A deep hole inner keyway processing device based on boring and milling machine X-axis feeding

Abstract

This invention discloses a deep-hole long keyway machining device based on X-axis feed of a boring and milling machine. It includes a boring and milling machine bed, a milling spindle with power input mounted on the machine bed, and a milling cutter mounted on the spindle. A transmission mechanism extending along the length of the boring and milling machine bed is provided between the milling spindle and the milling cutter. The advantages are: The innovative use of an X-axis-extending transmission mechanism between the milling spindle and the milling cutter constitutes a long-neck milling head structure. Machining along the length of the keyway is achieved by the movement of the slide and column along the X-axis. Compared to traditional boring and milling machines using Z-axis + W-axis feed, which inherently has lower machining accuracy and gradually decreases with increasing milling head extension length, this machining device uses X-axis feed, resulting in higher accuracy. Furthermore, the milling head remains stationary relative to the slide during machining, maintaining a constant machining accuracy without decreasing with increasing X-axis travel. Therefore, it can better meet the machining requirements of long keyways in deep holes.

Description

Technical Field

[0001] This invention relates to a milling technology, specifically a device for machining long keyways in deep holes based on the X-axis feed of a boring and milling machine. Background Technology

[0002] The keyway machining of ship rudder blades is a critical process in shipbuilding. The keyway connects the rudder stock and the rudder blade, transmitting extremely high torque and withstanding alternating loads. Therefore, it requires high precision and must meet various requirements for heavy-duty transmission. Depending on the rudder stock diameter, the keyway width ranges from 50mm to 300mm, and the length can reach 80% of the rudder blade thickness. High requirements are also placed on its surface roughness and symmetry.

[0003] Currently, traditional keyway machining (suitable for small and medium-sized rudder blades) generally employs large gantry milling machines or floor-type boring and milling machines. This involves mounting a milling cutter at the spindle end and utilizing the combined extension lengths of the boring spindle (W-axis) or the ram (Z-axis) and the boring spindle (W-axis) for machining. Conventional machining methods mainly include horizontal and vertical machining. Horizontal machining offers unrestricted workpiece clamping, but the horizontally extended milling cutter is affected by gravity; as the extension length increases, the resulting deflection deformation increases, leading to poorer machining accuracy. In vertical machining, the milling cutter extends vertically, and while largely unaffected by gravity, excessive extension can still cause deflection deviations and vibrations due to stress, thus affecting machining accuracy. Furthermore, vertical machining requires vertical workpiece clamping, which can be difficult due to irregular shapes, making it challenging to guarantee clamping accuracy. Additionally, the limited diameter of the workpiece's machining hole often restricts the dimensions of the boring spindle and ram that need to extend into it. Simultaneously, the relative movement between the ram and saddle can also affect machining accuracy due to the clearance between them. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a deep hole long keyway machining device based on X-axis feed of a boring and milling machine with small deflection and high machining accuracy.

[0005] To solve the above-mentioned technical problems, the present invention provides a deep hole internal long keyway machining device based on X-axis feed of a boring and milling machine, comprising a boring and milling machine bed, a milling spindle with power input mounted on the boring and milling machine bed, and a milling cutter mounted on the milling spindle. A transmission mechanism extending along the length direction of the boring and milling machine bed is provided between the milling spindle and the milling cutter.

[0006] The boring and milling machine bed is provided with an adjustment mechanism, which includes a slide block slidably mounted on the boring and milling machine bed along the X-axis, a slide saddle slidably mounted on the slide block along the Y-axis, and a slide ram slidably mounted on the slide saddle along the Z-axis. The milling spindle is rotatably mounted in the slide ram along the Z-axis.

[0007] The transmission mechanism includes a first transmission shaft fixedly connected to the milling shaft via a connecting disc, a second transmission shaft connected to the first transmission shaft via a first bevel gear set, a third transmission shaft fixedly connected to the second transmission shaft via a coupling, and a fourth transmission shaft connected to the third transmission shaft via a second bevel gear set. The milling cutter is fixedly mounted on the front end of the fourth transmission shaft.

[0008] The transmission mechanism is mounted on the slide block via a transmission housing. The transmission housing includes a connecting seat fixedly mounted on the end of the slide block, an extension body fixedly mounted on the front of the connecting seat, and a milling cutter head fixedly mounted on the front of the extension body. The first transmission shaft is rotatably mounted in the connecting seat, the second and third transmission shafts are rotatably mounted in the extension body, and the fourth transmission shaft is rotatably mounted in the milling cutter head.

[0009] It also includes a balancing mechanism, which includes a static balancing block fixed to the rear of the connecting seat and a follow-up balancing mechanism disposed at the bottom of the connecting seat.

[0010] The following balancing mechanism includes a mounting base, a lower support slidably mounted on the mounting base, and an upper support fixedly mounted on the bottom of the connecting base; a lower hinge seat and an upper hinge seat are rotatably mounted on the lower support seat and the upper support seat respectively, and a lever is hinged together on the lower hinge seat and the upper hinge seat; the lever is hinged to the upper hinge seat at one end with the lower hinge seat as the fulcrum, and a dynamic balancing block is fixed at the other end.

[0011] The mounting base is provided with a slide rail, and the lower support is slidably mounted on the slide rail.

[0012] The slide rail side is provided with a support structure for supporting the milling head when it is not in use.

[0013] The advantages of this invention are: (1) Taking advantage of the characteristics of large X-axis travel, good rigidity and high precision, an innovative transmission mechanism extending along the X-axis is set between the milling spindle and the milling cutter, thus forming a long-neck milling head structure. The slide and column move along the X-axis to realize the machining of the keyway length direction, the slide saddle moves along the Y-axis to realize the symmetry adjustment of the keyway width direction relative to the hole axis, and the slide ram moves along the Z-axis to realize the machining of the keyway depth direction. Compared with the traditional boring and milling machine that uses Z-axis + W-axis (i.e. the combination of slide ram and boring spindle extension) feed, the machining accuracy is low and will gradually decrease as the extension length of the milling head increases. This machining device uses X-axis feed, which has higher precision. At the same time, the milling head remains stationary relative to the slide during the machining process, and the machining accuracy always remains at a fixed level and will not decrease as its X-axis travel increases. Therefore, it can better meet the machining requirements of long keyways in deep holes. (2) A follow-up balancing mechanism is provided below the milling head. The follow-up balancing mechanism can unload the load to the ground without affecting the movement of the milling head, reduce the load on the cantilever beam structure, reduce the deflection deformation caused by the self-weight of the milling head, thereby slowing down its deformation and damage, and improving the machining accuracy and service life. (3) The slide rail is fixed with a protrusion and a detachable columnar support structure is provided on it. The support structure can support the milling head when it is not in use, thereby further improving its service life. (4) The milling head is not limited by the general machine tool specifications and can be installed on various machine tools with X-axis travel ≥3000mm. Therefore, it has a wide range of applications and strong applicability. Attached Figure Description

[0014] Figure 1 This is a perspective view of the present invention; Figure 2 This is a top view of the present invention; Figure 3 This is a schematic diagram of the structure of the milling head of the present invention; Figure 4 for Figure 1 Enlarged view of point A; Figure 5 for Figure 3 Enlarged view of point B; Figure 6 for Figure 3 Enlarged view of point C; Figure 7 This is a force analysis diagram of the milling cutter; Figure 8 This is a schematic diagram of the deflection curve of the fully extended slide of a boring and milling machine. Detailed Implementation

[0015] The following detailed description of the deep hole long keyway machining device based on X-axis feed of a boring and milling machine according to the present invention, with reference to the accompanying drawings and specific embodiments, will be further described in detail.

[0016] As shown in the figure, the deep hole long keyway machining device based on the X-axis feed of a boring and milling machine of the present invention includes a boring and milling machine bed 1 fixed on the ground. The length direction of the boring and milling machine bed 1 is taken as the X-axis, and a track is formed on its upper part. A slide 6 that can reciprocate along the X-axis is installed on the track. A column is fixed on the slide 6. The height direction of the column is taken as the Y-axis, and a track is formed on its side. A slide saddle 7 that can reciprocate along the Y-axis is installed on the track. The slide saddle 7 has a slot opened in the Z-axis direction and a slide ram 8 that can reciprocate within it is installed. The slide 6, slide saddle 7 and slide ram 8 together constitute the adjustment mechanism 2 of the entire boring and milling machine. A milling spindle 9 is rotatably mounted inside the slide ram 8 along the Z-axis, and a long-neck milling head is mounted on the milling spindle 9. The long-neck milling head consists of a transmission mechanism 4 connected to the milling spindle 9 and extending along the X-axis, and a milling cutter 5 mounted at the front end of the transmission mechanism 4. The milling spindle 9 is powered by a drive mechanism mounted inside the transmission mechanism 4 to rotate, and then the power is transmitted to the milling cutter 5 through the transmission mechanism 4 to achieve milling.

[0017] The transmission mechanism 4 consists of a first transmission shaft 15, a second transmission shaft 16, a third transmission shaft 17, and a fourth transmission shaft 18 arranged in sequence. The transmission shaft assembly is mounted on the connecting seat 11 through a hollow transmission housing 10. The transmission housing 10 specifically includes a connecting seat 11 fixed to the end of the slide 8 by means of a stop structure and screws, an extension body 12 fixedly mounted at the front of the connecting seat 11, and a milling cutter head 14 fixedly mounted at the front of the extension body 12. The first transmission shaft 15 is rotatably mounted in the connecting seat 11 by means of a deep groove ball bearing at the front and a pair of back-to-back angular contact bearings at the rear. The second transmission shaft 16 and the third transmission shaft 17 are rotatably mounted in the front and rear of the extension body 12 by means of a pair of oppositely arranged angular contact bearings at the front and rear, respectively. The fourth transmission shaft 18 is rotatably mounted in the milling cutter head 14 by means of a double row cylindrical roller bearing at the front and a pair of face-to-face tapered roller bearings at the rear. The milling spindle 9 and the first drive shaft 15 are fixedly connected by a connecting plate 19. The first drive shaft 15 and the second drive shaft 16 are connected by a bevel gear set 20. The second drive shaft 16 and the third drive shaft 17 are fixedly connected by a coupling 21. The third drive shaft 17 and the fourth drive shaft 18 are connected by a bevel gear set 22. The milling cutter 5 is fixedly mounted on the fourth drive shaft 18 through a tapered hole at its front end. During milling, the milling cutter 5 is mainly subjected to cutting forces in three directions: the tangential force Ft is along the tangential direction of the tool's rotation and is the main cutting force; the radial force Fᵣ points towards the radius of the tool, causing the tool to flex and vibrate; and the axial force F... a Along the tool axis, multiple sets of angular contact bearings can better withstand the cutting force in the corresponding direction, achieving axial positioning while retaining rotational freedom.

[0018] A mounting base 25 is also installed on the side of the milling machine bed 1. A slide rail 32 is fixedly installed on the mounting base 25. A lower support 26 that can reciprocate along the X-axis is slidably installed on the slide rail 32. A lower hinge seat 28 is rotatably installed inside the lower support 26. An upper support 27 is fixed on the lower surface of the connecting seat 11 and an upper hinge seat 29 is rotatably installed inside it. The lower hinge seat 28 and the upper hinge seat 29 are hinged together by a lever 30 through a U-shaped structure. The lever 30 uses the lower hinge seat 28 as the fulcrum, with one end hinged to the upper hinge seat 29 and the other end fixed to a dynamic balance block 31 through a long rod. The above structures together constitute the follow-up balancing mechanism 24 of the milling head. The follow-up balancing mechanism 24 can unload the load to the ground without affecting the movement of the milling head, reducing the load on the cantilever beam structure and thus slowing down its deformation and damage. A static balance block 23 is fixed to the rear of the connecting seat 11 via a long rod. The static balance block 23 and the follow-up balancing mechanism 24 together constitute the entire balancing mechanism. A protrusion is also fixed to the side of the slide rail 32, and a detachable columnar support structure 33 is provided on it. The support structure 33 is used to support the milling head when it is not in use, thereby further improving its service life.

[0019] In actual use, simply place the workpiece to be processed in front of the boring and milling machine bed 1, adjust its hole axis to be parallel to the X-axis of the machine tool using tools such as shims and side supports, and then adjust the position of the milling head through the adjustment mechanism 2 to start processing. Traditional boring and milling machines typically use a boring spindle slidably mounted inside the milling spindle 9. The keyway length is machined using Z-axis + W-axis feed (i.e., the combination of the slide ram 8 and the extended boring spindle). The keyway width is adjusted relative to the hole axis using the slide saddle 7 moving along the Y-axis. The keyway depth is machined using the slide 6 and column moving along the X-axis. However, the Z-axis + W-axis combined feed inherently has low machining accuracy (the machining accuracy of each axis from highest to lowest is X-axis > Y-axis > Z-axis > W-axis), and it gradually decreases as the milling head extension length increases. Furthermore, the clearance between the relative movements of the various structures also affects machining accuracy. Therefore, the overall machining accuracy of traditional boring and milling machines is low. This machining device, however, leverages the advantages of a large X-axis travel, high rigidity, and high accuracy (generally within 0.015mm / 1000). With a diameter of approximately 10 mm, this device innovatively incorporates a transmission mechanism 4 extending along the X-axis between the milling spindle 9 and the milling cutter 5, thus forming a long-neck milling head structure. The slide 6 and column move along the X-axis to achieve machining in the keyway length direction, the slide saddle 7 moves along the Y-axis to adjust the symmetry of the keyway width relative to the hole axis, and the slide ram 8 moves along the Z-axis to achieve machining in the keyway depth direction. This achieves an effective machining length ≥3m and a length-to-diameter ratio ≥10:1. During machining, the milling head remains stationary relative to the slide 6, and the machining accuracy remains constant without decreasing with increasing X-axis travel. Therefore, it can effectively meet the machining requirements of long keyways in deep holes. Furthermore, the device reduces the deflection deformation caused by the milling head's own weight through a balancing mechanism, further improving machining accuracy and extending the device's service life.

[0020] Furthermore, the milling head of this machining device is not limited by general machine tool specifications and can be installed on various machine tools with an X-axis travel of ≥3000mm, such as floor-type boring and milling machines like TK6913, TK6916, TK6920, and TK6926. Therefore, it has a wide range of applications and strong applicability.

[0021] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A deep hole internal long keyway machining device based on X-axis feed of a boring and milling machine, comprising a boring and milling machine bed (1), a milling spindle (9) with power input mounted on the boring and milling machine bed (1), and a milling cutter (5) mounted on the milling spindle (9), characterized in that: A transmission mechanism (4) extending along the length of the boring and milling machine bed (1) is provided between the milling spindle (9) and the milling cutter (5).

2. The deep hole internal long keyway machining device based on X-axis feed of a boring and milling machine according to claim 1, characterized in that: The boring and milling machine bed (1) is provided with an adjustment mechanism (2). The adjustment mechanism (2) includes a slide (6) slidably mounted on the boring and milling machine bed (1) along the X-axis, a slide saddle (7) slidably mounted on the slide (6) along the Y-axis, and a slide ram (8) slidably mounted on the slide saddle (7) along the Z-axis. The milling spindle (9) is rotatably mounted in the slide ram (8) along the Z-axis.

3. The deep hole internal long keyway machining device based on X-axis feed of a boring and milling machine according to claim 2, characterized in that: The transmission mechanism (4) includes a first transmission shaft (15) fixedly connected to the milling shaft (9) via a connecting disc (19), a second transmission shaft (16) forming a transmission relationship with the first transmission shaft (15) via a first bevel gear set (20), a third transmission shaft (17) fixedly connected to the second transmission shaft (16) via a coupling (21), and a fourth transmission shaft (18) forming a transmission relationship with the third transmission shaft (17) via a second bevel gear set (22). The milling cutter (5) is fixedly installed at the front end of the fourth transmission shaft (18).

4. The deep hole internal long keyway machining device based on X-axis feed of a boring and milling machine according to claim 3, characterized in that: The transmission mechanism (4) is mounted on the slide (8) via a transmission housing (10). The transmission housing (10) includes a connecting seat (11) fixedly mounted on the end of the slide (8), an extension body (12) fixedly mounted on the front of the connecting seat (11), and a milling cutter head (14) fixedly mounted on the front of the extension body (12). The first transmission shaft (15) is rotatably mounted in the connecting seat (11), the second transmission shaft (16) and the third transmission shaft (17) are rotatably mounted in the extension body (12), and the fourth transmission shaft (18) is rotatably mounted in the milling cutter head (14).

5. The deep hole internal long keyway machining device based on X-axis feed of a boring and milling machine according to claim 4, characterized in that: It also includes a balancing mechanism, which includes a static balancing block (23) fixed to the rear of the connecting seat (11) and a follow-up balancing mechanism (24) disposed at the bottom of the connecting seat (11).

6. The deep hole internal long keyway machining device based on X-axis feed of a boring and milling machine according to claim 5, characterized in that: The following balancing mechanism (24) includes a mounting base (25), a lower support (26) slidably mounted on the mounting base (25), and an upper support (27) fixedly mounted on the bottom of the connecting base (11); a lower hinge seat (28) and an upper hinge seat (29) are rotatably mounted on the lower support seat (26) and the upper support seat (27), respectively, and a lever (30) is hinged together on the lower hinge seat (28) and the upper hinge seat (29); the lever (30) is hinged to the upper hinge seat (29) at one end with the lower hinge seat (28) as the fulcrum, and a dynamic balancing block (31) is fixed at the other end.

7. The deep hole internal long keyway machining device based on X-axis feed of a boring and milling machine according to claim 6, characterized in that: The mounting base (25) is provided with a slide rail (32), and the lower support (26) is slidably mounted on the slide rail (32).

8. The deep hole internal long keyway machining device based on X-axis feed of a boring and milling machine according to claim 7, characterized in that: The slide rail (32) is provided with a support structure (33) on its side for supporting the milling head when it is not in use.

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