A lathe center for a hollow shaft

Abstract

The utility model provides a lathe center stand for hollow shaft belongs to mechanical technical field. It solved the problem of the existing center stand easy to damage workpiece. The lathe center stand for hollow shaft of this utility model includes lathe bed and the driving tailstock and tailstock top that set up horizontally on lathe bed, is equipped with slide between driving tailstock and tailstock top, and the slide is locked in the sliding position and is set up on lathe bed, is equipped with support block and drive mechanism on the slide, the front side of support block is the concave spherical surface matched with hollow shaft, and drive mechanism includes the drive shaft that can slide forward and backward, is equipped with support plate between the rear side of support block and drive shaft, and support plate is fixedly connected drive shaft, support block is set up on support plate through connecting assembly, and under the action of connecting assembly, support block can slide forward and backward relative to support plate, is equipped with telescopic spring between support block and support plate, and the both ends of telescopic spring are respectively pressed on support block and support plate. The lathe center stand for hollow shaft of this utility model is not easy to damage workpiece.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology and relates to a lathe center rest, particularly a lathe center rest for hollow shafts. Background Technology

[0002] The lathe center rest is an auxiliary device on a lathe used to support workpieces with a large length-to-diameter ratio (length to diameter). Its core function is to increase the rigidity of the workpiece and prevent it from bending, vibrating, or even being damaged during machining due to cutting forces, its own weight, or rotation, thereby ensuring machining accuracy and surface quality, and allowing for more efficient cutting.

[0003] An existing center support structure, such as the one disclosed in the Chinese Patent Database (application number: 202221888790.8) for machining slender shafts on a CNC lathe, involves a hollow hydraulic cylinder connected to one end of a hollow chuck tie rod, and the other end of the tie rod connected to a hollow chuck. A cylinder bracket is mounted on the cylinder side of the spindle box, and a second hydraulic cylinder is mounted on the bracket. A piston is located inside the second cylinder and connected to a connecting rod, which is located inside the hollow chuck tie rod. The other end of the connecting rod is threaded to the shaft head. A rotating device is located inside the chuck at the chuck end of the hollow chuck tie rod. The shaft head is fitted with the inner ring of an angular contact ball bearing of the rotating device with a clearance fit. The shaft head passes through the inner ring of an angular contact ball bearing and a needle roller bearing with a clearance fit. The outer ring of the needle roller bearing is housed within the inner hole of a second end cover, which is bolted to a sliding sleeve. One end is fixed, and the outer diameter of the sliding sleeve is clearance-fitted with the inner hole of the hollow tie rod. The sliding sleeve can move left and right inside the hollow tie rod. The inner diameter of the sliding sleeve is clearance-fitted with the outer ring of the angular contact ball bearing. The end cover presses the outer ring of the angular contact ball bearing, making the angular contact ball bearing and the sliding sleeve a single unit. The inner ring of the angular contact ball bearing is clamped by the spacer and the stepped surface of the shaft head, and locked by the lock nut II, making the shaft head and the angular contact ball bearing a single unit, that is, the shaft head and the sliding sleeve a single unit. The first end cover is fixed to the other end of the sliding sleeve by bolts. The second end cover is fixedly connected to the connecting plate. The connecting plate is fixedly connected to the end drive center. The end drive center is connected to the pawl by the transmission pin. In the horizontal direction, the tailstock center is provided at the relative position of the end drive center. A first material support frame is installed on the spindle box, and a second material support frame is installed on the tailstock body.

[0004] In the aforementioned tooling, the support bracket supports the slender shaft by contacting it. The height of the support bracket is adjusted manually. Due to the limitations of the operator, the force applied when adjusting the support bracket may vary, resulting in the support bracket impacting the slender shaft with a large force. This is especially true for hollow slender shafts, where a large force can easily cause sidewall dents and damage, affecting the quality of the workpiece. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a lathe center rest for hollow shafts that can reduce damage to hollow shafts.

[0006] The objective of this utility model can be achieved through the following technical solution: A lathe center rest for a hollow shaft includes a bed and a drive center and a tailstock center horizontally arranged on the bed, with the drive center and tailstock center arranged side by side. A slide is provided between the drive center and the tailstock center, and the slide is slidably arranged on the bed and locked in the sliding position. A support block and a drive mechanism are provided on the slide. The front side of the support block is a concave spherical surface that matches the hollow shaft. The drive mechanism includes a drive shaft that can slide back and forth. The feature is that a support plate is provided between the rear side of the support block and the drive shaft, and the support plate is fixedly connected to the drive shaft. The support block is set on the support plate through a connecting component, and under the action of the connecting component, the support block can slide back and forth relative to the support plate. A telescopic spring is provided between the support block and the support plate, and the two ends of the telescopic spring press against the support block and the support plate respectively.

[0007] In use, the hollow shaft is horizontally clamped between the drive center and the tailstock center; the support block is set on the rear side of the hollow shaft. When the drive mechanism is activated, the support block is moved forward through the cooperation of the drive shaft and the telescopic spring, so that the concave spherical surface on the support block is in contact with the outer circumference of the hollow shaft, so as to provide better support for the hollow shaft and avoid its machining vibration.

[0008] A telescopic spring is installed between the support block and the drive shaft to absorb the vibration and impact transmitted by the drive shaft, thereby effectively reducing the direct impact of the support block on the hollow shaft and providing better protection for the hollow shaft to reduce damage.

[0009] In the aforementioned lathe center rest for hollow shafts, the connecting assembly includes a bolt and a connecting structure that creates a sliding fit between the support block and the support plate. A stepped hole axially penetrates the bottom wall of the concave spherical surface, and a corresponding threaded hole is provided on the support plate. The bolt is slidably positioned in the stepped hole, and under the action of a telescopic spring, the head of the bolt presses against the stepped surface of the stepped hole, while the shank of the bolt extends out of the stepped hole and screws into the threaded hole. By separating the connecting assembly into the connecting structure and the bolt, which respectively provide a sliding fit and prevent the support block from moving forward and dislodging, the design complexity is reduced, and machining and assembly are facilitated.

[0010] In the lathe center rest for the hollow shaft described above, the telescopic spring is sleeved on the bolt rod. This not only ensures the stable operation of the telescopic spring, but also allows the bolt to be used for both limiting the telescopic spring and the support block, thus having a dual function, simplifying the structure and facilitating assembly.

[0011] In the aforementioned lathe center rest for hollow shafts, the support block consists of a positioning block and a guide plate fixed to the rear side of the positioning block. The positioning block is made of wood, and the aforementioned concave spherical surface is disposed on the positioning block. The guide plate is made of rigid material and is connected to the support plate via the aforementioned connecting structure. The natural elasticity of wood can absorb vibration and impact forces, further reducing direct hard contact with the hollow shaft, thereby further reducing damage to the hollow shaft.

[0012] In the aforementioned lathe center rest for hollow shafts, the connecting structure includes guide rods vertically fixed to the front side of the support plate. There are at least two guide rods evenly distributed along the circumference of the drive shaft. Guide holes matching the guide rods are passed through the guide plate, and corresponding clearance holes are provided on the positioning block. The number of guide holes, clearance holes, and guide rods are the same, and their positions correspond one-to-one. The front end of the guide rod passes through the corresponding guide hole and extends into the corresponding clearance hole. This design offers advantages such as simple structure and stable operation.

[0013] As another option, in the lathe center rest for the hollow shaft described above, the connecting structure includes a guide sleeve formed on the rear side of the guide plate. The shape and size of the inner hole of the guide sleeve are matched with the support plate, and the guide sleeve is sleeved on the outside of the support plate.

[0014] In the aforementioned lathe center rest for hollow shafts, a swing arm is provided below the support block. The rear end of the swing arm is hinged to the slide via a pivot, and the pivot axis extends left and right. The upper side of the front end of the swing arm has a support plane. A drive unit is also fixed on the slide to drive the swing arm to swing back and forth between the horizontal and inclined positions of the support plane. When the support plane is inclined, the support plane is in front of the concave spherical surface, and the support plane and the concave spherical surface cooperate to hold the hollow shaft, so as to further avoid vibration during hollow shaft machining and improve machining quality.

[0015] In the aforementioned lathe center rest for hollow shafts, the rocker arm includes a pressure block and an arm body hinged to a slide. A drive unit is connected to the rear end of the arm body. The pressure block is detachably fixed to the front end of the arm body. The pressure block is made of wear-resistant material, and its top surface is the aforementioned support plane. The pressure block features a detachable design for easy maintenance.

[0016] In the lathe center rest for the hollow shaft described above, the driving component is a horizontally arranged telescopic cylinder. The cylinder body of the telescopic cylinder is fixed on the slide, and the piston rod of the telescopic cylinder is fixed to the rear end of the swing arm.

[0017] Compared with existing technologies, the lathe center rest for hollow shafts has the following advantages: 1. A telescopic spring is installed between the support block and the drive shaft to absorb the vibration and impact transmitted by the drive shaft, thereby effectively reducing the direct impact of the support block on the hollow shaft and providing better protection for the hollow shaft to reduce damage.

[0018] 2. The positioning block used to contact the hollow shaft is made of wood. The natural elasticity of wood can absorb vibration and impact, further reducing direct hard contact with the hollow shaft, thereby further reducing damage to the hollow shaft. Attached Figure Description

[0019] Figure 1 This is a diagram showing the usage status of the lathe center rest used for hollow shafts.

[0020] Figure 2 It is a three-dimensional schematic diagram of the connection between the slide, the swing arm, and the support block.

[0021] Figure 3 It is a cross-sectional schematic diagram of the connection between the slide, the swing arm, and the support block.

[0022] Figure 4 yes Figure 3 Enlarged diagram of point A in the middle.

[0023] In the diagram, 1. Bed; 2. Drive center; 3. Tailstock center; 4. Spindle box; 5. Slide; 6. Guide rail; 7. Locking block; 8. Support block; 8a. Concave spherical surface; 8b. Positioning block; 8c. Guide plate; 8d. Guide hole; 8e. Clearance hole; 9. Drive shaft; 10. Support plate; 11. Telescopic spring; 12. Swing arm; 12a. Support plane; 12b. Pressure block; 13. Drive component; 14. Positioning cylinder; 15. Lead screw; 16. Guide sleeve; 17. Bolt 1; 18. Guide rod; 19. Hollow shaft. Detailed Implementation

[0024] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0025] Example 1: As Figure 1 As shown, the lathe center rest for hollow shafts includes a bed 1 and a drive center 2 and a tailstock center 3 horizontally mounted on the bed 1, with the drive center 2 and tailstock center 3 arranged side-by-side. In the actual product, a spindle box 4 and a tailstock are fixed on the bed 1. The drive center 2 is fixed to the spindle of the spindle box 4 so that the drive center 2 rotates synchronously with the spindle of the spindle box 4; the tailstock center 3 is fixed to the tailstock. The spindle box 4 and tailstock are existing products and will not be described in detail here.

[0026] Specifically A slide 5 is provided between the drive center 2 and the tailstock center 3. The slide 5 is slidably mounted on the bed 1 and locked in the sliding position. Specifically, a guide rail 6 is horizontally fixed on the bed 1, extending horizontally, and the upper end of the guide rail 6 is a dovetail. A locking block 7 is vertically mounted at the rear end of the slide 5, and the front side of the locking block 7 presses against the dovetail. The locking block 7 has a through-hole, and the slide 5 has a corresponding threaded hole. A bolt is installed in the through-hole, and the bolt head is screwed into the threaded hole, pressing against the locking block 7 to connect the locking block 7 and the slide 5. A dovetail groove matching the dovetail is formed between the locking block 7 and the front end of the slide 5, and the slide 5 is slidably mounted on the bed 1 through the cooperation of the dovetail groove and the dovetail block. When the slide 5 needs to be locked, the bolt is tightened, causing the locking block 7 to elastically deform forward and press against the dovetail, thus stably locking the slide 5.

[0027] like Figure 1 and Figure 2 As shown, the slide block 5 is provided with a support block 8 and a drive mechanism. The drive mechanism includes a drive shaft 9 that can slide back and forth, and the axis of the drive shaft 9 extends back and forth. The front side of the support block 8 is a concave spherical surface 8a that matches the hollow shaft 19. A support plate 10 is provided between the rear side of the support block 8 and the drive shaft 9, and the support plate 10 is fixedly connected to the drive shaft 9. The support block 8 is set on the support plate 10 through a connecting assembly, and under the action of the connecting assembly, the support block 8 can slide back and forth relative to the support plate 10. A telescopic spring 11 is provided between the support block 8 and the support plate 10, and the two ends of the telescopic spring 11 press against the support block 8 and the support plate 10 respectively.

[0028] In use, the hollow shaft 19 is horizontally clamped between the drive center 2 and the tailstock center 3; the support block 8 is set on the rear side of the hollow shaft 19. When the drive mechanism is activated, it drives the support block 8 to move forward through the cooperation of the drive shaft 9 and the telescopic spring 11, so that the concave spherical surface 8a on the support block 8 is attached to the outer circumferential surface of the hollow shaft 19 to provide better support for the hollow shaft 19 and prevent it from shaking during processing.

[0029] A telescopic spring 11 is installed between the support block 8 and the drive shaft 9 to absorb the vibration and impact transmitted by the drive shaft 9, thereby effectively reducing the direct impact of the support block 8 on the hollow shaft 19 and providing better protection for the hollow shaft 19 to reduce damage.

[0030] To further explain, a swing arm 12 is provided below the support block 8. The rear end of the swing arm 12 is hinged to the slide block 5 via a pivot, and the pivot axis extends left and right. The upper side of the front end of the swing arm 12 has a support plane 12a. A drive member 13 is also fixed on the slide block 5 to drive the swing arm 12 to swing back and forth between the horizontal and inclined positions of the support plane 12a. When the support plane 12a is horizontal, it is below the hollow shaft 19 and the two do not contact each other. When the support plane 12a is inclined, it is in front of the concave spherical surface 8a, and the support plane 12a and the concave spherical surface 8a cooperate to hold the hollow shaft 19, so as to further avoid the hollow shaft 19 from shaking during processing and improve the processing quality.

[0031] In actual use, the drive unit 13 first drives the swing arm 12 to swing so that the support plane 12a is in an inclined position, then inserts the hollow shaft 19, and finally pushes the support block 8 forward to hold the hollow shaft 19.

[0032] In this embodiment, The drive mechanism also includes a positioning cylinder 14 horizontally fixed on the slide block 5 and a lead screw 15 and nut assembly disposed on the positioning cylinder 14. Specifically, the lead screw and nut assembly includes a lead screw 15 horizontally rotatably disposed within the positioning cylinder 14 and a nut mounted on the lead screw 15. The rear end of the lead screw 15 extends out of the positioning cylinder 14, and the rear end of the drive shaft 9 extends into the positioning cylinder 14 and fixes the nut thereon. A guide sleeve 16 matching the drive shaft 9 is fixed to the front end of the positioning cylinder 14, and the guide sleeve 16 is sleeved on the drive shaft 9. An axial groove is formed on the inner wall of the guide sleeve 16, and a slider matching the groove is fixed to the outer wall of the drive shaft 9. The slider is slidably disposed in the groove to ensure that the drive shaft 9 can only move back and forth.

[0033] like Figures 2 to 4 As shown, the connecting assembly includes a bolt 17 and a connecting structure that creates a sliding fit between the support block 8 and the support plate 10. A stepped hole axially penetrates the bottom wall of the concave spherical surface 8a, and a corresponding threaded hole is provided on the support plate 10. The bolt 17 is slidably disposed in the stepped hole, and under the action of the telescopic spring 11, the head of the bolt 17 presses against the stepped surface of the stepped hole, while the shank of the bolt 17 extends out of the stepped hole and screws into the threaded hole. The connecting assembly is divided into a connecting structure and a bolt, both of which respectively serve the functions of a sliding fit and preventing the support block 8 from moving forward and dislodging, thus reducing design complexity and facilitating processing and assembly.

[0034] The telescopic spring 11 is installed as follows: the telescopic spring 11 is sleeved on the rod of bolt 17. This not only ensures the stable operation of the telescopic spring 11, but also allows bolt 17 to be used for limiting both the telescopic spring 11 and the support block 8, thus having a dual function to simplify the structure and facilitate assembly.

[0035] To further explain, the support block 8 consists of a positioning block 8b and a guide plate 8c fixed to the rear side of the positioning block 8b. The positioning block 8b is made of wood, and the aforementioned concave spherical surface 8a is disposed on the positioning block 8b. The guide plate 8c is made of a rigid material and is connected to the support plate 10 through the aforementioned connecting structure. The natural elasticity of wood can absorb vibration and impact forces, further reducing direct hard contact with the hollow shaft 19, thereby further reducing damage to the hollow shaft 19. In the actual product, the positioning block 8b is fixed to the guide plate 8c by adhesive bonding; the guide plate 8c is made of stainless steel or aluminum alloy.

[0036] like Figure 3 and Figure 4 As shown, the connecting structure includes guide rods 18 vertically fixed to the front side of the support plate 10. There are at least two guide rods 18, evenly distributed along the circumference of the drive shaft 9. A guide hole 8d matching the guide rod 18 is passed through the guide plate 8c. A corresponding clearance hole 8e is provided on the positioning block 8b. The number of guide holes 8d, clearance holes 8e, and guide rods 18 are the same, and their positions correspond one-to-one. The front end of the guide rod 18 passes through the corresponding guide hole 8d and extends into the corresponding clearance hole 8e. This design has advantages such as simple structure and stable operation. Preferably, there are three guide rods 18; the diameter of the clearance hole 8e is larger than the diameter of the guide hole 8d.

[0037] The structure of the swing arm 12 is as follows: The swing arm 12 includes a pressure block 12b and an arm body hinged to the slide block 5. The rear end of the arm body is connected to the drive component 13. The pressure block 12b is detachably fixed to the front end of the arm body. The pressure block 12b is made of wear-resistant material, and the top surface of the pressure block 12b is the aforementioned support plane 12a. The pressure block 12b adopts a detachable design for easy subsequent maintenance. Specifically, the pressure block 12b is detachably fixed to the front end of the arm body by vertically arranged screws, and the pressure block 12b has a stepped hole through it to accommodate the screw head. The wear-resistant material can be high manganese steel, nickel-chromium alloy, nickel-tungsten alloy, etc.

[0038] The drive component 13 is a horizontally arranged telescopic cylinder. The cylinder body is fixed on the slide 5, and the piston rod of the telescopic cylinder is fixed to the rear end of the swing arm 12. The telescopic cylinder is an existing product and can be directly obtained on the market. Of course, the drive component 13 can also be a push rod motor. In this case, the housing of the push rod motor is fixed on the slide 5, and the main shaft of the push rod motor is fixed to the rear end of the swing arm 12.

[0039] Example 2: The structure and principle of Example 2 are basically the same as those of Example 1. The difference is that the connection structure includes a guide sleeve 16 formed on the rear side of the guide plate 8c. The shape and size of the inner hole of the guide sleeve 16 are matched with the support plate 10, and the guide sleeve 16 is sleeved on the outside of the support plate 10.

[0040] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A lathe center rest for a hollow shaft, comprising a bed (1) and a drive center (2) and a tailstock center (3) horizontally arranged on the bed (1), wherein the drive center (2) and the tailstock center (3) are arranged side by side, a slide (5) is provided between the drive center (2) and the tailstock center (3), the slide (5) is slidably arranged on the bed (1) and locked in the sliding position, the slide (5) is provided with a support block (8) and a drive mechanism, the front side of the support block (8) is a concave spherical surface (8a) matching the hollow shaft (19), and the drive mechanism includes a drive shaft (9) that can slide back and forth, characterized in that, A support plate (10) is provided between the rear side of the support block (8) and the drive shaft (9), and the support plate (10) is fixedly connected to the drive shaft (9); the support block (8) is set on the support plate (10) through a connecting component, and under the action of the connecting component, the support block (8) can slide back and forth relative to the support plate (10); a telescopic spring (11) is provided between the support block (8) and the support plate (10), and the two ends of the telescopic spring (11) press against the support block (8) and the support plate (10) respectively.

2. The lathe center rest for a hollow shaft according to claim 1, characterized in that, The aforementioned connecting components include a bolt (17) and a connecting structure that forms a sliding fit between the support block (8) and the support plate (10). The bottom wall of the concave spherical surface (8a) has an axially penetrating stepped hole, and the support plate (10) is provided with a corresponding threaded hole. The bolt (17) is slidably disposed in the stepped hole, and under the action of the telescopic spring (11), the head of the bolt (17) presses against the stepped surface of the stepped hole, and the shank of the bolt (17) extends out of the stepped hole and is screwed into the threaded hole.

3. The lathe center rest for a hollow shaft according to claim 2, characterized in that, The telescopic spring (11) is sleeved on the rod of bolt one (17).

4. The lathe center rest for a hollow shaft according to claim 2 or 3, characterized in that, The support block (8) consists of a positioning block (8b) and a guide plate (8c) fixed to the rear side of the positioning block (8b). The positioning block (8b) is made of wood, and the concave spherical surface (8a) is provided on the positioning block (8b). The guide plate (8c) is made of rigid material, and the guide plate (8c) is connected to the support plate (10) through the connection structure.

5. The lathe center rest for a hollow shaft according to claim 4, characterized in that, The connection structure includes guide rods (18) that are vertically fixed on the front side of the support plate (10). There are at least two guide rods (18) and they are evenly distributed along the circumference of the drive shaft (9). The guide plate (8c) has a guide hole (8d) that matches the guide rod (18). The positioning block (8b) is provided with a corresponding clearance hole (8e). The number of guide holes (8d), clearance holes (8e) and guide rods (18) are the same and their positions correspond one-to-one. The front end of the guide rod (18) passes through the corresponding guide hole (8d) and extends into the corresponding clearance hole (8e).

6. The lathe center rest for a hollow shaft according to claim 4, characterized in that, The connecting structure includes a guide sleeve formed on the rear side of the guide plate (8c), the shape and size of the inner hole of the guide sleeve are matched with the support plate (10), and the guide sleeve is sleeved on the outside of the support plate (10).

7. The lathe center rest for a hollow shaft according to claim 1, characterized in that, A swing arm (12) is provided below the support block (8). The rear end of the swing arm (12) is hinged to the slide block (5) through a pivot, and the pivot axis extends to the left and right. The upper side of the front end of the swing arm (12) has a support plane (12a). A drive member (13) is also fixed on the slide block (5) for driving the swing arm (12) to swing so that the support plane (12a) switches back and forth between the horizontal and inclined positions. When the support plane (12a) is inclined, the support plane (12a) is in front of the concave spherical surface (8a), and the support plane (12a) and the concave spherical surface (8a) cooperate to hold the hollow shaft (19).

8. The lathe center rest for a hollow shaft according to claim 7, characterized in that, The swing arm (12) includes a pressure block (12b) and an arm body hinged to the slide (5). The rear end of the arm body is connected to the drive unit (13). The pressure block (12b) is detachably fixed to the front end of the arm body. The pressure block (12b) is made of wear-resistant material, and the top surface of the pressure block (12b) is the aforementioned support plane (12a).

9. The lathe center rest for a hollow shaft according to claim 7 or 8, characterized in that, The driving component (13) is a horizontally arranged telescopic cylinder. The cylinder body of the telescopic cylinder is fixed on the slide (5), and the piston rod of the telescopic cylinder is fixed to the rear end of the swing arm (12).

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