systems. The steering system and brake system are mostly independent pump sources. In addition to increasing costs, it is difficult to arrange them when the space of some construction machinery products is limited and there are too many system pump sources. Therefore, the design concept of oil source sharing has always been the development direction of construction machinery hydraulic systems, which is of great significance for simplifying hydraulic systems. At the same time, construction machinery vehicles have the situation of engine starting with load. When the load is large, it will cause problems such as jitter and long starting time, which will affect the engine life. Summary of the invention

[0003] In view of the above problems, the present invention proposes a control valve, a wet brake steering system for engineering machinery and engineering machinery, which can realize the sharing of oil source for work, steering and braking, and utilize the intermittent working characteristics of the braking system to avoid mutual interference between the two when working at the same time, thereby ensuring the steering and braking performance and simplifying the system structure.

[0004] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions: In a first aspect, the present invention provides a control valve, comprising a valve body, and a hydraulic reversing valve, a one-way valve, a shuttle valve and an electromagnetic reversing valve arranged in the valve body; The valve body is provided with an oil inlet of the control valve, an oil return port of the control valve, a first control valve LS oil port, a second control valve LS oil port, a third control valve LS oil port, and a working oil port of the control valve; The oil inlet of the hydraulic reversing valve is connected to the oil inlet of the control valve, the oil return port is connected to the oil return port of the control valve, the first control end is connected to the working oil port of the control valve and the working oil port of the hydraulic reversing valve, and the second control end is connected to the working oil port of the hydraulic reversing valve. The oil inlet of the one-way valve is connected to the oil inlet of the control valve, and the oil outlet of the one-way valve is connected to the working oil port of the control valve; The first oil port of the shuttle valve is connected to the LS oil port of the first control valve, the second oil port is connected to the LS oil port of the second control valve, and the third oil port is connected to the working oil port of the electromagnetic reversing valve; The oil inlet of the electromagnetic reversing valve is connected to the oil port LS of the third control valve, and the oil return port thereof is connected to the oil return port of the hydraulic reversing valve.

[0005] In combination with the first aspect, optionally, the control valve further includes a throttle valve I and a throttle valve II; The oil inlet of the throttle valve I is connected to the oil inlet of the control valve, and the oil outlet thereof is connected to the oil inlet of the hydraulic reversing valve and the oil inlet of the check valve respectively; The throttle valve II is arranged on the oil circuit between the working oil port of the hydraulic reversing valve and the shuttle valve.

[0006] In combination with the first aspect, optionally, when the pressure of the working oil port of the control valve is lower than the set value X1, the hydraulic reversing valve is in the spring position, and after the oil enters the control valve through the oil inlet of the control valve, part of the oil passes through the one-way valve and is sent to the working oil port of the control valve, and the remaining oil passes through the hydraulic reversing valve and is connected to the LS1 oil port of the first control valve, and the LS1 control signal generated by the LS1 oil port of the first control valve enters the first oil port of the shuttle valve and is connected to the LS oil port of the third control valve through the solenoid reversing valve; When the pressure of the working oil port of the control valve reaches the set value X2, X2>X1, the hydraulic reversing valve switches to the non-spring position, the one-way valve is in the cut-off position, and the oil inlet of the control valve is not connected to the working oil port of the control valve and the LS oil port of the first control valve.

[0007] In combination with the first aspect, optionally, when the solenoid reversing valve is energized, its valve core is in a non-spring position, and the LS oil port of the third control valve is connected to the return oil port of the control valve through the solenoid reversing valve; when the solenoid reversing valve is de-energized, its valve core is in a spring position, and the third oil port of the shuttle valve is connected to the LS oil port of the third control valve through the solenoid reversing valve.

[0008] In a second aspect, the present invention provides a wet brake steering system for engineering machinery, comprising: a pump, a hydraulic oil tank, a priority valve, and a control valve as described in any one of the first aspects; The oil inlet of the pump is connected to the hydraulic oil tank, and the oil outlet is connected to the oil inlet of the priority valve; The CF oil port of the priority valve is connected to the oil inlet of the steering gear and the oil inlet of the control valve respectively, and its EF oil port is used to be connected to the hydraulic working system; The oil outlet of the steering gear is used to be connected to the steering cylinder; The LS oil port of the third control valve is connected to the LS oil port of the priority valve, and the LS oil port of the second control valve is connected to the LS oil port of the steering gear; The oil return port of the priority valve, the oil return port of the steering gear, and the oil return port of the control valve are all connected to the hydraulic oil tank.

[0009] In combination with the second aspect, optionally, the engineering machinery wet brake steering system further includes a brake valve and an accumulator; The working oil port of the control valve is connected to the working oil port of the accumulator and the oil inlet of the brake valve respectively; The working oil port of the brake valve is used to be connected with the service brake.

[0010] In combination with the second aspect, optionally, when only steering action is performed, the solenoid reversing valve is in the spring position, the shuttle valve is in the second working position, the hydraulic reversing valve is in the non-spring position, and the LS port of the priority valve is connected to the LS oil port of the second control valve through the LS oil port of the third control valve, the solenoid reversing valve, and the shuttle valve in sequence, and the oil output by the pump is provided from the CF oil port of the priority valve to the oil inlet of the steering gear.

[0011] In combination with the second aspect, optionally, when only the accumulator charging action is performed, the pressure of the accumulator is lower than the set value X1, the hydraulic reversing valve and the electromagnetic reversing valve are both in the spring position, the shuttle valve is in the first working position, the priority valve is switched to the spring position, and the LS port of the priority valve is connected to the LS port of the first control valve through the LS oil port of the third control valve, the electromagnetic reversing valve, and the shuttle valve in sequence. The oil output by the pump is connected to the oil inlet of the control valve from the oil port CF of the priority valve. After the oil enters the control valve through the oil inlet of the control valve, part of the oil is sent to the working oil port of the control valve after passing through the one-way valve, and then enters the accumulator from the working oil port of the control valve. The remaining oil is connected to the LS1 oil port of the first control valve after passing through the hydraulic reversing valve. The LS1 control signal generated by the LS1 oil port of the first control valve enters the first oil port of the shuttle valve and then passes through the electromagnetic reversing valve to be connected to the LS oil port of the third control valve until the pressure of the accumulator rises to the set value X2, and the charging is completed.

[0012] In combination with the second aspect, optionally, when the steering action and the accumulator charging action are performed simultaneously, the hydraulic reversing valve and the electromagnetic reversing valve are both in the spring position, and the priority valve is in the spring position. If the pressure of the LS oil port of the first control valve is greater than that of the LS oil port of the second control valve, the LS oil port of the priority valve is connected to the LS oil port of the first control valve through the LS oil port of the third control valve, the solenoid reversing valve, and the shuttle valve in sequence; If the pressure of the LS oil port of the second control valve is greater than that of the LS oil port of the first control valve, the LS oil port of the priority valve is connected to the LS oil port of the second control valve through the LS oil port of the third control valve, the solenoid reversing valve, and the shuttle valve in sequence; In the above situations, the valve core of the priority valve will be in the spring position, and the oil output by the pump will be sent to the oil inlet of the steering gear and the oil inlet of the control valve provided from the CF oil port of the priority valve.

[0013] In combination with the second aspect, optionally, when neither the steering action nor the accumulator charging action is performed, the hydraulic reversing valve is in a non-spring position, and the LS port of the priority valve is connected to the LS oil port of the first control valve or the LS oil port of the second control valve through the LS oil port of the third control valve, the solenoid reversing valve, and the shuttle valve. If it is connected to the LS oil port of the first control valve, the LS port of the priority valve is connected to the return oil port of the control valve after passing through the hydraulic reversing valve. If it is connected to the LS oil port of the second control valve, the LS port of the priority valve is connected to the return oil port of the steering gear through the LS port of the steering gear.

[0014] In combination with the second aspect, optionally, the first oil port of the steering gear is respectively connected to the rodless chamber of steering cylinder I and the rod chamber of steering cylinder II, and the second oil port of the steering gear is respectively connected to the rod chamber of steering cylinder I and the rodless chamber of steering cylinder II.

[0015] The electromagnetic reversing valve is externally connected with a time delay relay. Only when the whole machine is started, the time delay relay works, so that the electromagnet of the electromagnetic reversing valve is energized, and its valve core is switched to a non-spring position (i.e., a non-working position). The oil outlet pressure of the pump is the standby pressure, ensuring the smooth start of the whole machine; after the whole machine is started, the time delay relay does not work, the electromagnet of the electromagnetic reversing valve remains in a de-energized state, and its valve core is always in the spring position.

[0016] In a third aspect, the present invention provides an engineering machinery comprising the control valve described in any one of the first aspect, or the engineering machinery wet brake steering system described in any one of the second aspect.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The control valve in the present invention feeds back the brake signal or the steering signal to the LS oil port of the priority valve through the shuttle valve, cooperates to realize the valve core reversal of the priority valve, and the pump provides flow according to the valve core position of the priority valve. When the whole machine is turning, the shuttle valve takes the high-pressure LS signal and connects it to the LS oil port of the priority valve, the priority valve is switched to the spring position (i.e., the left position), and the oil output by the pump is preferentially provided to the steering system from the CF oil port of the priority valve; when the whole machine has no steering action and the accumulator pressure is lower than the set value X1, the hydraulic reversing valve and the electromagnetic reversing valve are both in the spring position, i.e., the right position, the LS oil port of the priority valve is connected to the accumulator, i.e., connected to the brake signal LS1, the priority valve is switched to the spring position (left position), and the pump provides flow to the brake system, so that the accumulator pressure is increased to the highest set value X2, and the filling is completed; when the accumulator pressure reaches the set X2 and no steering is performed, the LS oil port of the priority valve is connected to the hydraulic oil tank through the hydraulic reversing valve or the steering gear, at this time the priority valve is switched to the non-spring position (i.e., the right position), the oil inlet of the priority valve is connected to the EF oil port, and the flow provided by the pump goes to the hydraulic working system.

[0018] Furthermore, when the whole machine is started, the delay relay works, so that the electromagnet of the two-position three-way electromagnetic reversing valve is energized and switched to the left position, and the oil port LS of the priority valve is connected to the hydraulic oil tank. At this time, the pump oil outlet pressure is the standby pressure, and the load of the whole machine is relatively small; after the whole machine is started, the delay relay does not work, and the electromagnet of the two-position three-way electromagnetic reversing valve is always de-energized and in the right position. The present application realizes the sharing of the oil source for working, steering and braking, avoids mutual interference when each action is working, ensures the steering and braking performance, and simplifies the system solution. The system makes the load very small when the whole machine is started, ensuring the smooth start of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor, among which: Figure 1 It is the hydraulic principle diagram of the control valve of the present invention; Figure 2 A hydraulic principle diagram of a wet brake steering system including the control valve of the present invention; In the figure, 1. pump, 2. priority valve, 3. steering gear, 41. steering cylinder I, 42. steering cylinder II, 5. accumulator, 6. brake valve, 7. control valve, 71. throttle valve I, 72. reversing valve, 73. check valve, 74. shuttle valve, 75. two-position three-way solenoid reversing valve, 76. throttle valve II, 8. time delay relay, 9. hydraulic oil tank. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may also include different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0022] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0023] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0024] The application principle of the present invention is described in detail below in conjunction with the accompanying drawings. Example 1

[0025] In an embodiment of the present invention, a control valve 7 is provided, such as Figure 1 As shown, it includes a valve body, and a hydraulic reversing valve 72, a one-way valve 73, a shuttle valve 74 and an electromagnetic reversing valve 75 arranged in the valve body; The valve body is provided with an oil inlet P7 of the control valve, an oil return port T7 of the control valve, a first control valve LS oil port LS1, a second control valve LS oil port LS2, a third control valve LS oil port LS3, and a working oil port A1 of the control valve; in a specific implementation process, a working oil port A2 of the control valve may also be provided on the valve body, and the working oil port A2 is connected to the working oil port A1, and the setting of the working oil port A2 depends on actual needs; The oil inlet of the hydraulic reversing valve 72 is connected to the oil inlet P7 of the control valve, and the oil return port is connected to the oil return port T7 of the control valve. Figure 1 The left end of the hydraulic reversing valve 72 is connected to the working oil port A1 of the control valve and its own working oil port respectively, and its second control end (i.e. Figure 1 The right end of the middle hydraulic reversing valve 72) is connected to its own working oil port; The oil inlet of the one-way valve 73 is connected to the oil inlet P7 of the control valve, and the oil outlet is connected to the working oil port A1 of the control valve; The first oil port of the shuttle valve 74 is connected to the first control valve LS oil port LS1, the second oil port is connected to the second control valve LS oil port LS2, and the third oil port is connected to the working oil port of the electromagnetic reversing valve 75; The oil inlet of the electromagnetic reversing valve 75 is connected to the oil port LS3 of the third control valve LS, and the oil return port thereof is connected to the oil return port of the hydraulic reversing valve 72. Figure 1 and 2 As shown, the electromagnetic reversing valve 75 can be a two-position three-way electromagnetic reversing valve.

[0026] Based on the control valve in the embodiment of the present invention, it is possible to realize that the hydraulic working system, the steering system and the braking system share the oil source.

[0027] In a specific implementation of the embodiment of the present invention, the control valve 7 further includes a throttle valve I 71 and a throttle valve II 76; The oil inlet of the throttle valve I 71 is connected to the oil inlet P7 of the control valve, and the oil outlet is connected to the oil inlet of the hydraulic reversing valve 72 and the oil inlet of the check valve 73 respectively. The throttle valve I 71 is used to control the filling flow from the oil inlet P7 to the working oil port A1; The throttle valve II 76 is arranged on the oil circuit between the working oil port of the hydraulic reversing valve 72 and the shuttle valve 74 .

[0028] In a specific implementation of the embodiment of the present invention, when the pressure of the working oil port A1 of the control valve is lower than the set value X1, the hydraulic reversing valve 72 is in the spring position (i.e. Figure 1 The one-way valve 73 is in the working position. After the oil enters the control valve 7 through the oil inlet P7 of the control valve, part of the oil is sent to the working oil port A1 of the control valve after passing through the one-way valve 73, and the rest of the oil is connected with the oil port LS1 of the first control valve after passing through the hydraulic reversing valve 72. The LS1 control signal generated by the oil port LS1 of the first control valve enters the first oil port of the shuttle valve 74 and is connected with the LS oil port LS3 of the third control valve through the solenoid reversing valve 75.

[0029] In a specific implementation of the embodiment of the present invention, when the pressure of the working oil port A1 of the control valve reaches the set value X2, X2>X1, the hydraulic reversing valve 72 is switched to the non-spring position (i.e. Figure 1 ), the one-way valve 73 is in the cut-off position, and the oil inlet P7 of the control valve is not connected to the working oil port A1 of the control valve and the first control valve LS oil port LS1.

[0030] In a specific implementation of the embodiment of the present invention, when the electromagnetic reversing valve 75 is energized, its valve core is in a non-spring position (i.e., a working position, specifically, Figure 1 The third control valve LS oil port LS3 is connected to the oil return port T7 of the control valve through the electromagnetic reversing valve 75; when the electromagnetic reversing valve 75 loses power, its valve core is in the spring position (i.e. Figure 1 The third oil port of the shuttle valve 74 is connected to the oil port LS3 of the third control valve LS through the electromagnetic reversing valve 75. Example 2

[0031] In an embodiment of the present invention, a wet brake steering system for engineering machinery is provided. Figure 2 As shown, it includes: a pump 1, a hydraulic oil tank 9, a priority valve 2, and the control valve 7 described in embodiment 1; The oil inlet of the pump 1 is connected to the hydraulic oil tank 9, and the oil outlet is connected to the oil inlet P2 of the priority valve 2; The CF oil port of the priority valve 2 is connected to the oil inlet P3 of the steering gear 3 and the oil inlet P7 of the control valve respectively, and its EF oil port is used to connect to the hydraulic working system; The oil outlet T3 of the steering gear 3 is used to connect to the steering cylinder; The LS oil port LS3 of the third control valve is connected to the LS oil port of the priority valve 2, and the LS oil port LS2 of the second control valve is connected to the LS oil port of the steering gear 3; The oil return port T2 of the priority valve 2 , the oil return port T3 of the steering gear 3 , and the oil return port T7 of the control valve are all connected to the hydraulic oil tank 9 .

[0032] In the specific implementation process, two throttling holes are set at the LS port of the priority valve 2. The brake signal LS1 at the LS oil port LS1 of the first control valve or the steering signal LS2 at the LS oil port LS2 of the second control valve is fed back to the LS oil port of the priority valve through the solenoid reversing valve 75 through the shuttle valve 74, so as to realize the valve core reversal of the priority valve; the priority valve 2 is also integrated with a relief valve for limiting the outlet pressure of the pump 1.

[0033] In a specific implementation of the embodiment of the present invention, the engineering machinery wet brake steering system further includes a brake valve 6 and an accumulator 5; The working oil port A1 of the control valve is connected to the working oil port of the accumulator 5 and the oil inlet of the brake valve 6 respectively; The working oil port A6 of the brake valve 6 is used to connect with the service brake; Specifically, the brake valve 6 includes a set of three-position three-way valves, the working oil port A of the three-position three-way valve is connected to the working oil port A6 of the brake valve 6, the oil inlet P of the three-position three-way valve is connected to the oil inlet P6 of the brake valve 6, and the oil return port T of the three-position three-way valve is connected to the oil return port T6 of the brake valve 6. The oil inlet P6 of the brake valve 6 is connected to the working oil port of the accumulator 5 and the oil port A1 of the control valve 7, the working oil port A6 of the brake valve 6 is connected to the service brake, and the oil return port T6 of the brake valve 6 is connected back to the hydraulic oil tank 9.

[0034] In a specific implementation of the embodiment of the present invention, when only the steering action is performed, the electromagnetic reversing valve 75 is in the spring position (i.e., the working position), and the shuttle valve 74 is in the second working position (i.e., the shuttle valve 74 is in the Figure 1 The hydraulic reversing valve 72 is in the non-spring position, and the LS port of the priority valve 2 is connected with the LS port LS2 of the second control valve via the LS port LS3 of the third control valve, the electromagnetic reversing valve 75, and the shuttle valve 74 in sequence, so that the oil output by the pump 1 is provided from the CF port of the priority valve 2 to the oil inlet P3 of the steering gear 3.

[0035] In a specific implementation of the embodiment of the present invention, when only the accumulator 5 is charged, the pressure of the accumulator 5 is lower than the set value X1, the hydraulic reversing valve 72 and the electromagnetic reversing valve 75 are both in the spring position (i.e., the working position), and the shuttle valve 74 is in the first working position (i.e., the shuttle valve 74 is in the Figure 1 The priority valve 2 is switched to the spring position (i.e. Figure 2The LS port of the priority valve 2 is switched to the left position), and the LS port of the priority valve 2 is connected to the LS port LS1 of the first control valve through the LS port LS3 of the third control valve, the electromagnetic reversing valve 75, and the shuttle valve 74 in sequence. The oil output by the pump 1 is connected to the oil inlet P7 of the control valve from the oil port CF of the priority valve 2. After the oil enters the control valve 7 through the oil inlet P7 of the control valve, part of the oil is sent to the working oil port A1 of the control valve after passing through the one-way valve 73, and then enters the accumulator 5 through the working oil port A1 of the control valve. The remaining oil is connected to the LS1 port of the first control valve after passing through the hydraulic reversing valve 72. The LS1 control signal generated by the LS1 port of the first control valve enters the first oil port of the shuttle valve 74 and is connected to the LS port LS3 of the third control valve through the electromagnetic reversing valve 75 until the pressure of the accumulator 5 is increased to the set value X2, and the filling is completed. Specifically, the left end of the hydraulic reversing valve 72 is designed to have a smaller effective area than the right end. When the pressure of the accumulator 5 (i.e., the pressure of the working oil port A1 of the control valve) is lower than the set value X1, the difference in pressure between the left and right ends of the hydraulic reversing valve 72 is smaller than the spring force at the right end of the hydraulic reversing valve 72. The hydraulic reversing valve 72 is in the right end spring position, and the shuttle valve 74 is in the left position. At this time, the oil port LS of the priority valve 2 is connected to the accumulator 5, that is, it is connected to the brake signal LS1. The flow provided by the pump 1 increases the pressure of the accumulator 5 to the maximum set value X2, completing the filling. When the pressure of the accumulator 5 (i.e., the working oil port A1 of the control valve) is lower than the set value X1, the pressure difference between the left and right ends of the hydraulic reversing valve 72 is smaller than the spring force at the right end of the hydraulic reversing valve 72. The hydraulic reversing valve 72 is in the right end spring position, and the shuttle valve 74 is in the left position. At this time, the oil port LS of the priority valve 2 is connected to the accumulator 5, that is, it is connected to the brake signal LS1. The flow provided by the pump 1 increases the pressure of the accumulator 5 to the maximum set value X2, completing the filling. When the pressure at the oil port A1 reaches the set value X2, the difference in pressure acting on the left and right ends of the reversing valve 72 is greater than the spring force at the right end of the reversing valve 72, and the reversing valve 72 is switched to the left position. The oil port LS of the priority valve 2 is connected to the hydraulic oil tank 9 through the reversing valve 72, or the oil port LS of the priority valve 2 is connected to the return oil port T3 of the steering gear through the LS port of the steering gear 3 after passing through the shuttle valve 74. At this time, the valve core of the priority valve 2 is in the right position, and the oil inlet P2 of the priority valve 2 is connected to the EF oil port. The flow provided by the pump 1 goes to the hydraulic working system, and the pressure of the accumulator 5 is cut off from the oil inlet P7 of the control valve under the action of the one-way valve 73.

[0036] In a specific implementation of the embodiment of the present invention, when the steering action and the accumulator 5 charging action are performed simultaneously; the hydraulic reversing valve 72 and the electromagnetic reversing valve 75 are both in the spring position, and the third control valve LS takes the high-pressure LS1 signal or LS2 signal through the shuttle valve 74 and communicates with the LS oil port of the priority valve 2; If the pressure of the first control valve LS port LS1 is greater than that of the second control valve LS port LS2, the LS port of the priority valve 2 is connected to the first control valve LS port LS1 through the third control valve LS port LS3, the solenoid reversing valve 75, and the shuttle valve 74 in sequence; If the pressure of the second control valve LS port LS2 is greater than that of the first control valve LS port LS1, the LS port of the priority valve 2 is connected to the second control valve LS port LS2 via the third control valve LS port LS3, the solenoid reversing valve 75 and the shuttle valve 74 in sequence; In the above situations, the valve core of the priority valve 2 will be in the spring position, and the oil output by the pump 1 will be sent from the CF oil port of the priority valve 2 to the oil inlet P3 of the steering gear 3 and the oil inlet P7 of the control valve.

[0037] In a specific implementation of the embodiment of the present invention, when neither the steering action nor the accumulator 5 charging action is performed, the hydraulic reversing valve 72 is in a non-spring position, and the LS port of the priority valve 2 is connected to the LS oil port LS1 of the first control valve or the LS oil port LS2 of the second control valve through the LS oil port LS3 of the third control valve, the solenoid reversing valve 75, and the shuttle valve 74. If it is connected to the LS oil port LS1 of the first control valve, the LS port of the priority valve 2 is connected to the return oil port T7 of the control valve after passing through the hydraulic reversing valve 72. If it is connected to the LS oil port LS2 of the second control valve, the LS oil port of the priority valve 2 is connected to the return oil port T3 of the steering gear 3 through the LS port of the steering gear 3.

[0038] In a specific implementation of an embodiment of the present invention, the first oil port L of the steering gear 3 is respectively connected to the rodless chamber of the steering cylinder I 41 and the rod chamber of the steering cylinder II 42, and the second oil port R of the steering gear 3 is respectively connected to the rod chamber of the steering cylinder I 41 and the rodless chamber of the steering cylinder II 42.

[0039] In a specific implementation of the embodiment of the present invention, the electromagnetic reversing valve 75 is externally connected to a time delay relay 8. Only when the whole machine is started, the time delay relay 8 works, so that the electromagnet of the electromagnetic reversing valve 75 is energized, and its valve core is switched to the non-spring position (i.e. Figure 1 The oil outlet pressure of the pump 1 is the standby pressure, and the load of the whole machine is small, which ensures the smooth start of the whole machine; after the whole machine is started, the delay relay 8 does not work, the electromagnet of the electromagnetic reversing valve 75 remains in the de-energized state, and its valve core is always in the spring position, that is, the valve core is in the right end under the action of the spring force. Figure 1 or Figure 2 The right position in the middle. Example 3

[0040] An embodiment of the present invention provides an engineering machinery, comprising the control valve 7 described in any one of Embodiment 1, or the engineering machinery wet brake steering system described in any one of Embodiment 2.

[0041] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0042] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A control valve, Features: It includes a valve body, and a hydraulic reversing valve, a one-way valve, a shuttle valve and an electromagnetic reversing valve arranged in the valve body; The valve body is provided with an oil inlet of the control valve, an oil return port of the control valve, a first control valve LS oil port, a second control valve LS oil port, a third control valve LS oil port, and a working oil port of the control valve; The oil inlet of the hydraulic reversing valve is connected to the oil inlet of the control valve, the oil return port is connected to the oil return port of the control valve, the first control end is connected to the working oil port of the control valve and the working oil port of the hydraulic reversing valve, and the second control end is connected to the working oil port of the hydraulic reversing valve. The oil inlet of the one-way valve is connected to the oil inlet of the control valve, and the oil outlet of the one-way valve is connected to the working oil port of the control valve; The first oil port of the shuttle valve is connected to the LS oil port of the first control valve, the second oil port is connected to the LS oil port of the second control valve, and the third oil port is connected to the working oil port of the electromagnetic reversing valve; The oil inlet of the electromagnetic reversing valve is connected to the oil port LS of the third control valve, and the oil return port thereof is connected to the oil return port of the hydraulic reversing valve.

2. A control valve according to claim 1, Features: The control valve also includes a throttle valve I and a throttle valve II; The oil inlet of the throttle valve I is connected to the oil inlet of the control valve, and the oil outlet thereof is connected to the oil inlet of the hydraulic reversing valve and the oil inlet of the check valve respectively; The throttle valve II is arranged on the oil circuit between the working oil port of the hydraulic reversing valve and the shuttle valve.

3. A control valve according to claim 1, Features: When the pressure of the working oil port of the control valve is lower than the set value X1, the hydraulic reversing valve is in the spring position, and after the oil enters the control valve through the oil inlet of the control valve, part of the oil passes through the one-way valve and is sent to the working oil port of the control valve, and the remaining oil passes through the hydraulic reversing valve and is connected to the LS1 oil port of the first control valve. The LS1 control signal generated by the LS1 oil port of the first control valve enters the first oil port of the shuttle valve and is connected to the LS oil port of the third control valve through the solenoid reversing valve; When the pressure of the working oil port of the control valve reaches the set value X2, X2>X1, the hydraulic reversing valve is switched to the non-spring position, the one-way valve is in the cut-off position, and the oil inlet of the control valve is not connected to the working oil port of the control valve and the LS oil port of the first control valve.

4. A control valve according to claim 1, Features: When the solenoid reversing valve is energized, its valve core is in the non-spring position, and the LS oil port of the third control valve is connected with the return oil port of the control valve through the solenoid reversing valve; when the solenoid reversing valve is de-energized, its valve core is in the spring position, and the third oil port of the shuttle valve is connected with the LS oil port of the third control valve through the solenoid reversing valve.

5. A wet brake steering system for engineering machinery, It is characterized in that include: A pump, a hydraulic oil tank, a priority valve, and a control valve according to any one of claims 1 to 4; The oil inlet of the pump is connected to the hydraulic oil tank, and the oil outlet is connected to the oil inlet of the priority valve; The CF oil port of the priority valve is connected to the oil inlet of the steering gear and the oil inlet of the control valve respectively, and its EF oil port is used to be connected to the hydraulic working system; The oil outlet of the steering gear is used to be connected to the steering cylinder; The LS oil port of the third control valve is connected to the LS oil port of the priority valve, and the LS oil port of the second control valve is connected to the LS oil port of the steering gear; The oil return port of the priority valve, the oil return port of the steering gear, and the oil return port of the control valve are all connected to the hydraulic oil tank.

6. A wet brake steering system for construction machinery according to claim 5, Features: The engineering machinery wet brake steering system also includes a brake valve and an accumulator; The working oil port of the control valve is connected to the working oil port of the accumulator and the oil inlet of the brake valve respectively; The working oil port of the brake valve is used to be connected with the service brake.

7. A wet brake steering system for construction machinery according to claim 5 or 6, Features: When only steering action is performed, the solenoid reversing valve is in the spring position, the shuttle valve is in the second working position, the hydraulic reversing valve is in the non-spring position, and the LS port of the priority valve is connected with the LS oil port of the second control valve through the LS oil port of the third control valve, the solenoid reversing valve, and the shuttle valve in sequence, and the oil output by the pump is provided from the CF oil port of the priority valve to the oil inlet of the steering gear.

8. The engineering machinery wet brake steering system according to claim 6, Features: When only the accumulator charging action is performed, the pressure of the accumulator is lower than the set value X1, the hydraulic reversing valve and the electromagnetic reversing valve are both in the spring position, the shuttle valve is in the first working position, the priority valve is switched to the spring position, the LS port of the priority valve is connected with the LS port of the first control valve through the LS port of the third control valve, the electromagnetic reversing valve, and the shuttle valve in sequence, the oil output by the pump is connected with the oil inlet of the control valve from the oil port CF of the priority valve, after the oil enters the control valve through the oil inlet of the control valve, part of the oil is sent to the working oil port of the control valve after passing through the one-way valve, and then enters the accumulator through the working oil port of the control valve, the remaining oil is connected with the LS1 port of the first control valve after passing through the hydraulic reversing valve, the LS1 control signal generated by the LS1 port of the first control valve enters the first oil port of the shuttle valve and then passes through the electromagnetic reversing valve to be connected with the LS port of the third control valve, until the pressure of the accumulator is increased to the set value X2, and the charging is completed.

9. The engineering machinery wet brake steering system according to claim 6, Features: When the steering action and the accumulator charging action are performed simultaneously, the hydraulic reversing valve and the electromagnetic reversing valve are both in the spring position, and the priority valve is in the spring position; If the pressure of the LS oil port of the first control valve is greater than that of the LS oil port of the second control valve, the LS oil port of the priority valve is connected to the LS oil port of the first control valve through the LS oil port of the third control valve, the solenoid reversing valve, and the shuttle valve in sequence; If the pressure of the LS oil port of the second control valve is greater than that of the LS oil port of the first control valve, the LS oil port of the priority valve is connected to the LS oil port of the second control valve through the LS oil port of the third control valve, the solenoid reversing valve, and the shuttle valve in sequence; In the above situations, the valve core of the priority valve will be in the spring position, and the oil output by the pump will be sent to the oil inlet of the steering gear and the oil inlet of the control valve provided from the CF oil port of the priority valve.

10. The engineering machinery wet brake steering system according to claim 6, Features: When neither the steering action nor the accumulator charging action is performed, the hydraulic reversing valve is in the non-spring position, and the LS port of the priority valve is connected to the LS oil port of the first control valve or the LS oil port of the second control valve through the LS oil port of the third control valve, the solenoid reversing valve, the shuttle valve, and if it is connected to the LS oil port of the first control valve, the LS port of the priority valve is connected to the return oil port of the control valve after passing through the hydraulic reversing valve; if it is connected to the LS oil port of the second control valve, the LS port of the priority valve is connected to the return oil port of the steering gear through the LS port of the steering gear.

11. The engineering machinery wet brake steering system according to claim 5, Features: The first oil port of the steering gear is connected to the rodless chamber of steering cylinder I and the rod chamber of steering cylinder II respectively, and the second oil port of the steering gear is connected to the rod chamber of steering cylinder I and the rodless chamber of steering cylinder II respectively.

12. The engineering machinery wet brake steering system according to claim 5, Features: The electromagnetic reversing valve is externally connected with a time delay relay. Only when the whole machine is started, the time delay relay works, so that the electromagnet of the electromagnetic reversing valve is energized, and its valve core is switched to the non-spring position. The oil outlet pressure of the pump is the standby pressure, ensuring the smooth start of the whole machine; after the whole machine is started, the time delay relay does not work, the electromagnet of the electromagnetic reversing valve remains in a de-energized state, and its valve core is always in the spring position.

13. A construction machine, It is characterized in that The invention comprises the control valve according to any one of claims 1 to 4, or the engineering machinery wet brake steering system according to any one of claims 5 to 12.

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