A center mechanism with good positioning stability

Abstract

The application discloses a tailstock mechanism with good positioning stability, which comprises a main body, a worm gear and a connecting assembly. The main body has a first inner cavity arranged along an axial direction and a second inner cavity perpendicular to the axial direction, and the first inner cavity and the second inner cavity are communicated. The worm gear is arranged in the first inner cavity of the main body and has an internal thread. The worm is arranged in the second inner cavity of the main body and is engaged with the worm gear. The connecting assembly is arranged in the first inner cavity, one end of the connecting assembly is provided with an external thread for being connected with the internal thread, and the other end of the connecting assembly is provided with at least one claw. The tailstock is connected to the end face of the main body through a fastener, the tailstock is provided with at least one through hole, and the through hole is arranged in correspondence with the claw to allow the claw to pass through. When the worm is rotated, the worm gear can drive the connecting assembly to move along the axial direction, so as to drive the claw to move along the axial direction. The tailstock mechanism can improve the positioning accuracy of the tailstock on a part to be machined, improve the clamping force and reliability of the claw on the part to be machined, and reduce the risk of wear of the claw on the part.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of machine tool processing auxiliary jig, in particular to a tailstock mechanism with good positioning stability. BACKGROUND

[0002] Tailstock is usually used to assist in processing shaft parts with large axial size. Specifically, during the processing of shaft parts, the cutter will generate radial cutting force on the parts, and when the axial size of the parts is too large and only one end is clamped by the machine tool, the parts will generate radial runout, resulting in low processing accuracy. Therefore, in order to improve the clamping reliability of the parts and reduce the radial runout of the parts, the end of the part to be processed is usually clamped by the spindle box chuck, and the other end is pressed by the tailstock. During processing, the tailstock is mainly used to center the shaft parts, bear the weight and cutting force of the parts.

[0003] A double tailstock mechanism with transmission capacity for a lathe is disclosed in Chinese Patent No. CN203695976U, and specifically discloses that the headstock tailstock assembly includes a clamping body, a movable tailstock, and at least three cylindrical telescopic shifting blades. One end of the clamping body is a mounting handle, and the other end is a disc-shaped mounting body. An axial hole is provided at the axial position of the mounting body. The movable tailstock is installed in the axial hole, and an axial support spring is provided between the inner end of the tailstock and the inner end surface of the axial hole. At least three cylindrical holes are provided on the end surface of the mounting body, and the telescopic shifting blades are installed in the cylindrical holes. At least three radial blind holes are provided on the circumference of the mounting body and communicate with the bottom of the main shaft hole. A wedge-shaped sliding block is provided in the radial blind hole. A top bead is provided at the inner end of the telescopic shifting blade in the cylindrical hole. The inclined surface of the wedge-shaped sliding block is in contact with the top bead, and a radial support spring is provided between the inner end of the wedge-shaped sliding block and the bottom of the radial blind hole. The double tailstock mechanism improves the clamping reliability of the parts under high-speed processing conditions by inserting the movable tailstock into the inner hole of the end surface of the shaft part and clamping the end surface of the part by the telescopic shifting blade.

[0004] 1. Since the movable tailstock is movably connected to the mounting body by an axial support spring, in order to allow the movable tailstock to move smoothly relative to the mounting body, the inner diameter of the axial hole must be larger than the outer diameter of the movable tailstock. Therefore, under the action of gravity, the movable tailstock will tilt downward, resulting in the inability to be concentric with the axial hole of the mounting body, thereby causing inaccurate positioning of the part to be processed. In addition, during processing, if the movable tailstock radially swings in the axial hole, it is also easy to cause the part to swing and result in processing defects.

[0005] 2. The clamping force of the retractable push blade on the end face of the part changes with the centrifugal force of the wedge-shaped slider (or the rotation speed of the machine tool spindle), and in the process of changing the clamping force, the relative movement between the retractable push blade and the end face of the part is likely to occur, which will generate friction and cause wear on the end face of the part. SUMMARY

[0006] In order to overcome the defects in the prior art, the embodiments of the present application provide a center mechanism with good positioning stability, which is used to solve at least one of the above problems.

[0007] The embodiments of the present application disclose a center mechanism with good positioning stability, which comprises:

[0008] A main body having a first inner cavity arranged in an axial direction and a second inner cavity perpendicular to the axial direction, the first inner cavity and the second inner cavity being in communication;

[0009] A worm gear arranged in the first inner cavity of the main body, the worm gear having an internal thread;

[0010] A worm arranged in the second inner cavity of the main body and engaged with the worm gear;

[0011] A connecting assembly arranged in the first inner cavity, one end of the connecting assembly being provided with an external thread for connecting with the internal thread, and the other end of the connecting assembly being provided with at least one claw;

[0012] A center, the center being connected to the end face of the main body through a fastener, the center being provided with at least one through hole corresponding to the claw for the claw to pass through; when the worm is rotated, the worm gear can drive the connecting assembly to move in the axial direction, thereby driving the claw to move in the axial direction.

[0013] Specifically, the main body comprises a handle part and a top part which are detachably connected, the first inner cavity and the second inner cavity are arranged in the handle part, the first inner cavity penetrates through both ends of the handle part, and along the direction from the top part to the center, the first inner cavity comprises a first section, a second section and a third section, the inner diameter of the second section is smaller than the inner diameters of the first section and the third section, and the worm gear is arranged in the first section.

[0014] Specifically, the side of the top part facing the first inner cavity is provided with a first boss extending into the first section of the first inner cavity, and the first boss is provided with a blind hole for limiting the worm gear.

[0015] Specifically, the connecting assembly comprises a movable disc and a connecting disc which are detachably connected, the external thread is arranged on the movable disc, and the claw is arranged on the connecting disc.

[0016] Specifically, the inner wall of the second section of the first inner cavity is provided with internal teeth, and the outer wall of the movable disc is provided with external teeth for engaging with the internal teeth.

[0017] Specifically, the top center is provided with a third inner cavity at one end of the main body, which communicates with the first inner cavity, and the connecting assembly is at least partially accommodated in the third inner cavity and can move axially in the third inner cavity.

[0018] Specifically, the top center comprises an integral connecting part and a pointed part, and the connecting part is connected to the main body by a bolt.

[0019] Specifically, one end of the second inner cavity penetrates the main body, and the other end of the second inner cavity is provided with a counterbore for accommodating one end of the worm, and the end of the worm away from the counterbore is provided with a second boss, and the second boss is provided with an internal hexagonal structure.

[0020] Specifically, the number of the clamping jaws is multiple, and the multiple clamping jaws are distributed circumferentially on the connecting assembly.

[0021] The present application has at least the following beneficial effects:

[0022] The top center is fixedly connected to the main body by a fastener, and after assembly, the top center cannot move, which can avoid the phenomenon of eccentricity (different axes) of the top center with the main body during work, and improves the positioning accuracy and stability of the top center to the parts to be processed; before processing the parts, the amount of the clamping jaw extending out of the top center is adjusted by the worm and worm gear structure, which can adjust the clamping force of the clamping jaw on the end face of the part to be processed, and improve the reliability of the clamping jaw on the part; compared with the prior art, the structure of the present embodiment can avoid the relative movement between the clamping jaw and the end face of the part during cutting, which causes the part to be worn; the solution disclosed in the Chinese patent with publication number CN203695976U has the risk of being thrown out of the installation body when the centrifugal force is too large, which has a safety risk, and the solution of the present application does not have such a risk; in addition, since the clamping jaw is adjustable, the clamping jaw can be suitable for the end faces of different parts.

[0023] In order to make the above and other objects, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0025] Figure 1 is a structural schematic view of a tailstock mechanism with good positioning stability in an embodiment of the present application;

[0026] Figure 2 is a structural schematic view of the internal structure of a tailstock mechanism with good positioning stability in an embodiment of the present application;

[0027] Figure 3 is a structural schematic view of a handle portion in one perspective in an embodiment of the present application;

[0028] Figure 4 is a structural schematic view of a handle portion in another perspective in an embodiment of the present application;

[0029] Figure 5 is a structural schematic view of a top portion in an embodiment of the present application;

[0030] Figure 6 is a structural schematic view of a connecting assembly in an embodiment of the present application;

[0031] Figure 7 is a structural schematic view of a tailstock in an embodiment of the present application;

[0032] Figure 8 is a structural schematic view of a worm arranged in a second inner cavity in an embodiment of the present application.

[0033] Reference signs in the above drawings: 1, main body; 11, handle portion; 12, top portion; 110, first inner cavity; 111, first section; 112, second section; 113, third section; 120, second inner cavity; 121, first boss; 2, worm wheel; 3, worm; 31, second boss; 4, connecting assembly; 41, movable disc; 411, first portion; 412, second portion; 413, third portion; 42, connecting disc; 5, clamping jaw; 6, tailstock; 61, connecting portion; 62, pointed portion; 610, third inner cavity; 620, through hole; 71, inner teeth; 72, outer teeth. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0035] In the description of the present application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "fixing", "connecting" should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, can be indirectly connected through an intermediate medium, and can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise explicitly specified and limited, the first feature "above" or "below" the second feature can include that the first feature and the second feature are in direct contact, or that the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, the first feature "above", "below" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0037] In the description of the present embodiment, it is necessary to understand that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application.

[0038] In addition, the terms "first", "second" and the like are only used to distinguish in the description, and have no special meaning.

[0039] In combination Figure 1 And Figure 2As shown, the center mechanism with good positioning stability of the embodiment mainly comprises a main body 1, a worm wheel 2, a worm 3, a connecting assembly 4, a center 6 and at least one claw 5. The main body 1 has a first inner cavity 110 arranged along the axial direction, in other words, the first inner cavity 110 extends along the axial direction of the main body 1. The main body 1 also has a second inner cavity 120 arranged perpendicular to the axial direction, and the first inner cavity 110 and the second inner cavity 120 are communicated. The worm wheel 2 and the connecting assembly 4 are arranged in the first inner cavity 110 of the main body 1. The worm wheel 2 has an internal thread structure (not shown in the figure), and one end of the connecting assembly 4 has an external thread structure (not shown in the figure) for connecting with the internal thread structure of the worm wheel 2. The claw 5 is connected to the end of the connecting assembly 4 away from the worm wheel 2. The worm 3 is arranged in the second inner cavity 120 of the main body 1, and the worm 3 is engaged with the worm wheel 2 through the communication between the first inner cavity 110 and the second inner cavity 120. The center 6 is connected to the end face of the main body 1 through a fastener, and the center 6 is coaxially arranged with the main body 1. The center 6 is provided with at least one through hole 620, and the position of the through hole 620 corresponds to the position of the claw 5 on the connecting assembly 4. Each through hole 620 is used for allowing one claw 5 to pass through. In this embodiment, the center 6 assembly comprises a plurality of claws 5 uniformly distributed in the circumferential direction, and correspondingly, the center 6 is provided with a plurality of through holes 620 uniformly distributed in the circumferential direction, and the plurality of through holes 620 on the center 6 correspond to the plurality of claws 5 one by one.

[0040] When the worm 3 is rotated, the worm wheel 2 can drive the connecting assembly 4 connected with it by threads to move along the axial direction under the driving of the worm 3, so as to drive the claw 5 to move along the axial direction, that is, the claw 5 can protrude out of the center 6 and retract into the center 6, thereby realizing the clamping of the end face of the part to be machined by the claw 5.

[0041] Through the above structure, the center mechanism with good positioning stability of the embodiment has at least the following advantages: the center 6 is fixedly connected with the main body 1 through a fastener, and after assembly, the center 6 cannot move, which can avoid the phenomenon that the center 6 is eccentric (different axes) with the main body 1 during work, thereby improving the positioning accuracy and stability of the center 6 to the part to be machined; before machining the part, the amount of the claw 5 protruding out of the center 6 is adjusted through the worm wheel 2 and the worm 3 structure, the clamping force of the claw 5 to the end face of the part to be machined can be adjusted, and the reliability of the claw 5 to clamp the part is improved. Compared with the prior art, the structure of the embodiment can avoid the relative movement between the claw 5 and the end face of the part during the cutting process, thereby preventing the part from being worn. In the scheme disclosed in the Chinese patent with publication number CN203695976U, when the centrifugal force is too large, the wedge-shaped sliding block has the possibility of being thrown out of the mounting body, which has a safety risk. However, the scheme of the present application does not have such a risk. In addition, since the claw 5 is adjustable, the claw 5 can be suitable for the end faces of different parts.

[0042] Specifically, as Figure 1 andFigure 2 As shown, the main body 1 of the present embodiment mainly comprises a handle 11 and a top 12 which are detachably connected, wherein the handle 11 is mainly used for mounting the worm gear 2, the worm 3 and the connecting assembly 4, and the top 12 is used for connecting the handle 11 and the main shaft of the machine tool. More specifically, as shown in the exploded view of the main body 1 of the present embodiment, Figure 3 and Figure 4 As shown, the first inner cavity 110 and the second inner cavity 120 are both provided on the handle 11, and the first inner cavity 110 penetrates through both ends of the handle 11 along the axial direction. Referring to the assembly view of the center mechanism of the present embodiment, along the direction from the top 12 to the center 6, the first inner cavity 110 comprises a first section 111, a second section 112 and a third section 113 in sequence, wherein the inner diameter of the second section 112 is smaller than that of the first section 111 and the third section 113. In other words, the second section 112 of the first inner cavity 110 is formed by the inner wall of a step formed in the first inner cavity 110. The worm gear 2 is provided in the first section 111 of the first inner cavity 110. The top 12 cooperates with the step in the first inner cavity 110 to position the worm gear 2 in the first section 111 of the first inner cavity 110.

[0043] As shown, Figure 5 The top 12 of the present embodiment has a first boss 121 on the side facing the first inner cavity 110, which extends into the first section 111 of the first inner cavity 110 and axially limits the worm gear 2. In addition, the first boss 121 is provided with a blind hole which is used to limit the worm gear 2 in the radial direction. Specifically, the worm gear 2 comprises a wheel body for engaging with the worm 3, and both ends of the wheel body have non-toothed portions. The non-toothed portion facing the top 12 extends into the above-mentioned blind hole and has a high-precision fit with the blind hole (coaxial and small gap between them), so as to realize the limitation of the blind hole to the worm gear 2.

[0044] As shown, Figure 6As shown, the connecting assembly 4 of the present embodiment mainly comprises a movable disc 41 and a connecting disc 42 which are detachably connected. The external thread structure is arranged on the movable disc 41, and the clamping jaws 5 are arranged on the connecting disc 42. More specifically, the movable disc 41 mainly extends into the first inner cavity 110 of the main body 1 to be connected with the worm wheel 2, and the connecting disc 42 is connected to one end of the movable disc 41 towards the tailstock 6 for mounting a plurality of clamping jaws 5. Preferably, the movable disc 41 can comprise a first portion 411, a second portion 412 and a third portion 413 which are connected in sequence, wherein the first portion 411 is provided with external threads (not shown in the figure) which are connected with the internal threads of the worm wheel 2, the second portion 412 is matched with the second section 112 of the first inner cavity 110, and the third portion 413 is matched with the third section 113 of the first inner cavity 110. Further, the outer wall of the second portion 412 of the movable disc 41 is provided with external teeth 72, and the inner wall of the second section 112 of the first inner cavity 110 is provided with internal teeth 71, and through the meshing of the external teeth 72 and the internal teeth 71, the rotation of the movable disc 41 can be effectively prevented, and the movement of the clamping jaws 5 during cutting can be avoided, and at the same time, the meshing mode can also improve the installation accuracy of the movable disc 41 and the coaxiality after the movable disc 41 is connected with the handle 11.

[0045] As shown in Figure 2 and 7 , the tailstock 6 of the present embodiment can be provided with a third inner cavity 610 which is communicated with the first inner cavity 110 at one end towards the main body 1, and at least part of the connecting assembly 4 is accommodated in the third inner cavity 610 and can move axially in the third inner cavity 610. Specifically, the tailstock 6 can comprise an integral connecting portion 61 and a pointed portion 62, the connecting portion 61 is connected to the end face of the main body 1 (the handle 11) by bolts, and the third inner cavity 610 is formed on the connecting portion 61 of the tailstock 6; the pointed portion 62 is used to penetrate into the hole of the part to be machined. When the movable disc 41 moves to the limit position (the third portion 413 of the movable disc 41 is stopped by the step in the first inner cavity 110) in the direction towards the handle 11, at least part of the movable disc 41 (the third portion 413) is also located in the third inner cavity 610 (i.e. the connecting portion 61 of the tailstock 6). By using the above scheme, the movable disc 41 is matched with the third inner cavity 610 through high-precision hole positioning, which can improve the coaxiality precision of the assembly of the tailstock 6 and the main body 1, and further improve the coaxiality precision of the tailstock 6 and the main shaft of the machine tool after installation, on the other hand, part of the connecting assembly 4 is located in the tailstock 6, which can reduce the installation space requirement of the connecting assembly 4 in the main body 1, and is beneficial to reduce the overall volume of the tailstock 6 assembly.

[0046] As shown in Figure 8As shown, one end of the second inner cavity 120 of the embodiment penetrates the main body 1 (the handle 11), and the other end can not penetrate, and the other end is provided with a counterbore for accommodating one end of the worm 3, and the end of the worm 3 away from the counterbore is provided with a second boss 31, and the side of the second boss 31 away from the worm 3 is provided with an internal hexagonal structure. In this way, when the worm 3 is rotated by using an internal hexagonal wrench, the worm 3 can drive the worm wheel 2 to rotate, and then the movable disc 41 can move in the axial direction, so as to drive the clamping jaw 5 to grip or release the end face of the part to be processed.

[0047] In summary, the working process of the center mechanism with good positioning stability of the embodiment is as follows: the top 12 of the main body 1 is connected with the machine tool spindle to install the center mechanism on the machine tool spindle, after the pointed part 62 of the center 6 penetrates into the hole of the part to be processed, the worm 3 is rotated by using an internal hexagonal wrench, the worm wheel 2 is rotated to drive the clamping jaw 5 on the connecting assembly 4 to move towards the end face of the part to grip the workpiece, after the processing is finished, the worm 3 is reversely rotated to make the clamping jaw 5 release the end face of the part.

[0048] The principle and implementation mode of the present application are described by using specific embodiments, and the above embodiment is only used to help understand the method of the present application and its core idea; meanwhile, for the general skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed, and the above description should not be understood as the limitation of the present application.

Claims

1. A top-mounted mechanism with good positioning stability, characterized in that, The utility model relates to a kind of connecting device, including: Main body, the main body has the first inner cavity and the second inner cavity being arranged along axial direction vertically, the first inner cavity and the second inner cavity are communicated; Worm wheel, is arranged in the first inner cavity of the main body, the worm wheel has internal thread; Worm, is arranged in the second inner cavity of the main body and is engaged with the worm wheel; Connecting assembly, is arranged in the first inner cavity, one end of the connecting assembly is equipped with external thread for being connected with the internal thread, the other end of the connecting assembly is equipped with at least one claw; Tip, the tip is connected to the end surface of the main body by fastener, the tip is equipped with at least one through hole, the through hole is arranged to correspond with the claw to be passed through by the claw;When rotating the worm, the worm wheel can drive the connecting assembly to move along axial direction, so as to drive the claw to move along axial direction, the tip includes integrally formed connecting portion and sharp portion, the connecting portion is connected with the main body by bolt; The main body includes detachably connected handle and top, the first inner cavity and the second inner cavity are arranged in the handle, the first inner cavity is through the both ends of the handle, along the direction from the top to the tip, the first inner cavity includes first section, second section and third section, the inner diameter of the second section is less than the inner diameter of the first section and the third section, the worm wheel is arranged in the first section;The side of the top towards the first inner cavity has first boss that enters the first section of the first inner cavity, the first boss is equipped with blind hole for limiting the worm wheel, the worm wheel includes wheel body for being engaged with worm, the both ends of the wheel body are respectively provided with non-toothed portion, and the non-toothed portion towards the top enters the blind hole and is high-precision matched with the blind hole;The connecting assembly includes detachably connected movable disc and connecting disc, the external thread is arranged on the movable disc, the claw is arranged on the connecting disc;The inner wall of the second section of the first inner cavity is equipped with internal tooth, the outer wall of the movable disc is equipped with external tooth for being engaged with the internal tooth;The movable disc includes first part, second part and third part connected in sequence, wherein, the first part is equipped with external thread for being connected with the internal thread of worm wheel, the second part cooperates with the second section of the first inner cavity, and the third part cooperates with the third section of the first inner cavity;The end of the tip towards the main body is equipped with third inner cavity communicated with the first inner cavity, at least part of the connecting assembly is accommodated in the third inner cavity and can move along axial direction in the third inner cavity;When movable disc moves to limit position in the direction towards handle, the third part of movable disc is stopped by the step in the first inner cavity, and at least part of the third part of movable disc is also located in the third inner cavity.

2. The center mechanism according to claim 1, wherein One end of the second inner cavity is through the main body, the other end of the second inner cavity is equipped with counterbore for accommodating one end of the worm, the second boss is equipped on the end of the worm away from the counterbore, and the internal hexagonal structure is equipped on the second boss.

3. The center mechanism according to claim 1, wherein The number of the claw is multiple, and multiple claws are distributed on the connecting assembly along the circumference.

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