Rice Transplanter Cam PM Sintered Part
The recommended heat treatment temperature for 45 steel stipulated in GB/T699-1999 standard is 850°C for normalizing, 840°C for quenching, and 600°C for tempering, and the performance achieved is yield strength ≥ 355MPa The GB/T699-1999 standard stipulates that the tensile strength of 45 steel is 600MPa, the yield strength is 355MPa, the elongation is 16%, and the reduction of area is 40%.
Product Introduction
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Rice transplanter cam PM sintered part |
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Item |
Material |
Production Process |
Sintering Temperature |
Mold |
Custom |
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rice transplanter cam |
45 steel |
Powder metallurgy pressing |
1180℃ |
To be customized |
Yes |
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Chemical composition |
C:0.42～0.50； Cr：≤0.25； Mn：0.50～0.80； Ni：≤0.25； P：≤0.035； S：≤0.035； Si：0.17～0.37 |
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Available Materials |
Low carbon stainless steel, titanium alloy (Ti, TC4), copper alloy, tungsten alloy, hard alloy, high temperature alloy (718, 713) |
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Product advantages
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Smoothness |
Dimensional accuracy |
Product density |
Appearance treatment |
Appropriate weight |
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Roughness 1～5μm |
（±0.1%～±0.5%） |
7.3-7.6g/CM³ |
heat treatment/grinding |
0.03g～400g） |
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Mechanical behavior |
σb\MPa:≥600 σs\MPa:≥355 δ5\%:≥16 ψ\%:≥40 hardness\HB:≤197 The recommended heat treatment temperature for 45 steel stipulated in GB/T699-1999 standard is 850°C for normalizing, 840°C for quenching, and 600°C for tempering, and the performance achieved is yield strength ≥ 355MPa The GB/T699-1999 standard stipulates that the tensile strength of 45 steel is 600MPa, the yield strength is 355MPa, the elongation is 16%, and the reduction of area is 40%. |
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heat treatment |
Heat treatment process of 45# (number) steel and 40Cr steel quenched and tempered Quenching and tempering is a double heat treatment of quenching and high temperature tempering, the purpose of which is to make the workpiece have good comprehensive mechanical properties. There are two types of quenched and tempered steel: carbon quenched and tempered steel and alloy quenched and tempered steel. Whether it is carbon steel or alloy steel, the carbon content is strictly controlled. If the carbon content is too high, although the strength of the quenched and tempered workpiece is high, the toughness is not enough. If the carbon content is too low, the toughness is increased but the strength is insufficient. In order to obtain good comprehensive performance of the quenched and tempered parts, the carbon content is generally controlled at 0.30~0.50%. During tempering and quenching, the entire cross-section of the workpiece is required to be hardened, so that the workpiece can obtain a microstructure dominated by fine needle-shaped quenched martensite. Through high-temperature tempering, a microstructure dominated by uniformly tempered sorbite is obtained. It is impossible for small factories to conduct metallographic analysis for each furnace, and generally only do hardness testing, that is to say, the hardness after quenching must reach the quenching hardness of the material, and the hardness after tempering should be checked according to the requirements of the diagram. |
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Research
Existing rice transplanters, especially ride-on high-speed rice transplanters, generally include an engine unit, a hydraulic stepless speed regulation system HST (hydraulic static transmission-HST), a gearbox assembly, a front axle, a rear axle, a main support, and a rear axle. The planting part and the seedbed support on the planting part, etc. The engine drives the HST through a belt, and the output shaft of the HST is rigidly connected to the input shaft of the rice transplanter gearbox. The output shaft of the gearbox is divided into the first output shaft driving the four-wheel walking and the second output shaft driving the planting part of the rice transplanter. The transmission system transmits power to the walking device and the rice transplanting device, that is, the gearbox needs to provide power to the four driving wheels and the planting part at the same time, and the planting arm is inserted for transplanting while walking. Chinese patent (application number CN201410247564.5, application date 20140605, authorized announcement number CN104025785B, authorized announcement date 20170517) discloses a planting part assembly of a hand-held rice transplanter, which is a non-riding hand-held The rice transplanter also includes a transplanting part.
Chinese patent (application number CN201911367203.3, application date 20191226, publication number CN111003589A, publication date 20200414) discloses a cylindrical cam type cable arrangement. Chinese patent (application number CN201911241748.X, application date 20191206, publication number CN111005336A, publication date 20200414) discloses a municipal road sweeper based on cylindrical cam rotation. Chinese patent (application number CN201110154950.6, application date 20110609, authorized announcement number CN102229359B, authorized announcement date 20130417) discloses a cylindrical cam flapping wing drive mechanism. These three Chinese patents all include the typical structure and usage of cylindrical cams. When the rice transplanter is planting the seedlings, the transplanting components must first separate the seedlings from the seedling blanket one by one. The seedling blanket is installed on the seedbed support, the rice transplanter moves forward longitudinally, and the seedbed support moves laterally to perform linear reciprocating motion. This linear motion is usually performed by The second output shaft of the gearbox is transformed by a cylindrical cam after it rotates. The cylindrical cam responds quickly and has a simple and compact structure. The cylindrical cam active rotary part has a built-in helical curve shape distribution profile, and has a follower guide key, and the second output shaft of the gearbox drives the cam main screw shaft to rotate in one direction (similar to the engine in a traditional car, only one The direction of rotation, the reverse gear needs to increase the reverse rotation of the reverse gear), the follower guide key drives the seedbed support to move in a straight line in the spiral track, and after the seedbed support moves to the end of one end, the follower guide key moves along the cam The spiral track of the curved profile reverses and moves to the other end, so that the unidirectional rotation of the second output shaft of the gearbox is converted into the linear reciprocating lateral swing of the seedbed support (similar to the periodic swing of a simple pendulum).
The cylindrical cam structure applied to the horizontal linear reciprocating motion of the rice transplanter has some disadvantages: 1. The cam and the follower are in point contact or line contact, which is easy to wear and is only suitable for occasions where the force transmission is not large; 2. The accuracy of the cam profile Higher, need to use CNC machine tools for processing.
After several years of actual use of the cylindrical cam structure applied to the horizontal linear reciprocating motion of the rice transplanter, there may be problems: 1. The lubricating oil added is of poor quality or has not been replaced for a long time; or the external sheath is damaged after repeated stretching and the lubricating oil leaks , The active rotating part of the cam and the guide key of the follower part intensify the wear and tear during operation in harsh environments; 2. Or the lack of machining accuracy at some inflection points of the cam causes the spiral track to wear out; When the track is a single track without a branch, the transition is smooth; but when changing from the critical point to the reverse track, there is a branch at the junction and if the junction of the branch is due to lack of oil or the track processing technology is not good enough, the spiral track will diverge. The fork is worn and deformed, or the lower part of the crescent bud of the guide key is thinned, and the deviation may cause a stuck fault. The screw shaft rotates but the guide key cannot move to further aggravate the wear. Afterwards, the second output shaft of the gearbox unidirectionally rotates clockwise, the active rotation shaft of the cam rotates idly, the follower guide key stagnates as if stuck, the seedbed no longer moves laterally, and the rice transplanting operation terminates. This can easily lead to user complaints: (1) In the busy farming season, the after-sales service personnel have to be asked to replace the follower guide key or the active screw shaft at the same time, which greatly delays the farming time in remote areas; (2) The cam mechanism and The guide key is a precision part, and the installation and disassembly workload is relatively large; (3) The rice transplanter needs to be driven out for field maintenance, and some fields will affect the orderliness of the next operation.
Chinese patent (application number CN202010999275.6, application date 20200922, publication number CN111903295A, publication date 20201110) discloses a large rice seedling transplanter, which introduces the optimization of the non-uniform speed transmission characteristics of the phase-changing elliptical gear system, which can adapt to higher For the seedlings, by making the translational movement of the seedling-carrying platform regular and intermittent, the seedling blanket can be made to stay for a period of time for each movement of a certain distance for the transplanting component to separate the seedlings.
Chinese patent (application number CN201911033640.1, application date 20191028, publication number CN110735903A, publication date 20200131) discloses a ride-on rice transplanter for laterally moving delivery boxes, and introduces the power input shaft, The power transmission shaft, the transmission shaft of the traversing box and the screw shaft are provided with a guide groove on the screw shaft, and the slider is arranged in the guide groove. The slider moves reciprocatingly with the rotation of the screw shaft, and a guide column is also arranged on the slider.
The above-mentioned patent does not involve the device content of the reversing problem in the linear reciprocating mechanism (transverse box) of the rice transplanter, and does not explain the preventive solutions for faults such as reversing sticking of the drive mechanism of the planting part.
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