Jib luffing hydraulic control module, hydraulic control system and crane

Abstract

The application discloses a boom luffing hydraulic control module, a hydraulic control system and a crane. The mechanical control type multi-way reversing valve and the pressure reducing valve are used in linkage to form a linkage pressure reducing module. When the valve rod of the mechanical control type multi-way reversing valve is switched from the luffing working position to the falling working position, the valve rod of the pressure reducing valve can be driven to move synchronously, so that a controllable pressure output of the pressure reducing valve can be obtained by controlling the displacement of the valve rod of the mechanical control type multi-way reversing valve. The boom luffing hydraulic control module of the application is used in cooperation with the mechanical control type multi-way reversing valve and the pressure reducing valve, which not only solves the problem that the mechanical control type multi-way reversing valve cannot be used in cooperation with the pressure reducing valve in the field of cranes, but also realizes effective and accurate control over the opening pressure of the self-weight falling type balance valve, overcomes the problem that the boom shakes due to the frequent opening and closing of the balance valve in the falling working condition, and improves the stability of the boom control system.

Description

Technical Field

[0001] This invention belongs to the field of hoisting machinery, and relates to crane technology, particularly to a boom luffing hydraulic control module, a hydraulic control system, and a crane. Background Technology

[0002] In the small-to-medium tonnage (8-12 tons) crane industry, the hydraulic devices controlling the boom's luffing motion commonly employ a mechanically operated multi-way directional valve, combined with a power-operated lowering balance valve. For example... Figure 1 As shown, when the mechanically operated multi-way directional valve is switched to the boom-starting position, the hydraulic fluid sequentially enters the balance valve through port B3, then through port B, and finally enters the luffing cylinder through port C (located in the rodless chamber of the luffing cylinder), thus lifting the cylinder, i.e., boom-starting. When switched to the boom-lowering position, the hydraulic fluid enters the luffing cylinder through port A3 through port D (located in the rod chamber of the luffing cylinder). After entering port D, the hydraulic fluid compresses the cylinder piston, causing it to move downwards, thus lowering the hydraulic fluid. During the boom-lowering operation, when the hydraulic fluid just enters the rod chamber of the luffing cylinder, the balance valve is locked. The balance valve is only opened when the pressure at port X reaches the opening pressure P3 (P3 is generally around 4.5MPa to 9MPa). Figure 2 As shown, the opening condition for the balance valve channels ① to ② is: P1A1 + P2A2 + P3A3 > F S +P T A T Where P1 is the pressure at port B of the balance valve, A1 is the area at port B of the balance valve, P3 is the pressure at port X of the balance valve, A3 is the area at port X of the balance valve, and F S To set the spring force for the balance valve, P T For the oil pressure in the spring chamber of the balance valve, A T P is the area of ​​the valve stem in the spring chamber of the balance valve. T When P2 is connected, the pressures of the two are the same, i.e., P T =P2, so the opening conditions for ① to ② become: P1A1 + P3A3 > F S +P2(A T-A2). When P3 increases to achieve cylinder descent, i.e., boom drop, the area of ​​action of P3 on the balance valve spool is larger than that of P1. Therefore, fluctuations in P3 will lead to larger fluctuations in the spool position and the throttling orifice area - hydraulic resistance, resulting in larger fluctuations in flow rate. Larger flow rate fluctuations, in turn, will cause fluctuations in P3, significantly impacting system stability. If the pressure of the oil entering the end face A3 of the balance valve spool is too high, the balance valve will suddenly open with a larger opening. This will cause the pressure in the rodless chamber of the luffing cylinder to drop suddenly due to the sudden opening of the closed space. The oil that was originally filling the sealed chamber will also instantly lose pressure, causing P3 to fall below the reverse opening pressure of the balance valve, thus closing the power-down balance valve. When the hydraulic system continues to supply oil, P3 will reach the reverse opening pressure of the balance valve, and the luffing balance valve will open. This will result in frequent opening and closing of the balance valve during boom drop operations, causing the boom to shake.

[0003] As mentioned above, the existing hydraulic devices for controlling the boom luffing motion of cranes cannot directly and effectively control the opening pressure of the balance valve. During the lowering operation, the frequent opening and closing of the balance valve causes the boom to shake, resulting in poor system stability and affecting the crane's lifting operations. Summary of the Invention

[0004] The purpose of this invention is to provide a boom luffing hydraulic control module, a hydraulic control system, and a crane to solve the problem that existing hydraulic devices for controlling the boom luffing movement of cranes cannot be directly and effectively controlled. During the lowering operation, the frequent opening and closing of the balance valve causes boom vibration, resulting in poor system stability and affecting crane lifting operations.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a boom luffing hydraulic control module, including a mechanically operated multi-way directional valve, a balance valve, and a pressure reducing valve. The outlet of the mechanically operated multi-way directional valve in the lowering position is connected to the rod chamber of the luffing cylinder. The outlet of the mechanically operated multi-way directional valve in the raising position is connected to the inlet of the balance valve. The outlet of the balance valve is connected to the rodless chamber of the luffing cylinder. The piston rod of the luffing cylinder is connected to the crane boom. The inlet of the pressure reducing valve is connected to the outlet of the mechanically operated multi-way directional valve in the lowering position, and the outlet of the pressure reducing valve is connected to the control port of the balance valve, so as to open the balance valve when the crane boom needs to be lowered. When the valve stem of the mechanically operated multi-way directional valve switches from the raising position to the lowering position, it can drive the valve stem of the pressure reducing valve to move synchronously. Therefore, by controlling the displacement of the valve stem of the mechanically operated multi-way directional valve, the output pressure of the pressure reducing valve can be controlled.

[0007] Optionally, the valve rod of the mechanical-operated multi-way reversing valve is coaxially arranged with the valve rod of the pressure reducing valve but not connected, and when the valve rod of the mechanical-operated multi-way reversing valve is switched from the raised working position to the lowered working position, can be in rigid contact with the valve rod of the pressure reducing valve and push the valve rod of the pressure reducing valve to realize synchronous movement of the valve rod of the mechanical-operated multi-way reversing valve and the valve rod of the pressure reducing valve.

[0008] Optionally, the valve rod of the mechanical-operated multi-way reversing valve is rigidly connected with the valve rod of the pressure reducing valve, so that when the valve rod of the mechanical-operated multi-way reversing valve is switched from the raised working position to the lowered working position, the valve rod of the mechanical-operated multi-way reversing valve can move synchronously with the valve rod of the pressure reducing valve.

[0009] Optionally, the balance valve is a self-weight falling balance valve or a power lowering balance valve.

[0010] The application further provides a boom luffing hydraulic control system, which comprises a luffing oil cylinder and the boom luffing hydraulic control module as claimed in any one of the above.

[0011] Optionally, the balance valve is a self-weight falling balance valve.

[0012] Optionally, the balance valve is a power lowering balance valve.

[0013] The application further provides a crane, which comprises the boom luffing hydraulic control system as claimed in the above.

[0014] The application has the following technical effects relative to the prior art:

[0015] The boom luffing hydraulic control module provided by the present application innovatively uses a mechanical control type multi-way reversing valve and a pressure reducing valve in linkage to form a linkage pressure reducing module, wherein when the valve rod of the mechanical control type multi-way reversing valve is switched from a luffing-up working position to a luffing-down working position, the valve rod of the pressure reducing valve can be driven to move synchronously, so that when the valve rod displacement of the mechanical control type multi-way reversing valve changes, a synchronously changed valve rod displacement of the pressure reducing valve can be obtained, and thus a controllable pressure output of the pressure reducing valve can be obtained by controlling the valve rod displacement of the mechanical control type multi-way reversing valve. The boom luffing hydraulic control module provided by the present application uses the mechanical control type multi-way reversing valve and the pressure reducing valve in linkage, which not only solves the problem that the mechanical control type multi-way reversing valve cannot be used in linkage with the pressure reducing valve in the field of cranes, but also realizes effective and accurate control over the opening pressure of a self-weight luffing type balance valve, and overcomes the problem that the balance valve is frequently opened and closed to cause the boom to shake in the luffing-down working condition, so that the stability of the boom control system is improved.

[0016] The boom luffing hydraulic control system provided by the present application comprises the boom luffing hydraulic control module described above, and has the advantages of the boom luffing hydraulic control module, which will not be described herein again.

[0017] The crane provided by the present application comprises the boom luffing hydraulic control system described above, and has the advantages of the boom luffing hydraulic control module, which will not be described herein again. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0019] Figure 1 It is a principle schematic diagram of the existing boom luffing hydraulic control module;

[0020] Figure 2 It is a force schematic diagram of the existing power luffing type balance valve;

[0021] Figure 3 It is a principle schematic diagram of the boom luffing hydraulic control module disclosed by the embodiments of the present application;

[0022] Figure 4 It is a structure schematic diagram of the boom luffing hydraulic control module disclosed by the embodiments of the present application;

[0023] Figure 5 It is a cooperation schematic diagram of the valve rod of the pressure reducing valve and the valve rod of the mechanical control type multi-way reversing valve disclosed by the embodiments of the present application;

[0024] Figure 6A pressure reducing valve rod displacement and output pressure relationship diagram disclosed by the embodiment of the present application.

[0025] Wherein, the reference signs are:

[0026] 100, a boom luffing hydraulic control module;

[0027] 1, a mechanical control multi-way directional valve; 1-1, a mechanical control multi-way directional valve rod; 1-2, a reset spring;

[0028] 2, a pressure reducing valve; 2-1, a pressure reducing valve rod; 2-2, an oil outlet; 2-3, an oil inlet; 2-4, an oil return;

[0029] 3, a power lowering type balance valve;

[0030] 4, a luffing cylinder; 4-1, a rod cavity; 4-2, a rodless cavity;

[0031] 5, a self-weight luffing balance valve. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0033] One of the purposes of the present application is to provide a boom luffing hydraulic control module to solve the problem that the existing hydraulic device for controlling the boom luffing movement of a crane cannot directly and effectively control the opening pressure of a balance valve, the balance valve is frequently opened and closed during the luffing condition, the boom shakes, the system stability is poor, and the crane hoisting operation is affected.

[0034] Another purpose of the present application is to provide a boom luffing hydraulic control system with the above boom luffing hydraulic control module.

[0035] Still another purpose of the present application is to provide a crane with the above boom luffing hydraulic control system.

[0036] In order to make the above purposes, features and advantages of the present application more apparent and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0037] Embodiment one

[0038] As Figure 3As shown, the embodiment provides a boom luffing hydraulic control module 100, which comprises a mechanical control multi-way directional valve 1, a pressure reducing valve 2 and a self-weight luffing balance valve 5. The oil outlet of the mechanical control multi-way directional valve 1 in the luffing work position is connected with the rod cavity 4-1 of the luffing cylinder 4. The oil outlet of the mechanical control multi-way directional valve 1 in the luffing work position is connected with the oil inlet of the self-weight luffing balance valve 5. The oil outlet of the self-weight luffing balance valve 5 is connected with the rodless cavity 4-2 of the luffing cylinder 4. The rod cavity 4-1 and the rodless cavity 4-2 of the luffing cylinder 4 are distributed up and down. The piston rod of the luffing cylinder 4 is connected with the crane boom. The oil inlet 2-3 of the pressure reducing valve 2 is connected with the oil outlet of the mechanical control multi-way directional valve 1 in the luffing work position. The oil outlet 2-2 of the pressure reducing valve 2 is connected with the control port of the self-weight luffing balance valve 5, so as to reversely open the self-weight luffing balance valve 5 when the crane boom needs to luff. The valve rod of the mechanical control multi-way directional valve 1, i.e. the mechanical control multi-way directional valve rod 1-1, can drive the valve rod of the pressure reducing valve 2, i.e. the pressure reducing valve rod 2-1, to move synchronously when switching from the luffing work position to the luffing work position, so as to control the output pressure of the pressure reducing valve 2 by controlling the displacement of the valve rod of the mechanical control multi-way directional valve 1.

[0039] In the embodiment, the valve rod of the mechanical control multi-way directional valve 1 and the valve rod of the pressure reducing valve 2 are coaxially arranged but not connected. When the valve rod of the mechanical control multi-way directional valve 1 switches from the luffing work position to the luffing work position, it can be in rigid contact with the valve rod of the pressure reducing valve 2 and push the valve rod of the pressure reducing valve 2, so as to realize the synchronous movement of the mechanical control multi-way directional valve rod 1-1 and the pressure reducing valve rod 2-2 in the luffing work position. In actual operation, the mechanical control multi-way directional valve rod 1-1 and the pressure reducing valve rod 2-2 can also be connected by thread connection and the like. However, considering that it is only necessary to provide a pressure for the self-weight luffing balance valve 5 to reversely open the self-weight luffing balance valve 5 in the luffing work position, and the self-weight luffing balance valve 5 is equivalent to a one-way valve in the luffing work position, which has no opening condition and can be opened by the oil from the mechanical control multi-way directional valve 1, so it is not necessary to start the pressure reducing valve 2 in the luffing work position. Therefore, it is only necessary to ensure that the mechanical control multi-way directional valve rod 1-1 is in rigid contact with the pressure reducing valve rod 2-2 and moves synchronously in the luffing work position, so the mechanical control multi-way directional valve rod 1-1 and the pressure reducing valve rod 2-2 do not need to be connected, but it is necessary to ensure that the mechanical control multi-way directional valve rod 1-1 is in rigid contact with the pressure reducing valve rod 2-2 and moves synchronously when switching from the luffing work position to the luffing work position.

[0040] Next, the working principle of the boom luffing hydraulic control module 100 will be described in detail by taking the installation of the boom luffing hydraulic control module 100 in a small-tonnage crane as an example.

[0041] The scheme will cooperate the hydraulic device of the traditional mechanical control multi-way valve with the power down type balance valve, adjust the mechanical control multi-way reversing valve 1, increase the pressure reducing valve 2, and cooperate with the self-weight falling range balance valve 5. Among them, the mechanical control multi-way reversing valve rod 1-1 and the pressure reducing valve rod 2-1 are coaxially arranged, which can ensure that the mechanical control multi-way reversing valve rod 1-1 is in rigid contact with the pressure reducing valve rod 2-1 when switching to the falling range working position. In this way, the displacement of the pressure reducing valve rod 2-1 can be controlled by controlling the displacement of the mechanical control multi-way reversing valve rod 1-1. The displacement of the pressure reducing valve rod 2-1 is proportional to the pressure output (see Figure 6 ), and the pressure output of the pressure reducing valve 2 can be controlled by controlling the displacement of the mechanical control multi-way reversing valve rod 1-1, so as to realize effective and accurate control of the opening pressure of the self-weight falling range balance valve 5, overcome the problem of frequent opening and closing of the balance valve leading to the swing of the boom in the falling range working condition, and improve the stability of the boom control system.

[0042] In actual work, as shown in Figure 3 , the oil inlet of the pressure reducing valve 2 takes oil source through A3 port, outputs oil liquid, and leads to the P port of the self-weight falling range balance valve 5, which is used to open the self-weight falling range balance valve 5 in reverse when falling. When the mechanical control multi-way reversing valve 1 is switched to the lifting range working position, the oil liquid enters the A port of the self-weight falling range balance valve 5 through B3 port in turn, and finally enters the C port of the variable amplitude oil cylinder 4, i.e. the rodless chamber 4-2, through the B port of the self-weight falling range balance valve 5, so as to realize the lifting of the piston rod of the variable amplitude oil cylinder 4, i.e. the lifting. When the mechanical control multi-way reversing valve 1 is switched to the falling range working position, the oil liquid enters the rod chamber 4-1 of the variable amplitude oil cylinder 4 through A3 port and D port of the variable amplitude oil cylinder 4. The opening pressure of the self-weight falling range balance valve 5 is 9Bar~25Bar, i.e. only 30bar pressure is needed on the falling side to open the self-weight falling range balance valve 5 in reverse. However, the conventional power down type balance valve 3 needs an opening pressure of 4.5MPa~9MPa to open the power down type balance valve 3.

[0043] Therefore, the boom luffing hydraulic control module 100 of the technical solution innovatively uses the mechanical control type multi-way reversing valve and the pressure reducing valve in linkage to form a linkage pressure reducing module, wherein the mechanical control type multi-way reversing valve rod and the pressure reducing valve rod are in rigid contact, so that when the mechanical control type multi-way reversing valve rod displacement changes, a synchronous changing pressure reducing valve rod displacement is obtained, so that a controllable pressure reducing valve pressure output, that is, a controllable linkage pressure reducing module pressure output, can be obtained by controlling the mechanical control type multi-way reversing valve rod displacement. The boom luffing hydraulic control module 100 of the technical solution, by the cooperation of the mechanical control type multi-way reversing valve and the pressure reducing valve, not only solves the problem that the mechanical control type multi-way reversing valve cannot be used with the pressure reducing valve in the field of cranes, but also realizes effective and accurate control of the opening pressure of the self-weight falling type balance valve, overcomes the problem of boom shaking caused by frequent opening and closing of the balance valve in the luffing condition, and improves the stability of the boom control system.

[0044] Embodiment Two

[0045] The embodiment provides a boom luffing hydraulic control system, which comprises a luffing cylinder 4 and the boom luffing hydraulic control module 100 disclosed in Embodiment One, the oil outlet of the mechanical control type multi-way reversing valve 1 in the luffing working position is connected with the rod cavity 4-1 of the luffing cylinder 4, the oil outlet of the self-weight luffing balance valve 5 is connected with the rodless cavity 4-2 of the luffing cylinder 4, and the piston rod of the luffing cylinder 4 is connected with the crane boom.

[0046] The boom luffing hydraulic control system is suitable for small-tonnage cranes. When the boom luffing hydraulic control module 100 is used, the mechanical control type multi-way reversing valve rod 1-1 and the pressure reducing valve rod 2-1 in the boom luffing hydraulic control module 100 can be in rigid contact, so as to control the displacement of the pressure reducing valve rod 2-1 by controlling the displacement of the mechanical control type multi-way reversing valve rod 1-1. The displacement of the pressure reducing valve rod 2-1 is proportional to the pressure output (see Figure 6 ), so that the pressure output of the pressure reducing valve 2 can be controlled by controlling the displacement of the mechanical control type multi-way reversing valve rod 1-1, and effective and accurate control of the opening pressure of the self-weight falling type balance valve is realized, the problem of boom shaking caused by frequent opening and closing of the balance valve in the luffing condition is overcome, and the stability of the boom control system is improved.

[0047] Embodiment Three

[0048] This embodiment proposes a crane, including a boom luffing hydraulic control system as disclosed in Embodiment 2, which controls the luffing (lifting and lowering) of the boom in the crane. The mechanically operated multi-way directional valve stem 1-1 and the pressure reducing valve stem 2-1 in the boom luffing hydraulic control module 100 are in rigid contact. The displacement of the pressure reducing valve stem 2-1 can be controlled by controlling the displacement of the mechanically operated multi-way directional valve stem 1-1. The displacement of the pressure reducing valve stem 2-1 is proportional to the pressure output (see...). Figure 6 Furthermore, by controlling the displacement of the valve stem 1-1 of the mechanically operated multi-way directional valve, the pressure reducing valve 2 can obtain a controllable pressure output, thereby achieving effective and precise control of the opening pressure of the gravity-falling balance valve. This overcomes the problem of boom shaking caused by frequent opening and closing of the balance valve during the descent operation, thus improving the stability of the boom control system.

[0049] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0050] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A boom luffing hydraulic control module, characterized in that, The system includes a mechanically operated multi-way directional valve, a balance valve, and a pressure reducing valve. When the mechanically operated multi-way directional valve is in the lowering position, its outlet is connected to the rod chamber of the luffing cylinder. When the mechanically operated multi-way directional valve is in the raising position, its outlet is connected to the inlet of the balance valve. The outlet of the balance valve is connected to the rodless chamber of the luffing cylinder, and the piston rod of the luffing cylinder is connected to the crane boom. The inlet of the pressure reducing valve is connected to the outlet of the mechanically operated multi-way directional valve in the lowering position, and the outlet of the pressure reducing valve is connected to the control port of the balance valve, so as to open the balance valve when the crane boom needs to be lowered. When the valve stem of the mechanically operated multi-way directional valve switches from the raising position to the lowering position, it can drive the valve stem of the pressure reducing valve to move synchronously. Therefore, by controlling the displacement of the valve stem of the mechanically operated multi-way directional valve, the output pressure of the pressure reducing valve can be controlled.

2. The boom luffing hydraulic control module according to claim 1, characterized in that, The valve stem of the mechanically operated multi-way directional valve is coaxially arranged with the valve stem of the pressure reducing valve but not connected. When the valve stem of the mechanically operated multi-way directional valve switches from the starting working position to the ending working position, it can rigidly contact the valve stem of the pressure reducing valve and push the valve stem of the pressure reducing valve, so as to realize the synchronous movement of the valve stem of the mechanically operated multi-way directional valve and the valve stem of the pressure reducing valve.

3. The boom luffing hydraulic control module according to claim 1, characterized in that, The valve stem of the mechanically operated multi-way directional valve is rigidly connected to the valve stem of the pressure reducing valve, so that when the valve stem of the mechanically operated multi-way directional valve switches from the starting working position to the ending working position, the valve stem of the mechanically operated multi-way directional valve can move synchronously with the valve stem of the pressure reducing valve.

4. The boom luffing hydraulic control module according to any one of claims 1 to 3, characterized in that, The balancing valve is either a gravity-fed balancing valve or a power-driven balancing valve.

5. A boom luffing hydraulic control system, characterized in that, The system includes a luffing cylinder and a boom luffing hydraulic control module as described in any one of claims 1 to 3. When the mechanically operated multi-way directional valve is in the lowering working position, its oil outlet is connected to the rod chamber of the luffing cylinder. The oil outlet of the balance valve is connected to the rodless chamber of the luffing cylinder. The piston rod of the luffing cylinder is used to connect to the crane boom.

6. The boom luffing hydraulic control system according to claim 5, characterized in that, The balancing valve is a gravity-fed balancing valve.

7. The boom luffing hydraulic control system according to claim 5, characterized in that, The balance valve is a power-operated downward-release balance valve.

8. A crane, characterized in that, Includes the boom luffing hydraulic control system as described in any one of claims 5 to 7.

Images