Climbing ladder of a working machine and control method thereof

Abstract

This invention discloses a ladder for construction machinery and its control method, belonging to the field of construction machinery technology. The ladder includes a fixed frame, a ladder frame, a rotating support, and a flipping support. The rotating support is located at the bottom of the fixed frame, and one end of the ladder frame is connected to the rotating support. The rotating support can rotate around a first vertical axis, allowing the ladder frame to rotate between a first position and a second position relative to the fixed frame. The flipping support is located at the bottom of the fixed frame, and the ladder frame is connected to the flipping support. The flipping support can rotate around a second horizontal axis, allowing the ladder frame to flip between a horizontal and a vertical state relative to the fixed frame. When the ladder frame is in the first vertical position, it can be climbed. When it is in the second horizontal position, it is stored in the storage space at the bottom of the fixed frame. This invention has a compact structure, and when stored, it does not exceed the width of the underframe, avoiding damage from bumps and collisions, and significantly improving the convenience and safety of the driver getting on and off the vehicle.

Description

Technical Field

[0001] This invention relates to a ladder for engineering machinery and its control method, belonging to the field of engineering machinery technology. Background Technology

[0002] Tracked or wheeled excavators are mainly divided into an upper section and an lower section, with the cab located on the upper section and the tracks or wheels on the lower section. The cab is relatively high off the ground, requiring a ladder for the operator to get in and out. Currently, both wheeled and tracked excavators have fixed footrests on the lower frame for entry, and handrails on both sides of the cab doorway to provide three-point support for the operator.

[0003] The cab of a wheeled excavator needs to be positioned as far forward as possible on the upper frame to reduce blind spots in the lower front of the cab. However, because the lower frame needs to accommodate the turning space of the front wheels, the footrests are positioned further back from the cab doorway. This forces the operator to lean forward to grip the cab handrails when getting in and out, severely impacting comfort. Medium and large tracked excavators have fixed footrests on the lower frame, but these footrests protrude from the outer side of the tracks, making them susceptible to damage from impacts during operation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a ladder for engineering machinery and its control method, so that a set of ladders can be used on both the left and right sides, which significantly improves the convenience and safety of the driver getting on and off the vehicle.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] In a first aspect, the present invention provides a ladder for engineering machinery, comprising:

[0007] Fixture;

[0008] Ladder rack;

[0009] A rotating bracket is provided at the bottom of the fixed frame, one end of the ladder is connected to the rotating bracket, and the rotating bracket is rotatable about a first axis so that the ladder can rotate relative to the fixed frame about the first axis, the first axis extending in the vertical direction;

[0010] A flip-up bracket is provided at the bottom of the fixed frame, and the ladder frame is connected to the flip-up bracket. The flip-up bracket is rotatable about a second axis so that the ladder frame can rotate relative to the fixed frame about the second axis, and the second axis extends in the horizontal direction.

[0011] The ladder frame rotates between a first position and a second position around the first axis, and rotates between a horizontal state and a vertical state around the second axis. When the ladder frame is in the first position and in a vertical state, it can be climbed. When the ladder frame is in the second position and in a horizontal state, it is stored in the storage space at the bottom of the fixed frame.

[0012] Furthermore, the ladder frame can rotate simultaneously around the first axis and the second axis, and / or the ladder frame can rotate independently around the first axis and the second axis.

[0013] Furthermore, the rotating bracket has a fan-shaped plate structure, and its outer edge is provided with gear teeth. The center of the pitch circle of the gear teeth is located on the first axis, and the distribution range of the gear teeth corresponds to the rotation stroke of the rotating bracket around the first axis.

[0014] Furthermore, the rotating bracket is also provided with a front limiting bracket and a rear limiting bracket to limit the rotation range of the flipping bracket around the second axis.

[0015] Furthermore, the flip-up bracket is mounted on the rotating bracket and can rotate together with the rotating bracket around the first axis; the flip-up bracket includes a rocker arm and a connecting rod, one end of the rocker arm is hinged to the rotating bracket, the other end of the rocker arm is hinged to one end of the connecting rod, the other end of the connecting rod is hinged to the ladder frame, and the rotation of the flip-up bracket around the second axis is achieved by the swinging of the rocker arm relative to the rotating bracket.

[0016] Furthermore, the ladder frame is connected to the rotating support via a first hinge point, and the ladder frame is connected to the connecting rod via a second hinge point; when the rocker arm rotates around the second axis, it drives the ladder frame to flip between a horizontal and a vertical state around the second axis via the connecting rod.

[0017] Furthermore, it also includes a first drive motor and a second drive motor. The first drive motor drives the tilting bracket to rotate around the second axis through a first worm gear reducer and a drive gear. The second drive motor is fixed on the rotating bracket and drives the rotating bracket to rotate around the first axis through a second worm gear reducer.

[0018] Secondly, the present invention provides a control method for a ladder of construction machinery, used to control the ladder of the construction machinery described in any of the preceding claims, comprising:

[0019] In response to the unfolding command, the rotating bracket is controlled to rotate around the first axis, causing the ladder to rotate from the second position to the first position;

[0020] Control the rotating bracket to rotate around the second axis, causing the ladder to rotate from a horizontal state to a vertical state, so that the ladder is in a climbable state;

[0021] In response to a storage command, the flipping bracket is controlled to rotate in the opposite direction around the second axis, causing the ladder to flip from a vertical state to a horizontal state;

[0022] Control the rotating bracket to rotate in the opposite direction around the first axis, causing the ladder frame to rotate from the first position back to the second position, so that the ladder frame is stored in the storage space at the bottom of the fixed frame.

[0023] Furthermore, it also includes:

[0024] During the rotation or flipping of the ladder frame, the current values ​​of the first drive motor and the second drive motor are detected in real time by a current sensor;

[0025] When the current of the first drive motor or the second drive motor exceeds the set threshold, it is determined that the ladder frame has moved into position or is obstructed, and the first drive motor or the second drive motor is controlled to stop operating.

[0026] Furthermore, it also includes:

[0027] After the ladder frame is retracted to the second position, the position sensor detects whether the ladder frame is retracted in place. If it is not in place, an alarm is issued and the construction machinery is prohibited from performing walking or turning actions.

[0028] And / or, when the ladder rack is detected to be in place, the tail end of the ladder rack is attracted by an electromagnet to fix both ends.

[0029] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0030] This invention provides a ladder for construction machinery and its control method. By rotating the support around the vertical axis, the ladder can be rotated out from the storage position at the bottom of the fixed frame to the unfolding position on the left or right side of the cab. Then, the ladder is driven to flip from the horizontal state to the vertical state by the flipping support. This allows a set of ladders to be used when the upper frame of the construction machinery rotates to the left or right side, eliminating the need for a set of fixed footrests on each side as in the prior art, thus reducing costs. Moreover, regardless of the relative position of the cab and the lower frame, the access passage can be arranged in the most comfortable position. Attached Figure Description

[0031] Figure 1 This is a structural diagram of a ladder for engineering machinery provided in an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the unfolded electric folding ladder provided in an embodiment of the present invention on a wheeled excavator;

[0033] Figure 3 This is a schematic diagram of the electric folding ladder provided in an embodiment of the present invention being stored on a wheeled excavator;

[0034] Figure 4 This is a schematic diagram of the structure of the rotating bracket provided in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the structure of the first worm gear reducer provided in an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the ladder provided in an embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of the control logic for the unfolding and retraction of the boarding ladder provided in an embodiment of the present invention.

[0038] In the diagram: 1. Rotating support; 2. First worm gear reducer; 3. Rocker arm; 4. Connecting rod; 5. Ladder; 6. Second worm gear reducer; 7. Drive gear; 8. Bearing; 9. Upper frame; 10. Gear teeth; 11. Bearing mounting hole; 12. Front limit bracket; 13. Rear limit bracket; 14. Reducer fixing point; 15. Ladder hinge fixing point; 16. First drive motor; 17. Reducer output shaft; 18. First hinge point; 19. Second hinge point. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0040] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] Example 1: This example describes a ladder for engineering machinery, the structure of which is as follows. Figures 1 to 7 As shown. It should be noted that the fixing frame in this embodiment can be a separate frame specifically designed for the ladder, or it can directly utilize the excavator's upper frame 9. The following explanation uses the upper frame 9 as the fixing frame.

[0043] The ladder of the construction machinery includes: upper frame 9, ladder 5, rotating support 1, first worm gear reducer 2, rocker arm 3, connecting rod 4, second worm gear reducer 6, drive gear 7, and bearing 8.

[0044] The rotating bracket 1 is mounted on the bottom of the upper frame 9 via bearings 8. The inner and outer rings of the bearings 8 are fixedly connected to the rotating bracket 1 and the upper frame 9, respectively. A bearing mounting hole 11 is provided at the rotation center of the rotating bracket 1 for mounting the bearing 8. The rotating bracket 1 has a fan-shaped plate structure, with gear teeth 10 on its outer edge. The center of the pitch circle of the gear teeth 10 is located on the first axis, and the distribution range of the gear teeth 10 corresponds to the rotational stroke of the rotating bracket 1 around the first axis, which is 90° in this embodiment. The rotating bracket 1 also has a reducer fixing point 14, a ladder hinge fixing point 15, a front limiting bracket 12, and a rear limiting bracket 13 to limit the rotational range of the rocker arm 3. Figure 4 As shown.

[0045] like Figure 5 As shown, the body of the first worm gear reducer 2 is fixed to the rotating bracket 1 via the reducer fixing point 14. The first worm gear reducer 2 includes a first drive motor 16 and a reducer output shaft 17, the output shaft of which is fixedly connected to the rocker arm 3. The body of the second worm gear reducer 6 is fixed to the upper frame 9, and its output shaft is fixedly connected to the drive gear 7. The drive gear 7 meshes with the gear teeth 10 on the rotating bracket 1.

[0046] like Figure 6 As shown, one end of ladder 5 is hinged to ladder hinge fixing point 15 of rotating bracket 1 via first hinge point 18. Both ends of connecting rod 4 are hinged to rocker arm 3 and ladder 5 respectively, wherein the hinge point between connecting rod 4 and ladder 5 is second hinge point 19. Rocker arm 3 is hinged to rotating bracket 1.

[0047] The working principle of this embodiment is as follows:

[0048] When the ladder needs to be deployed, the controller controls the second drive motor of the second worm gear reducer 6 to drive the drive gear 7 to rotate clockwise. The rotating bracket 1, which meshes with the drive gear 7, rotates counterclockwise, causing the ladder 5 and its connecting mechanism to unscrew from the bottom of the upper frame 9. When the rotating bracket 1 rotates to the end position of the gear teeth 10, the current of the second drive motor increases due to stall. After the current sensor detects the set threshold, it sends a signal to the controller, and the rotation stops. At this time, the ladder 5 has been unscrewed from the storage position to the ready-to-deploy position on the left or right side of the cab, and the ladder 5 is still in a horizontal state. Subsequently, the first drive motor 16 of the first worm gear reducer 2 drives the rocker arm 3 to rotate clockwise. The rocker arm 3, through the connecting rod 4 hinged to it, drives the ladder 5 to rotate around the first hinge point 18 until the rocker arm 3 contacts the rear limit bracket 13 on the rotating bracket 1 and stops. At this time, the ladder 5 flips from a horizontal state to a vertical state, which can be used by the driver to get on and off the vehicle.

[0049] When the ladder needs to be stored, the operation is performed in reverse order: the first worm gear reducer 2 drives the rocker arm 3 to rotate counterclockwise, so that the ladder 5 returns from the vertical state to the horizontal state; then the second worm gear reducer 6 drives the rotating bracket 1 to rotate clockwise, so that the ladder 5 is stored back at the bottom of the upper frame 9.

[0050] Since both the first worm gear reducer 2 and the second worm gear reducer 6 have a self-locking function, when the system is powered off, the ladder 5 will remain in the state it was in when the power was off and will not be displaced due to its own weight or other external forces.

[0051] When stowed, the ladder 5 is located at the bottom of the upper frame 9 and does not extend beyond the left and right outer contours of the lower frame of the construction machinery, thus avoiding collisions during travel or operation.

[0052] Reference to the control logic for ladder deployment and storage Figure 7 .

[0053] In addition to the basic unfolding and storage functions mentioned above, this ladder can also be equipped with an alarm function for not being fully retracted: a position sensor is placed near the fully retracted position of the ladder. When the sensor does not detect that the ladder 5 has been retracted to the preset position, the vehicle cannot move or turn, and a prominent alarm is issued on the vehicle system.

[0054] An additional electromagnet reinforcement function can be added: a position sensor is placed near the fully retracted position of the ladder, and an electromagnet is placed on the upper frame 9 near the tail of the ladder 5. When the position sensor detects that the ladder 5 is fully retracted, the electromagnet attracts the tail of the ladder 5, changing the ladder from being fixed at one end to being fixed at both ends, thus improving reliability during crushing operations or long-term, severe vibrations. This function can be added simultaneously with an incomplete retraction alarm function.

[0055] The core of the engineering machinery ladder provided in this embodiment lies in the composite motion design of the rotating support 1 and the tilting support. Specific beneficial effects are as follows:

[0056] (1) By rotating the bracket 1 around the vertical axis, the ladder 5 can be rotated out from the storage position at the bottom of the upper frame 9 to the position to be unfolded on the left or right side of the cab. Then, the ladder 5 is driven to flip from the horizontal state to the vertical state by the rocker arm 3 and the connecting rod 4. This allows a set of ladders to be used when the upper frame of the engineering machinery is rotated to the left or right side. Unlike existing technologies, there is no need to set a set of fixed foot pedals on each side, which reduces costs. Moreover, regardless of the relative position of the cab and the lower frame, the access passage can be arranged in the most comfortable position.

[0057] (2) Since the ladder 5 is located at the bottom of the upper frame 9 and does not extend beyond the left and right outer contours of the lower frame when it is in the storage state, the construction machinery is less likely to be damaged by collisions during driving or working, and will not increase the width of the whole machine.

[0058] (3) The ladder 5 is automatically unfolded or stored by electric control, which is simple and labor-saving to operate.

[0059] (4) The current of the drive motor is detected by the current sensor. When the ladder 5 is obstructed or reaches the end of its movement, the controller automatically stops the drive motor to avoid damage to the parts.

[0060] (5) The self-locking characteristics of the first worm gear reducer 2 and the second worm gear reducer 6 ensure that the ladder 5 remains in its current state after the power is cut off, and will not be displaced due to gravity or external force, thus ensuring high safety.

[0061] (6) Position sensors and electromagnets can be added to realize alarms for incomplete storage and storage reinforcement functions, further improving safety and reliability.

[0062] Example 2: This example provides a control method for controlling the climbing ladder of any of the engineering machinery described in Example 1, such as... Figure 7 As shown, it includes:

[0063] In response to the unfolding command, the rotating bracket 1 is controlled to rotate around the first axis, thereby driving the ladder 5 to rotate from the second position to the first position;

[0064] Then, control the rotating bracket to rotate around the second axis, causing the ladder 5 to rotate from a horizontal state to a vertical state, so that the ladder 5 is in a climbable state;

[0065] In response to the storage command, the flipping bracket is controlled to rotate in the opposite direction around the second axis, causing the ladder 5 to flip from a vertical state to a horizontal state;

[0066] Then, the rotating bracket 1 is controlled to rotate in the opposite direction around the first axis, driving the ladder 5 to rotate from the first position back to the second position, so that the ladder 5 is stored in the storage space at the bottom of the fixed frame.

[0067] In a further embodiment, it also includes:

[0068] During the rotation or flipping of the ladder 5, the current values ​​of the first drive motor and the second drive motor are detected in real time by a current sensor.

[0069] When the current of the first drive motor or the second drive motor exceeds the set threshold, it is determined that the ladder 5 has moved into position or is obstructed, and the first drive motor or the second drive motor is controlled to stop operating.

[0070] In a further embodiment, it also includes:

[0071] After the ladder 5 is retracted to the second position, the position sensor detects whether the ladder 5 is retracted in place. If it is not in place, an alarm is issued and the construction machinery is prohibited from performing walking or rotating actions.

[0072] And / or, when the ladder 5 is detected to be in place, the tail of the ladder 5 is attracted by an electromagnet to fix both ends.

[0073] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A ladder for engineering machinery, characterized in that, include: Fixture; Ladder rack; A rotating bracket is provided at the bottom of the fixed frame, one end of the ladder is connected to the rotating bracket, and the rotating bracket is rotatable about a first axis so that the ladder can rotate relative to the fixed frame about the first axis, the first axis extending in the vertical direction; A flip-up bracket is provided at the bottom of the fixed frame, and the ladder frame is connected to the flip-up bracket. The flip-up bracket is rotatable about a second axis so that the ladder frame can rotate relative to the fixed frame about the second axis, and the second axis extends in the horizontal direction. The ladder frame rotates between a first position and a second position around the first axis, and rotates between a horizontal state and a vertical state around the second axis. When the ladder frame is in the first position and in a vertical state, it can be climbed. When the ladder frame is in the second position and in a horizontal state, it is stored in the storage space at the bottom of the fixed frame.

2. The ladder for engineering machinery according to claim 1, characterized in that, The ladder frame can rotate simultaneously around the first axis and the second axis, and / or the ladder frame can rotate independently around the first axis and the second axis.

3. The ladder for engineering machinery according to claim 2, characterized in that, The rotating bracket has a fan-shaped plate structure, and its outer edge is provided with gear teeth. The center of the pitch circle of the gear teeth is located on the first axis, and the distribution range of the gear teeth corresponds to the rotation stroke of the rotating bracket around the first axis.

4. The ladder for engineering machinery according to claim 1, characterized in that, The rotating bracket is also provided with a front limit bracket and a rear limit bracket to limit the rotation range of the flipping bracket around the second axis.

5. The ladder for engineering machinery according to claim 1, characterized in that, The flip-up bracket is mounted on the rotating bracket and can rotate together with the rotating bracket around the first axis. The flip-up bracket includes a rocker arm and a connecting rod. One end of the rocker arm is hinged to the rotating bracket, the other end of the rocker arm is hinged to one end of the connecting rod, and the other end of the connecting rod is hinged to the ladder frame. The rotation of the flip-up bracket around the second axis is achieved by the swinging of the rocker arm relative to the rotating bracket.

6. The ladder for engineering machinery according to claim 1, characterized in that, The ladder frame is connected to the rotating support through a first hinge point, and the ladder frame is connected to the connecting rod through a second hinge point; when the rocker arm rotates around the second axis, it drives the ladder frame to flip between a horizontal and a vertical state around the second axis through the connecting rod.

7. The ladder for engineering machinery according to claim 1, characterized in that, It also includes a first drive motor and a second drive motor. The first drive motor drives the tilting bracket to rotate around the second axis through a first worm gear reducer and a drive gear. The second drive motor is fixed on the rotating bracket and drives the rotating bracket to rotate around the first axis through a second worm gear reducer.

8. A control method for a ladder of construction machinery, used to control the ladder of the construction machinery according to any one of claims 1 to 7, characterized in that, include: In response to the unfolding command, the rotating bracket is controlled to rotate around the first axis, causing the ladder to rotate from the second position to the first position; Control the rotating bracket to rotate around the second axis, causing the ladder to rotate from a horizontal state to a vertical state, so that the ladder is in a climbable state; In response to a storage command, the flipping bracket is controlled to rotate in the opposite direction around the second axis, causing the ladder to flip from a vertical state to a horizontal state; Control the rotating bracket to rotate in the opposite direction around the first axis, causing the ladder frame to rotate from the first position back to the second position, so that the ladder frame is stored in the storage space at the bottom of the fixed frame.

9. The control method for the climbing ladder of engineering machinery according to claim 8, characterized in that, Also includes: During the rotation or flipping of the ladder frame, the current values ​​of the first drive motor and the second drive motor are detected in real time by a current sensor; When the current of the first drive motor or the second drive motor exceeds the set threshold, it is determined that the ladder frame has moved into position or is obstructed, and the first drive motor or the second drive motor is controlled to stop operating.

10. The control method for the ladder of engineering machinery according to claim 8, characterized in that, Also includes: After the ladder frame is retracted to the second position, the position sensor detects whether the ladder frame is retracted in place. If it is not in place, an alarm is issued and the construction machinery is prohibited from performing walking or turning actions. And / or, when the ladder rack is detected to be in place, the tail end of the ladder rack is attracted by an electromagnet to fix both ends.

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