Pull boring device for guaranteeing wall thickness difference of ultra-long hollow shaft part

Abstract

The utility model relates to a pull boring device for guaranteeing the wall thickness difference of an ultra-long hollow shaft part, which is used for processing the ultra-long hollow shaft part on a deep hole drilling and boring machine, and comprises a boring cutter body, four planes are milled on the excircle surface of the left end of the boring cutter body, a long guide key slot is processed on a cylindrical surface clamped by the planes, and the long guide key slot is connected with the long guide key slot. A fine boring cutter groove and a short guide key groove are machined in the middle of the boring cutter body, a groove for installing a set screw is formed above the fine boring cutter groove, a threaded hole for installing the set screw is machined in the groove, and a fine boring cutter is pressed and fixed in the fine boring cutter groove through the set screw. A square thread and a positioning spigot are machined at the right end of the boring cutter body, the boring cutter body is connected with the boring rod through the square thread and the positioning spigot, the machining mode of boring the ultra-long hollow shaft parts in a pull mode is achieved through the pull boring device, the extending length of the boring rod is shortened, the stability and rigidity of the boring rod are enhanced, outlet deviation is reduced, and the machining efficiency is improved. And the process requirement that the full-length wall thickness difference of the ultra-long hollow shaft part is smaller than or equal to 3 mm is met.

Description

Technical Field

[0001] This utility model belongs to the field of machining technology, and in particular relates to a boring device for machining ultra-long hollow shaft parts on a deep hole drilling and boring machine, which is used to ensure the wall thickness difference of ultra-long hollow shaft parts. Background Technology

[0002] Currently, when machining ultra-long hollow shafts with inner diameters ranging from φ105mm to φ150mm (lengths ranging from 9500mm to 12000mm), the excessive extension of the boring bar during the inner hole machining process easily causes vibration, resulting in excessive deviations at the exit of the machined inner hole. This leads to a total wall thickness difference of >4mm for the ultra-long hollow shafts, exceeding the process dimensional requirements. To improve the inner hole machining quality and ensure that the total wall thickness difference of ultra-long hollow shafts is ≤3mm, it is necessary to design a broaching and boring device on a deep hole drilling and boring machine to ensure the wall thickness difference of ultra-long hollow shafts. Utility Model Content

[0003] The purpose of this utility model is to overcome the shortcomings of the existing technology and provide a boring device for machining ultra-long hollow shaft parts on a deep hole drilling and boring machine, which is used to ensure the wall thickness difference of ultra-long hollow shaft parts.

[0004] The technical solution of this utility model is implemented as follows: A boring device for ensuring the wall thickness difference of ultra-long hollow shaft-like parts includes a boring tool body. Four planes are milled on the outer circular surface of the left end of the boring tool body. A long guide keyway is machined on the cylindrical surface between the planes. A fine boring tool groove and a short guide keyway are machined in the middle part of the boring tool body. A groove for installing a set screw is opened above the fine boring tool groove. A threaded hole for installing the set screw is machined in the groove. The fine boring tool is pressed and fixed in the fine boring tool groove by the set screw. A square thread and a positioning stop are machined on the right end of the boring tool body. The boring tool body is connected to the boring bar through the square thread and the positioning stop.

[0005] The inner hole at the left end of the boring bar body is a weight reduction hole, and the inner hole at the right end is an oil inlet hole.

[0006] The precision boring tool groove is located in the middle of the long guide keyway and the short guide keyway, and extends through the boring tool body. The upper plane of the precision boring tool groove is flush with the center line of the boring tool body.

[0007] An oil outlet is machined at the bottom of the inner hole on the right end of the boring bar, near the groove of the precision boring tool. High-pressure oil from the inner hole of the boring bar flows onto the rake face of the precision boring tool through the oil outlet.

[0008] A nylon guide key is installed in the short guide keyway of the boring tool body and secured with screws. A nylon guide key is also installed in the long guide keyway of the boring tool body.

[0009] The boring bar has eight guide keyways, including four long guide keyways on the left end and four short guide keyways in the middle. Both long and short guide keyways are evenly distributed along the circumference of the boring bar and are oriented in the same direction. Neither the long nor short guide keyways are milled through in the length direction. The long guide keyways are 10mm from the left end face of the boring bar, and the short guide keyways are 10mm from the right end face of the boring bar's large table. Each short guide keyway has two threaded holes machined for installing nylon guide keys.

[0010] The positive effects of the technical solution of this utility model are as follows: By designing a special boring device, the processing method of boring ultra-long hollow shaft parts is realized. The length of the boring bar extension is shortened, the stability and rigidity of the boring bar are enhanced, the exit deviation is reduced, and the process requirement of the total wall thickness difference of ultra-long hollow shaft parts is guaranteed to be ≤3mm. Attached Figure Description

[0011] Figure 1 This is a front view of the boring bar body of this utility model.

[0012] Figure 2 This is a left view of the boring bar body of this utility model.

[0013] Figure 3 This is a top view of the boring bar body of this utility model.

[0014] Figure 4 This is a partial enlarged view of part I of the boring tool body of this utility model.

[0015] Figure 5 This is a structural AA view of the boring bar body of this utility model.

[0016] The diagram labels are as follows: 1. Long guide keyway; 2. Boring tool body; 3. Short guide keyway; 4. Locating stop; 5. Square thread; 6. Oil outlet; 7. Fine boring tool groove. Detailed Implementation

[0017] Example 1: A boring device for machining ultra-long hollow shafts on a deep hole drilling and boring machine, used to ensure the wall thickness difference of ultra-long hollow shafts, includes a boring bar body 2. Four planes are milled on the outer circular surface of the left end of the boring bar body 2. A long guide keyway 1 is machined on the cylindrical surface between the planes. A fine boring tool groove 7 and a short guide keyway 3 are machined in the middle part of the boring bar body 2. A groove for installing a set screw is opened above the fine boring tool groove 7. A threaded hole for installing the set screw is machined in the groove. The fine boring tool is pressed and fixed in the fine boring tool groove 7 by the set screw. A square thread 5 and a positioning stop 4 are machined on the right end of the boring bar body 2. The boring bar body 2 is connected to the boring bar through the square thread 5 and the positioning stop 4. The inner hole at the left end of the boring bar body 2 is a weight reduction hole, and the inner hole at the right end is an oil inlet hole.

[0018] The boring bar body 2 has eight guide keyways, including four long guide keyways 1 at the left end and four short guide keyways 3 in the middle. The long guide keyways 1 and short guide keyways 3 are evenly distributed along the circumference of the boring bar body 2, and their directions are consistent. Neither the long guide keyways 1 nor the short guide keyways 3 are milled through in the length direction. The long guide keyways 1 are 10mm from the left end face of the boring bar body 2, and the short guide keyways 3 are 10mm from the right end face of the boring bar body 2's large table. Each short guide keyway 3 has two threaded holes machined for installing nylon guide keys.

[0019] The boring bar body 2 has a through-hole precision boring bar groove 7 machined in the middle position of the long guide keyway 1 and the short guide keyway 3. Above the precision boring bar groove 7, there is a groove for installing set screws, and three threaded holes for installing set screws are machined in the groove.

[0020] The precision boring tool is installed in the tool groove 7 and is pressed and fixed by a set screw. The upper surface of the precision boring tool groove 7 is flush with the center line of the boring tool body 2.

[0021] An oil outlet 6 is machined at the bottom of the inner hole on the right end of the boring bar body 2, and at the position near the opening of the precision boring tool groove 7. The high-pressure oil in the inner hole of the boring bar flows onto the rake face of the precision boring tool through the oil outlet 6, so as to cool the precision boring tool head and flush away the chips.

[0022] The method for using a boring device to ensure the wall thickness difference of ultra-long hollow shaft parts is as follows:

[0023] The incoming material for ultra-long hollow shaft parts is a hollow forging blank. First, it is machined on a lathe to face one end and machine a pilot hole. The diameter of the pilot hole is the same as the diameter of the boring hole after broaching, with a diameter tolerance of ±0.5mm and a depth of 200-250mm. Next, a nylon guide key is installed in the short guide keyway 3 of the boring bar 2 and secured with screws. On the lathe, the outer diameter of the secured nylon guide key is machined to be 0.1mm smaller than the diameter of the pilot hole. Then, a precision boring tool is installed on the precision boring tool groove 7 of the boring bar 2, and a nylon guide key is installed in the long guide keyway 1 of the boring bar 2. Finally, the part is bored on a deep hole drilling and boring machine using a reverse pulling method, meaning the extension length of the boring bar changes from long to short.

[0024] After connecting the boring bar 2 to the boring bar via the square thread 5 and the positioning stop 4 on the boring bar 2, the boring bar 2, with the nylon guide key and the fine boring tool installed, is pushed into the machined pilot hole. The nylon guide key in the short guide keyway 3 acts as a front guide. Then the fine boring tool begins boring. Subsequently, the nylon guide key installed in the long guide keyway 1 supports the inner surface of the bored hole. When all the nylon guide keys installed in the long guide keyway 1 have entered the bored inner hole, the boring bar 2 is withdrawn, the nylon guide key in the short guide keyway 3 is removed, and the boring bar 2 is pushed into the bored inner hole to continue boring.

[0025] By designing a dedicated boring device, the machining method of boring ultra-long hollow shaft parts was realized. The length of the boring bar extension was shortened, the stability and rigidity of the boring bar were enhanced, the exit deviation was reduced, and the process requirement of the total wall thickness difference of ultra-long hollow shaft parts being ≤3mm was guaranteed.

Claims

1. A device for guaranteeing the wall thickness difference of an oversize hollow shaft, comprising a boring tool body (2), characterized in that: Four planes are milled on the outer circular surface of the left end of the boring tool body (2). A long guide keyway (1) is machined on the cylindrical surface between the planes. A fine boring tool groove (7) and a short guide keyway (3) are machined in the middle part of the boring tool body (2). A groove for installing a set screw is opened above the fine boring tool groove (7). A threaded hole for installing the set screw is machined in the groove. The fine boring tool is pressed and fixed in the fine boring tool groove (7) by the set screw. A square thread (5) and a positioning stop (4) are machined on the right end of the boring tool body (2). The boring tool body (2) is connected to the boring bar through the square thread (5) and the positioning stop (4).

2. The device for ensuring the wall thickness difference of the super-long hollow shaft according to claim 1, characterized in that: The inner hole at the left end of the boring bar body (2) is a weight reduction hole, and the inner hole at the right end is an oil inlet hole.

3. The device for ensuring the wall thickness difference of the super-long hollow shaft according to claim 1, characterized in that: The precision boring tool groove (7) is located in the middle of the long guide keyway (1) and the short guide keyway (3), and extends through the boring tool body (2). The upper plane of the precision boring tool groove (7) is flush with the center line of the boring tool body (2).

4. The device for ensuring the wall thickness difference of the super-long hollow shaft according to claim 2, characterized in that: An oil outlet (6) is machined at the bottom of the inner hole on the right end of the boring bar body (2) and at the position close to the opening of the precision boring bar groove (7). The high pressure oil in the inner hole of the boring bar flows onto the front face of the precision boring bar through the oil outlet (6).

5. The device for ensuring the wall thickness difference of the super-long hollow shaft according to claim 1, characterized in that: A nylon guide key is installed in the short guide keyway (3) of the boring tool body (2) and secured with screws. A nylon guide key is also installed in the long guide keyway (1) of the boring tool body (2).

6. The device for ensuring the wall thickness difference of the super-long hollow shaft according to claim 1, characterized in that: The boring bar body (2) has 8 guide keyways, including 4 long guide keyways (1) at the left end of the boring bar body (2) and 4 short guide keyways (3) in the middle. The long guide keyways (1) and the short guide keyways (3) are evenly distributed along the circumference of the boring bar body (2), and the directions of the long guide keyways (1) and the short guide keyways (3) are consistent. The long guide keyways (1) and the short guide keyways (3) are not milled through in the length direction. The long guide keyway (1) is 10mm away from the left end face of the boring bar body, and the short guide keyway (3) is 10mm away from the right end face of the boring bar body. Each short guide keyway (3) has a threaded hole for installing a nylon guide key.

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