CN108569640A - Lift crotch and the inflight meal vehicle with the lifting crotch - Google Patents

Abstract

The invention discloses a lifting fork frame and an aviation food truck with the lifting fork frame. A proportional reversing valve is arranged on the main road of the hydraulic system of the lifting fork frame, and a controller is connected to the proportional reversing valve to control the input The current value of the current of the proportional solenoid of the proportional directional valve. Among them, the controller gives the corresponding current value to the proportional electromagnet according to multiple height intervals in the stroke of the lifting fork, so as to control the hydraulic flow supplied to the hydraulic system, and then control the lifting or lowering of the lift car by the lifting fork speed. The present invention realizes the controller's control of the lifting speed according to different heights by adopting the design of the controller to adjust the current of the proportional electromagnet of the proportional throttle valve. The invention can make the speed transition smoothly during the moving process of the carriage, avoid damage to the goods in the carriage, and improve the comfort of the staff in the carriage.

Description

Lifting fork frame and aviation food truck with the lifting fork frame

technical field

The invention relates to the technical field of special lifting equipment for vehicles, in particular, to a lifting fork frame and an aviation food truck with the lifting fork frame.

Background technique

Aviation food trucks are special vehicles for airports, which are specially used for catering for passenger aircraft. Due to the wide variety of passenger aircraft, aviation food carts used for catering are generally divided into ordinary aviation food carts suitable for ordinary passenger aircraft and A380 aviation food carts suitable for large passenger aircraft such as A380 aircraft. The maximum lifting height of the ordinary aviation food truck is 6.2m, and the cabin is connected to the cabin door through the four-way platform to prepare meals for the aircraft. The height of the aircraft cabin door that this type of food truck can serve is generally below 6.2m. The maximum lifting height of the A380 aviation food truck body reaches 8.1m, and its lifting height exceeds 6.2m when serving meals for the A380 aircraft.

During the initial height of the descent process, due to the change of the load and the fixed value of the back pressure of the hydraulic circuit, the cabin shakes and moves at a non-uniform speed during the initial period of descent from the highest position. The solution in this area for the problems referred to above is to adopt a switch type electromagnetic reversing valve with a diameter of 10 to control the lifting of the compartment. Based on this existing design, the ascent speed of the carriage is determined by the engine speed after the throttle is increased, and it is basically not adjustable. When descending, use oil return throttling speed regulation or two-speed throttling speed regulation, and only one or two kinds of descending can be set. Speed, it is more difficult to solve the vibration problem in the lowering of the cabinet.

Furthermore, when the A380 aviation food truck is serving meals for the A380 aircraft, the height of the floor of the car from the ground reaches 8.1m, and the whole car is moved forward by 3m. At this time, the center of gravity of the whole car changes significantly, and the stability of the whole car is a problem that must be considered. During the catering process, the overall weight of the aircraft changes significantly, and the height of the cabin door from the ground drops significantly. The height of the four-way platform of the food truck docked with the cabin door also needs to be lowered accordingly, so as to ensure the seamless connection between the four-way platform and the cabin door . At the same time, due to the manufacturing and assembly precision of the fork frame and the leakage of the hydraulic lock of the lifting cylinder of the control fork frame, the lifting fork frame of the A380 aviation food truck will automatically sink slowly when it stops at a certain height. When the fork frame stops at a height of 6.1m , the sinking amount in the height direction reaches 30mm/h, and the automatic lowering of the fork frame is a common problem in the hydraulic system of food trucks at present.

Contents of the invention

A main object of the present invention is to overcome at least one defect of the above-mentioned prior art, and provide a lifting fork that can provide more than three kinds of lowering speeds.

Another main purpose of the present invention is to overcome at least one defect of the above-mentioned prior art, and provide an aviation food truck having the above-mentioned lifting fork and being suitable for large aircraft such as A380.

To achieve the above object, the present invention adopts the following technical solutions:

According to one aspect of the present invention, a lifting fork frame is provided, which is arranged between the frame and the compartment of a truck. The lifting fork includes a fork assembly, a hydraulic system for driving the fork assembly up and down, and a controller for controlling the hydraulic system. Wherein, a proportional reversing valve is provided on the main road of the hydraulic system, and the controller is connected to the proportional reversing valve to control the current value of the current input to the proportional electromagnet of the proportional reversing valve. Wherein, the controller provides a current of a corresponding current value to the proportional electromagnet according to a plurality of height intervals in the stroke of the lifting fork, thereby controlling the hydraulic flow supplied to the hydraulic system, and further controlling the Lifting fork lifts the speed of ascent or descent of the carriage.

According to one embodiment of the present invention, the multiple height intervals in the stroke of the lifting fork include at least a high interval, a stable interval and a low interval from high to low. Wherein, when the lifting fork is in the high range, the stable range and the low range, the current values of the current given by the controller to the proportional electromagnet are respectively the first current value, the second current value and the first current value. Three current values, the third current value is greater than the first current value and smaller than the second current value.

According to one embodiment of the present invention, the lifting assembly includes a double-stage lifting hydraulic cylinder, and the multiple height intervals in the stroke of the lifting fork also include the stage change when the primary cylinder and the secondary cylinder are staged interval. Wherein, when the lifting fork is in the stage changing interval, the current value of the current supplied by the controller to the proportional electromagnet is the first current value.

According to one embodiment of the present invention, the level change interval is between the high interval and the stable interval. Alternatively, the level change interval is between the stable interval and the low interval. Alternatively, the level-changing interval is included in the stable interval, the stable interval includes a first stable interval and a second stable interval, and the height of the level-changing interval is smaller than the first stable interval and greater than the The second stable interval.

According to one embodiment of the present invention, the lifting fork rises and stops at a certain height, and when the lifting fork automatically descends, the controller controls the hydraulic system to drive the lifting fork back to the original height , and the current value of the current given by the controller to the proportional electromagnet during the recovery process is the first current value.

According to one embodiment of the present invention, the controller is a PLC controller.

According to one embodiment of the present invention, a rotary angle encoder is provided on the rotating shaft of the lifting fork to detect the rotation angle of the fork of the lifting fork. Wherein, the controller is connected to the rotary angle encoder, so as to calculate the height range where the lifting fork is located according to the angle.

According to another aspect of the present invention, an airline food cart is provided, including a frame and a compartment. Wherein, the aviation food cart further includes the lifting fork frame described in the above embodiment.

According to one of the embodiments of the present invention, the aviation food cart also includes a four-way platform, the four-way platform is arranged at the end of the carriage close to the aircraft door, and a detection switch is provided on the four-way platform; wherein , the controller is connected to the detection switch, and a rotary encoder is used to detect the fork angle of the lifting fork when the lifting fork is raised and lowered, and the height position of the carriage is calculated by the controller When the carriage is raised and docked with an aircraft and the aircraft descends relative to the carriage to the height of the detection switch, the detection switch is triggered, the controller controls the lifting fork to descend, and the The current value of the current given by the controller to the proportional electromagnet is the first current value.

According to one embodiment of the present invention, the plurality of height intervals in the stroke of the lifting fork include the high level interval, the first stable interval, the level change interval, the second stable interval and the When the above low range, and the current value of the current given by the controller to the proportional electromagnet is the first current value, the second current value and the third current value, the high range is between 6.8m and 8.1 m, the first stable interval is between 5.5m and 6.8m, the transition interval is between 5.3m and 5.5m, the second stable interval is between 3.4m and 5.3m, and the low interval is between 3.4 m or less; and/or, the first current value is between 0.2A-0.4A, the second current value is between 0.9A-1A, and the third current value is between 0.5A-0.6A.

As can be seen from the above technical solutions, the advantages and positive effects of the lifting fork frame proposed by the present invention and the aviation food truck with the lifting fork frame are:

The lifting fork frame and the aviation food truck proposed by the present invention realize the control of the lifting speed by the controller according to different heights by adopting the design of the controller to adjust the current of the proportional electromagnet of the proportional throttle valve. Through the above design, the present invention can make the speed transition smoothly during the movement of the carriage, avoid damage to the goods in the carriage, and improve the comfort of the staff in the carriage. Moreover, the present invention can flexibly adjust the moving speed of the fork to address problems such as shaking and uneven speed during the movement of the lifting fork.

Description of drawings

Various objects, features and advantages of the present invention will become more apparent by considering the following detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The drawings are merely exemplary illustrations of the invention and are not necessarily drawn to scale. In the drawings, the same reference numerals designate the same or similar parts throughout. in:

Fig. 1 is a schematic structural view of a lifting fork according to an exemplary embodiment;

Fig. 2 is the bottom view of lifting fork shown in Fig. 1;

Fig. 3 is a schematic diagram of the hydraulic system of the lifting fork shown in Fig. 1;

Fig. 4 is a control schematic diagram of the lifting fork shown in Fig. 1 .

Wherein, the reference signs are explained as follows:

100. Lifting fork;

111. Left front outrigger;

112. Left rear outrigger;

120. Shaft;

130. Rotary angle encoder;

140. Two-stage lift hydraulic cylinder;

141. Primary cylinder;

142. Secondary cylinder;

210. System main road;

211. Proportional reversing valve;

212. Main lift cylinder;

220. Horizontal expansion branch;

221. Horizontal telescopic oil cylinder for left front outrigger;

222. Horizontal telescopic oil cylinder for the left rear outrigger;

223. Horizontal telescopic oil cylinder for the right front outrigger;

224. Horizontal telescopic oil cylinder for the right rear outrigger;

230. Lifting branch;

231. Left front outrigger lift cylinder;

232. Left rear outrigger lift cylinder;

233. Right front outrigger lift cylinder;

234. Right rear outrigger lift cylinder;

240. Chassis hydraulic power unit.

Detailed ways

Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and that the description and drawings therein are illustrative in nature and not intended to limit the present invention. invention.

In the following description of various exemplary embodiments of the invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of example different exemplary structures, systems, and embodiments in which aspects of the invention may be implemented and steps. It is to be understood that other specific arrangements of components, structures, exemplary means, systems and steps may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Moreover, although the terms "upper," "lower," "between," "side," etc. may be used in this specification to describe various exemplary features and elements of the invention, these terms are used herein only for Convenience, for example, according to the directions of the examples described in the attached drawings. Nothing in this specification should be construed as requiring a particular three-dimensional orientation of structures in order to fall within the scope of this invention.

Lifting fork implementation

Referring to Fig. 1, Fig. 1 representatively shows a structural schematic diagram of a lifting fork that can embody the principle of the present invention. In this exemplary embodiment, the elevating fork proposed by the present invention is described by taking an elevating fork suitable for an aviation food truck as an example. Those skilled in the art can easily understand that in order to apply the lifting fork to other types of vehicles or other types of equipment, various modifications, additions, substitutions, deletions or other modifications are made to the following specific embodiments variations, which are still within the scope of the principles of the lifting fork proposed by the present invention.

As shown in FIG. 1 , in this embodiment, the lifting fork frame 100 proposed by the present invention can be arranged between the frame and the compartment of the truck, so as to realize the lifting of the compartment relative to the frame. Specifically, the lifting fork frame 100 mainly includes a fork frame assembly, a hydraulic system for driving the fork frame assembly up and down, and a controller for controlling the hydraulic system. With reference to Fig. 2 to Fig. 4, Fig. 2 representatively shows a bottom view of a lifting fork frame 100 capable of embodying the principle of the present invention; Fig. 3 representatively shows a lifting fork frame 100 capable of embodying the principle of the present invention A schematic diagram of the hydraulic system; FIG. 4 representatively shows a control schematic diagram of the lifting fork 100 that can embody the principle of the present invention. The structure, connection mode and functional relationship of each main component of the lifting fork frame 100 proposed by the present invention will be described in detail below in conjunction with the above-mentioned drawings.

As shown in FIGS. 1 and 2 , in this embodiment, the fork assembly can refer to related designs of existing lifting forks. Specifically, the fork frame assembly mainly includes front outriggers and rear outriggers arranged crosswise, and the middle parts of the front outriggers and the rear outriggers are rotatably connected. The front outriggers include a left front outrigger 111 and a right front outrigger arranged in parallel, and the rear outriggers include a left rear outrigger 112 and a right rear outrigger arranged in parallel. Wherein, with reference to the existing design of lifting fork frame 100 on vehicles such as aviation food carts, one end of the left front support leg 111 and the right front support leg is rotatably connected to the front end of the vehicle frame of the aviation food cart through a rotating shaft, and the left front support leg 111 and the front end of the right front support leg The other end of the right front supporting leg is rotatably and slidably connected to the bottom of the compartment of the airline food truck. One end of the left rear support leg 112 and the right rear support leg is rotatable and slidably connected to the vehicle frame of the aviation food cart, and the other end of the left rear support leg 112 and the right rear support leg is rotatable and slidably connected to the bottom of the compartment Front end. A main lift cylinder 212 is arranged between the front outrigger and the rear outrigger. The cylinder body of the main lift cylinder 212 is rotatably connected to the lower half of the front outrigger, and the cylinder rod is rotatably connected to the upper part of the rear outrigger. half. In other embodiments, the fork frame assembly can also refer to other structural designs of the existing lifting fork frame, and is not limited to this embodiment.

As shown in FIG. 3 , in this embodiment, most of the structure of the hydraulic system can refer to the relevant system design of the hydraulic system of the existing lifting fork. Specifically, the hydraulic system uses the chassis hydraulic power unit 240 installed on the frame of the aviation food truck to provide power, and supplies oil to each oil cylinder through the system main road 210 and each system branch to control the working state of each oil cylinder. Wherein, the main system road 210 and each system branch are connected in parallel, and the system branch mainly includes a transverse expansion branch 220 and a lifting branch 230 . The system main road 210 is used to supply oil to the main lift cylinder 212, and the lateral telescopic branch circuit 220 is used to supply oil to the left front outrigger horizontally telescopic oil cylinder 221, the left rear outrigger horizontally telescopic oil cylinder 222, the right front outrigger horizontally telescopic oil cylinder 223 and the right rear Outrigger horizontal telescopic oil cylinder 224 supplies oil, and lifting branch 230 is used for lifting oil cylinder 231 to left front outrigger, left rear outrigger lifting oil cylinder 232, right front outrigger lifting oil cylinder 233 and right rear outrigger lifting oil cylinder 234 Fuel. In other embodiments, the above-mentioned structure of the hydraulic system can also refer to other system designs of the hydraulic system of the existing lifting fork, and is not limited to this embodiment.

As shown in Figure 3, in this embodiment, a proportional reversing valve 211 is provided on the system trunk 210, and the controller is connected to the proportional reversing valve 211 to control the current input to the proportional solenoid of the proportional reversing valve 211. current value. Specifically, the controller can provide a current with a corresponding current value to the proportional electromagnet according to multiple height intervals in the stroke of the lifting fork frame 100, thereby controlling the hydraulic pressure supplied to each cylinder (such as the main lifting cylinder 212) of the hydraulic system. flow, and then control the lifting or lowering speed of the lifting fork frame 100 lifting the carriage.

Further, in this embodiment, the multiple height intervals in the stroke of the lifting fork 100 may at least include a high interval, a stable interval and a low interval from high to low. Specifically, the high range is the initial height range where shaking is likely to occur when the carriage rises to a high position and is ready to descend, the stable range is the height range when the carriage descends steadily, and the low range is the height range when the carriage descends to a low position. Wherein, when the lifting fork frame 100 is in the high range, the stable range and the low range, the current values of the currents given by the controller to the proportional electromagnet are respectively the first current value, the second current value and the third current value, and, the first The third current value is greater than the first current value and smaller than the second current value.

Through the above-mentioned design, when the lifting fork frame 100 lifts the car up to a high position and is ready to descend, it is easy to shake in the high position range. At this time, the current that the controller provides to the proportional electromagnet of the proportional reversing valve 211 is a relatively small first current value, thereby controlling the valve opening of the proportional reversing valve 211 to be closed (that is, a small part is opened), so that the compartment is Slowly descend in the high range to avoid shaking in the carriage. When the lifting fork frame 100 lowers the cabin to a stable interval, the controller provides the current to the proportional electromagnet of the proportional reversing valve 211 with a larger second current value, thereby controlling the valve port of the proportional reversing valve 211 to fully open (or the opening degree is relatively large), so that the compartment can be quickly lowered in a stable range to ensure the descending efficiency of the compartment. When the lifting fork frame 100 lowers the compartment to the low-level range, the controller provides the current to the proportional electromagnet of the proportional reversing valve 211 as the third smaller current value, thereby controlling the valve port of the proportional reversing valve 211 to roughly half. Open, so that the carriage descends slowly in the low range, so as to avoid accidents and ensure the safety of operating and maintenance personnel.

Based on the above, the controller can provide a current of corresponding current value to the proportional electromagnet of the proportional reversing valve 211 according to multiple height intervals of the lifting fork frame 100 in its stroke, thereby controlling the proportional reversing valve 211. The opening of the valve port controls the hydraulic flow supplied to the main circuit 210 of the hydraulic system, so as to control the lifting fork frame 100 to lift the carriage at a corresponding speed in different height ranges in its stroke. In other embodiments, multiple different height intervals in the stroke of the lifting fork 100 are not limited to the above-mentioned height intervals in this embodiment, and can be flexibly defined according to the actual demand for the lifting fork 100 to lift the carriage. Furthermore, the current values of the currents corresponding to different height intervals can be adjusted accordingly according to the requirements for the lifting speed, and are not limited to this embodiment.

Further, in this embodiment, when the main lifting cylinder 212 adopts the double-stage lifting hydraulic cylinder 140, which is a common type of the existing lifting fork frame, the multiple height intervals in the stroke of the lifting fork frame 100 may at least include The level change interval is the height interval corresponding to the level change between the first stage cylinder 141 and the second stage cylinder 142 of the two-stage lift hydraulic cylinder 140 . Wherein, when the lifting fork frame 100 is in the above-mentioned shift interval, the current value of the current supplied by the controller to the proportional electromagnet of the proportional reversing valve 211 may be the first current value. Through the above design, when the lifting fork frame 100 lowers the cabin to the height range corresponding to the level change between the primary cylinder 141 and the secondary cylinder 142 of the dual-stage lifting hydraulic cylinder 140, the box will vibrate obviously. At this time, the current that the controller provides to the proportional electromagnet of the proportional reversing valve 211 is a relatively small first current value, thereby controlling the valve opening of the proportional reversing valve 211 to be closed (that is, a small part is opened), so that the compartment is Slowly descend during the level change interval to alleviate the shaking phenomenon of the carriage.

Wherein, according to the specific structure of the lifting fork frame 100 and the double-stage lifting hydraulic cylinder 140, the above-mentioned level change range can be between the high range and the stable range, or can be between the stable range and the low range, and can also include within the stable range. When the level-changing interval is within the stable interval, the stable interval further includes a first stable interval and a second stable interval, and the height of the level-changing interval is smaller than the first stable interval and greater than the second stable interval.

Further, in this embodiment, when the lifting fork frame 100 lifts the carriage and stops at a certain height, and the lifting fork frame 100 automatically descends, the controller can control the hydraulic system to drive the lifting fork frame 100 back to the original height, and the During the pick-up process, the current value of the current supplied by the controller to the proportional electromagnet of the proportional reversing valve 211 is preferably the first current value. Specifically, in combination with the application environment of the aviation food truck in this embodiment, the above situation may specifically include that when the cabin is at a certain height and the four-way platform is in the extended state, the cabin is slow due to the leakage of the main lift cylinder 212. The phenomenon of automatic decline.

Further, in this embodiment, the controller may preferably be a PLC controller.

As shown in FIG. 1 , in this embodiment, a rotary angle encoder 130 is provided on the rotating shaft of the lifting fork 100 to detect the rotation angle of the fork of the lifting fork 100 . Wherein, the controller is connected to the rotary angle encoder 130, so as to calculate the height of the lifting fork frame 100 according to the angle measured by the rotary angle encoder 130, so as to compare the current height with the value preset in the controller. In what height interval (for example, the high interval, the first stable interval, the level change interval, the second stable interval, and the low interval in this embodiment), the controller further provides the ratio of the proportional reversing valve 211 to the proportional valve 211 according to different height intervals. The electromagnet provides currents of corresponding current values (for example, the first current value, the second current value, and the third current value in this embodiment). In other embodiments, other components or methods may be used to replace the rotary angle encoder 130 in this embodiment, so as to detect the rotation angle of the fork frame of the lifting fork frame 100, so as to calculate the height of the lifting fork frame 100 , or use other elements or methods to directly detect the height of the lifting fork 100, which is not limited to this embodiment.

Furthermore, considering that the lifting fork 100 is affected by various factors in a real working environment, the above-mentioned height intervals actually have certain changes. Therefore, in this embodiment, the controller can determine which height range the lifting fork 100 is in by detecting the shaking of the lifting fork 100 during operation by related components, so as to provide a current with a corresponding current value. For example, the rotary angle encoder 130 can also be used to detect the angle change rate of the lifting fork 100 , so as to calculate whether the lifting fork 100 (carriage) shakes or the specific degree of shaking.

Specifically, in the stable interval, under normal circumstances, the lifting fork frame 100 lifts the car up and down without shaking, that is, the angular velocity of the rotating shaft (the change in the rotation angle detected by the rotation angle encoder 130 per unit time) within a certain period of time. It is a fixed value or slowly changing (continuously increasing or continuously decreasing) within a period of time (for example, 3 to 4s). In this case, the valve core is gradually switched from one position to another after the proportional reversing valve 211 receives the electric signal. transition process). When vibration occurs, the angular velocity of the rotating shaft fluctuates frequently within a period of time. By detecting that the angular velocity of the rotating shaft within this period of time (for example, 3 to 4s) is less than 0.015rad/s (the angular velocity value is for reference only, it can be adjusted according to different The descending speed of a type of carriage requires flexible adjustment of the angular velocity value), and when it exceeds a certain number of times (for example, 3 times), it can be considered that the descending of the carriage produces a shaking phenomenon. If there is vibration in the judgment result, the controller outputs the current of the first current value (or the second current value) to control the opening of the reversing valve to be closed, so as to avoid continuous vibration when the carriage descends. After the duration of the first current value output by the controller exceeds 5s, the current value of the output current of the controller increases to the second current value, and the valve port of the proportional reversing valve 211 is controlled to fully open, and the carriage descends rapidly. In addition, for the two descending processes of "high interval → stable interval" (or "first stable interval → level-changing interval → second stable interval") and "stable interval → low interval", the height position of the carriage can be further combined relevant information to judge.

Based on the above exemplary description, the control principle of the lifting fork proposed by the present invention can be shown in FIG. 4 . Among them, the rotary angle encoder inputs an angle signal to the PLC controller, and the PLC controller can know the fork angle of the lifting fork frame, and can further calculate the height position of the corresponding carriage according to the fork frame angle, and at the same time can Calculate the angular velocity of the lifting fork according to the angle of the fork. As above, when the operator presses a micro button, the micro button inputs a micro adjustment signal to the PLC controller. According to the current different motion states or height positions of the lifting fork, the PLC controller gives the corresponding current value to the proportional electromagnet of the proportional directional valve, thereby controlling the valve port opening of the proportional directional valve (such as a small part open, half open or fully open), and then control the lifting speed of the lifting fork.

It should be noted at this point that the lifting fork shown in the drawings and described in this specification is but one example of many types of lifting fork with which the principles of the invention can be employed. It should be clearly understood that the principles of the present invention are in no way limited to any detail of the lifting fork or any component of the lifting fork shown in the drawings or described in this specification.

Airline Food Cart Implementation

In this embodiment, the airline food truck proposed by the present invention is described by taking an airline food truck suitable for an A380 aircraft as an example. Those skilled in the art can easily understand that, in order to apply the design of the aviation food cart to other types of aircraft or other types of vehicle equipment, various modifications are made to the following specific embodiments, Additions, substitutions, deletions or other changes which are still within the scope of the principles of the proposed airline food cart of the present invention.

In this embodiment, the air food cart proposed by the present invention mainly includes a vehicle frame, a compartment and the lifting fork frame proposed by the present invention.

Further, in this embodiment, the airline food cart also includes a four-way platform. Specifically, the carriage is set on the four-way platform, the lifting fork is set between the vehicle frame and the four-way platform, and a detection switch is set on the four-way platform. Among them, the controller is connected with the detection switch. When the carriage rises and docks with an aircraft and the aircraft descends to the height of the detection switch relative to the carriage, the detection switch is triggered, the controller controls the lifting fork to descend, and the controller sends the proportional electromagnet The current value of the given current is the first current value, that is, the valve opening of the proportional reversing valve is partially opened, and the carriage is controlled to slowly descend to the same height as the four-way platform and the cabin door, thereby realizing fine adjustment of the height of the carriage.

Further, in this embodiment, based on multiple height intervals in the stroke of the lifting fork including the high interval, the first stable interval, the level change interval, the second stable interval and the low interval, and the controller gives the proportional electromagnet The current values of the current are respectively the design of the corresponding first current value, second current value and third current value, combined with the parameters such as the door height of the A380 aircraft and the specific working height of the aviation food truck suitable for the A380 aircraft. , the above-mentioned high range can be between 6.8m and 8.1m, the first stable interval can be between 5.5m and 6.8m, the level change interval can be between 5.3m and 5.5m, and the second stable interval can be between 3.4m and 5.3m , the low range can be below 3.4m. Moreover, the first current value may be between 0.2A˜0.4A, the second current value may be between 0.9A˜1A, and the third current value may be between 0.5A˜0.6A. Furthermore, the above-mentioned countermeasures against the slow automatic descent of the carriage caused by hydraulic leakage may be performed by the controller when the height of the automatic descent of the carriage exceeds 0.1m-0.2m.

It should be noted that the specific height ranges of the above-mentioned altitude intervals and the specific values of each current value can be flexibly adjusted according to different types of application environments (such as aircraft models, aviation food truck structures), and are not limited by this embodiment. limit.

It should be noted at this point that the air food cart shown in the drawings and described in this specification is but one example of many types of air food carts that can employ the principles of the present invention. It should be clearly understood that the principles of the present invention are in no way limited to any details of the air food cart or any components of the air food cart shown in the drawings or described in this specification.

To sum up, the lifting fork frame and aviation food truck proposed by the present invention realize the control of the lifting speed by the controller according to different heights by adopting the design of the controller to adjust the current of the proportional electromagnet of the proportional throttle valve. Through the above design, the present invention can make the speed transition smoothly during the movement of the carriage, avoid damage to the goods in the carriage, and improve the comfort of the staff in the carriage. Moreover, the present invention can flexibly adjust the moving speed of the fork to address problems such as shaking and uneven speed during the movement of the lifting fork.

Exemplary implementations of the lifting fork frame proposed by the present invention and the aviation food truck with the lifting fork frame are described and/or illustrated above in detail. However, the embodiments of the present invention are not limited to the specific embodiments described herein, rather, the components and/or steps of each embodiment can be used independently and separately from other components and/or steps described herein. Each component and/or each step of one embodiment may also be used in combination with other components and/or steps of other embodiments. When referring to elements/components/etc. described and/or illustrated herein, the terms "a", "an" and "aforementioned" etc. are used to mean that there are one or more elements/components/etc. The terms "comprising", "including" and "having" are used in an open inclusive sense and mean that there may be additional elements/components/etc. besides the listed elements/components/etc. In addition, the terms "first" and "second" in the claims and the specification are used only as signs and do not limit the number of objects.

Although the lifting fork frame proposed by the present invention and the aviation food truck having the lifting fork frame have been described according to different specific embodiments, those skilled in the art will recognize that the present invention can be defined within the spirit and scope of the claims. Implement the changes.

Claims (10)

1. a kind of lifting crotch, it is set between the vehicle frame and compartment of lorry, the lifting crotch includes crotch component, described in driving The hydraulic system of crotch component lifting and the controller of the control hydraulic system；It is characterized in that, the hydraulic system System main line is equipped with proportional reversing valve, and the controller is connected to the proportional reversing valve, to control the input ratio The current value of the electric current of the proportion electro-magnet of reversal valve；Wherein, the controller is according to multiple in the lifting crotch stroke Height section, the electric current of corresponding current value is provided to the proportion electro-magnet, to control the liquid for supplying the hydraulic system Flow is pressed, and then controls the speed risen or fallen that the lifting fork frame torr lifts the compartment.

2. lifting crotch according to claim 1, which is characterized in that multiple height in the lifting crotch stroke Section includes at least high-order section, steady section and low level section from high to low；Wherein, the lifting crotch is in the height When position section, steady section and low level section, the current value difference for the electric current that the controller is provided to the proportion electro-magnet For the first current value, the second current value and third current value, the third current value is more than first current value and is less than institute State the second current value.

3. lifting crotch according to claim 2, which is characterized in that the lifting assembly includes twin-stage lifting hydraulic cylinder, Multiple height sections in the lifting crotch stroke, which further include first-stage cylinder, changes a grade section when being changed grade with secondary cylinder；Its In, the lifting crotch is in described when changing grade section, the electric current for the electric current that the controller is provided to the proportion electro-magnet Value is first current value.

4. lifting crotch according to claim 3, which is characterized in that grade section of changing is between the high-order section and institute It states between steady section；Alternatively, grade section of changing is between the steady section and the low level section；Alternatively, described A grade section to be changed to be contained within the steady section, the steady section includes the first steady section and the second steady section, and The height for changing grade section is less than the described first steady section and is more than the described second steady section.

5. lifting crotch according to claim 2, which is characterized in that the lifting crotch rises and is still in a height, And the lifting crotch, when declining automatically, the controller controls the hydraulic system and the lifting crotch is driven to go up to former height Degree, and the current value for the electric current that the controller is provided to the proportion electro-magnet during the rise is first electric current Value.

6. lifting crotch according to claim 1, which is characterized in that the controller is PLC controller.

7. lifting crotch according to claim 1~6 any one of them, which is characterized in that set in the shaft of the lifting crotch There is rotation angle encoder, the angle that the crotch to detect the lifting crotch rotates；Wherein, the controller is connected to institute Rotation angle encoder is stated, to obtain the height section residing for the lifting crotch according to the angle calculation.

8. a kind of inflight meal vehicle, including vehicle frame and compartment；It is characterized in that, the inflight meal vehicle further includes：

If claim 1~7 any one of them lifts crotch, the lifting fork be set up in the vehicle frame and the compartment it Between.

9. inflight meal vehicle according to claim 8, which is characterized in that the inflight meal vehicle further includes four-way platform, The four-way platform is set to the compartment close to that one end of aircraft door, and the four-way platform is equipped with detection switch；Wherein, The controller is connected to the detection switch, and the lifting fork is detected using a rotary encoder when lifting crotch lifts The crotch angle of frame, and by controller calculate and learn that height and position residing for the compartment, the compartment rise and dock When an aircraft and the relatively described compartment of the aircraft drop to the height of the detection switch, the detection switch triggering, institute It states controller and controls the lifting descending of fork, and the current value of electric current that the controller is provided to the proportion electro-magnet is First current value.

10. inflight meal vehicle according to claim 8, which is characterized in that multiple described in the lifting crotch stroke Height section includes the high-order section, the first steady section, described changes a grade section, the second steady section and described Low level section, and the current value of electric current that the controller is provided to the proportion electro-magnet is respectively the first current value, second When current value and third current value,

The high position section is situated between 6.8m~8.1m, the first steady section between 5.5m~6.8m, grade section of changing In 5.3m~5.5m, the second steady section is between 3.4m~5.3m, and the low level section is between 3.4m or less；And/or

First current value is situated between 0.2A~0.4A, second current value between 0.9A~1A, the third current value In 0.5A~0.6A.