Portal crane deviation rectifying device

Abstract

A deviation rectifying device of a portal crane is characterized in that a deflector rod and a limiting device are arranged in a main beam of the crane, the limiting device is fixed on the main beam, and the deflector rod is fixed above the limiting device in a suspended manner through a fixing bracket. A U-shaped frame type trigger is arranged at the end of the shifting rod, the limiting device is provided with a limiting base, a supporting plate is arranged on the limiting base, and two sound-light alarm travel switches, two power supply travel switches and two displacement encoders are fixed to the supporting plate. The displacement encoder is triggered by deviation of the driving lever, the displacement encoder is in signal connection with the PLC, and the PLC receives signals and sends instructions to the sound-light alarm travel switch and the power supply travel switch. The deviation value can be displayed in real time, and operators can conveniently intervene in operation at any time according to needs. According to the method, an electrical system does not need to be adjusted, automatic deviation correction can be achieved, when deviation reaches the preset threshold value due to special reasons or emergencies, equipment can be automatically stopped, and the threshold values of the deviation correction system in different deviation stages are adjusted.

Description

Technical Field

[0001] The present invention belongs to the field of shipbuilding and design, and particularly relates to a deviation rectifying device for a gantry crane. Background Art

[0002] A deviation rectifying device for a crane is a device that can indicate the deviation situation to the driver when the running mechanisms on both sides of a gantry crane, a loading and unloading bridge and other lifting equipment are asynchronous and deviate, and can also adjust and correct the running deviation when it reaches the designed specified value.

[0003] In China, relevant specifications and safety regulations in the crane industry require that gantry cranes and loading and unloading bridges with a span greater than 40 meters must be equipped with a deviation rectifying device for the traveling mechanism.

[0004] The deviation rectifying device consists of a signal detection device and an electrical control system. The signal detection device is used to detect the distance difference between the traveling mechanisms on both sides of the lifting equipment and convert the distance difference into an electrical signal and transmit it to the electrical control system.

[0005] The difference detection device of the deviation rectifying system mostly uses an absolute encoder or a proximity switch to obtain the distance difference between the traveling mechanisms on both sides of the lifting equipment. The detection device using an absolute encoder compares the linear speed difference of the actual rotation of the trolley wheels on both sides of the lifting equipment to compare the distance difference between the two traveling mechanisms; the detection device using a proximity switch needs to install some induction points parallel to the tracks of the traveling mechanisms on both sides of the lifting equipment. When there is a time difference in the actions of the proximity switches on both sides of the traveling mechanisms, the electrical control system starts to perform the deviation rectifying action.

[0006] Regardless of which type of the above deviation rectifying device, the principle of its electrical control system is basically the same, that is, the PLC system adjusts the two frequency converters of the traveling drive mechanisms on both sides of the control equipment according to the signals fed back by the detection device, so as to achieve the purpose of reducing the deviation of the running mechanisms on both sides. The difference is that the deviation value detection device detects the deviation value in different ways. Some obtain the distance deviation by installing an absolute encoder on the driven wheel of the traveling mechanism, and some obtain the distance deviation through various types of contact switches and trigger magnets, etc.

[0007] The accuracy of obtaining the deviation value is directly related to the effectiveness of the deviation rectification system. Currently, there are more or less some deficiencies in the deviation value detection devices used in various deviation rectification systems. For example, in the detection device using an absolute encoder, the encoder needs to be installed on the driven wheel of the traveling mechanism. However, due to problems such as wheel diameter deviation, wear, track joints, "rail gnawing", and wheel slippage, the encoder cannot accurately reflect the actual running distance or speed of the traveling mechanism. When comparing the detection values of the absolute encoders on both sides of the traveling mechanism, the difference is also inaccurate. The detection method of obtaining the deviation value using proximity switches requires a large number of trigger magnets to be arranged on both sides of the track. Moreover, when the span of the lifting equipment is large, it is a very difficult problem to ensure that the connection line of the two magnets at the same trigger point is absolutely perpendicular to the track. In addition, when the running distance of the lifting equipment is long, a large number of trigger magnets need to be installed on the ground. The positions of the large number of trigger magnets arranged on the ground are extremely likely to change with the settlement of the ground or be damaged by vehicles on the ground, etc., resulting in some magnets being unable to trigger the proximity switch, and thus the deviation rectification system cannot work properly. Summary of the Invention

[0008] To solve the above problems, the present invention provides a deviation rectification device for a gantry crane, aiming to achieve the purpose that the crane can automatically verify the deviation situation of the traveling mechanism, display the deviation value of the traveling mechanism in real time, and facilitate the operator to intervene in the operation of the crane in a timely manner at any time. The technical solution adopted is as follows:

[0009] A deviation rectification device for a gantry crane, the traveling mechanism of the crane includes a rigid leg and a flexible leg, the main girder is located between the rigid leg and the flexible leg, the rigid leg is fixedly connected to the main girder, the flexible leg is connected to the main girder through a flexible hinge, the flexible leg can rotate relative to the main girder, and forms an acute angle with the rigid leg.

[0010] A push rod and a limiting device are arranged inside the main girder. The push rod is horizontally arranged inside the main girder, a trigger device is fixed at the end of the push rod, the trigger device is a U-shaped frame, the opening of the U-shaped frame faces outward, the push rod is connected to the bottom plate of the U-shaped frame, the limiting device is fixed inside the main girder, the U-shaped frame is located above the limiting device, and a first horizontal adjusting bolt is arranged at the opening of the U-shaped frame. The first horizontal adjusting bolt sequentially passes through the two side plates of the U-shaped frame and is fixed in cooperation with a nut.

[0011] The push rod is fixed inside the main girder through a fixed bracket. One end of the fixed bracket is fixed at the position where the flexible leg is close to the main girder, and the other end extends upward through the outer wall of the main girder and penetrates into the main girder to fix the push rod in a suspended manner.

[0012] The limit device includes a limit base fixed on the main beam. Above the limit base, there is a support plate arranged along the length direction of the limit base. At both ends of the support plate, there are height adjustment bolts. The lower surface of the support plate is fixed with an adjustment plate. On both sides of one end of the support plate, there are vertical plates symmetrically arranged. The adjustment plate is located between the two vertical plates. The second horizontal adjustment bolt passes through the vertical plate and cooperates with a nut, and abuts against both sides of the adjustment plate.

[0013] The combination of the first horizontal adjustment bolt and the second horizontal adjustment bolt can adjust the positions of the sound and light alarm travel switch and the power supply travel switch relative to the U-shaped frame. The height adjustment bolt is used to adjust the position of the displacement encoder relative to the head of the lever, ensuring that when the running mechanism deviates, the travel of the displacement encoders in both positive and negative directions is the same. At the same time, the adjustable displacement encoder mounting seat can also improve the tolerance of the deviation correction device to installation errors.

[0014] At the other end of the support plate, there are a sound and light alarm travel switch, a power supply travel switch, and a displacement encoder. The displacement encoder is located inside the U-shaped frame, and the sound and light alarm travel switch and the power supply travel switch are located outside the U-shaped frame. There are two displacement encoders, which are staggered and arranged inside the insert bar. The probes of the two displacement encoders are respectively aligned with the side plates of the U-shaped frame adjacent to them. On the outer sides of the two side plates of the U-shaped frame, there are respectively a sound and light alarm travel switch and a power supply travel switch. The sound and light alarm travel switch and the power supply travel switch are symmetrically arranged. The displacement encoder is signal-connected to the PLC, and the PLC controls the sound and light alarm travel switch and the power supply travel switch.

[0015] The specific usage method of the deviation correction device for the gantry crane is as follows:

[0016] S1: Align the traveling mechanisms on both sides of the rigid leg and the flexible leg with the reference points, adjust the horizontal adjustment bolts to make the probe extension lengths of the displacement encoders in both positive and negative directions the same, and zero the readings of the displacement encoders.

[0017] S2: Start the flexible leg to move forward or backward. When the deviation of the flexible leg relative to the reference point reaches the preset threshold of 2‰ of the span, adjust the sound and light alarm travel switch to the trigger state. Continue to start the flexible leg. When the deviation of the flexible leg relative to the reference point reaches the preset threshold of 3‰ of the span, adjust the power supply travel switch to the trigger state, and at the same time adjust the display value of the displacement encoder to the actually measured deviation value.

[0018] S3: Move the flexible leg back to the reference point. If the display position of the displacement encoder returns to zero, it is considered that the deviation correction adjustment in this direction is completed, and the deviation correction device adjustment in the other direction can be carried out according to step S2. If the actually measured values of the extreme deviations in both positive and negative directions are the same, but the displacement encoder does not return to zero or the displayed displacements are different, then repeat steps S1 and S2.

[0019] S4: When there is a deviation between the flexible leg and the rigid leg, the U-shaped frame will squeeze the probe of the displacement encoder, causing a change in the extended length of the probe. The displacement encoder converts the displacement signal into an electrical signal and transmits it to the PLC system. The PLC system compares the value formed by the electrical signal with a preset threshold. When the deviation is less than 3‰ of the span threshold, the U-shaped frame will trigger the audible and visual alarm travel switch to notify the operator to intervene in the crane.

[0020] S5: If an emergency occurs and the deviation formed by the rigid leg and the flexible leg cannot be eliminated effectively and in real time by the deviation correction action, resulting in the further accumulation of the deviation reaching 3‰ of the span threshold, the U-shaped frame will trigger the power supply travel switch, and the operating mechanism of the crane will be powered off and stop running.

[0021] For the above-mentioned deviation correction device of a gantry crane, further, the support plate is T-shaped, with the wider side of the support plate close to the lever and the narrower side away from the lever.

[0022] For the above-mentioned deviation correction device of a gantry crane, further, the travel switch and the displacement encoder are fixed on the support plate through brackets.

[0023] For the above-mentioned deviation correction device of a gantry crane, further, the length of the lever is set in proportion to the stroke of the displacement encoder, and the stroke of the displacement encoder / tan0.17 ≈ the length of the lever. The lever will convert a small angular deviation into displacement and amplify it. The length of the lever needs to be set in proportion to the stroke of the selected displacement encoder. If the length of the lever is too long, the displacement of the triggering device will be greater than the stroke of the displacement encoder, causing damage to the displacement encoder during use; if the length of the lever is insufficient, the displacement of the triggering device will be insufficient, the travel switch is likely to be accidentally touched, or the detection accuracy of the displacement encoder will be insufficient.

[0024] Due to the existence of the flexible hinge, when the flexible leg rotates relative to the main girder, the lever will also rotate together, and the maximum rotation angle is 0.17°. In summary, the relationship between the length of the lever and the stroke of the selected displacement encoder is: the stroke of the displacement encoder / tan0.17 ≈ the length of the lever.

[0025] For the above-mentioned deviation correction device of a gantry crane, further, when the deviation of the traveling mechanism relative to the reference point reaches 3‰ of the span, this is the maximum acute angle formed by the flexible leg and the rigid leg, and the angle is 0.17°.

[0026] For the above-mentioned deviation correction device of a gantry crane, further, the maximum detection accuracy of the displacement encoder is ±0.3μm, and the maximum measurement stroke is 50mm.

[0027] For the above-mentioned deviation correction device of a gantry crane, further, the extended probe lengths of the two displacement encoders are the same.

[0028] The above-mentioned portal crane deviation rectification device, further, the rigid leg is welded or flange-connected to the main beam.

[0029] Theoretically, the included angles between the planes where the traveling mechanisms on both sides of the hoisting equipment are located and the longitudinal axis of the gantry are both 90°. When the traveling mechanisms of the hoisting equipment deviate, the included angles between the planes where the traveling mechanisms are located and the longitudinal axis of the gantry will be greater than or less than 90°, and the flexible leg will rotate a very small angle relative to the main beam with the flexible hinge as the center. The principle of this patent is to use a set of mechanical devices to convert the change value of the included angle between the plane where the traveling mechanism of the hoisting equipment deviates and the plane where the longitudinal axis of the gantry is located into a displacement change value, and amplify it to a magnitude that can be detected by a detection element. The two sets of detection elements installed on the detection device detect the displacement values in two directions, and the detection element converts the displacement value into an electrical signal and transmits it to the PLC system. The PLC system judges whether to perform a deviation rectification action according to the preset threshold.

[0030] The beneficial effects of the present invention are:

[0031] 1. Simple installation, commissioning and maintenance, with reduced workload.

[0032] 2. Little affected by external factors, and will not be affected by common adverse factors such as wheel diameter deviation or wear, track joints, "rail gnawing", wheel slipping or damage to trigger magnets.

[0033] 3. Can display the deviation value in real time, which is convenient for the operator to intervene in the operation at any time according to needs. Automatic deviation rectification and manual deviation rectification can be realized. When the deviation reaches the preset threshold due to special reasons or emergencies, the equipment can be automatically stopped.

[0034] 4. Convenient to modify the preset value, and only need to adjust the adjustment bolt of the deviation detection system to adjust the threshold value of the deviation rectification system at different deviation stages. There is no need to adjust the electrical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic diagram of the result of the present invention;

[0036] Figure 2 is a top view structural schematic diagram of the trigger device and the limit device;

[0037] Figure 3 is a sectional view structural schematic diagram of the trigger device and the limit device;

[0038] Among them, 1 - flexible leg, 2 - lever, 3 - limit device, 4 - sound and light alarm travel switch, 5 - displacement encoder, 6 - U-shaped frame, 7 - first horizontal adjustment bolt, 8 - second horizontal adjustment bolt, 9 - height adjustment bolt, 10 - power supply travel switch. DETAILED DESCRIPTION OF THE INVENTION

[0039] The present invention will be further described with reference to the accompanying drawings.

[0040] A deviation rectification device for a gantry crane. The traveling mechanism of the crane includes a rigid leg and a flexible leg. The main girder is located between the rigid leg and the flexible leg. The rigid leg is fixedly connected to the main girder, and the flexible leg is connected to the main girder through a flexible hinge. The flexible leg can rotate relative to the main girder and forms an acute angle with the rigid leg. Taking the gantry crane as an example, according to the industry standard "GBT3811-2008 9.7.2.11 Deviation Indicator or Limiter", the maximum allowable deviation distance value between the rigid leg and the flexible leg is ±3‰ of the span, which is converted into an angle of approximately 0.17°.

[0041] As Figure 1 shown, a dial rod and a limit device are arranged inside the main girder. The dial rod is horizontally arranged inside the main girder, and a trigger device is fixed at the end of the dial rod. The trigger device is a U-shaped frame with an outward opening. The dial rod is connected to the bottom plate of the U-shaped frame. The limit device is fixed inside the main girder, and the U-shaped frame is located above the limit device. The dial rod is fixed inside the main girder through a fixed bracket. One end of the fixed bracket is fixed at the position where the flexible leg is close to the main girder, and the other end extends upward through the outer wall of the main girder and penetrates into the main girder to fix the dial rod in suspension.

[0042] As Figure 2 、 3 shown, the limit device includes a limit base fixed on the main girder. A support plate is arranged above the limit base. The support plate is arranged along the length direction of the limit base. Height adjustment bolts are arranged at both ends of the support plate. An adjustment plate is fixed on the lower surface of the support plate. Vertical plates are symmetrically arranged on both sides of one end of the support plate. The adjustment plate is located between the two vertical plates. The second horizontal adjustment bolt passes through the vertical plate and cooperates with a nut, and abuts against both sides of the adjustment plate.

[0043] An audible and visual alarm travel switch, a power supply travel switch and a displacement encoder are arranged at the other end of the support plate. The displacement encoder is located inside the U-shaped frame, and the audible and visual alarm travel switch and the power supply travel switch are located outside the U-shaped frame; there are two displacement encoders, and the two displacement encoders are staggered and arranged inside the insert bar. The probes of the two displacement encoders are respectively aligned with the adjacent side plates of the U-shaped frame; audible and visual alarm travel switches and power supply travel switches are respectively arranged on the outer sides of the two side plates of the U-shaped frame, and the audible and visual alarm travel switches and the power supply travel switches are symmetrically arranged.

[0044] The displacement encoder adopts the telescopic grating micrometer principle, with a maximum detection accuracy of plus or minus 0.3μm and a maximum measurement stroke of 50mm. The measurement stroke is determined according to the equipment type. The larger the span, the larger the stroke of the selected displacement encoder. The travel switch selects a micro-motion travel switch to improve the system accuracy and action speed.

[0045] The length of the lever needs to be set proportionally to the stroke of the selected displacement encoder, where the stroke of the displacement encoder / tan0.17 ≈ the length of the lever. When the span of the crane is small, the length of the lever can be appropriately increased, which can effectively avoid faults such as accidental triggering of the travel switch caused by wind load, sudden braking, etc. during operation.

[0046] The specific usage method is as follows:

[0047] S1: Align the traveling mechanisms on both sides of the rigid leg and the flexible leg with the reference point, adjust the horizontal adjustment bolts so that the probe extension lengths of the displacement encoders in both positive and negative directions are the same, and zero the displacement encoder readings.

[0048] S2: Start the flexible leg to move forward or backward. When the deviation of the flexible leg relative to the reference point reaches the preset threshold of 2‰ of the span, adjust the audible and visual alarm travel switch to the triggered state. Continue to start the flexible leg. When the deviation of the flexible leg relative to the reference point reaches the preset threshold of 3‰ of the span, adjust the power supply travel switch to the triggered state, and at the same time adjust the displayed value of the displacement encoder to the actually measured deviation value.

[0049] S3: Move the flexible leg back to the reference point. If the displacement encoder shows that the position returns to zero, it is considered that the deviation adjustment in this direction is completed, and the deviation correction device adjustment in the other direction can be carried out according to step S2; if the actually measured values of the extreme deviations in both positive and negative directions are the same, but the displacement encoder does not return to zero or the displayed displacements are different, repeat steps S1 and S2.

[0050] S4: When there is a deviation between the flexible leg and the rigid leg, the U-shaped frame will squeeze the probe of the displacement encoder, causing a change in the probe extension length. The displacement encoder converts the displacement signal into an electrical signal and transmits it to the PLC system. The PLC system compares the value formed by the electrical signal with the preset threshold. When the deviation is less than the 3‰ span threshold, the U-shaped frame will trigger the audible and visual alarm travel switch to notify the operator to intervene in the crane.

[0051] S5: If an unexpected situation occurs and the deviation correction action cannot effectively eliminate the deviation formed by the rigid leg and the flexible leg in real time, resulting in the deviation further accumulating to reach the 3‰ span threshold, the U-shaped frame will trigger the power supply travel switch, and the operating mechanism of the crane will be powered off and stop running.

[0052] When there is a deviation in the operating mechanism, causing the flexible leg to rotate relative to the main beam, the lever will convert the small angular deviation into a position deviation and amplify it. The displacement encoder trigger device at the head of the lever will cause a change in the stroke of the displacement encoder installed on the mounting seat of the limit device or trigger the travel switch.

[0053] Start the walking mechanism on the flexible leg side to walk in the positive or negative direction. When the deviation of the walking mechanism relative to the reference point reaches 2‰ of the span, adjust the position of the travel switch that controls the sound and light alarm and adjust the travel switch to the trigger state; continue to start the walking mechanism. When the deviation of the walking mechanism relative to the reference point reaches 3‰ of the span, adjust the installation position of the travel switch that controls the power supply of the walking mechanism and adjust the travel switch to the trigger state. At the same time, adjust the displayed value of the displacement encoder to the actual measured deviation value. Drive the walking mechanism on the flexible leg side back to the reference point. If the displayed position of the displacement encoder returns to zero, it is considered that the deviation correction adjustment in this direction is completed, and the deviation correction device in the other direction can be adjusted according to the above method. If the actual measured values ​​of the limit deviations in the positive and negative directions are the same, but the displacement encoder does not return to zero or the displayed displacement is different, continue to adjust the position of the zero point of the displacement encoder by adjusting the bolt.

[0054] During the operation of the equipment, when the walking mechanisms on both sides deviate, the flexible legs will rotate relative to the main beam. At this time, the lever installed on the flexible leg will swing around the center of the flexible hinge circle driven by the flexible leg, and the position of the trigger device at the head of the lever relative to the position of the limit device mounting seat installed in the main beam will also change. At this time, the trigger device at the head of the lever will squeeze the probe of the displacement encoder on the position limit device mounting seat, causing the displacement encoder to change in the extension length. The displacement encoder converts the displacement signal into an electrical signal and transmits it to the PLC system. After transmission, the deviation value is displayed on the display in the driver's cab. At the same time, the safety system will compare the input value with the preset threshold. When the deviation is greater than the threshold, the whole system will perform a deviation correction action. If an emergency occurs, the deviation correction action cannot effectively eliminate the deviation of the walking mechanisms on both sides of the rigid and flexible legs in real time, resulting in the deviation further accumulating to reach the maximum allowable deviation threshold. The trigger device will trigger the travel switch, the trolley running mechanism will be powered off, and the operation will stop to prevent safety accidents.

Claims

1. A gantry crane deviation correction device, characterized in that: The walking mechanism of the crane comprises a rigid leg and a flexible leg (1), a main beam is located between the rigid leg and the flexible leg, the rigid leg is fixedly connected to the main beam, the flexible leg is connected to the main beam via a flexible hinge, the flexible leg is rotatable relative to the main beam, and forms an acute angle with the rigid leg; A lever (2) and a limiting device (3) are arranged inside the main beam. The lever is arranged horizontally inside the main beam. A trigger device is fixed to the end of the lever. The trigger device is a U-shaped frame (6). The opening of the U-shaped frame faces outward. The lever is connected to the bottom plate of the U-shaped frame. The limiting device is fixed inside the main beam. The U-shaped frame is located above the limiting device. A first horizontal adjustment bolt (7) is arranged at the opening of the U-shaped frame. The first horizontal adjustment bolt passes through two side plates of the U-shaped frame in sequence and is fixed in cooperation with a nut. The lever is fixed inside the main beam through a fixing bracket, one end of the fixing bracket is fixed to the flexible leg near the main beam, and the other end extends upward to penetrate the outer wall of the main beam and extends into the main beam to suspend and fix the lever; The limiting device comprises a limiting base fixed on the main beam, a support plate is arranged above the limiting base, the support plate is arranged along the length direction of the limiting base, height adjustment bolts (9) are arranged at both ends of the support plate, an adjustment plate is fixed on the lower surface of the support plate, vertical plates are symmetrically arranged on both sides of one end of the support plate, the adjustment plate is located between the two vertical plates, and a second horizontal adjustment bolt (8) passes through the vertical plate and cooperates with a nut to press against both sides of the adjustment plate; The other end of the support plate is provided with an audible and visual alarm travel switch (4), a power travel switch (10) and a displacement encoder (5), the displacement encoder is located on the inner side of the U-shaped frame, and the audible and visual alarm travel switch and the power travel switch are located on the outer side of the U-shaped frame; there are two displacement encoders, the two displacement encoders are staggeredly arranged on the inner side of the insertion strip, and the probes of the two displacement encoders are respectively aligned with the adjacent U-shaped frame side plates; the outer sides of the two side plates of the U-shaped frame are respectively provided with an audible and visual alarm travel switch and a power travel switch, and the audible and visual alarm travel switch and the power travel switch are symmetrically arranged; The displacement encoder is connected to the PLC signal, and the PLC controls the sound and light alarm travel switch and the power travel switch.

2. A gantry crane deviation correction device according to claim 1, characterized in that: The support plate is T-shaped, with a wider side of the support plate being arranged close to the lever and a narrower side being arranged away from the lever.

3. A gantry crane deviation correction device according to claim 1, characterized in that: The travel switch and the displacement encoder are fixed on the supporting plate through a bracket.

4. A gantry crane deviation correction device according to claim 1, characterized in that: The length of the lever is set in proportion to the stroke of the displacement encoder, and the displacement encoder stroke / tan0.17≈the length of the lever.

5. The gantry crane deviation correction device according to claim 1, characterized in that: When the deviation of the walking mechanism relative to the reference point reaches 3‰ of the span, the maximum acute angle formed by the flexible leg and the rigid leg is 0.17°.

6. A gantry crane deviation correction device according to claim 1, characterized in that: The maximum detection accuracy of the displacement encoder is plus or minus 0.3μm, and the maximum measuring stroke is 50mm.

7. The gantry crane deviation correction device according to claim 1, characterized in that: The extended probes of the two displacement encoders have the same length.

8. The gantry crane deviation correction device according to claim 1, characterized in that: The rigid legs are welded or flanged to the main beam.

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