A method of machining a connecting rod having an abnormal blank length

Abstract

The application relates to a machining method of a connecting rod with abnormal blank length, and comprises the following steps: step one, marking the big and small head center lines of the big and small holes of the abnormal connecting rod on the surface of the abnormal connecting rod screened by length detection; the big and small head center lines of the big and small holes of the abnormal connecting rod are first marked, then the big and small head center lines are respectively taken as horizontal lines to mark the big and small head distance lines and the big and small head allowance lines, the big and small head cutting lines are respectively determined according to the big and small head distance lines and the big and small head allowance lines, then the big head and the small head of the abnormal connecting rod are cut apart according to the big and small head cutting lines, the abnormal connecting rod is machined by adopting the marking mode, the big head and the small head of the abnormal connecting rod can be fully recycled, the scrap is reduced, and the big head and the small head of the remaining abnormal connecting rod can be machined according to normal process subsequently.

Description

Technical Field

[0001] This invention belongs to the field of connecting rod processing technology with abnormal blank length, and specifically relates to a processing method for connecting rods with abnormal blank length. Background Technology

[0002] When developing connecting rods for domestic production, the connecting rod blanks selected are generally those developed by domestic professional forging plants. Because marine medium-speed engine connecting rods are relatively long, such as the 270 diesel engine connecting rod which is 1.220m long and weighs 145kg, although metal molds are used for forging, the high temperature of forging itself and the subsequent heat treatment process will cause a small portion of the connecting rod blanks in each batch to be outside the tolerance range (+3.5mm, -2mm). Generally, 5% of the connecting rod blanks in each batch will be outside the tolerance range. Abnormal connecting rods with blank lengths outside the tolerance range cannot be scribed and cut in the normal scribing method.

[0003] In the existing technology, the normal scribing method involves scribing distance lines and allowance lines only along the center line of the large end or the center line of the small end of the connecting rod blank. Then, the cutting line is taken at the middle position of the distance line and the allowance line. For abnormal connecting rods, the large end and small end of the connecting rod cut along the cutting line scribing method are prone to being too short or too long. This will cause the following problems: if the length is too short, it will be scrapped directly, resulting in a large loss; if the length is too long, it will be inconvenient to process it together with normal connecting rods according to the normal process. Summary of the Invention

[0004] The purpose of this invention is to provide a method for processing connecting rods with abnormal blank lengths in order to solve the above-mentioned problems, thereby addressing the shortcomings of the prior art.

[0005] The present invention achieves the above objectives through the following technical solutions:

[0006] A method for machining a connecting rod with an abnormal blank length includes the following steps:

[0007] Step 1: Mark the center lines of the large and small ends of the round holes at both ends of the abnormal connecting rods identified by length detection on the surface of the abnormal connecting rods.

[0008] Step 2: Using the center line of the small end of the circular hole of the abnormal connecting rod as the horizontal line, mark the small end distance line at a distance of L1. Using the small end distance line as the horizontal line, mark the small end allowance line on the side of the small end distance line away from the small end of the abnormal connecting rod.

[0009] Using the center line of the round hole on the side of the abnormal connecting rod big end that is close to the abnormal connecting rod small end as the horizontal line, mark the big end distance line at a distance of L2. Using the big end distance line as the horizontal line, mark the big end allowance line on the side of the big end distance line that is far away from the abnormal connecting rod big end.

[0010] Among them, the distance between the small end allowance line and the small end distance line, and the distance between the large end allowance line and the large end distance line are both L0;

[0011] Step 3: Cut the abnormal connecting rod between the small end allowance line and the small end distance line, and between the large end allowance line and the large end distance line.

[0012] As a further optimization of the present invention, in step one, the abnormal connecting rod is the connecting rod blank whose length value is not within the standard range. The abnormal connecting rod includes two types: blank length greater than the standard range and blank length less than the standard range.

[0013] As a further optimization of the present invention, the method for cutting abnormal connecting rods with blank lengths exceeding the standard range is specifically as follows:

[0014] The abnormal connecting rod is cut by using the midpoint between the small end allowance line and the small end distance line as the small end cutting line.

[0015] The abnormal connecting rod is cut by using the midpoint between the large end allowance line and the large end distance line as the large end cutting line.

[0016] Both the small and large ends can be retained after cutting for further processing.

[0017] As a further optimization of the present invention, there are two types of abnormal connecting rods with a blank length less than the standard range, specifically:

[0018] The first method: The midpoint between the small end allowance line and the small end distance line is the small end cutting line; the midpoint between the large end allowance line and the large end distance line is the large end cutting line; the distance between the small end cutting line and the large end cutting line...

[0019] The second method: The midpoint between the small end allowance line and the small end distance line is the small end cutting line, and the midpoint between the large end allowance line and the large end distance line is the large end cutting line. The distance L between the small end cutting line and the large end cutting line is... a for

[0020] As a further optimization of the present invention, the first method for cutting abnormal connecting rods with blank length less than the standard range is to cut along the small end cutting line, the large end cutting line, or between the small end cutting line and the large end cutting line. After cutting, both the small end and the large end of the abnormal connecting rod can be retained for subsequent processing.

[0021] As a further optimization of the present invention, the second method for cutting abnormal connecting rods with blank length less than the standard range is to cut along the small end cutting line or the large end cutting line. If the cutting is done along the small end cutting line, the small end is retained for subsequent processing, and if the cutting is done along the large end cutting line, the large end is retained for subsequent processing.

[0022] As a further optimization of the present invention, in step two, L0 is 15-18mm.

[0023] The beneficial effects of this invention are as follows:

[0024] 1) This invention first scribing out the center lines of the large and small ends of the circular holes at both ends of the abnormal connecting rod, and then using the center lines of the large and small ends as horizontal lines to scribing out the distance lines and allowance lines of the large and small ends. Based on the distance lines and allowance lines of the large and small ends, the cutting lines of the large and small ends are determined respectively. Then, the large and small ends of the abnormal connecting rod are cut and separated according to the cutting lines of the large and small ends. By using this scribing method to process the abnormal connecting rod, the large and small ends of the abnormal connecting rod can be fully recovered, reducing scrap. The large and small ends of the remaining abnormal connecting rod can be processed according to the normal process.

[0025] 2) This invention can reclassify abnormal connecting rods whose blank length is less than the standard range and assign them to corresponding cutting methods, which can maximize the recovery of abnormal connecting rods, reduce scrap, and the large or small ends of the recovered abnormal connecting rods can be processed according to normal processes. Attached Figure Description

[0026] Figure 1 This is a comparative schematic diagram of the abnormal connecting rod (abnormal connecting rod with blank length greater than the standard range, abnormal connecting rod with blank length less than the standard range) and the normal connecting rod (topmost) of the present invention.

[0027] Figure 2 This is a schematic diagram of the marking lines for abnormal connecting rods whose blank length exceeds the standard range according to the present invention.

[0028] Figure 3 This is a schematic diagram of the marking line for the first type of abnormal connecting rod with a blank length less than the standard range according to the present invention.

[0029] Figure 4 This is a schematic diagram of the marking line for the second type of abnormal connecting rod with a blank length less than the standard range according to the present invention.

[0030] Figure 5 This is the invention Figure 3 Enlarged view of the structure of part A.

[0031] In the diagram: 11. Center line of the small end; 12. Distance line of the large end; 13. Allowance line of the large end; 14. Cutting line of the large end; 15. Distance line of the small end; 16. Allowance line of the small end; 17. Cutting line of the small end; 18. Center line of the large end.

[0032] 21. Second center line of small end; 22. Second distance line of large end; 23. Second allowance line of large end; 24. Second cutting line of large end; 25. Second distance line of small end; 26. Second allowance line of small end; 27. Second cutting line of small end; 28. Second center line of large end;

[0033] 31. Three center lines for the small end; 32. Three distance lines for the large end; 33. Three allowance lines for the large end; 34. Three cutting lines for the large end; 35. Three distance lines for the small end; 36. Three allowance lines for the small end; 37. Three cutting lines for the small end; 38. Three center lines for the large end. Detailed Implementation

[0034] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0035] Example 1

[0036] like Figure 1-2 As shown, a method for machining a connecting rod with an abnormal blank length includes the following steps:

[0037] Step 1: Mark the center line of the small end of the round hole at both ends of the abnormal connecting rod selected by length detection on the surface of the abnormal connecting rod.

[0038] Step 2: Using the center line of the small end of the circular hole of the abnormal connecting rod as the horizontal line, mark the small end distance line as L1 distance. Using the small end distance line as the horizontal line, mark the small end allowance line as L1 distance on the side of the small end distance line as L1 distance away from the small end of the abnormal connecting rod.

[0039] Using the center line of the round hole on the side of the abnormal connecting rod near the small end of the abnormal connecting rod as the horizontal line, mark the large end distance line -12 at a distance of L2. Using the large end distance line -12 as the horizontal line, mark the large end allowance line -13 on the side of the large end distance line -12 away from the large end of the abnormal connecting rod.

[0040] Among them, the distance between the small end distance line 15 and the small end allowance line 16, and the distance between the large end distance line 12 and the large end allowance line 13 are both L0, and L0 is 15-18mm.

[0041] Step 3: Use the midpoint between the small end distance line 15 and the small end allowance line 16 as the small end cutting line 17 to cut the abnormal connecting rod.

[0042] The abnormal connecting rod is cut using the middle position of the large end distance line 12 and the large end allowance line 13 as the large end cutting line 14.

[0043] Both the small and large ends can be retained after cutting for further processing.

[0044] It should be noted that in this embodiment, L1 is the acceptable length between the small end center line -11 and the small end distance line -15; L2 is the acceptable length between the large end distance line -12 and the large end center line -18. Taking the connecting rod of the 270 diesel engine as an example, the standard range is 1218-1223.5mm, L1 is 645mm, and L2 is 195mm.

[0045] Example 2

[0046] like Figure 1 , 3 As shown in Figure 5, a method for machining a connecting rod with an abnormal blank length includes the following steps:

[0047] Step 1: Mark the center line 21 of the small end and the center line 28 of the large end of the circular hole at both ends of the abnormal connecting rod selected by length detection on the surface of the abnormal connecting rod.

[0048] Step 2: Using the center line 21 of the small end of the circular hole of the abnormal connecting rod as a horizontal line, mark the small end distance line 25 at a distance of L1. Using the small end distance line 25 as a horizontal line, mark the small end allowance line 26 on the side of the small end distance line 25 away from the small end of the abnormal connecting rod.

[0049] Using the center line 28 of the round hole on the side of the abnormal connecting rod big end that is close to the abnormal connecting rod small end as the horizontal line, mark the big end distance line 22 at a distance of L2. Using the big end distance line 22 as the horizontal line, mark the big end allowance line 23 on the side of the big end distance line 22 that is far away from the abnormal connecting rod big end.

[0050] Among them, the distance between the small end distance line 25 and the small end allowance line 26, and the distance between the large end distance line 22 and the large end allowance line 23 are both L0, and L0 is 15-18mm;

[0051] Step 3: The midpoint between the small end allowance line 26 and the small end distance line 25 is the small end cutting line 27. The midpoint between the large end allowance line 23 and the large end distance line 22 is the large end cutting line 24. The distance between the small end cutting line 27 and the large end cutting line 24 is... hour;

[0052] Cut along the middle of the small end cutting line 27 or the large end cutting line 24 or the small end cutting line 27 and the large end cutting line 24. After cutting, both the small end and the large end of the abnormal connecting rod can be retained for subsequent processing.

[0053] Preferably, the cutting is performed along the middle of the small-end cutting line 27 and the large-end cutting line 24, which can leave a relatively even length allowance for the large and small ends, facilitating subsequent processing.

[0054] It should be noted that in this embodiment, L1 is the acceptable length between the small end center line 21 and the small end distance line 25; L2 is the acceptable length between the large end distance line 22 and the large end center line 28. Taking the connecting rod of a 270 type diesel engine as an example, the standard range is 1218-1223.5mm, L1 is 645mm, and L2 is 195mm.

[0055] Example 3

[0056] like Figure 1 , 4 As shown, a method for machining a connecting rod with an abnormal blank length includes the following steps:

[0057] Step 1: Mark the center line 31 of the small end and the center line 38 of the large end of the round hole at both ends of the abnormal connecting rod selected by length detection on the surface of the abnormal connecting rod.

[0058] Step 2: Using the center line 31 of the small end of the circular hole of the abnormal connecting rod as the horizontal line, mark the small end distance line 35 at a distance of L1. Using the small end distance line 35 as the horizontal line, mark the small end allowance line 36 on the side of the small end distance line 35 away from the small end of the abnormal connecting rod.

[0059] Using the center line 38 of the round hole on the side of the abnormal connecting rod big end that is close to the abnormal connecting rod small end as the horizontal line, mark the big end distance line 32 at a distance of L2. Using the big end distance line 32 as the horizontal line, mark the big end allowance line 33 on the side of the big end distance line 32 that is far away from the abnormal connecting rod big end.

[0060] Among them, the distance between the small end distance line 35 and the small end allowance line 36, and the distance between the large end distance line 32 and the large end allowance line 33 are both L0, and L0 is 15-18mm;

[0061] Step 3: The midpoint between the small end allowance line 36 and the small end distance line 35 is the small end cutting line 37. The midpoint between the large end allowance line 33 and the large end distance line 32 is the large end cutting line 34. The distance between the small end cutting line 27 and the large end cutting line 24 is... hour;

[0062] Cut along the small end cutting line 37 or the large end cutting line 34. If you cut along the small end cutting line 37, you will retain the small end for subsequent processing. If you cut along the large end cutting line 34, you will retain the large end for subsequent processing.

[0063] It should be noted that in this embodiment, L1 is the acceptable length between the small end center line 31 and the small end distance line 35; L2 is the acceptable length between the large end distance line 32 and the large end center line 38. Taking the connecting rod of a 270 type diesel engine as an example, the standard range is 1218-1223.5mm, L1 is 645mm, and L2 is 195mm.

[0064] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for machining a connecting rod with an abnormal blank length, characterized in that: Includes the following steps: Step 1: Mark the center lines of the large and small ends of the round holes at both ends of the abnormal connecting rods identified by length detection on the surface of the abnormal connecting rods. The abnormal connecting rod includes two types: connecting rod blank length greater than the standard range and connecting rod blank length less than the standard range; the connecting rod is a standard connecting rod for a 270 type diesel engine. Step 2: Using the center line of the small end of the circular hole of the abnormal connecting rod as the horizontal line, mark the small end distance line at a distance of L1. Using the small end distance line as the horizontal line, mark the small end allowance line on the side of the small end distance line away from the small end of the abnormal connecting rod. Using the center line of the round hole on the side of the abnormal connecting rod big end that is close to the abnormal connecting rod small end as the horizontal line, mark the big end distance line at a distance of L2. Using the big end distance line as the horizontal line, mark the big end allowance line on the side of the big end distance line that is far away from the abnormal connecting rod big end. Among them, the distance between the small end allowance line and the small end distance line, and the distance between the large end allowance line and the large end distance line are both L0; Step 3: Cut the abnormal connecting rod between the small end allowance line and the small end distance line and / or between the large end allowance line and the large end distance line, as follows: (1) The specific method for cutting abnormal connecting rods with a blank length greater than the standard range is as follows: the abnormal connecting rod is cut with the middle position of the small end allowance line and the small end distance line as the small end cutting line; the abnormal connecting rod is cut with the middle position of the large end allowance line and the large end distance line as the large end cutting line; after cutting, both the small end and the large end can be retained for subsequent processing. (2) The specific method for cutting abnormal connecting rods with a blank length less than the standard range is as follows: the middle position of the small end allowance line and the small end distance line is the small end cutting line, the middle position of the large end allowance line and the large end distance line is the large end cutting line, and the distance between the small end cutting line and the large end cutting line is... At that time, cut along the small end cutting line, or the large end cutting line, or the middle position of the small end cutting line and the large end cutting line. After cutting, the small end and the large end of the abnormal connecting rod can be retained for subsequent processing. (3) The second method for cutting abnormal connecting rods with a blank length less than the standard range is as follows: the middle position of the small end allowance line and the small end distance line is the small end cutting line, the middle position of the large end allowance line and the large end distance line is the large end cutting line, and the distance L between the small end cutting line and the large end cutting line is... a for Cutting along the small end cutting line will preserve the small end for subsequent processing, while cutting along the large end cutting line will preserve the large end for subsequent processing.

2. The method for machining a connecting rod with abnormal blank length according to claim 1, characterized in that: In step two, L0 is 15-18 mm.

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