Boom type engineering machinery and boom variable amplitude hydraulic control system

Abstract

The utility model discloses an arm support type engineering machine and an arm support variable amplitude hydraulic control system, which comprises a hydraulic pump, a reversing valve, a first hydraulic oil cylinder, a second hydraulic oil cylinder, a first balance valve, a second balance valve and a third balance valve, the second balance valve is connected with a rodless cavity of the second hydraulic oil cylinder; the reversing valve is connected with rod cavities of the first hydraulic oil cylinder and the second hydraulic oil cylinder through a third balance valve; and the first balance valve and the second balance valve are both atmospheric balance valves. The atmospheric balance valve can be opened at the same time and keep the same opening degree under the same pilot pressure, it is ensured that the first hydraulic oil cylinder and the second hydraulic oil cylinder can change the amplitude at the same time and the amplitude of the amplitude is the same, and then the stability of amplitude change lifting is ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to engineering machinery technical field especially relates to a kind of arm support type engineering machinery and arm support amplitude hydraulic control system. BACKGROUND

[0002] The lifting of arm support amplitude mechanism is the common working condition of arm support type engineering machinery.In the lifting of arm support amplitude, to simplify structure, two hydraulic cylinders are usually used to control, and when arm support amplitude mechanism lifts, especially when amplitude drops, two hydraulic cylinders bear a lot when descending, only two hydraulic cylinders lift synchronously, can ensure the smooth operation of arm support amplitude action, which puts forward higher requirements for hydraulic system control.

[0003] At present, the control scheme of the two hydraulic cylinders of arm support amplitude lifting mainly has two kinds: one is that one balance valve is configured for each of the two hydraulic cylinders, for example, the arm support amplitude hydraulic control system disclosed in publication No.CN213445927U;The other is that two balance valves are configured for each of the two hydraulic cylinders, and two reversing valves are used to control respectively.The two control schemes cannot ensure that two balance valves are opened simultaneously, resulting in that there is synchronization deviation between two hydraulic cylinders when starting to drop, and in the process of running, the opening degree of the balance valves configured for two hydraulic cylinders is inconsistent due to back pressure, further affecting the synchronization of two hydraulic cylinders, and further affecting the stability of amplitude lifting (especially amplitude drop). CONTENT OF UTILITY MODEL

[0004] The utility model aims at providing an arm support type engineering machinery and arm support amplitude hydraulic control system to solve the problem that when arm support amplitude lifts, especially when amplitude drops, two balance valves of hydraulic cylinders cannot be opened simultaneously or have consistent opening degree, resulting in unstable amplitude lifting.

[0005] The utility model solves the above technical problem through the following technical scheme: an arm support amplitude hydraulic control system, comprising hydraulic pump, reversing valve, first hydraulic cylinder, second hydraulic cylinder, first balance valve and second balance valve, the oil outlet of the hydraulic pump is connected with the P port of the reversing valve, the A port of the reversing valve is connected with the C1 port of the first balance valve and second balance valve, the C2 port of the first balance valve is connected with the rodless cavity of the first hydraulic cylinder, the C2 port of the second balance valve is connected with the rodless cavity of the second hydraulic cylinder;

[0006] The hydraulic control system further comprises third balance valve, the B port of the reversing valve is connected with the rod cavity of the first hydraulic cylinder and second hydraulic cylinder through the third balance valve, the C3 port of the first balance valve and second balance valve is further connected on the pipeline between the third balance valve and the B port of the reversing valve;Wherein, the first balance valve and the second balance valve are both atmospheric type balance valve.

[0007] Further, the hydraulic control system further comprises a first electromagnetic valve and a second electromagnetic valve connected in series, the first electromagnetic valve is connected to a pipeline between the C2 port of the first balance valve and the rodless chamber of the first hydraulic cylinder, and the second electromagnetic valve is connected to a pipeline between the C2 port of the second balance valve and the rodless chamber of the second hydraulic cylinder.

[0008] Further, the first electromagnetic valve and the second electromagnetic valve are both normally closed electromagnetic ball valves with position detection.

[0009] Further, the reversing valve is a three-position four-way electromagnetic reversing valve.

[0010] Further, a first one-way throttle valve is arranged on the pipeline between the C2 port of the first balance valve and the rodless chamber of the first hydraulic cylinder, and a second one-way throttle valve is arranged on the pipeline between the C2 port of the second balance valve and the rodless chamber of the second hydraulic cylinder.

[0011] Based on the same concept, the utility model further provides an arm support type engineering machinery, including arm support amplitude hydraulic control system as described above.

[0012] Compared with the prior art, the utility model has the advantages that:

[0013] The arm support amplitude hydraulic control system provided by the utility model adopts the atmospheric balance valve for the balance valve configured by the first hydraulic cylinder and the second hydraulic cylinder, which can ensure the simultaneous opening and the same opening degree under the same pilot pressure, ensures the simultaneous action and the same action amplitude of the first hydraulic cylinder and the second hydraulic cylinder, and ensures the stability of amplitude lifting.

[0014] The arm support amplitude hydraulic control system provided by the utility model further adds the first electromagnetic valve and the second electromagnetic valve, the first electromagnetic valve and the second electromagnetic valve are opened when the amplitude is lowered, the rodless chamber of the first hydraulic cylinder and the rodless chamber of the second hydraulic cylinder are communicated, and then the rodless chambers of the first hydraulic cylinder and the second hydraulic cylinder are simultaneously returned to oil, thereby avoiding the problem that the first hydraulic cylinder and the second hydraulic cylinder are out of synchronization during amplitude lowering. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, obviously, the drawings in the following description are only one embodiment of the utility model, and for the ordinary skilled in the art, other drawings can also be obtained according of these drawings without creative labor.

[0016] Figure 1 It is the structure principle diagram of the boom luffing hydraulic control system in the embodiment of the utility model.

[0017] The figure mark explanation: 1 - first hydraulic cylinder, 2 - second hydraulic cylinder, 3 - first balance valve, 4 - second balance valve, 5 - reversing valve, 6 - third balance valve, 7 - first electromagnetic valve, 8 - second electromagnetic valve, 9 - first one-way throttle valve, 10 - second one-way throttle valve, 11 - hydraulic pump. DETAILED DESCRIPTION

[0018] The technical scheme in the utility model will be clearly and completely described below in combination with the drawings in the embodiment of the utility model, obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skilled in the art without creative labor belong to the scope of protection of the utility model.

[0019] The technical scheme of the present application will be described in detail below with specific examples. The following specific examples can be combined with each other, and the same or similar concepts or processes may not be described in some embodiments.

[0020] As Figure 1 Indicated, the utility model embodiment provides a kind of boom luffing hydraulic control system, including hydraulic pump 11, reversing valve 5, first hydraulic cylinder 1, second hydraulic cylinder 2, first balance valve 3, second balance valve 4 and third balance valve 6, the oil outlet of hydraulic pump 11 is connected with the P port of reversing valve 5, the A port of reversing valve 5 is connected with the C1 port of first balance valve 3 and second balance valve 4, the C2 port of first balance valve 3 is connected with the rodless cavity of first hydraulic cylinder 1, the C2 port of second balance valve 4 is connected with the rodless cavity of second hydraulic cylinder 2;The B port of reversing valve 5 is connected with the rod cavity of first hydraulic cylinder 1 and second hydraulic cylinder 2 by third balance valve 6, the C3 port of first balance valve 3 and second balance valve 4 is also connected on the pipeline between third balance valve 6 and the B port of reversing valve 5;Wherein, first balance valve 3 and second balance valve 4 are all atmospheric type balance valve.

[0021] The utility model discloses an arm support amplitude hydraulic control system, first hydraulic cylinder 1 and second hydraulic cylinder 2 each configuration one balance valve (that is first balance valve 3 and second balance valve 4), first hydraulic cylinder 1 and second hydraulic cylinder 2 share one balance valve (that is third balance valve 6), first hydraulic cylinder 1 and second hydraulic cylinder 2 share one reversing valve 5, and the lifting of first hydraulic cylinder 1 and second hydraulic cylinder 2 is controlled through one reversing valve 5, and the system structure is simplified.

[0022] In the embodiment of the utility model, the hydraulic control system further comprises a first electromagnetic valve 7 and a second electromagnetic valve 8 connected in series, the first electromagnetic valve 7 is connected to the pipeline between the C2 port of the first balance valve 3 and the rodless cavity of the first hydraulic cylinder 1, and the second electromagnetic valve 8 is connected to the pipeline between the C2 port of the second balance valve 4 and the rodless cavity of the second hydraulic cylinder 2.

[0023] When the first balance valve 3 and the second balance valve 4 are not opened at the same time or have different opening degrees, the first electromagnetic valve 7 and the second electromagnetic valve 8 ensure that the rodless cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 return oil synchronously, thereby ensuring that the first hydraulic cylinder 1 and the second hydraulic cylinder 2 descend synchronously in amplitude, and ensuring the stability of the amplitude descent.

[0024] When the amplitude rises, the high-pressure hydraulic oil flows to the rodless cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 through the reversing valve 5, the first balance valve 3 and the second balance valve 4, the third balance valve 6 is opened at the same time, and the hydraulic oil in the rod cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 returns to the oil tank through the third balance valve 6 and the reversing valve 5. The third balance valve 6 stabilizes the working pressure in the rodless cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 during the amplitude rise, and suppresses the impact of a single hydraulic cylinder caused by pressure mutation when the first hydraulic cylinder 1 and the second hydraulic cylinder 2 start, which leads to different rising speeds. When the amplitude rises, the first electromagnetic valve 7 and the second electromagnetic valve 8 lose power and remain closed, and the rodless cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 are disconnected.

[0025] When the amplitude is descending, hydraulic oil flows to the rod cavity of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 through the reversing valve 5 and the third balance valve 6 respectively, and the first balance valve 3 and the second balance valve 4 are opened at the same time, and the hydraulic oil in the rodless cavity of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 returns to the oil tank through the first balance valve 3 and the second balance valve 4 and the reversing valve 5; when the first balance valve 3 and the second balance valve 4 are opened, the first electromagnetic valve 7 and the second electromagnetic valve 8 are powered on at the same time to ensure that the rodless cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 are communicated. The first balance valve 3 and the second balance valve 4 are atmospheric balance valves, which avoid the problem of different step-down caused by the failure to open at the same time due to the existence of oil return back pressure error; the first electromagnetic valve 7 and the second electromagnetic valve 8 make the rodless cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 communicate when the amplitude of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 is descending, so that the rodless cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 can return to oil at the same time even if the first balance valve 3 and the second balance valve 4 are not opened at the same time or the opening degree is inconsistent, thereby avoiding the problem of different step-down of the first hydraulic cylinder 1 and the second hydraulic cylinder 2, and double-ensuring the step-down synchronization of the amplitude by the atmospheric balance valve, and avoiding the pressure holding problem caused by the different return of the rodless cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2.

[0026] In the specific embodiment of the utility model, the first electromagnetic valve 7 and the second electromagnetic valve 8 are both normally closed electromagnetic ball valves with position detection. The position detection can monitor whether the valve core normally opens and closes, and timely alarm is given when abnormal opening and closing occurs, thereby avoiding the failure caused by abnormal closing and improving safety; when the connecting pipeline between the rodless cavities of the first hydraulic cylinder 1 and the second hydraulic cylinder 2 bursts, the first electromagnetic valve 7 and the second electromagnetic valve 8 are powered off to close, so that the first hydraulic cylinder 1 and the second hydraulic cylinder 2 do not descend, thereby ensuring safety.

[0027] In the specific embodiment of the utility model, the reversing valve 5 is a three-position four-way electromagnetic reversing valve.

[0028] In the specific embodiment of the utility model, the first one-way throttle valve 9 is arranged on the pipeline between the C2 port of the first balance valve 3 and the rodless cavity of the first hydraulic cylinder 1, and the second one-way throttle valve 10 is arranged on the pipeline between the C2 port of the second balance valve 4 and the rodless cavity of the second hydraulic cylinder 2.

[0029] The first one-way throttle valve 9 and the second one-way throttle valve 10 can avoid the pressure impact caused by excessive flow during the momentary action of the boom.

[0030] The above only discloses the specific embodiment of the utility model, but the protection scope of the utility model is not limited to this, any skilled person in the technical field can easily think of changes or modifications within the technical range disclosed by the utility model, which should be covered in the protection scope of the utility model.

Claims

1. An arm-variable hydraulic control system, comprising a hydraulic pump, a reversing valve, a first hydraulic cylinder, a second hydraulic cylinder, a first balance valve and a second balance valve, wherein an outlet of the hydraulic pump is connected with a P port of the reversing valve, an A port of the reversing valve is connected with C1 ports of the first balance valve and the second balance valve, a C2 port of the first balance valve is connected with a rodless chamber of the first hydraulic cylinder, and a C2 port of the second balance valve is connected with a rodless chamber of the second hydraulic cylinder; characterized in that: the hydraulic control system further comprises a third balance valve, a B port of the reversing valve is connected with rod chambers of the first hydraulic cylinder and the second hydraulic cylinder through the third balance valve, and C3 ports of the first balance valve and the second balance valve are further connected with a pipeline between the third balance valve and the B port of the reversing valve; wherein the first balance valve and the second balance valve are both atmospheric balance valves. The hydraulic control system further comprises a first electromagnetic valve and a second electromagnetic valve connected in series, the first electromagnetic valve is connected with a pipeline between the C2 port of the first balance valve and the rodless chamber of the first hydraulic cylinder, and the second electromagnetic valve is connected with a pipeline between the C2 port of the second balance valve and the rodless chamber of the second hydraulic cylinder.

2. The hydraulic control system for luffing of a boom according to claim 1, characterized in that: The first electromagnetic valve and the second electromagnetic valve are both normally closed electromagnetic ball valves with position detection.

3. The hydraulic control system for luffing of a boom according to claim 2, characterized in that: The reversing valve is a three-position four-way electromagnetic reversing valve.

4. The hydraulic control system for luffing of a boom according to claim 1, characterized in that: A first one-way throttle valve is arranged on a pipeline between the C2 port of the first balance valve and the rodless chamber of the first hydraulic cylinder, and a second one-way throttle valve is arranged on a pipeline between the C2 port of the second balance valve and the rodless chamber of the second hydraulic cylinder.

5. The hydraulic control system for luffing of a boom according to claim 1, characterized in that: The arm-variable hydraulic control system according to any one of claims 1-5 is applied to an arm-type engineering machine.

6. A boom-type construction machine characterized by comprising: ​

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