Loader and overload protection control method for a loader

Abstract

The application discloses a loader and an overload protection control method of the loader, which comprises a vehicle body, a bucket, a position detection device and a pressure detection device, the bucket is rotatably installed on the vehicle body along an axis extending in a first direction, the position detection device is used for detecting the lifting position of the bucket, and the pressure detection device is used for detecting the load of the bucket. According to the technical scheme of the application, the load of the bucket of the loader is identified by the pressure detection device, so that the operator can control the load condition of the bucket of the loader at any time, and meanwhile, the control system can make corresponding responses according to the load condition of the bucket, so as to avoid the overload operation of the loader. Meanwhile, the position detection device is arranged on the loader and used for detecting the lifting position of the bucket of the loader, and the pressure detection device starts to calculate the load of the bucket only when the bucket runs in a preset measurement range, so as to ensure the accuracy of the load calculation of the bucket.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering machinery, in particular to a loader and an overload protection control method of the loader. BACKGROUND

[0002] The loader is a kind of earthwork construction machinery widely used in highway, railway, building, water and electricity, port, mine and other construction projects, which is mainly used for shoveling soil, sand, lime, coal and other bulk materials, and can also be used for light digging of ore, hard soil and other materials, however, the existing loader usually relies on manual judgment to control the load of the loader bucket during construction, which often leads to overloading of the loader, affecting the service life of the loader, and also has safety hazards. SUMMARY

[0003] The main purpose of the present application is to provide a loader, which aims to provide a high-efficiency, intelligent and accurate load identification loader.

[0004] To achieve the above purpose, the loader provided by the present application comprises:

[0005] A vehicle body;

[0006] A bucket is rotatably installed on the vehicle body along an axis extending in a first direction;

[0007] A position detection device is used to detect the lifting position of the bucket; and

[0008] A pressure detection device is used to detect the load of the bucket.

[0009] Optionally, the bucket has a boom, and the bucket is rotatably installed on the vehicle body along an axis extending in a first direction through the boom;

[0010] The loader further comprises a driving assembly, and the driving assembly comprises:

[0011] A boom lifting oil cylinder has an oil cylinder body and a telescopic rod, the telescopic rod is movably arranged on the oil cylinder body, the oil cylinder body is fixedly connected with the vehicle body, and the telescopic rod is fixedly connected with the boom to drive the boom to rotate along an axis extending in a first direction;

[0012] An oil circuit control assembly is used to control the extension direction and extension speed of the telescopic rod; and

[0013] A circuit board assembly is electrically connected with the pressure detection device and the oil circuit control assembly.

[0014] Optionally, the position detection device further comprises a distance sensor arranged on the telescopic rod to detect the distance between the telescopic rod and the oil cylinder body.

[0015] Optionally, the oil path control assembly comprises an oil pressure sensor to detect the oil path pressure in the oil path control assembly.

[0016] The pressure detection device comprises the oil pressure sensor.

[0017] Optionally, the shovel has a swing arm, and the shovel is rotatably mounted on the vehicle body along an axis extending in the first direction by the swing arm.

[0018] The position detection device comprises a plurality of Hall sensors and a magnet structure, and the plurality of Hall sensors are arranged on the vehicle body.

[0019] The magnet structure is arranged on the opposite side of the swing arm and the Hall sensors, the magnet structure can rotate with the swing arm, and in the movement stroke of the magnet structure, the magnet structure can be respectively aligned with the plurality of Hall sensors to generate electrical signals.

[0020] The shovel has a swing arm, and the shovel is rotatably mounted on the vehicle body along an axis extending in the first direction by the swing arm.

[0021] The position detection device comprises an angle sensor arranged on the swing arm to measure the rotation angle of the swing arm.

[0022] The shovel has a swing arm, and the shovel is rotatably mounted on the vehicle body along an axis extending in the first direction by the swing arm.

[0023] The position detection device comprises a mechanical contact and a plurality of contact sensors, and the plurality of contact sensors are arranged on the vehicle body.

[0024] The mechanical contact is arranged on the opposite side of the swing arm and the contact sensors, the mechanical contact can rotate with the swing arm, and in the movement stroke of the mechanical contact, the mechanical contact can be respectively touched with the plurality of contact sensors to generate a plurality of different electrical signals.

[0025] Optionally, the loader further comprises an alarm device electrically connected with the position detection device and the pressure detection device.

[0026] The shovel comprises a shovel body and a rotating arm, and one end of the rotating arm is rotatably mounted on the vehicle body along the first direction.

[0027] The bucket body is rotatably mounted on the other end of the rotating arm.

[0028] The application further provides a load protection control method of the loader.

[0029] When the bucket of the loader is in the upgoing state and in the preset measuring interval, a plurality of instantaneous load pressure values at different time points on the oil circuit of the boom lifting cylinder of the loader are acquired.

[0030] An effective load pressure value is determined according to the plurality of instantaneous load pressure values.

[0031] A first mapping relationship is inquired according to the effective load pressure value, so as to determine an actual load weight, wherein the first mapping relationship comprises a correlation between the effective load pressure value and the actual load weight.

[0032] An overload protection strategy is determined according to the actual load weight.

[0033] Optionally, the determination of the overload protection strategy according to the actual load weight comprises:

[0034] A ratio k of the actual load weight to the maximum allowable loading capacity of the bucket of the loader is calculated.

[0035] When 1 < k ≤ 1.1, a display system of the loader is controlled to display a light overload prompt information.

[0036] When 1.1 < k ≤ 1.2, the display system of the loader is controlled to display a moderate overload prompt information, and an oil pump arranged on the oil circuit of the boom lifting cylinder is controlled to adjust the rotating speed, so as to reduce the lifting speed.

[0037] When 1.2 < k ≤ 1.5, the display system of the loader is controlled to display a heavy overload prompt information, and the oil pump arranged on the oil circuit of the boom lifting cylinder is controlled to adjust the rotating speed, so as to stop the lifting.

[0038] Optionally, before the acquisition of the plurality of instantaneous load pressure values at different time points on the oil circuit of the boom lifting cylinder of the loader, the method further comprises:

[0039] An actual position of an operating handle of the loader is acquired.

[0040] A second mapping relationship is inquired according to the actual position of the operating handle, so as to determine an actual operating state of the bucket of the loader, wherein the actual operating state comprises the upgoing state.

[0041] Optionally, before the acquiring multiple instantaneous load pressure values of the oil circuit of the lift cylinder of the loader at different time points when the dipper of the loader is in the upstroke state and is in the preset measurement interval, the method further comprises:

[0042] acquiring an actual position of the dipper of the loader;

[0043] comparing the actual position of the dipper, the preset lower starting position and the preset upper ending position to determine a time position state of the dipper, the actual position state comprising a state of being in the preset measurement interval between the preset lower starting position and the preset upper ending position.

[0044] The technical scheme of the present application is provided with a pressure detection device and a position detection device, the pressure detection device can identify the load of the dipper of the loader, so that the operator of the loader can control the load of the dipper of the loader at any time, and the pressure detection device can also provide load data for the control system, so that the control system can make corresponding response according to the load data provided by the pressure detection device to avoid overloading operation of the loader; at the same time, the position detection device can detect the lifting condition of the dipper of the loader, and the pressure detection device only starts to calculate the load of the dipper when the dipper is running in the preset measurement interval, thereby improving the accuracy of the load calculation of the dipper. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and those skilled in the art can obtain other drawings according to the structures shown in these drawings without any creative effort.

[0046] Figure 1 a structural schematic view of an embodiment of the dipper provided by the present application;

[0047] Figure 2 a flowchart of a first embodiment of the overload protection control method of the loader provided by the present application;

[0048] Figure 3 a flowchart of a second embodiment of the overload protection control method of the loader provided by the present application;

[0049] Figure 4 a flowchart of a third embodiment of the overload protection control method of the loader provided by the present application;

[0050] Figure 5 a flowchart of a fourth embodiment of the overload protection control method of the loader provided by the present application.

[0051] BRIEF DESCRIPTION OF DRAWINGS

[0052] Reference Name Reference Name 1 Bucket 3 Position detection device 11 Boom 31 Hall sensor 12 Bucket body 32 Magnet structure 2 Boom lift cylinder

[0053] The objectives, features and advantages of the present application will be further illustrated with reference to the following embodiments and accompanying drawings. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be apparently and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative work fall within the scope of protection of the present application.

[0055] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the accompanying drawings). If the certain posture changes, the directionality indications also change accordingly.

[0056] In addition, the descriptions involving “first”, “second” and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first” and “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it. When the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection required by the present application.

[0057] The loader is a kind of earthwork construction machinery widely used in highway, railway, building, water and electricity, port, mine and other construction projects. It is mainly used for shoveling soil, sand, lime, coal and other bulk materials. It can also perform light shoveling operation on ore, hard soil and the like. However, the existing loader usually relies on manual judgment to control the load of the loader bucket during construction, which often leads to overload operation of the loader, affecting the service life of the loader, and also has safety hazards.

[0058] To solve the above problems, the present application provides a loader, which aims to provide a loader capable of efficiently, intelligently and accurately identifying the load of the bucket, wherein Figure 1 The structure diagram of an embodiment of the bucket provided by the present application.

[0059] Please refer to Figure 1The loader comprises a vehicle body, a bucket 1, a position detection device 3 and a pressure detection device, the bucket 1 is rotatably installed on the vehicle body along an axis extending in a first direction, the position detection device 3 is used to detect the lifting position of the bucket 1, and the pressure detection device is used to detect the load of the bucket 1.

[0060] The technical scheme of the present application is provided with the pressure detection device and the position detection device 3, the pressure detection device can identify the load of the bucket 1 of the loader, so that the operator of the loader can know the load of the bucket 1 at any time, and the pressure detection device can also provide load data for the control system, so that the control system can make corresponding responses according to the load data provided by the pressure detection device to avoid the overload operation of the loader; at the same time, the position detection device 3 can detect the lifting of the bucket 1 of the loader, and only when the bucket 1 runs in the preset measurement range, the pressure detection device starts to calculate the load of the bucket 1, thereby improving the accuracy of the load calculation of the bucket 1.

[0061] Need to explain, the response of the control system includes reminding the operator, reducing the lifting speed of the bucket 1, stopping the bucket, etc., wherein, in an embodiment of the present application, the bucket 1 has a movable arm 11, the bucket 1 is rotatably installed on the vehicle body along an axis extending in a first direction through the movable arm 11, the loader further comprises a driving assembly, the driving assembly comprises a movable arm lifting oil cylinder 2, an oil circuit control assembly and a circuit board assembly, the movable arm lifting oil cylinder 2 has an oil cylinder body and a telescopic rod, the telescopic rod is movably arranged on the oil cylinder body, the oil cylinder body is fixedly connected with the vehicle body, the telescopic rod is fixedly connected with the movable arm 11, and is used to drive the movable arm 11 to rotate along the axis extending in the first direction, the oil circuit control assembly is used to control the extension direction and extension speed of the telescopic rod, the circuit board assembly is electrically connected with the pressure sensing device and the oil circuit control assembly, and the control system controls the movable arm lifting oil cylinder 2 to control the lifting of the bucket 1.

[0062] Specifically, the control system is taken as the carrier of the circuit board assembly, the control system is stored in the circuit board assembly and connected with the pressure detection device, the position detection device 3, the boom lifting oil cylinder 2 and the oil path control assembly through the circuit board assembly, the first threshold value, the second threshold value, the third threshold value and the fourth threshold value are preset in the control system, when the load of the bucket 1 is greater than the first threshold value and less than the second threshold value, the control system judges that the bucket 1 is in a slight overload state, at this time, the control system does not react, but only reminds the operator that the bucket 1 is overloaded, when the load of the bucket 1 is greater than the second threshold value and less than the third threshold value, the control system judges that the bucket 1 is in a moderate overload state, the control system reminds the operator of the moderate overload, and the control system controls the rotation speed of the oil pump in the oil path control assembly to control the oil supply speed of the oil path control assembly to the boom lifting oil cylinder 2, so as to reduce the operation speed of the telescopic rod of the boom lifting oil cylinder 2 and the lifting speed of the boom 11, thereby achieving the purpose of protecting the bucket 1, further, when the load of the bucket 1 is greater than the third threshold value and less than the fourth threshold value, the control system reminds the operator of the serious overload and issues an alarm, and at the same time, the control system controls the oil pump to stop oil supply, so that the boom 11 stops upward lifting.

[0063] It should be noted that the first threshold value, the second threshold value, the third threshold value and the fourth threshold value can be any value that can judge the overload of the oil cylinder, and the present application does not limit this, in an embodiment of the present application, the ratio of the actual load weight of the bucket 1 of the loader to the maximum allowable load of the bucket 1 of the loader is denoted as k, when 1 < k ≤ 1.1, the control system judges that the loader is slightly overloaded, when 1.1 < k ≤ 1.2, the control system judges that the loader is moderately overloaded, and when 1.2 < k ≤ 1.5, the control system judges that the loader is heavily overloaded.

[0064] The pressure detection device measures the load of the bucket 1 in various ways, the pressure detection device can be a pressure sensor arranged in the bucket, or a resistance sensor arranged on the boom 11, and the present application does not limit this, considering that the bucket 1 belongs to an open environment and needs to frequently contact various corrosive substances in the outside world, the pressure detection device arranged on the bucket 1 is easy to be damaged, and it can be understood that when the loader uses the boom lifting oil cylinder 2 to drive the movement of the bucket 1, the load of the bucket 1 should have a certain mapping relationship with the oil path pressure in the boom lifting oil cylinder 2, therefore, in an embodiment of the present application, the pressure detection device includes an oil pressure sensor, specifically, the oil path control assembly includes an oil pressure sensor, the oil pressure sensor is used to detect the oil path pressure in the oil path control assembly, in this way, the load of the bucket 1 and the oil path pressure in the boom lifting oil cylinder 2 are mapped to obtain the load condition of the bucket 1.

[0065] The bucket 1 load and the oil path pressure in the boom lifting oil cylinder 2 can be obtained through a large number of experiments, for example, the bucket 1 load can be set as M, and the load value of the bucket 1 is calculated through the formula M = a (P-P0), wherein P is the pressure load measured by the oil pressure sensor when the bucket 1 is in a load state, P0 is the pressure load measured by the oil pressure sensor when the bucket 1 is in an empty state, and a is the relationship coefficient between the bucket 1 load M and the oil pressure load, which can be obtained through the formula by continuously changing the size of the bucket 1 load M in the experiment.

[0066] Understandably, when the loader is loading materials, the bucket 1 will be inserted into the material pile, at this time, the lifting of the bucket 1 will not only have the gravity of the materials, but also the friction between the materials, and when the bucket 1 is lifted upward to the vicinity of the limit area of the loader, the bucket 1 will be limited by the machine of the loader, thereby causing the load of the bucket 1 to rise sharply, based on which, when the movement position of the bucket 1 is too low or the movement position of the bucket 1 is too high, the real value of the load of the bucket 1 cannot be obtained, therefore, only when the bucket 1 is located in the preset measurement interval, the load of the bucket 1 measured by the pressure detection device can be close to the real load of the bucket 1, based on which, the position detection device 3 is arranged to detect the lifting position of the bucket 1.

[0067] The position detection device 3 detects the lifting position of the bucket 1 in multiple ways, in an embodiment of the present application, the Hall principle is used to detect the lifting position of the bucket 1, specifically, the bucket 1 has a boom 11, the bucket 1 is rotatably installed on the vehicle body through the axis of the boom 11 extending in the first direction, the position detection device 3 comprises a plurality of Hall sensors 31 and a magnet structure 32, the plurality of Hall sensors 31 are arranged on the vehicle body, the magnet structure 32 is arranged on the opposite side of the boom 11 and the Hall sensors 31, the magnet structure 32 can rotate with the boom 11, and in its movement stroke, the magnet structure 32 can be respectively aligned with the plurality of Hall sensors 31 to generate electrical signals, so as to determine the running position of the boom 11, and further to enable the control system to determine whether the boom 11 is located in the preset measurement interval, so as to ensure the accuracy of the measurement of the pressure detection device.

[0068] The Hall sensor 31 can be replaced by a mechanical contact to enable the control system to grasp the movement of the boom 11, and in another embodiment of the present application, the dipper 1 has a boom 11, the dipper 1 is rotatably mounted on the vehicle body through an axis extending in the first direction, the position detection device 3 comprises a mechanical contact and a plurality of contact sensors, the plurality of contact sensors are arranged on the vehicle body, the mechanical contact is arranged on the opposite side of the boom 11 and the contact sensors, the mechanical contact can rotate with the boom 11, and in its movement stroke, the mechanical contact can respectively touch the plurality of contact sensors to enable the plurality of contact sensors to generate a plurality of different electrical signals, so as to determine the running position of the boom 11, and thus the control system can determine whether the boom 11 is in the preset measurement interval to ensure the accuracy of the measurement of the pressure detection device.

[0069] It can be understood that the movement position of the boom 11 should have a certain mapping relationship with the rotation angle of the boom 11 around the vehicle body, and therefore the Hall sensor 31 can also be replaced by an angle sensor, and in an embodiment of the present application, the dipper 1 has a boom 11, the dipper 1 is rotatably mounted on the vehicle body through an axis extending in the first direction, the position detection device 3 comprises an angle sensor, the angle sensor is arranged on the boom 11 to measure the rotation angle of the boom 11, and through the preset mapping relationship between the rotation angle of the boom 11 and the position of the boom 11 in the control system, the control system can clearly grasp the movement of the boom 11, and thus the control system can determine whether the boom 11 is in the preset measurement interval to ensure the accuracy of the measurement of the pressure detection device.

[0070] At the same time, when the driving assembly adopts the boom lifting oil cylinder 2, the extension length of the telescopic rod of the boom lifting oil cylinder 2 should have a certain mapping relationship with the movement position of the boom 11, and therefore the Hall sensor 31 can also be replaced by a distance sensor, and in an embodiment of the present application, the position detection device 3 further comprises a distance sensor, the distance sensor is arranged on the telescopic rod to detect the distance between the telescopic rod and the oil cylinder body, the control system can obtain the movement position of the boom 11 through the distance between the telescopic rod and the oil cylinder body detected by the distance sensor and the preset mapping relationship between the distance and the movement position of the boom 11 in the system, and thus the control system can determine whether the boom 11 is in the preset measurement interval to ensure the accuracy of the measurement of the pressure detection device.

[0071] The loader further comprises an alarm device electrically connected with the position detection device 3 and the pressure detection device, so that the loader can give an early warning to the operator and remind the operator to pay attention to engineering safety when the bucket 1 is overloaded.

[0072] The bucket 1 comprises a bucket body 12 and a movable arm 11, one end of the movable arm 11 is rotatably installed on the vehicle body in the first direction, and the bucket body 12 is rotatably installed on the other end of the movable arm 11, and the loader further comprises a rotating motor, the rotating motor has a rotating shaft, the rotating shaft extends into the movable arm 11 and is fixedly connected with the bucket body 12 to drive the bucket body 12 to rotate.

[0073] The present application further provides a kind of overload protection control method of loader, please refer to Figure 2 , Figure 2 The first embodiment of the flowchart of the overload protection control method of the loader provided by the present application, the overload protection control method of the loader comprises:

[0074] S10: when the bucket of the loader is in the uplink state and in the preset measurement interval, obtain multiple instantaneous load pressure values at different times on the oil circuit of the movable arm lifting cylinder of the loader.

[0075] It should be noted that the execution subject of the overload protection control method of the loader of the present embodiment can be an overload protection control device of the loader or an overload protection control system containing the device with the same or similar function as the device, and the following will be specifically described with the device.

[0076] It should be noted that for the bucket of the loader in the uplink state and in the preset measurement interval, it can be obtained by manually judging and sending instructions to the overload protection control device, or it can be obtained by the overload protection control device itself, and the present application does not limit this.

[0077] It can be understood that when the loader loads materials, the bucket will be inserted into the material pile, at this time the lifting of the bucket will not only have the gravity of the materials, but also have the friction between the materials, and when the bucket is lifted up to the vicinity of the limit area of the loader, the bucket will be limited by the mechanical limit of the loader, so that the load of the bucket rises sharply, based on this, it can be known that when the movement position of the bucket is too low or the movement position of the bucket is too high, the real value of the load of the bucket cannot be reflected, therefore, for the measurement of the load of the bucket, the movement range when the bucket has no material resistance and no mechanical resistance is needed, which is the preset measurement interval.

[0078] At the same time, the overload protection control device sets a plurality of preset nodes in the preset measurement interval during the upward movement of the bucket, and obtains the pressure value of the oil circuit control assembly when the bucket reaches the preset nodes through the oil pressure sensor arranged in the oil circuit control assembly.

[0079] In a specific implementation, the overload protection control device sets a plurality of preset nodes in the preset measurement interval according to different models of the loader, and obtains a plurality of instantaneous load pressure values when the bucket passes through the preset nodes through the oil pressure sensor arranged in the oil circuit control assembly when the bucket is in the upward state and in the preset measurement interval.

[0080] S20: determining an effective load pressure value according to the plurality of instantaneous load pressure values.

[0081] It can be understood that when the bucket is uniformly ascending, the instantaneous load pressure values obtained by the overload protection control device when the bucket passes through the preset nodes should remain unchanged. However, in actual operation, because the loader and the bucket itself have resistance, the ascending of the bucket cannot be completely uniform, and therefore, the instantaneous load pressure values obtained by the overload protection control device when the bucket passes through the preset nodes are also different. In order to obtain the real load of the oil circuit, in a specific implementation, the overload protection control device fits the plurality of instantaneous load pressure values to form a pressure value curve, and obtains an average pressure value of the plurality of instantaneous load pressure values through the pressure value curve. The average pressure value minus the no-load pressure value of the oil circuit pressure assembly when the bucket is in a no-load state is the effective load pressure value.

[0082] S30: querying a first mapping relationship according to the effective load pressure value to determine an actual load weight, wherein the first mapping relationship includes the correlation between the effective load pressure value and the actual load weight.

[0083] It can be understood that when the bucket uses the boom lifting oil cylinder to provide driving force, the load of the bucket must have a mapping relationship with the oil pressure in the oil circuit. Based on this, the relationship between the load weight of the bucket and the oil pressure can be determined, that is, the first mapping relationship, by repeatedly experimenting, constantly changing the load weight of the bucket, and recording the oil pressure in the oil circuit under each load weight.

[0084] In a specific implementation, the overload protection control device only needs to obtain the real weight in the bucket according to the effective load pressure value and the obtained first mapping relationship.

[0085] S40: determining an overload protection strategy according to the actual load weight.

[0086] The overload protection strategy can be displaying an alarm or slowing down or stopping the operation of the bucket, and the application does not limit this.

[0087] In the above embodiment, the overload protection control device can obtain the instantaneous load pressure value of the bucket in the uplink state and at each preset node in the preset measurement interval through the oil pressure sensor arranged in the oil circuit control assembly, and can calculate the effective load pressure value according to the instantaneous load pressure value, query the first mapping relationship according to the effective load pressure value to determine the actual load weight, and finally determine the overload protection strategy according to the actual load weight to protect the loader and prevent the loader from affecting the service life and use safety of the loader due to overload operation.

[0088] Please refer to Figure 3 , Figure 3 The flowchart of the second embodiment of the overload protection control method of the loader provided by the application, which determines the overload protection strategy according to the actual load weight, includes:

[0089] S410: Calculate the ratio k of the actual load weight to the maximum allowable loading capacity of the bucket of the loader.

[0090] S420: When 1 < k ≤ 1.1, control the display system of the loader to display a mild overload prompt information.

[0091] S430: When 1.1 < k ≤ 1.2, control the display system of the loader to display a moderate overload prompt information, and control the oil pump arranged on the oil circuit of the boom lifting oil cylinder to adjust the rotating speed to reduce the lifting speed.

[0092] S440: When 1.2 < k ≤ 1.5, control the display system of the loader to display a severe overload prompt information, and control the oil pump arranged on the oil circuit of the boom lifting oil cylinder to adjust the rotating speed to stop lifting.

[0093] In the above embodiment, the overload protection control device determines the actual load weight and the maximum allowable loading amount of the bucket of the loader to calculate the ratio k, to determine the actual load weight to determine the overload protection strategy, specifically, when 1

[0094] Please refer to Figure 4 , Figure 4 The flowchart of the third embodiment of the overload protection control method of the loader provided by the present application, before the multiple instantaneous load pressure values of the oil circuit of the boom lifting oil cylinder of the loader at different times are obtained when the bucket of the loader is in the upstroke state and is in the preset measurement interval, further comprises:

[0095] S1: obtaining the actual position of the operating handle of the loader;

[0096] S2: querying the second mapping relationship according to the actual position of the operating handle to determine the actual operating state of the bucket of the loader, wherein the actual operating state comprises the upstroke state.

[0097] It can be understood that the loader generally controls the forward and backward movement of the loader and the lifting and lowering of the bucket through the operating handle, so there should be a mapping relationship between the operating handle and the actual operating state of the bucket of the loader, i.e. the second mapping relationship. Through the second mapping relationship, the overload protection control device can obtain whether the bucket is in the upstroke state.

[0098] In the above embodiment, the actual position of the operating handle is used to query the second mapping relationship to determine the actual operating state of the bucket of the loader. Compared with manually observing and then giving an instruction to the overload protection control device, the upstroke state can be obtained more quickly and efficiently through the actual position of the operating handle.

[0099] Please refer to Figure 5 , Figure 5 The flowchart of the fourth embodiment of the overload protection control method of the loader provided by the present application, before the multiple instantaneous load pressure values of the oil circuit of the boom lifting oil cylinder of the loader at different times are obtained when the bucket of the loader is in the upstroke state and is in the preset measurement interval, further comprises:​

[0100] S3: Obtain the actual position of the bucket of the loader.

[0101] It should be noted that the actual position of the bucket refers to the position of the bucket during the upward process, and in specific implementation, the position detection device is arranged in the loader, which can be a magnet structure arranged on the bucket of the loader and a Hall sensor arranged on the vehicle body, or an angle sensor for measuring the rotation angle of the bucket, and the present application does not limit this. The actual position of the bucket can be obtained through the position detection device.

[0102] S4: Compare the actual position of the bucket, the preset lower starting position and the preset upper ending position to determine the time position state of the bucket, and the actual position state includes a preset measurement interval state between the preset lower starting position and the preset upper ending position.

[0103] It should be noted that according to the above analysis, the actual load weight measured by the pressure detection device is most accurate when the bucket is in the preset measurement interval, so the lower starting point and the upper ending point are arranged during the upward process of the bucket, and the lower starting point and the upper ending point jointly define the preset measurement interval, and each has a Hall sensor to test whether the bucket enters or leaves the preset measurement interval.

[0104] In the above embodiment, the overload protection control device measures the actual position of the bucket through the position detection device arranged on the loader, and determines the time position state of the bucket by comparing the actual position of the bucket, the preset lower starting position and the preset upper ending position, and the actual position state includes a preset measurement interval state between the preset lower starting position and the preset upper ending position. In this way, the overload protection control device can more accurately determine the running state of the bucket, and improve the running accuracy of the overload protection control device.

[0105] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the inventive concept of the present application, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. An overload protection control method of a loader characterized by, The method comprises the following steps: When the bucket of the loader is in the upgoing state and in the preset measurement interval, a plurality of instantaneous load pressure values at different time points on the oil circuit of the boom lifting cylinder of the loader are obtained; An effective load pressure value is determined according to the plurality of instantaneous load pressure values; An actual load weight is determined according to the effective load pressure value by querying a first mapping relationship, wherein the first mapping relationship comprises the correlation between the effective load pressure value and the actual load weight; An overload protection strategy is determined according to the actual load weight; The determination of the overload protection strategy according to the actual load weight comprises: A ratio k of the actual load weight to the maximum allowable loading capacity of the bucket of the loader is calculated; When 1 < k ≤ 1.1, a display system of the loader is controlled to display a light overload prompt information; When 1.1 < k ≤ 1.2, the display system of the loader is controlled to display a moderate overload prompt information, and an oil pump arranged on the oil circuit of the boom lifting cylinder is controlled to adjust the rotation speed to reduce the lifting speed; When 1.2 < k ≤ 1.5, the display system of the loader is controlled to display a heavy overload prompt information, and the oil pump arranged on the oil circuit of the boom lifting cylinder is controlled to adjust the rotation speed to stop lifting; Before the plurality of instantaneous load pressure values at different time points on the oil circuit of the boom lifting cylinder of the loader are obtained when the bucket of the loader is in the upgoing state and in the preset measurement interval, the method further comprises: An actual position of an operating handle of the loader is obtained; An actual operating state of the bucket of the loader is determined by querying a second mapping relationship according to the actual position of the operating handle, wherein the actual operating state comprises the upgoing state.

2. The overload protection control method of a loader as claimed in claim 1, characterized in that, Before the plurality of instantaneous load pressure values at different time points on the oil circuit of the boom lifting cylinder of the loader are obtained when the bucket of the loader is in the upgoing state and in the preset measurement interval, the method further comprises: An actual position of the bucket of the loader is obtained; The actual position state of the bucket is determined by comparing the actual position of the bucket, a preset lower starting point position and a preset upper ending point position, wherein the actual position state comprises the preset measurement interval state between the preset lower starting point position and the preset upper ending point position.

3. A loader for implementing the overload protection control method of the loader as claimed in any one of claims 1 to 2, characterized by, The loader comprises: a vehicle body; a bucket rotatably mounted on the vehicle body along an axis extending in a first direction; a position detection device configured to detect a lifting position of the bucket; and a pressure detection device configured to detect a load of the bucket. The bucket has a boom, and the bucket is rotatably mounted on the vehicle body along an axis extending in a first direction through the boom. The loader further comprises a driving assembly, which comprises: a boom lifting cylinder having a cylinder body and a telescopic rod movably arranged on the cylinder body, the cylinder body being fixedly connected to the vehicle body, and the telescopic rod being fixedly connected to the boom to drive the boom to rotate along the axis extending in the first direction; an oil circuit control assembly configured to control the extension direction and extension speed of the telescopic rod; and a circuit board assembly electrically connected to the pressure detection device and the oil circuit control assembly. ​ The oil path control assembly comprises an oil pressure sensor for detecting the oil path pressure in the oil path control assembly. The pressure detection device comprises the oil pressure sensor. The bucket has a boom, and the bucket is rotatably mounted on the vehicle body along an axis extending in a first direction by the boom. The position detection device comprises a plurality of Hall sensors and a magnet structure. The magnet structure is arranged on the opposite side of the boom and the Hall sensors, and can rotate with the boom.

4. The loader of claim 3, wherein, The magnet structure can be aligned with the Hall sensors in the movement range of the magnet structure to generate electrical signals.

5. The loader of claim 3, wherein, The Hall sensors and the magnet structure are replaced by distance sensors arranged on the telescopic rod to detect the distance between the telescopic rod and the cylinder body. The Hall sensors and the magnet structure are replaced by angle sensors arranged on the boom to measure the rotation angle of the boom. The Hall sensors and the magnet structure are replaced by mechanical contacts and a plurality of contact sensors arranged on the vehicle body.

6. The loader of claim 3, wherein, The mechanical contacts are arranged on the opposite side of the boom and the contact sensors, and can rotate with the boom. The mechanical contacts can be aligned with the contact sensors in the movement range of the mechanical contacts to generate different electrical signals. The loader further comprises an alarm device electrically connected with the position detection device and the pressure detection device. The bucket comprises a bucket body and a rotating arm rotatably mounted on the vehicle body at one end. The bucket body is rotatably mounted on the other end of the rotating arm.

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