A rotating center with quick-change center head

Abstract

The present invention relates to the field of tail centers of numerically controlled vertical milling machines, and specifically to a rotating center center with a quick-change center head. The invention solves the problems of poor versatility, unreasonable resource utilization, inconvenient storage and management of existing rotating centers, and includes a center center body, a thrust bearing, a needle bearing, a center center head and a set screw; the center center body includes a tail portion, a positioning portion and a head portion fixedly arranged in sequence; the tail portion is used to be fixed to the machine tool; the positioning portion is in the shape of a round pancake; the head portion is in the shape of a cylinder; an annular groove is provided at the end face of the head portion along its outer circumference; the thrust bearing passes through the head portion and is close to the end face of the positioning portion; the needle bearing is sleeved on the outer circumference of the head portion; the center center head has an inner hole, which is buckled on the needle bearing through the inner hole; the set screw passes through the center center head radially and is fixed in the annular groove of the head portion. The present invention can quickly switch centers of different specifications through the set screw to match different types of parts, thereby enhancing versatility and improving utilization.

Description

Technical Field

[0001] The invention relates to the field of tail centers of numerically controlled vertical milling machines, and in particular to a rotating center center with a quick-change center head. Background Art

[0002] The center is often used as a machine tool accessory in mechanical processing. When machining shaft sleeve parts, it uses the center hole to position and support the workpiece, while allowing the machined parts to achieve higher dimensional accuracy. There are two types of centers: fixed centers and rotating centers. The fixed center has a simple structure, high precision, and strong bearing capacity, and can perform precision machining on workpieces that require high positioning accuracy.

[0003] When using a fixed center to process several holes evenly distributed in the circumferential direction on a CNC vertical milling machine, it is generally used in conjunction with a three-jaw machine. One end of the shaft part is clamped with the three-jaw machine, and the other end is supported by the center hole of the shaft part with a center center. After processing a hole, one end of the three-jaw machine rotates a fixed angle, and the part rotates accordingly. The tail center and the inner hole of the part rotate relative to each other by friction, and then another hole is processed. However, since the center hole of some parts is large and the contact area with the tail center is too large, the inner hole will get stuck with the center when the part rotates. The center needs to be manually loosened, rotated to the desired angle, and tightened again, and the operation steps are cumbersome.

[0004] Therefore, a rotating center can be considered. When machining parts, the tail of the workpiece can be directly supported by the rotating center. When one end of the three-jaw clamping shaft part rotates, the other end of the part rotates with the rotating center, and there will be no jamming phenomenon, and manual operation is no longer required. However, due to the wide variety of workpieces that need to be processed and the varying sizes of center holes, each product requires a corresponding rotating center. In this way, during machining, there are many types of machine tool centers, poor versatility, unreasonable resource utilization, and inconvenience in storage and management. Summary of the invention

[0005] In order to solve the problems of poor versatility of existing rotating vertices, unreasonable resource utilization, inconvenient storage and management, the present invention provides a rotating vertices with quick-change vertices to improve the versatility of the vertices and facilitate management and use.

[0006] The technical solution of the present invention is to provide a rotating top with a quick-change top head, which is special in that it includes a top body, a thrust bearing, a needle bearing, a top head and a set screw;

[0007] The tip body comprises a tail portion, a positioning portion and a head portion which are fixedly arranged in sequence; the central axes of the tail portion, the positioning portion and the head portion are located in the same straight line;

[0008] The tail portion is used for fixing to the machine tool;

[0009] The positioning portion is in a circular shape, and its diameter is larger than the maximum diameter of the tail portion;

[0010] The head is cylindrical, and its diameter is smaller than the diameter of the positioning portion; an annular groove is provided along the outer circumference of the end surface of the head, and the end surface is the end away from the positioning portion;

[0011] The thrust bearing passes through the head and is close to the end surface of the positioning portion;

[0012] The needle roller bearing is sleeved on the outer circumference of the head and cooperates with it;

[0013] The top head has an inner hole, and is buckled on the needle bearing through the inner hole. The inner hole matches the needle bearing, and the end face of the opening end of the top head is in close contact with the thrust bearing.

[0014] The set screw passes through the top head radially and is fixed in the annular groove of the head.

[0015] Furthermore, the shape of the tip is adapted to the center hole at the tail of the workpiece to be processed.

[0016] Furthermore, the above-mentioned top tip includes a mating end and a tip end, the above-mentioned mating end is cylindrical, the above-mentioned tip end is frustum-shaped, and the above-mentioned inner hole is opened along the axial direction of the cylindrical mating end.

[0017] Furthermore, the inner hole is a stepped hole, the needle bearing cooperates with the small end of the stepped hole, the head extends into the large end of the stepped hole, and the set screw passes through the large end of the stepped hole and is fixed in the annular groove of the head.

[0018] Furthermore, in order to facilitate the removal of the center, the tail is installed with a round nut through threaded fit. When working, the tail of the center is directly installed into the tailstock of the machine tool by taper, and the conical surface fits and fixes. When the center needs to be removed from the machine tool, the round nut is screwed to push the center off the tailstock of the machine tool in the opposite direction.

[0019] Furthermore, there are two set screws, which are evenly distributed along the outer circumference of the mating end.

[0020] Furthermore, the distance between the bottom of the groove and the inner peripheral surface of the large end of the step hole is greater than the depth of the groove; and there is a gap between the end surface of the head away from the positioning portion and the bottom of the inner hole.

[0021] The beneficial effects of the present invention are:

[0022] 1. The quick-change center head and rotating center provided by the present invention have a simple structure. During the processing, the tail of the workpiece rotates with the rotating center, which can avoid the situation where the tail center and the workpiece are stuck when the CNC vertical milling machine processes shaft sleeve parts.

[0023] 2. The present invention can quickly switch the top heads of different specifications to match different types of parts through the set screws, thereby enhancing versatility and improving utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the general assembly drawing of the rotating center of the present invention;

[0025] Figure 2 This is a structural diagram of the main body of the rotating center of the present invention;

[0026] Figure 3 It is a structural diagram of the top head in the rotating top of the present invention;

[0027] In the figure: 1-round nut, 2-top body, 21-tail, 22-positioning part, 23-head, 24-annular groove, 3-thrust bearing, 4-top head, 41-matching end, 42-tip, 43-small end of step hole, 44-large end of step hole, 5-needle bearing, 6-set screw. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0029] When processing parts with complex structures, the existing top cannot be used due to incompatibility of structure, so a top that is compatible with the parts to be processed must be designed. However, if a new top is designed for each top just because the head is different, the cost will increase. The present invention designs a quick-change top head structure for the purpose of saving costs and improving versatility.

[0030] from Figure 1 It can be seen that the rotating center of the quick-change center head of the present invention mainly includes a round nut 1, a center body 2, a thrust bearing 3, a center head 4, a needle bearing 5 and a set screw 6. The central axes of the round nut 1, the center body 2, the thrust bearing 3, the center head 4 and the needle bearing 5 are all located in a straight line.

[0031] Combination Figure 2, the center body 2 includes a tail 21, a positioning part 22 and a head 23; the central axes of the tail 21, the positioning part 22 and the head 23 are located in the same straight line and are arranged in sequence. The tail 21 is a cone with a certain taper, and the round nut 1 is installed on the tail 21 through a threaded connection and is located at one end close to the top head 4; the present embodiment uses a nut M60x2. When working, the tail is directly installed into the tailstock of the machine tool, and the conical surface is matched and fixed. When the top needs to be removed from the machine tool, the round nut is screwed to reversely push the top off the tailstock of the machine tool. The positioning part 22 is a round pancake with a certain thickness, and its diameter is greater than the maximum diameter of the tail 21; the head 23 is a cylindrical shape with a diameter smaller than the diameter of the positioning part 22. At the end face of the head 23, which is the end away from the positioning part 22, an annular groove 24 is provided along its outer circumference. The top head 4 is fixed by a set screw 6 and the annular groove 24, which will be described in detail later. The thrust bearing 3 passes through the head 23 and is close to the right end face of the positioning portion 22. The needle bearing 5 is sleeved on the outer circumference of the head and cooperates with it. The top head 4 has an inner hole, which is buckled on the needle bearing 5 through the inner hole, and the inner hole cooperates with the needle bearing 5, and the open end face of the top head 4 is close to the thrust bearing 3. The set screw 6 passes through the top head 4 along the radial direction of the top head and is fixed in the annular groove 24 of the head 23 to prevent the top head from axial movement and slipping. In this embodiment, the hexagon socket set screw M5 is selected.

[0032] In specific applications, the top heads with different external shapes can be designed according to the tail structure of the workpiece to be processed. Figure 3 As shown, it includes an integrally arranged mating end 41 and a tip 42, the mating end 41 is cylindrical, the tip 42 is truncated cone, and the inner hole is opened along the axial direction of the cylindrical mating end 41. The inner hole is a stepped hole, the needle bearing 5 is sleeved on the head, and is matched with the small end 43 of the stepped hole, the head 23 extends into the large end 44 of the stepped hole, so that the groove 24 is located in the large end 44 of the stepped hole, and the distance between the bottom of the groove 24 and the inner circumference of the large end 44 of the stepped hole is greater than the depth of the groove 24, there is a gap between the end face of the head away from the positioning portion 22 and the bottom of the inner hole, and the set screw 6 passes through the large end 44 of the stepped hole and is fixed in the annular groove 24 of the head 23. In order to achieve uniform axial force, two set screws can be selected and evenly distributed along the outer circumference of the mating end 41.

[0033] Before machining parts on a CNC vertical milling machine, select a suitable top head according to the inner hole size of the part, disassemble the set screw, remove the original top head, replace it with the newly selected top head, and then tighten the set screw. After the top head is selected and installed, the workpiece is pressed against the milling machine and machining can be carried out. When one end of the shaft workpiece is driven to rotate by the three claws, the tail of the workpiece and the rotating top follow the rotation, and the whole process is completed.

Claims

1. A rotating center with a quick-change center head, characterized in that: It includes a center body (2), a thrust bearing (3), a needle bearing (5), a center head (4) and a set screw (6); The tip body (2) comprises a tail portion (21), a positioning portion (22) and a head portion (23) which are fixedly arranged in sequence; the central axes of the tail portion (21), the positioning portion (22) and the head portion (23) are located in the same straight line; The tail portion (21) is used for fixing to a machine tool; the tail portion (21) is a cone with a certain taper; The positioning portion (22) is in the shape of a round cake, and its diameter is greater than the maximum diameter of the tail portion (21); The head (23) is cylindrical, and its diameter is smaller than the diameter of the positioning portion (22); an annular groove (24) is provided along the outer circumference of the end surface of the head (23), and the end surface is the end away from the positioning portion (22); The thrust bearing (3) passes through the head portion (23) and is close to the end surface of the positioning portion (22); The needle bearing (5) is sleeved on the outer circumference of the head (23) and cooperates therewith; The top head (4) has an inner hole, and is buckled onto the needle bearing (5) through the inner hole. The inner hole matches the needle bearing (5), and the end face of the open end of the top head (4) is in close contact with the thrust bearing (3). The tip (4) comprises a mating end (41) and a tip (42), the mating end (41) is cylindrical, the tip (42) is frustum-shaped, and the inner hole is opened along the axial direction of the cylindrical mating end (41); The inner hole is a stepped hole, the needle bearing (5) cooperates with the small end (43) of the stepped hole, and the head (23) extends into the large end (44) of the stepped hole; The set screw (6) passes through the top head (4) in the radial direction of the top head and is fixed in the annular groove (24) of the head (23).

2. The rotating centering head with quick-change centering head according to claim 1, characterized in that: The shape of the top tip (4) is adapted to the center hole at the tail of the workpiece to be processed.

3. The rotating centering head with quick-change centering head according to any one of claims 1-2, characterized in that: The tail portion (21) is mounted with a round nut (1) through threaded engagement.

4. The rotating centering head with quick-change centering head according to claim 3, characterized in that: There are two set screws (6) which are evenly distributed along the outer circumference of the mating end (41).

5. The rotating centering head with quick-change centering head according to claim 4, characterized in that: The distance between the bottom of the annular groove (24) and the inner circumferential surface of the large end (44) of the stepped hole is greater than the depth of the annular groove (24); and there is a gap between the end surface of the head away from the positioning portion (22) and the bottom of the inner hole.

Images