WO2023173391A1 - Crankshaft of seven-bellcrank six-support structure and machining process therefor - Google Patents

Abstract

A crankshaft of a seven-bellcrank six-support structure. A through-type central lubricating oil hole (20) is formed in the crankshaft and located at the rotation center of an input shaft (1); branch lubricating oil holes communicated with the through-type central lubricating oil hole (20) are formed in all connecting rods; the front three bellcranks and the rear three bellcranks of the crankshaft are mirror-symmetrically distributed relative to a middle bellcrank; and a keyway (28) is formed on the input shaft (1) of the crankshaft. The crankshaft is different from a traditional seven-bellcrank that needs eight supports, and only needs six supports, is smaller in required size, and is not fully supported. Further provided is a machining method for a crankshaft, comprising the following steps: performing rough machining on the crankshaft by using a turning-milling composite machining center, i.e., sequentially performing rough turning, fine turning, fine milling, and milling machining on a keyway (28), and performing drilling machining on a through-type central lubricating oil hole (20) and all branch lubricating oil holes; and performing fine grinding on the crankshaft by using a numerically controlled crankshaft grinding machine. According to the method, a high-precision device is used for machining, so that high-speed cutting machining can be achieved, a requirement for machining precision can also be satisfied, guarantee is provided for the machining precision of a seven-bellcrank six-support crankshaft, and the machining efficiency of the crankshaft is improved.

Description

A crankshaft with seven cranks and six supports and its processing technology Technical field

The invention belongs to the technical field of crankshaft structure design and processing, and in particular relates to a crankshaft with a seven-crank and six-support structure and its processing technology.

Background technique

After entering the 21st century, equipment innovation has accelerated, large-scale equipment has emerged in an endless stream, and the requirements for crankshafts have gradually increased. Simple four-crank crankshafts and six-crank crankshafts can no longer meet the needs of current equipment. At the same time, crankshafts are in manufacturing technology, Great changes have also taken place in cutting tools and other aspects. The traditional multi-tool turning process and manual grinding process have become increasingly difficult to meet the crankshaft precision processing requirements for large equipment due to low processing accuracy and poor flexibility.

At present, rough machining equipment generally uses multi-tool lathes to turn crankshaft main journals and connecting rod journals. The quality of the process is poor, it is easy to produce large machining stress, and it is difficult to achieve a reasonable machining allowance. Finishing machining generally uses ordinary crankshaft grinders for a series of processes such as rough grinding, semi-finishing grinding, fine grinding, and polishing. The above processes usually rely on manual operations, and there are problems with unstable processing quality and poor dimensional consistency. In addition, most of the production lines used to process crankshafts are ordinary equipment. For rough machining, ordinary external milling is used to process the main journal and connecting rod neck, and then CNC precision turning of the main journal and connecting rod neck is carried out, and then after multiple processes of grinding, it is transferred to finishing. process.

Therefore, the traditional crankshaft processing method results in too many production line equipment, long product turnover lines, and large site occupation. Its production efficiency is entirely improved by decomposing the processes and margins of multiple equipment, and the improvement capacity is extremely limited.

Contents of the invention

In view of the problems existing in the prior art, the present invention provides a seven-crank and six-support structure crankshaft and its processing technology. The seven-crank and six-support structure crankshaft is smaller in size than the traditional fully supported crankshaft, and can reduce the overall cost of the equipment. Compared with the fully supported crankshaft, the connecting rod and crank are reduced in size, which can improve processing efficiency and reduce processing costs; compared with the traditional crankshaft processing technology, the new process uses high-precision equipment, which can not only achieve high-speed cutting processing, but also meet the requirements of The machining accuracy is required to provide guarantee for the machining accuracy of the crankshaft with seven crankshafts and six supports, and at the same time improve the processing efficiency of the crankshaft. It can not only ensure the working reliability of the crankshaft with seven crankshafts and six supports, but also improve production efficiency and increase economic benefits. It provides the crankshaft with Provide new ideas for structural design and processing.

In order to achieve the above object, the present invention adopts the following technical solution: a crankshaft with seven crankshafts and six supports, including an input shaft, a front end spindle, a first crank, a first connecting rod, a first support, a second connecting rod, and a second crank. , the third connecting rod, the second bearing, the fourth connecting rod, the third bearing, the fifth connecting rod, the third crank, the sixth connecting rod, the fourth bearing, the seventh connecting rod, the fourth crank, the rear end spindle and Rear end shaft; the input shaft, front end spindle, first crank, first connecting rod, first support, second connecting rod, second crank, third connecting rod, second support, fourth connecting rod, third The support, fifth connecting rod, third crank, sixth connecting rod, fourth support, seventh connecting rod, fourth crank, rear end spindle and rear end shaft are sequentially distributed along the axial direction.

In the input shaft, front spindle, first crank, first connecting rod, first support, second connecting rod, second crank, third connecting rod, second support, fourth connecting rod, third support, third The five connecting rods, the third crank, the sixth connecting rod, the fourth bearing, the seventh connecting rod, the fourth crank, the rear end spindle and the rear end shaft are provided with through-type central lubricating oil holes along the axial direction, and the through-type center The lubricating oil hole is located at the center of rotation of the input shaft.

First branch lubricating oil is respectively provided in the first, second, third, fourth, fifth, sixth and seventh connecting rods along the radial direction. holes, the second branch lubrication oil hole, the third branch lubrication oil hole, the fourth branch lubrication oil hole, the fifth branch lubrication oil hole, the sixth branch lubrication oil hole and the seventh branch lubrication oil hole, The seven branch lubrication oil holes are all connected with the through-type central lubrication oil hole.

The front spindle, first crank, first connecting rod, first support, second connecting rod, second crank and third connecting rod constitute the first three cranks, and the fifth connecting rod, third crank and sixth connecting rod The connecting rod, the fourth support, the seventh connecting rod, the fourth crank and the rear end spindle form the rear three cranks, the second support, the fourth connecting rod and the third support form the middle crank, and the front three cranks and the rear The three cranks are distributed mirror-symmetrically relative to the middle crank.

A keyway is provided on the input shaft.

A processing technology for a seven-crank and six-support structure crankshaft, including the following steps:

Step 1: Select a turn-milling composite machining center, complete the clamping of the crankshaft to be processed in the turn-milling composite machining center, and complete the subsequent rough machining process of the crankshaft through the turn-milling composite machining center;

Step 2: First rough-turn the entire crankshaft, then fine-turn the rough-turned crankshaft, then fine-mill the fine-turned crankshaft, then mill keyway 28 on the fine-milled crankshaft, and finally finish milling The rear crankshaft is drilled and processed with a through-type central lubrication oil hole and all branch lubrication oil holes;

Step 3: Select a CNC crankshaft grinder, take out the rough-machined crankshaft from the turning-milling compound machining center, and then clamp it into the CNC crankshaft grinder. Finally, the crankshaft is finely ground through the CNC crankshaft grinder until the crankshaft is completed. Finishing process.

In step two, the selected CNC crankshaft grinder uses CBN grinding wheels, the grinding linear speed is 120m/s, and it is equipped with a double grinding wheel headstock.

In step two, when machining the keyway, use A1 ₂ O ₃ , TiC or ZrO ₂ outer coating tools.

In step two, when processing the through-type central lubricating oil hole and all branch lubricating oil holes, a carbide gun drill is used.

In step two, when drilling the through-type center lubricating oil hole, the through-type center lubricating oil hole needs to be processed in two times. The first drilling process uses the axial end face of the input shaft as the positioning surface to complete the first three crankshaft sides. To process the through-type central lubricating oil hole, the second drilling process uses the axial end face of the rear end shaft as the positioning surface to complete the processing of the through-type central lubricating oil hole on the rear three crank side.

Beneficial effects of the present invention:

The seven-crank and six-support structure crankshaft of the present invention and its processing technology. The seven-crank and six-support structure crankshaft is smaller in volume than the traditional fully supported crankshaft, and can reduce the total volume of the equipment. Compared with the fully supported crankshaft, the connecting rod The number of crankshafts and crankshafts is reduced, which can improve processing efficiency and reduce processing costs; compared with the traditional crankshaft processing technology, the new process uses high-precision equipment, which can not only achieve high-speed cutting processing, but also meet the requirements of processing accuracy. It is seven crankshafts and six crankshafts. It guarantees the machining accuracy of the supported crankshaft and improves the crankshaft machining efficiency. It not only ensures the working reliability of the seven crankshaft and six supported crankshafts, but also improves production efficiency, increases economic benefits, and provides new ideas for crankshaft structural design and processing.

Description of the drawings

Figure 1 is a schematic structural diagram of a crankshaft with seven cranks and six supports according to the present invention;

In the figure, 1—input shaft, 2—front spindle, 3—first crank, 4—first connecting rod, 5—first bearing, 6—second connecting rod, 7—second crank, 8—third connecting rod. Rod, 9—second support, 10—fourth connecting rod, 11—third support, 12—fifth connecting rod, 13—third crank, 14—sixth connecting rod, 15—fourth support, 16—th Seven connecting rods, 17—fourth crank, 18—rear end spindle, 19—rear end shaft, 20—through-type center lubricating oil hole, 21—first branch lubricating oil hole, 22—second branch lubricating oil hole , 23—Third branch lubrication oil hole, 24—Fourth branch lubrication oil hole, 25—Fifth branch lubrication oil hole, 26—Sixth branch lubrication oil hole, 27—Seventh branch lubrication oil hole , 28—Keyway.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, a crankshaft with seven cranks and six supports includes an input shaft 1, a front spindle 2, a first crank 3, a first connecting rod 4, a first support 5, a second connecting rod 6, and a second crank. 7. Third connecting rod 8, second support 9, fourth connecting rod 10, third support 11, fifth connecting rod 12, third crank 13, sixth connecting rod 14, fourth support 15, seventh connecting rod 16. The fourth crank 17, the rear end spindle 18 and the rear end shaft 19; the input shaft 1, the front end spindle 2, the first crank 3, the first connecting rod 4, the first support 5, the second connecting rod 6, the third Second crank 7, third connecting rod 8, second support 9, fourth connecting rod 10, third support 11, fifth connecting rod 12, third crank 13, sixth connecting rod 14, fourth support 15, seventh The connecting rod 16, the fourth crank 17, the rear main shaft 18 and the rear shaft 19 are sequentially distributed along the axial direction.

In the input shaft 1, front spindle 2, first crank 3, first connecting rod 4, first support 5, second connecting rod 6, second crank 7, third connecting rod 8, second support 9, third Four connecting rods 10, third bearing 11, fifth connecting rod 12, third crank 13, sixth connecting rod 14, fourth bearing 15, seventh connecting rod 16, fourth crank 17, rear end spindle 18 and rear end A through-type central lubricating oil hole 20 is provided in the shaft 19 along the axial direction, and the through-type central lubricating oil hole 20 is located at the rotation center of the input shaft 1 .

The first connecting rod 4, the second connecting rod 6, the third connecting rod 8, the fourth connecting rod 10, the fifth connecting rod 12, the sixth connecting rod 14 and the seventh connecting rod 16 are respectively arranged in the radial direction. There are 21 lubricating oil holes for the first branch, 22 lubricating oil holes for the second branch, 23 lubricating oil holes for the third branch, 24 lubricating oil holes for the fourth branch, 25 lubricating oil holes for the fifth branch, and 25 lubricating oil holes for the sixth branch. The lubricating oil hole 26 and the seventh branch lubricating oil hole 27 are all connected with the through-type central lubricating oil hole 20 .

The front spindle 2, the first crank 3, the first connecting rod 4, the first support 5, the second connecting rod 6, the second crank 7 and the third connecting rod 8 constitute the first three cranks, and the fifth connecting rod 12. The third crank 13, the sixth connecting rod 14, the fourth support 15, the seventh connecting rod 16, the fourth crank 17 and the rear end spindle 18 constitute the rear three cranks. The second support 9 and the fourth connecting rod 10 and the third support 11 form a middle crank, and the first three cranks and the rear three cranks are mirror-symmetrically distributed relative to the middle crank.

A keyway 28 is provided on the input shaft 1 .

Specifically, the crankshaft with seven cranks and six supports of the present invention is different from the traditional fully supported crankshaft that requires eight supports under the condition of seven cranks. Eight supports require a larger volume, while the present invention only requires six supports. , the required volume is smaller, and it is an incomplete support. During the crankshaft rotation process of the present invention, since the rotation centers of the seven connecting rods are in an eccentric state with the rotation center of the input shaft 1, each connecting rod will come into contact with the lubricating oil every time it rotates, thereby causing the lubricating oil to enter the corresponding The lubrication work is completed in the branch lubricating oil hole. At the same time, the lubricating oil entering the branch lubricating oil hole will also flow into the through-type central lubricating oil hole 20, so that the lubrication of all positions of the entire crankshaft can be achieved, and the crankshaft can be prevented from being damaged during operation. Larger friction occurs, thus avoiding any impact on the overall reliability of the crankshaft system.

A processing technology for a seven-crank and six-support structure crankshaft, including the following steps:

Step 1: Select a turn-milling composite machining center, complete the clamping of the crankshaft to be processed in the turn-milling composite machining center, and complete the subsequent rough machining process of the crankshaft through the turn-milling composite machining center;

Specifically, the turning and milling compound machining center is used to rough machine the crankshaft. Compared with traditional rough machining that requires multiple machine tools, errors caused by repeated clamping and positioning of the workpiece are avoided. The workpiece only needs to pass through the turning and milling compound machining center once. Clamping, because the turn-milling compound machining center integrates deep hole boring, milling, drilling and three-coordinate functions, the workpiece can be processed with all features on the crankshaft through one clamping, preventing the reduction of processing accuracy due to repeated clamping and positioning. ;

Step 2: First rough-turn the entire crankshaft, then fine-turn the rough-turned crankshaft, then fine-mill the fine-turned crankshaft, then mill keyway 28 on the fine-milled crankshaft, and finally finish milling The rear crankshaft is drilled and processed with a through-type central lubricating oil hole 20 and all branch lubricating oil holes;

Step 3: Select a CNC crankshaft grinder, take out the rough-machined crankshaft from the turning and milling compound machining center, and then clamp it into the CNC crankshaft grinder. Finally, the crankshaft is finely ground through the CNC crankshaft grinder until the crankshaft is completed. Finishing process.

In step two, the selected CNC crankshaft grinder uses CBN grinding wheels, the grinding linear speed is 120m/s, and it is equipped with a double grinding wheel headstock.

In step two, when machining the keyway 28, an A1 ₂ O ₃ , TiC or ZrO ₂ outer coating tool is used.

In step two, when processing the through-type central lubricating oil hole 20 and all branch lubricating oil holes, a carbide material gun drill is used.

In step two, when drilling the through-type central lubricating oil hole 20, the through-type central lubricating oil hole 20 needs to be processed in two times. The first drilling process uses the axial end face of the input shaft 1 as the positioning surface, and the first three steps are completed. To process the through-type central lubricating oil hole 20 on the crank side, the second drilling process uses the axial end face of the rear end shaft 19 as the positioning surface to complete the processing of the through-type central lubricating oil hole 20 on the rear three crank side.

Specifically, using the selected CNC crankshaft grinder can shorten the processing time by 50%, save more than 50% of the processing cost, have extremely high processing efficiency, and have good economics; the selected CNC crankshaft grinder can reduce the processing time by 50% by applying workpiece rotation and Grinding wheel feed servo linkage control technology can complete the fine grinding of all connecting rods and supports with one clamping without changing the crankshaft rotation center; the selected CNC crankshaft grinding uses a hydrostatic spindle, a hydrostatic guide rail, and a hydrostatic feed wire Bar, double grinding wheel headstock and linear grating closed-loop control, using the control system produced by TOYADA Machinery, the roundness accuracy after grinding can reach 0.002mm; in addition, in terms of tool selection, it is not limited to high-speed steel and carbide. Superhard material tools can also be used. When processing the keyway 28, A1 ₂ O ₃ , TiC or ZrO ₂ outer coating tools can be used. These tools are more durable and capable of high-precision milling. When processing through When installing the center lubricating oil hole 20 and all branch lubricating oil holes, gun drills are used instead of ordinary extended high-speed steel drill bits, and carbide materials are used instead of high-speed steel materials. The improvement of tool materials plays an important role in the development of crankshaft machining technology. effect. Superhard material tools create conditions for processing difficult-to-machine materials. At the same time, due to their high hardness, tool wear during processing is relatively small, which can extend the tool replacement cycle, make the processing process more efficient, and improve the overall processing efficiency. In addition, due to the strength of the tool itself, The improvement of the tool deformation during the process of machining the crankshaft is relatively small, which can improve the machining accuracy. Using the composite machining method, the machining accuracy required for each area of the crankshaft is different, and the machining technology suitable for its use is also different. Using The composite machining method can select more reasonable machining methods for different positions to achieve processing work, thereby alleviating the relatively low production efficiency and automation caused by the traditional crankshaft production line, which is mostly composed of ordinary machine tools and special machine tools.

The solutions in the examples are not intended to limit the scope of patent protection of the present invention. Any equivalent implementation or modification that does not depart from the scope of the present invention is included in the patent scope of this case.

Claims (10)

1. A crankshaft with seven cranks and six supports, which is characterized in that it includes an input shaft, a front-end spindle, a first crank, a first connecting rod, a first support, a second connecting rod, a second crank, a third connecting rod, a second Support, fourth connecting rod, third support, fifth connecting rod, third crank, sixth connecting rod, fourth support, seventh connecting rod, fourth crank, rear end spindle and rear end shaft; the input shaft , front end spindle, first crank, first connecting rod, first support, second connecting rod, second crank, third connecting rod, second support, fourth connecting rod, third support, fifth connecting rod, third The third crank, the sixth connecting rod, the fourth bearing, the seventh connecting rod, the fourth crank, the rear end spindle and the rear end shaft are sequentially distributed along the axial direction.
2. A crankshaft with seven cranks and six supports according to claim 1, characterized in that: the input shaft, the front end spindle, the first crank, the first connecting rod, the first support, the second connecting rod, the second Crank, third connecting rod, second bearing, fourth connecting rod, third bearing, fifth connecting rod, third crank, sixth connecting rod, fourth bearing, seventh connecting rod, fourth crank, rear end spindle A through-type central lubricating oil hole is provided in the rear end shaft along the axial direction, and the through-type central lubricating oil hole is located at the rotation center of the input shaft.
3. A crankshaft with seven cranks and six supports according to claim 2, characterized in that: in the first connecting rod, the second connecting rod, the third connecting rod, the fourth connecting rod, the fifth connecting rod, and the third connecting rod, The six connecting rods and the seventh connecting rod are respectively provided with a first branch lubrication oil hole, a second branch lubrication oil hole, a third branch lubrication oil hole, a fourth branch lubrication oil hole, and a fifth branch lubrication oil hole along the radial direction. Lubricating oil hole of the first branch, the lubricating oil hole of the sixth branch and the lubricating oil hole of the seventh branch. The seven lubricating oil holes of the branch are all connected with the through-type central lubricating oil hole.
4. A crankshaft with seven cranks and six supports according to claim 1, characterized in that: the front spindle, the first crank, the first connecting rod, the first support, the second connecting rod, the second crank and the third The connecting rods constitute the front three cranks, the fifth connecting rod, the third crank, the sixth connecting rod, the fourth support, the seventh connecting rod, the fourth crank and the rear end spindle constitute the rear three cranks, and the second The support, the fourth connecting rod and the third support form a middle crank, and the front three cranks and the rear three cranks are mirror-symmetrically distributed relative to the middle crank.
5. A crankshaft with seven cranks and six supports according to claim 1, characterized in that: a keyway is provided on the input shaft.
6. The processing technology of the crankshaft with seven cranks and six supporting structures according to claim 1, which is characterized in that it includes the following steps:

   Step 1: Select a turn-milling composite machining center, complete the clamping of the crankshaft to be processed in the turn-milling composite machining center, and complete the subsequent rough machining process of the crankshaft through the turn-milling composite machining center;

   Step 2: First rough-turn the entire crankshaft, then fine-turn the rough-turned crankshaft, then fine-mill the fine-turned crankshaft, then mill keyway 28 on the fine-milled crankshaft, and finally finish milling The rear crankshaft is drilled and processed with a through-type central lubrication oil hole and all branch lubrication oil holes;

   Step 3: Select a CNC crankshaft grinder, take out the rough-machined crankshaft from the turning and milling compound machining center, and then clamp it into the CNC crankshaft grinder. Finally, the crankshaft is finely ground through the CNC crankshaft grinder until the crankshaft is completed. Finishing process.
7. The processing technology of a crankshaft with seven cranks and six supports according to claim 6, characterized in that: in step two, the selected CNC crankshaft grinding uses a CBN grinding wheel, the grinding linear speed is 120m/s, and a double grinding wheel head is configured shelf.
8. The processing technology of a crankshaft with a seven-crank and six-support structure according to claim 6, characterized in that in step two, when processing the keyway, an A1 ₂ O ₃ , TiC or ZrO ₂ outer coating tool is used.
9. The processing technology of the seven crankshaft and six support structure crankshaft according to claim 6, characterized in that: in step two, when processing the through-type central lubricating oil hole and all branch lubricating oil holes, a carbide material gun is used Drill.
10. The processing technology of the crankshaft with seven cranks and six supports according to claim 6, characterized in that in step two, when drilling the through-type central lubricating oil hole, the through-type central lubricating oil hole needs to be processed in two times. , the first drilling process uses the axial end face of the input shaft as the positioning surface to complete the processing of the through-type central lubricating oil holes on the front three crankshaft sides. The second drilling process uses the axial end face of the rear end shaft as the positioning surface to complete the processing of the rear three Processing of the through-type central lubricating oil hole on the crank side.

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