Rotary cushion valve of automobile crane

Abstract

The invention discloses an automobile crane rotary cushion valve. The problem that an existing rotary cushion valve is single in function is solved. The valve comprises a valve body, the valve body is provided with a main oil inlet, an oil return port, a first working oil port and a second working oil port, and the valve further comprises a main valve rod, a second valve rod, a first oil return port, a second oil return port and a third oil return port, and the main valve rod receives pressure oil at the main oil inlet and controls the flow direction of the pressure oil at the main oil inlet through reversing; the unloading valve rod is arranged in the valve body, an oil inlet of the unloading valve rod is connected with the first working oil port or the second working oil port, an oil outlet of the unloading valve rod is connected with the oil return port, and the unloading valve rod enables the first working oil port or the second working oil port to be connected with the oil return port through reversing; pressure oil of the oil outlet of the main valve rod is connected with the oil return opening through the three-way pressure compensator. The invention also has the advantages of simple structure, convenience in assembly, reliable action, long service life and the like.

Description

Technical Field

[0001] The invention relates to a crane control multi-channel, in particular to a slewing buffer valve for a truck crane. Background Art

[0002] A crane is a multi-action lifting machine capable of vertically lifting and horizontally transporting heavy objects within a certain range. It is also known as an overhead crane, overhead crane, or crane. A truck crane is a type of crane mounted on a standard or custom automobile chassis, with the driving cab and lifting control room separated. This type of crane offers advantages such as high maneuverability and rapid transfer.

[0003] The slewing buffer valve on a truck crane generates significant inertial and impact forces when the crane's slewing mechanism starts, brakes, or suddenly changes direction. A slewing buffer valve absorbs and mitigates these forces, reducing wear and impact on slewing mechanism components (such as the slewing bearing, gears, and bearings), extending the equipment's service life and lowering maintenance costs. However, existing slewing buffer valves are typically only compatible with open-center or load-sensing systems. Traditional open-center valves require a larger pilot signal to operate the load when the load is heavy, and a smaller pilot signal to operate the load when the load is light. This can even cause the flow rate to exceed the load's required output pressure at the minimum handle output, leading to a higher minimum speed. Existing load-sensing systems typically lack a return diverter valve, and the slewing buffer valve structure cannot achieve low-pressure unloading. The slewing buffer valve's buffering function ends when the main valve stem closes, and it lacks a time-delayed buffering function. Summary of the Invention

[0004] In order to solve the problem of single function of the existing rotary buffer valve in the background technology, the present invention provides a rotary buffer valve for a truck crane.

[0005] The technical solution of the present invention is: a rotary buffer valve for a truck crane, comprising a valve body, wherein the valve body is provided with a main oil inlet, an oil return port, a first working oil port and a second working oil port, and further comprising: A main valve stem is disposed within the valve body and slidably engages with the valve body; the main valve stem has a first position connecting the main oil inlet to the first working oil port, a second position at a neutral position, and a third position connecting the main oil inlet to the second working oil port; the main valve stem receives pressure oil at the main oil inlet and controls the flow direction of the pressure oil at the main oil inlet by reversing. The pilot oil port is connected to the main valve stem control chamber to drive the main valve stem to change direction; A first oil channel is used to connect the main valve stem oil outlet and the first working oil port; The second oil channel is used to connect the main valve stem oil outlet and the second working oil port; An unloading valve stem is provided in the valve body, wherein the oil inlet of the unloading valve stem is connected to the first working oil port or the second working oil port, and the oil outlet of the unloading valve stem is connected to the oil return port. The unloading valve stem is connected to the first working oil port or the second working oil port and the oil return port by reversing. Three-way pressure compensator, the pressure oil at the main valve stem oil outlet is connected to the oil return port through the three-way pressure compensator, and after the main valve stem is reversed, the pressure oil at the main valve stem oil outlet enters the control chamber of the three-way pressure compensator and is used to close the three-way pressure compensator.

[0006] As a further improvement of the present invention, the pilot oil of the pilot oil port is connected to both ends of the unloading valve stem through the third oil channel and the fourth oil channel respectively and is used to drive the unloading valve stem and the main valve stem to move synchronously.

[0007] As a further improvement of the present invention, the third oil channel and the fourth oil channel are both provided with a first one-way valve and a throttle valve, and the first one-way valve and the throttle valve are arranged in parallel; the pilot oil of the pilot oil port is connected to the two ends of the unloading valve stem through the first one-way valve to drive the unloading valve stem and the main valve stem to move synchronously; the pilot oil at both ends of the unloading valve stem returns oil through the throttle valve, so that the unloading valve stem is delayed in resetting to realize the delayed buffering function.

[0008] As a further improvement of the present invention, it also includes a fifth oil channel connected to the first oil channel and a sixth oil channel connected to the second oil channel. The fifth oil channel and the sixth oil channel are respectively connected to the two ends of the unloading valve stem for driving the unloading valve stem to reverse so that the opening and closing characteristics of the unloading valve stem are affected by the load.

[0009] As a further improvement of the present invention, it also includes a shuttle valve and a seventh oil channel, the seventh oil channel is provided with a first back pressure valve, the first back pressure valve selects the pressure oil of the first working oil port or the second working oil port through the shuttle valve and is connected to the return oil port.

[0010] As a further improvement of the present invention, it also includes a damping hole, which is arranged between the first back pressure valve and the shuttle valve and allows the pressure oil of the first working oil port or the second working oil port to pass through the shuttle valve and the damping hole to open the first back pressure valve after the main valve stem is reset.

[0011] As a further improvement of the present invention, it also includes a shuttle valve and a first reversing valve. The shuttle valve selects the pressure oil of the first working oil port or the second working oil port and is connected to the first reversing valve. The oil outlet of the first reversing valve is connected to the return oil port through the second back pressure valve.

[0012] As a further improvement of the present invention, it also includes a third back pressure valve, the first reversing valve is connected to the oil return port through the second back pressure valve and / or the third back pressure valve, and the opening pressure of the second back pressure valve is greater than the opening pressure of the third back pressure valve.

[0013] As a further improvement of the present invention, it also includes a shuttle valve and a second reversing valve, wherein the second reversing valve has a first position of cut-off and a second position in which the pressure oil of the first working oil port or the second working oil port is selected through the shuttle valve after reversing and connected to the return oil port.

[0014] As a further improvement of the present invention, the three-way pressure compensator is detachably connected to the valve body.

[0015] The present invention has the beneficial effect of providing a three-way pressure compensator, ensuring that the output flow rate is controlled solely by the pilot signal, regardless of load, regardless of load. The addition of a relief valve stem allows the first or second working oil port to be unloaded via the relief valve stem, thereby reducing vibration and shock generated during the crane's slewing process, minimizing the bumps and discomfort experienced by the operator in the cab, improving operational stability, and protecting the operator. The present invention also has the advantages of a simple structure, easy assembly, reliable operation, and a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attachment Figure 1 Schematic diagram of the structure of an embodiment of the present invention.

[0017] Attachment Figure 2 It is a schematic diagram of a partial cross-sectional structure of an embodiment of the present invention.

[0018] Attachment Figure 3 Schematic diagram of the cross-sectional structure of an embodiment of the present invention.

[0019] Attachment Figure 4 This is a schematic diagram of the hydraulic principle of embodiment 1 of the present invention.

[0020] Attachment Figure 5 This is a schematic diagram of the hydraulic principle of the second embodiment of the present invention.

[0021] In the figure, 1. valve body; 11. first oil channel; 12. second oil channel; 13. third oil channel; 14. fourth oil channel; 15. first check valve; 16. throttle valve; 17. fifth oil channel; 18. sixth oil channel; 19. seventh oil channel; 191. first back-pressure valve; 192. damping hole; 2. main valve stem; 3. pilot oil port; 4. unloading valve stem; 5. three-way pressure compensator; 6. shuttle valve; 71. first reversing valve; 72. second back-pressure valve; 73. third back-pressure valve; 8. second reversing valve; P, main oil inlet; T, oil return port; A, first working oil port; B, second working oil port. DETAILED DESCRIPTION

[0022] The embodiments of the present invention will be further described below with reference to the accompanying drawings: Depend on Figure 1 Combine Figure 2-5As shown, a slewing buffer valve for a truck crane includes a valve body 1, on which a main oil inlet P, an oil return port T, a first working oil port A, and a second working oil port B are provided, and further includes: The main valve stem 2 is disposed in the valve body 1 and is slidably engaged with the valve body 1. The main valve stem 2 has a first position that connects the main oil inlet P with the first working oil port A, a second position that is a neutral position, and a third position that connects the main oil inlet P with the second working oil port B. The main valve stem 2 receives the pressure oil at the main oil inlet and controls the flow direction of the pressure oil at the main oil inlet P by reversing. The pilot oil port 3 is connected to the control chamber of the main valve stem 2 and is used to drive the main valve stem 2 to change direction; The first oil channel 11 is used to connect the oil outlet of the main valve stem 2 and the first working oil port A; The second oil passage 12 is used to connect the oil outlet of the main valve stem 2 and the second working oil port B; The unloading valve stem 4 is provided in the valve body 1. The oil inlet of the unloading valve stem 4 is connected to the first working oil port A or the second working oil port B, and the oil outlet of the unloading valve stem 4 is connected to the oil return port T. The unloading valve stem 4 is connected to the first working oil port A or the second working oil port B and the oil return port T by reversing. The three-way pressure compensator 5, the pressure oil at the oil outlet of the main valve stem 2 is connected to the return oil port T through the three-way pressure compensator 5. After the main valve stem 2 is switched, the pressure oil at the oil outlet of the main valve stem 2 enters the control chamber of the three-way pressure compensator 5 and is used to close the three-way pressure compensator 5. The beneficial effect of the present invention is that the provision of a three-way pressure compensator can ensure that the output flow is only controlled by the pilot signal regardless of the load, and is independent of the load. The addition of an unloading valve stem allows the first working oil port or the second working oil port to be unloaded through the unloading valve stem, thereby reducing the vibration and impact generated by the crane during the rotation process, reducing the bumps and discomfort experienced by the operator in the cab, improving operational stability, and at the same time protecting the operator. The present invention also has the advantages of simple structure, easy assembly, reliable operation, and long service life. The provision of the unloading valve stem of the present invention improves operational stability while protecting the operator. Specifically, the present invention can make the crane's slewing motion smoother, avoiding load shaking or even loss of control caused by sudden starting or braking, thereby improving the crane's safety and stability during operation and facilitating operators to more accurately control the position of the load. This is especially true when performing high-precision lifting operations, such as installing equipment in a confined space or in situations where high lifting position requirements are required. The slewing buffer function can effectively reduce the swing of the load, thereby improving operational efficiency and quality. The present invention reduces vibration and impact generated during the crane's slewing process, reduces the bumps and discomfort experienced by operators in the cab, improves the operating environment, reduces operator fatigue, helps operators maintain a good working state, and reduces safety accidents caused by fatigue or operational inconvenience.

[0023] The pilot oil from the pilot oil port 3 is connected to both ends of the unloading valve stem 4 via the third and fourth oil passages 13, 14, respectively, and is used to drive the unloading valve stem 4 to operate synchronously with the main valve stem 2. Specifically, the third and fourth oil passages 13, 14 are each provided with a first one-way valve 15 and a throttle valve 16, which are arranged in parallel. The pilot oil from the pilot oil port 3 is connected to both ends of the unloading valve stem 4 via the first one-way valve 15, and is used to drive the unloading valve stem 4 to operate synchronously with the main valve stem 2. The pilot oil from both ends of the unloading valve stem 4 is returned through the throttle valve 16, causing the unloading valve stem 4 to reset after a delay, thus achieving a delayed buffering function.

[0024] The unloading valve stem and the main valve stem share a common pilot control oil source. The pilot control oil of the pilot oil port is equipped with a first one-way valve and a throttle valve on the unloading valve stem control oil circuit (the third oil channel 13 and the fourth oil channel 14). The oil enters the unloading valve stem control chamber through the one-way throttle valve (the first one-way valve and the throttle valve), thereby realizing the response synchronization of the unloading valve stem and the main valve stem during reversing. When the handle returns to its position, the return oil in the control chamber of the unloading valve stem realizes the throttling effect through the throttle valve (damping), delaying the resetting of the unloading valve stem and making it lag behind the main valve stem. In this way, after the main valve stem is fully closed, the independent unloading valve stem is delayed in closing, and the independent return oil valve stem (unloading valve stem) is now connected to the return oil T port, which also realizes the function of delayed buffering.

[0025] The present invention also includes a fifth oil passage 17 connected to the first oil passage 11 and a sixth oil passage 18 connected to the second oil passage 12. The fifth oil passage 17 and the sixth oil passage 18 are respectively connected to the two ends of the unloading valve stem 4 to drive the unloading valve stem 4 to switch direction so that the opening and closing characteristics of the unloading valve stem 4 are affected by the load. The pilot control chamber of the unloading valve stem is designed with an oil intake channel from the A / B load port. When the one-way throttle valve on the pilot control oil circuit is blocked (see the attached embodiment for the second embodiment), the unloading valve stem 4 is opened and closed. Figure 5 ), and simultaneously opening the A / B load port oil intake channels, the pilot control of the independent oil return valve spool can be changed to load control of ports A and B. The opening and closing characteristics of the unloading valve stem are now affected by the load. Rotary loads are typical alternating loads, and the pressure during the initial startup phase also exhibits a typical sine wave state. At this time, the movement of the independent oil return valve spool is closely linked to the load, enabling load-dependent output of the oil return. The time lag characteristic is controlled by the frequency response of each component, which also makes the movement smoother.

[0026] The present invention also includes a shuttle valve 6 and a seventh oil passage 19. The seventh oil passage 19 is equipped with a first back-pressure valve 191. This first back-pressure valve 191 selects the pressure oil from the first working oil port A or the second working oil port B through the shuttle valve 6 and connects to the oil return port T. Specifically, the present invention also includes a damping orifice 192, located between the first back-pressure valve 191 and the shuttle valve 6. Upon the return of the main valve stem 2, the pressure oil from the first working oil port A or the second working oil port B passes through the shuttle valve 6 and the damping orifice 192, opening the first back-pressure valve 191. The present invention provides a BY1 oil passage (the seventh oil passage). Upon the return of the main valve stem, the first back-pressure valve is opened at the A / B working ports via the shuttle valve and the damping orifice, achieving a rigid stop for slewing. This method can be used to achieve a rigid stop when a quick slewing stop is sometimes required to improve speed and efficiency under low or no-load conditions.

[0027] The present invention also includes a shuttle valve 6 and a first reversing valve 71. The shuttle valve 6 selects the pressure oil from the first working oil port A or the second working oil port B and is connected to the first reversing valve 71. The oil outlet of the first reversing valve 71 is connected to the oil return port T via a second back-pressure valve 72. Specifically, the present invention also includes a third back-pressure valve 73. The first reversing valve 71 is connected to the oil return port T via the second back-pressure valve 72 and / or the third back-pressure valve 73. The opening pressure of the second back-pressure valve 72 is greater than the opening pressure of the third back-pressure valve 73. The present invention provides an oil circuit consisting of a solenoid valve DC1 (first reversing valve) and second and third back-pressure valves. Depending on the buffering requirements, the solenoid valve DC1 can be energized to achieve limited buffering. Limited buffering and delayed buffering can be used in combination, which is also a common application. Specifically, the opening pressure of the first back pressure valve is greater than the opening pressure of the second back pressure valve, which is greater than the opening pressure of the third back pressure valve. That is, as long as the first reversing valve is reversed, oil is returned from the second back pressure valve and the third back pressure valve first, and the unloading valve stem can also be used to return oil.

[0028] The present invention also includes a shuttle valve 6 and a second reversing valve 8. The second reversing valve 8 has a first position of shutoff and a second position in which, after reversing, the shuttle valve 6 selects the pressure oil from either the first working oil port A or the second working oil port B and connects to the oil return port T. A solenoid valve DC2 (second reversing valve) is provided. When solenoid valve DC2 is energized, free sliding is achieved without back pressure. This mode allows the crane to switch to when the boom is subjected to lateral forces, energizing the second reversing valve and enabling free sliding. Under the influence of lateral forces, the crane boom rotates to the appropriate position to maintain the load vertically, improving safety. Specifically, the present invention provides delayed buffering through the unloading valve stem. The unloading valve stem can be controlled by pilot oil from the same pilot port as the main valve stem, or by control oil from the load ports (the first and second working oil ports). Furthermore, the buffer valve of the present invention offers functions such as rigid stop, limited buffering, and free sliding, and these functions can be used in combination.

[0029] The three-way pressure compensator 5 is detachably connected to the valve body 1. The present invention can detachably connect the three-way pressure compensator 5 to the valve body 1, so that the product can adapt to open center and load sensitive systems. That is, the present invention has a wide range of adaptability, reduces the number of open molds, and reduces costs. The three-way pressure compensator can ensure that the output flow is only controlled by the pilot signal and is independent of the load under any load. In the description of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or they can refer to internal connections between two components. A person of ordinary skill in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0031] Technical personnel should note: Although the present invention has been described according to the above specific implementation methods, the inventive concept of the present invention is not limited to this invention. Any modification using the inventive concept will be included in the scope of protection of the patent right of the present invention.

Claims

1. A slewing buffer valve for a truck crane, comprising a valve body (1), wherein the valve body (1) is provided with a main oil inlet (P), an oil return port (T), a first working oil port (A) and a second working oil port (B), and wherein: Also includes: A main valve stem (2) is disposed in the valve body (1) and is slidably engaged with the valve body (1); the main valve stem (2) has a first position for connecting the main oil inlet (P) with the first working oil port (A), a second position of a neutral position, and a third position for connecting the main oil inlet (P) with the second working oil port (B); the main valve stem (2) receives the pressure oil at the main oil inlet and controls the flow direction of the pressure oil at the main oil inlet (P) by reversing. The pilot oil port (3) is connected to the control chamber of the main valve stem (2) and is used to drive the main valve stem (2) to change direction; A first oil passage (11) is used to connect the oil outlet of the main valve stem (2) and the first working oil port (A); A second oil passage (12) is used to connect the oil outlet of the main valve stem (2) and the second working oil port (B); An unloading valve stem (4) is provided in the valve body (1), wherein the oil inlet of the unloading valve stem (4) is connected to the first working oil port (A) or the second working oil port (B), and the oil outlet of the unloading valve stem (4) is connected to the return oil port (T). The unloading valve stem (4) is connected to the first working oil port (A) or the second working oil port (B) and the return oil port (T) by reversing. A three-way pressure compensator (5) is provided, wherein the pressure oil at the oil outlet of the main valve stem (2) is connected to the oil return port (T) through the three-way pressure compensator (5), and after the main valve stem (2) is switched, the pressure oil at the oil outlet of the main valve stem (2) enters the control chamber of the three-way pressure compensator (5) and is used to close the three-way pressure compensator (5).

2. The rotary buffer valve of a truck crane according to claim 1, characterized in that The pilot oil of the pilot oil port (3) is connected to both ends of the unloading valve stem (4) through the third oil passage (13) and the fourth oil passage (14) respectively and is used to drive the unloading valve stem (4) and the main valve stem (2) to move synchronously.

3. The rotary buffer valve of a truck crane according to claim 2, characterized in that The third oil passage (13) and the fourth oil passage (14) are both provided with a first one-way valve (15) and a throttle valve (16), and the first one-way valve (15) and the throttle valve (16) are arranged in parallel; the pilot oil of the pilot oil port (3) is connected to the two ends of the unloading valve stem (4) through the first one-way valve (15) to drive the unloading valve stem (4) and the main valve stem (2) to move synchronously; the pilot oil at the two ends of the unloading valve stem (4) is returned through the throttle valve (16) so that the unloading valve stem (4) is delayed in resetting to realize a delayed buffering function.

4. The rotary buffer valve of a truck crane according to claim 1, characterized in that The invention also includes a fifth oil passage (17) connected to the first oil passage (11) and a sixth oil passage (18) connected to the second oil passage (12). The fifth oil passage (17) and the sixth oil passage (18) are respectively connected to the two ends of the unloading valve stem (4) for driving the unloading valve stem (4) to switch direction so that the opening and closing characteristics of the unloading valve stem (4) are affected by the load.

5. The rotary buffer valve of a truck crane according to claim 1, characterized in that It also includes a shuttle valve (6) and a seventh oil passage (19). The seventh oil passage (19) is provided with a first back pressure valve (191). The first back pressure valve (191) selects the pressure oil of the first working oil port (A) or the second working oil port (B) through the shuttle valve (6) and is connected to the return oil port (T).

6. The rotary buffer valve of a truck crane according to claim 5, characterized in that The invention also includes a damping hole (192), which is arranged between the first back pressure valve (191) and the shuttle valve (6) and allows the pressure oil of the first working oil port (A) or the second working oil port (B) to pass through the shuttle valve (6) and the damping hole (192) to open the first back pressure valve (191) after the main valve stem (2) is reset.

7. The rotary buffer valve of a truck crane according to claim 1, characterized in that It also includes a shuttle valve (6) and a first reversing valve (71). The shuttle valve (6) selects the pressure oil of the first working oil port (A) or the second working oil port (B) and is connected to the first reversing valve (71). The oil outlet of the first reversing valve (71) is connected to the return oil port (T) through the second back pressure valve (72).

8. The rotary buffer valve of a truck crane according to claim 7, characterized in that The invention also includes a third back-pressure valve (73), wherein the first reversing valve (71) is connected to the oil return port (T) via the second back-pressure valve (72) and / or the third back-pressure valve (73), and the opening pressure of the second back-pressure valve (72) is greater than the opening pressure of the third back-pressure valve (73).

9. The rotary buffer valve of a truck crane according to claim 1, characterized in that The shuttle valve (6) and the second reversing valve (8) are further included. The second reversing valve (8) has a first position in which the valve is cut off and a second position in which the pressure oil of the first working oil port (A) or the second working oil port (B) is selected through the shuttle valve (6) after reversing and connected to the return oil port (T).

10. The rotary buffer valve of a truck crane according to claim 1, characterized in that The three-way pressure compensator (5) is detachably connected to the valve body (1).

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