Telescopic system and crane for realizing simultaneous telescopic boom

Abstract

The present invention discloses a telescopic system and a crane for realizing simultaneous telescopic boom extension. The telescopic system includes a first telescopic oil cylinder, a second telescopic oil cylinder, a first balancing valve, a second balancing valve, a control valve and a system reversing valve. The control valve includes a valve body, an overflow valve and a reversing valve body. The control oil source can control the reversing of the control valve under the action of the reversing valve body, so that the oil is simultaneously fed into the rodless chamber of the first telescopic oil cylinder and the rodless chamber of the second telescopic oil cylinder through the system reversing valve and the control valve, so as to realize simultaneous extension of the boom; and the oil in the rodless chamber of the second telescopic oil cylinder and the oil in the rodless chamber of the first telescopic oil cylinder are simultaneously returned through the control valve and the system reversing valve, so as to realize simultaneous retraction of the boom. The present invention can realize simultaneous extension and sequential extension of five-section booms of a double-cylinder rope row structure, meet the requirements of various telescopic working conditions of the boom, is easy to operate and can avoid the impact of switching between oil inlet and return of the cylinders.

Description

Technical Field

[0001] The invention relates to a telescopic system, and in particular to a telescopic system and a crane for realizing simultaneous telescopic movement of a boom. Background Art

[0002] The hydraulic system of the crane mainly includes telescopic system, luffing system, slewing system and winch system. The crane needs to coordinate the actions of various systems to lift heavy objects. When performing long-distance lifting operations, the crane needs to extend the boom to reach the location of the heavy object. After the lifting is completed, the boom is retracted.

[0003] At present, the telescopic system of truck cranes mostly adopts double-cylinder rope-row structure and single-cylinder pin structure. The double-cylinder rope-row structure is widely used in five-section boom truck crane products due to its advantages of simple structure, reliability and low cost. However, the current double-cylinder rope-row structure telescopic system cannot achieve simultaneous telescopic of the five-section boom, and there is a certain switching impact in sequential telescopic.

[0004] In the prior art, in order to solve the above problems, a patent document with patent application number CN201711390920.9 and publication date May 29, 2018 discloses a double-cylinder rope telescopic system and a crane for realizing synchronous recovery of the boom, which can realize synchronous recovery and sequential recovery of the boom.

[0005] However, the defects of this patent are that the boom extension and retraction process requires the operation of the switching valve, which causes switching shocks and cannot achieve simultaneous extension and retraction of the boom. Since the telescopic switching valve needs to be operated to control the oil circuit switching of the first telescopic cylinder and the second telescopic cylinder, there is a switching shock in the boom extension and retraction process, which also affects the convenience of the telescopic operation. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a telescopic system and a crane for realizing simultaneous telescopic movement of the boom, a telescopic system that enables the crane boom to be simultaneously telescopic, and a five-section boom of a double-cylinder rope-row structure five-section boom crane that can be telescoped simultaneously or sequentially, thereby meeting the needs of various telescopic working conditions of the boom. Simultaneous telescopic movement does not require switching of the oil inlet and return oil of the cylinder during the telescopic process, so the operation is convenient and switching shock can be avoided.

[0007] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0008] On the one hand, the present invention provides a telescopic system for realizing simultaneous telescopic boom extension and retraction, comprising a first telescopic oil cylinder, a second telescopic oil cylinder, a first balancing valve, a second balancing valve, a control valve and a system reversing valve, wherein the control valve comprises a reversing valve body;

[0009] The rodless chamber of the first telescopic oil cylinder is connected to the first balancing valve, the control valve and the system reversing valve in sequence to form an oil inlet and oil return oil path of the chamber, and the rod chamber of the first telescopic oil cylinder is connected to the system reversing valve to form an oil inlet and oil return oil path of the chamber;

[0010] The rodless chamber of the second telescopic oil cylinder is connected to the second balancing valve, the control valve and the system reversing valve in sequence to form an oil inlet and return oil path of the chamber;

[0011] The rod chamber of the second telescopic oil cylinder is connected to the rod chamber of the first telescopic oil cylinder and the system reversing valve to form an oil inlet and return oil path of the chamber;

[0012] Under the action of the reversing valve body, the control oil source controls the reversing of the control valve, so that the oil flows into the rodless chamber of the first telescopic oil cylinder and the rodless chamber of the second telescopic oil cylinder through the system reversing valve and the control valve at the same time, so as to realize the simultaneous extension of the boom; and the oil in the rodless chamber of the second telescopic oil cylinder and the oil in the rodless chamber of the first telescopic oil cylinder are returned through the control valve and the system reversing valve at the same time, so as to realize the simultaneous retraction of the boom.

[0013] In some embodiments, the control valve also includes a valve body and a relief valve. The rodless chamber of the first telescopic cylinder is connected to the first balancing valve, the valve body and the system reversing valve in sequence. The rodless chamber of the second telescopic cylinder is connected to the second balancing valve, the valve body and the system reversing valve in sequence. The relief valve is connected to the valve body.

[0014] In some embodiments, the valve body is a three-position reversing valve. When the control oil source is set to control the valve body to be reversing to the middle position by setting the reversing valve body, and the control system reversing valve is reversing to the right position, the oil passes through the system reversing valve, the valve body, the first balancing valve, the core tube of the first telescopic oil cylinder, and the second balancing valve, and simultaneously enters the rodless chamber of the first telescopic oil cylinder and the rodless chamber of the second telescopic oil cylinder, so as to realize the simultaneous extension of the boom;

[0015] When the control oil source is controlled by setting the reversing valve body to control the valve body to switch to the middle position, and the system reversing valve is controlled to switch to the left position, so that the oil passes through the system reversing valve and enters the rod chamber of the first telescopic oil cylinder and the rod chamber of the second telescopic oil cylinder at the same time, the oil in the rodless chamber of the second telescopic oil cylinder can be returned through the second balancing valve, the core tube of the first telescopic oil cylinder and the valve body, and the oil in the rodless chamber of the first telescopic oil cylinder can be returned through the first balancing valve and the valve body, so as to realize the simultaneous retraction of the boom.

[0016] In some embodiments, the reversing valve body is an electric proportional pressure reducing valve, and the control oil source can control the valve body to achieve reversal by setting the control current of the electric proportional pressure reducing valve.

[0017] In some embodiments, the control oil source controls the current by setting the electric proportional pressure reducing valve to switch the valve body to the left position, and controls the system reversing valve to switch to the right position, so that the first telescopic cylinder is extended; the control current is set by setting the electric proportional pressure reducing valve to switch the valve body to the right position, and controls the system reversing valve to switch to the right position, so that the second telescopic cylinder is extended, so as to realize sequential extension of the boom.

[0018] In some embodiments, the control oil source controls the current by setting the electric proportional pressure reducing valve to switch the valve body to the right position, and controls the system reversing valve to switch to the left position, so as to retract the second telescopic cylinder; controls the current by setting the electric proportional pressure reducing valve to switch the valve body to the left position, and controls the system reversing valve to switch to the left position, so as to retract the first telescopic cylinder, so as to realize sequential retraction of the boom.

[0019] In some embodiments, the reversing valve body is an electromagnetic reversing valve, which is connected to the valve body, a control oil source and an oil leakage circuit. When the electromagnetic reversing valve gains or loses power, the control valve body is reversed.

[0020] In some embodiments, the reversing valve body includes a first solenoid reversing valve and a second solenoid reversing valve. The first solenoid reversing valve is connected to the valve body, the second solenoid reversing valve, a control oil source and an oil leakage circuit. When the first solenoid reversing valve and the second solenoid reversing valve gain or lose power, the control valve body is reversed.

[0021] In some embodiments, the reversing valve body includes an electromagnetic reversing valve 1, an electromagnetic reversing valve 2, an electromagnetic reversing valve 3 and an electromagnetic reversing valve 4, and the valve body includes a first cartridge reversing valve, a second cartridge reversing valve, a third cartridge reversing valve and a fourth cartridge reversing valve. The electromagnetic reversing valve 1, the electromagnetic reversing valve 2, the electromagnetic reversing valve 3 and the electromagnetic reversing valve 4 are correspondingly connected to the first cartridge reversing valve, the second cartridge reversing valve, the third cartridge reversing valve and the fourth cartridge reversing valve. When the electromagnetic reversing valve 1, the electromagnetic reversing valve 2, the electromagnetic reversing valve 3 and the electromagnetic reversing valve 4 gain or lose power, the valve body is controlled to reversing.

[0022] On the other hand, the present invention further provides a crane, comprising the telescopic system for realizing simultaneous telescopic movement of the boom.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a telescopic system and crane for realizing simultaneous telescopic boom extension. The telescopic system includes a first telescopic oil cylinder, a second telescopic oil cylinder, a first balancing valve, a second balancing valve, a control valve and a system reversing valve. The control valve includes a valve body, an overflow valve and a reversing valve body. The control oil source can control the reversing of the control valve under the action of the reversing valve body, so that the oil is simultaneously fed into the rodless chamber of the first telescopic oil cylinder and the rodless chamber of the second telescopic oil cylinder through the system reversing valve and the control valve, so as to realize simultaneous extension of the boom; and the oil in the rodless chamber of the second telescopic oil cylinder and the oil in the rodless chamber of the first telescopic oil cylinder are simultaneously returned through the control valve and the system reversing valve, so as to realize simultaneous retraction of the boom. The present invention can realize simultaneous and sequential telescopic extension of five sections of the double-cylinder rope row structure, meet the requirements of various telescopic working conditions of the boom, is easy to operate and can avoid the impact of switching between oil inlet and return of the cylinder.

[0025] The present invention can realize the simultaneous extension and retraction of the five-section boom of the double-cylinder rope row structure five-section boom crane and realize the requirements of various telescopic working conditions of the boom. Those skilled in the art can freely switch the telescopic mode according to the working conditions to obtain various telescopic modes of the boom. At the same time, the telescopic mode of the present invention solves the switching impact problem existing in the telescopic process of the boom, and can improve the convenience of telescopic operation and telescopic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of a telescopic system for realizing simultaneous telescopic movement of a boom provided in the first embodiment of the present invention;

[0027] Figure 2 It is a structural schematic diagram of a telescopic system for realizing simultaneous telescopic movement of a boom provided in the second embodiment of the present invention;

[0028] Figure 3 It is a structural schematic diagram of a telescopic system for realizing simultaneous telescopic movement of a boom provided in Embodiment 3 of the present invention;

[0029] Figure 4 It is a structural schematic diagram of a telescopic system for realizing simultaneous telescopic movement of a boom provided in a fourth embodiment of the present invention;

[0030] In the figure:

[0031] 1. System reversing valve;

[0032] 2. Control valve;

[0033] 2.1. Valve body; 2.2. Reversing valve body; 2.3. Overflow valve;

[0034] 2.2-1, first electromagnetic reversing valve; 2.2-2, second electromagnetic reversing valve;

[0035] 21-1, first cartridge reversing valve; 21-2, second cartridge reversing valve; 21-3, third cartridge reversing valve; 21-4, fourth cartridge reversing valve; 22-1, electromagnetic reversing valve 1; 22-2, electromagnetic reversing valve 2; 22-3, electromagnetic reversing valve 3; 22-4, electromagnetic reversing valve 4;

[0036] 3. The first balancing valve;

[0037] 4. The first telescopic cylinder;

[0038] 5. Second balancing valve;

[0039] 6. The second telescopic cylinder. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0043] The present invention provides a telescopic system for realizing simultaneous telescopic boom extension and retraction, comprising a first telescopic oil cylinder 4, a second telescopic oil cylinder 6, a first balancing valve 3, a second balancing valve 5, a control valve 2 and a system reversing valve 1, wherein the control valve 2 comprises a valve body 2.1, a reversing valve body 2.2 and a relief valve 2.3.

[0044] The rodless chamber of the first telescopic oil cylinder 4 is connected to the first balancing valve 3, the control valve 2 and the system reversing valve 1 in sequence to form the oil inlet and oil return oil paths of the chamber, and the rod chamber of the first telescopic oil cylinder 4 is connected to the system reversing valve 1 to form the oil inlet and oil return oil paths of the chamber. Specifically, the rodless chamber of the first telescopic oil cylinder 4 is connected to the first balancing valve 3, the valve body 2.1 and the system reversing valve 1 in sequence.

[0045] The rodless chamber of the second telescopic oil cylinder 6 is connected to the second balancing valve 5, the control valve 2 and the system reversing valve 1 in sequence to form the oil inlet and oil return oil paths of the chamber. Specifically, the rodless chamber of the second telescopic oil cylinder 6 is connected to the second balancing valve 5, the valve body 2.1 and the system reversing valve 1 in sequence, wherein the overflow valve 2.3 is connected to the valve body 2.1.

[0046] The rod chamber of the second telescopic oil cylinder 6 is connected to the rod chamber of the first telescopic oil cylinder 4 and the system reversing valve 1 to form an oil inlet and return oil path of the chamber.

[0047] The essence of the present invention is that the oil source is controlled to control the reversing of the control valve 2 under the action of the reversing valve body 2.2, so that the oil simultaneously enters the rodless chamber of the first telescopic cylinder 4 and the rodless chamber of the second telescopic cylinder 6 through the system reversing valve 1 and the control valve 2 to achieve the simultaneous extension of the boom; the oil in the rodless chamber of the second telescopic cylinder 6 and the oil in the rodless chamber of the first telescopic cylinder 4 are simultaneously returned through the control valve 2 and the system reversing valve 1 to achieve the simultaneous retraction of the boom.

[0048] It should be noted that, in some embodiments, the valve body 2.1 is a three-position reversing valve. When the control oil source is controlled by setting the reversing valve body 2.2 to control the valve body 2.1 to be switched to the middle position, and the system reversing valve 1 is controlled to be switched to the right position, the oil passes through the system reversing valve 1, the reversing valve body 2.2, the first balancing valve 3, the core tube of the first telescopic cylinder 4 and the second balancing valve 5, and simultaneously enters the rodless chamber of the first telescopic cylinder 4 and the rodless chamber of the second telescopic cylinder 6, so as to realize the simultaneous extension of the boom.

[0049] When the control oil source is controlled by setting the reversing valve body 2.2 to control the valve body 2.1 to switch to the middle position, and the system reversing valve 1 is switched to the left position, so that the oil passes through the system reversing valve 1 and simultaneously enters the rod chamber of the first telescopic cylinder 4 and the rod chamber of the second telescopic cylinder 6, the oil in the rodless chamber of the second telescopic cylinder 6 can be returned through the second balancing valve 5, the core tube of the first telescopic cylinder 4 and the valve body 2.1, and the oil in the rodless chamber of the first telescopic cylinder 4 can be returned through the first balancing valve 3 and the valve body 2.1, so as to realize the simultaneous retraction of the boom.

[0050] It should be noted that the telescopic system can be used for a boom structure composed of five boom sections, but the present invention is not limited thereto. After understanding the essential content of the present invention, those skilled in the art can design the boom structure into a six-section boom or other number of boom sections.

[0051] In addition, it should be noted that the present invention adopts a double-cylinder rope row structure, which is a structure on the crane that realizes the extension and retraction of the boom through the drive of ropes, pulleys, the first telescopic cylinder 4, the second telescopic cylinder 6 and other components, and the oil source switching of the telescopic switching valve.

[0052] Those skilled in the art can freely switch the telescopic mode according to the working conditions to obtain a variety of arm telescopic modes. At the same time, the telescopic mode of the present invention solves the switching impact problem existing in the arm telescopic process, and can improve the convenience of telescopic operation and telescopic efficiency.

[0053] In order to describe the essence of the present invention in detail, the present invention is illustrated by the following examples.

[0054] Embodiment 1:

[0055] In this embodiment, the telescopic system includes a system reversing valve 1, a control valve 2, a reversing valve body 2.2, a valve body 2.1, a relief valve 2.3, a first balancing valve 3, a first telescopic oil cylinder 4, a second balancing valve 5 and a second telescopic oil cylinder 6, see Figure 1 Specifically, the reversing valve body 2.2 is an electric proportional pressure reducing valve, and the control oil source can control the valve body 2.1 to achieve reversal by setting the control current of the electric proportional pressure reducing valve.

[0056] The rodless chamber of the first telescopic cylinder 4 is connected to the first balancing valve 3, the valve body 2.1 and the system reversing valve 1 in sequence to form the oil inlet and return oil circuits of the chamber, and the rod chamber of the first telescopic cylinder 4 is connected to the system reversing valve 1 to form the oil inlet and return oil circuits of the chamber.

[0057] The rodless chamber of the second telescopic cylinder 6 is connected in sequence to the second balancing valve 5, the reversing valve body 2.2 and the overflow valve 2.3 to form an oil return circuit of the chamber, and is connected in sequence to the system reversing valve 1, the reversing valve body 2.2 and the second balancing valve 5 to form an oil inlet circuit of the chamber.

[0058] The rod chamber of the second telescopic oil cylinder 6 is connected to the rod chamber of the first telescopic oil cylinder 4 and the system reversing valve 1 to form an oil inlet and return oil path of the chamber.

[0059] It should be noted that, in this embodiment, the reversing valve body 2.2 is an electric proportional pressure reducing valve.

[0060] Specifically, under the action of the control oil source, the valve body 2.1 is located in the middle position by setting the control current of the electric proportional pressure reducing valve, and the system reversing valve 1 is controlled to the right position. The oil passes through the system reversing valve 1, the valve body 2.1, the first balancing valve 3, the core tube of the first telescopic cylinder 4, and the second balancing valve 5, and enters the rodless chambers of the first telescopic cylinder 4 and the second telescopic cylinder 6 at the same time. The first telescopic cylinder 4 and the second telescopic cylinder 6 are extended at the same time. In this case, the second, third, fourth and fifth arms are extended at the same time.

[0061] Specifically, under the action of the reversing valve body 2.2, the control oil source sets the electric proportional pressure reducing valve control current to make the valve body 2.1 in the middle position, and controls the system reversing valve 1 to the left position, so that the oil enters the rod chambers of the first telescopic oil cylinder 4 and the second telescopic oil cylinder 6 through the system reversing valve 1 at the same time, and can make the oil in the rodless chamber of the second telescopic oil cylinder 6 return through the second balancing valve 5, the core tube of the second telescopic oil cylinder 6 and the valve body 2.1, and make the oil in the rodless chamber of the first telescopic oil cylinder 4 return through the first balancing valve 3 and the valve body 2.1, so that the first telescopic oil cylinder 4 and the second telescopic oil cylinder 6 are retracted at the same time. In this case, the second, third, fourth and fifth sections of the boom are retracted at the same time.

[0062] Those skilled in the art should understand that the telescopic system can also achieve sequential extension and sequential retraction.

[0063] Specifically, the steps of extending the arms sequentially are as follows:

[0064] Under the action of the reversing valve body 2.2, the control oil source sets the electric proportional pressure reducing valve control current to make the valve body 2.1 in the left position, and controls the system reversing valve 1 to the right position. The oil enters the rodless chamber of the first telescopic oil cylinder 4 through the system reversing valve 1, the valve body 2.1, and the first balancing valve 3, and the first telescopic oil cylinder 4 extends. In this case, the second section boom extends;

[0065] Under the action of the reversing valve body 2.2, the control oil source sets the electric proportional pressure reducing valve control current to make the valve body 2.1 in the right position, and controls the system reversing valve 1 to the right position. The oil enters the rodless chamber of the second telescopic cylinder 6 through the system reversing valve 1, the valve body 2.1, the core tube of the first telescopic cylinder 4, and the second balancing valve 5, and the second telescopic cylinder 6 is extended. In this case, the third, fourth, and fifth sections of the boom are extended.

[0066] Similarly, the steps for sequential retraction of the boom are as follows:

[0067] Under the action of the reversing valve body 2.2, the control oil source sets the electric proportional pressure reducing valve control current to make the valve body 2.1 in the right position, and controls the system reversing valve 1 to the left position. The oil enters the rod chambers of the first telescopic cylinder 4 and the second telescopic cylinder 6 through the system reversing valve 1. The oil in the rodless chamber of the second telescopic cylinder 6 returns through the second balancing valve 5, the core tube of the first telescopic cylinder 4, the valve body 2.1, and the system reversing valve 1, and the second telescopic cylinder 6 retracts. In this case, the third, fourth, and fifth sections of the boom retract.

[0068] Under the action of the control oil source, the electric proportional pressure reducing valve control current is set to make the valve body 2.1 in the left position, and the system reversing valve 1 is controlled to the left position. The oil enters the rod chambers of the first telescopic cylinder 4 and the second telescopic cylinder 6 through the system reversing valve 1. The oil in the rodless chamber of the first telescopic cylinder 4 returns through the first balancing valve 3, the valve body 2.1, and the system reversing valve 1, and the first telescopic cylinder 4 retracts. In this case, the second-section arm retracts.

[0069] Embodiment 2:

[0070] The difference between the second embodiment and the first embodiment is that in the second embodiment, the reversing valve body 2.2 includes a first solenoid reversing valve 2.2-1 and a second solenoid reversing valve 2.2-2, that is, the electric proportional pressure reducing valve in the first embodiment is replaced by the first solenoid reversing valve 2.2-1 and the second solenoid reversing valve 2.2-2.

[0071] The working principle diagram of the present invention is shown in Figure 2 Specifically, the first solenoid reversing valve 2.2-1 and the second solenoid reversing valve 2.2-2 are respectively arranged on both sides of the valve body 2.1, and the first solenoid reversing valve 2.2-1 is connected with the valve body 2.1, the second solenoid reversing valve 2.2-2, the control oil source and the oil leakage circuit. When the first solenoid reversing valve 2.2-1 and the second solenoid reversing valve 2.2-2 are powered on and off, the control valve body 2.1 is reversed.

[0072] Embodiment three:

[0073] The difference between the third embodiment and the second embodiment is that in the third embodiment, the reversing valve body 2.2 only includes one electromagnetic reversing valve.

[0074] The working principle diagram of the present invention is shown in Figure 3 The electromagnetic reversing valve is connected to the valve body 2.1, the control oil source and the oil leakage circuit. When the electromagnetic reversing valve gains or loses power, the control reversing valve body 2.2 is switched.

[0075] Embodiment 4:

[0076] The difference between Example 4 and Example 3 is that in Example 4, the reversing valve body 2.2 includes an electromagnetic reversing valve 1 22-1, an electromagnetic reversing valve 22-2, an electromagnetic reversing valve 3 22-3 and an electromagnetic reversing valve 4 22-4, and the valve body 2.1 includes a first cartridge reversing valve 21-1, a second cartridge reversing valve 21-2, a third cartridge reversing valve 21-3 and a fourth cartridge reversing valve 21-4.

[0077] The working principle diagram of the present invention is shown in Figure 4 The electromagnetic reversing valve 1 22-1, the electromagnetic reversing valve 22-2, the electromagnetic reversing valve 3 22-3 and the electromagnetic reversing valve 4 22-4 are connected to the first cartridge reversing valve 21-1, the second cartridge reversing valve 21-2, the third cartridge reversing valve 21-3 and the fourth cartridge reversing valve 21-4 respectively. When the electromagnetic reversing valve 1 22-1, the electromagnetic reversing valve 22-2, the electromagnetic reversing valve 3 22-3 and the electromagnetic reversing valve 4 22-4 are energized or de-energized, the control valve body 2.1 is switched.

[0078] Embodiment five:

[0079] The present invention also provides a crane, which adopts the telescopic system for realizing simultaneous telescopic extension of the boom described in the first, second, third and fourth embodiments.

[0080] It should be noted that any other form of replacement made by those skilled in the art after understanding the essential content of the present invention is within the protection scope of the present invention. In the present invention, the structure of the telescopic system is not limited to the structure described in Embodiment 1, Embodiment 2, Embodiment 3, and Embodiment 4.

[0081] The crane provided by the present invention includes a telescopic system, in which the control oil source controls the reversing of the control valve 2 under the action of the reversing valve body 2.2, so that the oil is simultaneously fed into the rodless chamber of the first telescopic oil cylinder 4 and the rodless chamber of the second telescopic oil cylinder 6 through the system reversing valve 1 and the control valve 2, so as to achieve simultaneous extension of the boom; and the oil in the rodless chamber of the second telescopic oil cylinder 6 and the oil in the rodless chamber of the first telescopic oil cylinder 4 are returned, so as to achieve simultaneous retraction of the boom. The present invention can achieve simultaneous and sequential extension of the five-section boom of the double-cylinder rope row structure, meet the needs of various telescopic working conditions of the boom, is easy to operate, and can avoid the impact of switching between oil inlet and return of the cylinder.

[0082] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A telescopic system for realizing simultaneous telescopic and retractable booms, It is characterized in that It includes a first telescopic oil cylinder, a second telescopic oil cylinder, a first balancing valve, a second balancing valve, a control valve and a system reversing valve, wherein the control valve includes a reversing valve body; The rodless chamber of the first telescopic oil cylinder is connected to the first balancing valve, the control valve and the system reversing valve in sequence to form an oil inlet and oil return oil path of the chamber, and the rod chamber of the first telescopic oil cylinder is connected to the system reversing valve to form an oil inlet and oil return oil path of the chamber; The rodless chamber of the second telescopic oil cylinder is connected to the second balancing valve, the control valve and the system reversing valve in sequence to form an oil inlet and return oil path of the chamber; The rod chamber of the second telescopic oil cylinder is connected to the rod chamber of the first telescopic oil cylinder and the system reversing valve to form an oil inlet and return oil path of the chamber; The control oil source controls the reversing of the control valve under the action of the reversing valve body, so that the oil flows into the rodless chamber of the first telescopic oil cylinder and the rodless chamber of the second telescopic oil cylinder through the system reversing valve and the control valve at the same time, so as to realize the simultaneous extension of the boom; and the oil in the rodless chamber of the second telescopic oil cylinder and the oil in the rodless chamber of the first telescopic oil cylinder are returned through the control valve and the system reversing valve at the same time, so as to realize the simultaneous retraction of the boom; The control valve further comprises a valve body and a relief valve, the rodless chamber of the first telescopic oil cylinder is sequentially connected to a first balancing valve, a valve body and a system reversing valve, the rodless chamber of the second telescopic oil cylinder is sequentially connected to a second balancing valve, a valve body and a system reversing valve, and the relief valve is connected to the valve body; The valve body is a three-position reversing valve. When the control oil source is set to control the valve body to be reversing to the middle position by setting the reversing valve body, and the control system reversing valve is reversing to the right position, the oil passes through the system reversing valve, the valve body, the first balancing valve, the core tube of the first telescopic oil cylinder and the second balancing valve, and simultaneously enters the rodless chamber of the first telescopic oil cylinder and the rodless chamber of the second telescopic oil cylinder, so as to realize the simultaneous extension of the boom; When the control oil source is controlled by setting the reversing valve body to control the valve body to switch to the middle position, and the system reversing valve is controlled to switch to the left position, so that the oil passes through the system reversing valve and enters the rod chamber of the first telescopic oil cylinder and the rod chamber of the second telescopic oil cylinder at the same time, the oil in the rodless chamber of the second telescopic oil cylinder can be returned through the second balancing valve, the core tube of the first telescopic oil cylinder and the valve body, and the oil in the rodless chamber of the first telescopic oil cylinder can be returned through the first balancing valve and the valve body, so as to realize the simultaneous retraction of the boom.

2. The telescopic system for realizing simultaneous telescopic movement of a boom according to claim 1, It is characterized in that The reversing valve body is an electric proportional pressure reducing valve, and the control oil source can control the valve body to achieve reversing by setting the control current of the electric proportional pressure reducing valve.

3. The telescopic system for realizing simultaneous telescopic movement of the boom according to claim 2, It is characterized in that The control oil source controls the electric proportional pressure reducing valve to control the current, so that the valve body is switched to the left position, and the control system reversing valve is switched to the right position, so that the first telescopic oil cylinder is extended; the control current is set by the electric proportional pressure reducing valve to control the current, so that the valve body is switched to the right position, and the control system reversing valve is switched to the right position, so that the second telescopic oil cylinder is extended, so as to realize the sequential extension of the boom.

4. The telescopic system for realizing simultaneous telescopic movement of the boom according to claim 2, It is characterized in that The control oil source controls the electric proportional pressure reducing valve to control the current, so that the valve body is switched to the right position, and the control system reversing valve is switched to the left position, so that the second telescopic oil cylinder is retracted; the control current is set by the electric proportional pressure reducing valve to control the current, so that the valve body is switched to the left position, and the control system reversing valve is switched to the left position, so that the first telescopic oil cylinder is retracted, so as to realize the sequential retraction of the boom.

5. The telescopic system for realizing simultaneous telescopic movement of a boom according to claim 1, It is characterized in that The reversing valve body is an electromagnetic reversing valve, which is connected to the valve body, a control oil source and an oil leakage circuit. When the electromagnetic reversing valve gains or loses power, the control valve body is reversed.

6. The telescopic system for realizing simultaneous telescopic movement of a boom according to claim 1, It is characterized in that The reversing valve body includes a first solenoid reversing valve and a second solenoid reversing valve. The first solenoid reversing valve is connected to the valve body, the second solenoid reversing valve, a control oil source and an oil leakage circuit. When the first solenoid reversing valve and the second solenoid reversing valve gain or lose power, the control valve body is reversed.

7. A crane, It is characterized in that A telescopic system for realizing simultaneous telescopic extension of a boom as described in any one of claims 1 to 6.

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