阅读说明：本技术 一种长管坯料高精度内孔车削装置及方法 (High-precision inner hole turning device and method for long pipe blank ) 是由 黄泉龙 于 2019-12-03 设计创作，主要内容包括：本发明公开了一种长管坯料高精度内孔车削装置及方法,其特征在于,弹性夹具体前端为带外锥的端面开槽弹性涨夹结构,后端为外螺纹,中间导向圆柱区域设置有滚动限位装置,其外锥、外螺纹以及弹性涨夹内孔和导向圆柱外圆同轴；滚动支承块为一环形内锥结构,内部设有滚动限位装置；其内锥、外圆及内孔三者同轴,内孔与导向圆柱间隙配合移动连接并由滚动限位装置限位；螺母端面均匀布置有三个以上轴向螺纹通孔；滚动支承块位于弹性夹具体的前端,螺母与弹性夹具体后端的外螺纹同轴连接并通过锁紧装置固定,涨夹时,挤压螺栓挤压滚动支承块的端面,产生轴向移动进而迫使弹性夹具体的弹性涨夹部分均匀内缩,直至抱紧工件外圆。(The invention discloses a turning device and a turning method for a high-precision inner hole of a long tube blank, which are characterized in that the front end of an elastic clamp body is of an end surface slotting elastic expansion clamp structure with an outer cone, the rear end of the elastic clamp body is provided with an external thread, a rolling limiting device is arranged in the middle guide cylinder area, and the outer cone, the external thread, the elastic expansion clamp inner hole and the guide cylinder excircle are coaxial; the rolling supporting block is of an annular inner cone structure, and a rolling limiting device is arranged in the rolling supporting block; the inner cone, the outer circle and the inner hole are coaxial, and the inner hole is in clearance fit with the guide cylinder, movably connected and limited by the rolling limiting device; more than three axial thread through holes are uniformly distributed on the end face of the nut; the rolling supporting block is located at the front end of the elastic clamp body, the nut is coaxially connected with the external thread at the rear end of the elastic clamp body and fixed through the locking device, and when the expansion clamp is used, the extrusion bolt extrudes the end face of the rolling supporting block to generate axial movement so as to force the elastic expansion clamp part of the elastic clamp body to uniformly contract inwards until the excircle of a workpiece is held tightly.)

1. A high-precision inner hole turning device for long tube blanks is characterized in that a device clamp comprises,

the front end of the elastic clamp body (1) is of an end face slotting elastic expansion clamp structure with an outer cone, the rear end of the elastic clamp body (1) is provided with an external thread, a rolling limiting device is arranged in the middle guide cylinder area, and the outer cone and the external thread of the elastic clamp body (1) and an inner hole of the elastic expansion clamp are coaxial with the excircle of the guide cylinder;

the rolling supporting block (2), the rolling supporting block (2) is a ring-shaped inner cone structure, and a rolling limiting device is arranged in the rolling supporting block (2); the inner cone, the outer circle and the inner hole of the rolling supporting block (2) are coaxial, and the inner hole of the rolling supporting block (2) is in clearance fit movable connection with the guide cylinder of the elastic clamp body (1);

and

the nut (4) is of an internal thread structure, more than three axial thread through holes are uniformly distributed on the end face of the nut (4), and the internal thread of the nut (4) is coaxial with the external thread of the elastic clamp body (1);

the rolling supporting block (2) is positioned at the front end of the elastic clamp body (1), and a rolling limiting device on the elastic clamp body (1) is correspondingly connected with a rolling limiting device in the rolling supporting block (2); the nut (4) is connected with the external thread at the rear end of the elastic clamp body (1) and is fixed through the locking device, when the expansion clamp is used, the extrusion bolt (5) is screwed in to penetrate through the axial thread through hole of the nut (4) and then extrudes the end face of the rolling supporting block (2), and the rolling supporting block (2) generates axial movement to further force the elastic expansion clamp part of the elastic clamp body (1) to uniformly contract inwards until the outer circle of the workpiece (7) is tightly held.

2. The long tube blank high-precision inner hole turning device as claimed in claim 1, wherein the rolling limiting device on the elastic clamp body (1) is composed of more than two radial holes symmetrically arranged in the middle guide cylindrical area of the elastic clamp body (1) and pull pins (3) arranged on the radial holes; the rolling limiting device in the rolling supporting block (2) is more than two through grooves symmetrically arranged in the rolling supporting block (2); the pull pins (3) are correspondingly connected with the through grooves one by one; one end of the pulling pin (3) is tightly matched and installed in a radial hole on the elastic clamp body (1), and the other end of the pulling pin is positioned in a through groove of the rolling supporting block (2), is in sliding connection with the through groove in the axial direction and is in limiting connection in the rolling direction.

3. The long tube blank high-precision inner hole turning device as claimed in claim 1, wherein the outer conical part of the elastic clamp body (1) is in contact with the inner conical surface of the rolling support block (2) to form a wedge-shaped structure, and the wedge-shaped structure is wedged into the inner conical surface under the action of an axial external force.

4. The long tube blank high-precision inner hole turning device is characterized in that three radial holes and three pull pins are symmetrically arranged in the middle guide cylindrical area of the elastic clamp body (1), and three through grooves are symmetrically arranged in the rolling bearing block (2).

5. The long tube blank high-precision inner hole turning device according to claim 1, wherein the locking device of the nut (4) and the elastic clamp body (1) consists of more than two radial internal thread through holes symmetrically arranged on the side edge of the nut (4) and a fastening bolt (6) connected on the radial internal thread through holes; the nut (4) is connected with the external thread at the rear end of the elastic clamp body (1) and is fixed through a fastening bolt (6).

6. The long tube blank high-precision inner hole turning device is characterized in that four axial threaded through holes are machined in the end face of the nut (4), and four extrusion bolts (5) simultaneously extrude the end face of the rolling support block (2).

7. The turning device for the high-precision inner hole of the long tube blank as claimed in claim 1, wherein the outer circle of the rolling bearing block (2) is a fine grinding cylindrical surface, the roundness is less than 0.005, and the inner cone is a grinding surface.

8. The method for turning the inner hole of the long tube blank by using the high-precision inner hole turning device of the long tube blank as claimed in claim 1,

(1) firstly, the rolling supporting block (2) is sleeved from the rear end of the elastic clamp body (1), a rolling limiting device on the elastic clamp body (1) corresponds to a rolling limiting device in the rolling supporting block (2) in position until the inner cone of the rolling limiting device is attached to the axial part of the outer cone of the elastic clamp body (1); when the nut (4) is screwed into the rear end of the elastic clamp body (1) until the full thread enters and is fixed by the locking device; then, screwing in an extrusion bolt (5) in an axial threaded hole uniformly arranged on the end surface of the nut (4);

(2) after the turning device is sleeved on the outer circle of the workpiece and moves to a processing position, the extrusion bolts (5) are symmetrically screwed to force the rolling supporting block (2) to move downwards in the way that the inner hole of the rolling supporting block is in clearance fit with the guide cylinder of the elastic clamp body (1) and the inner cone is axially extruded towards the outer conical surface of the elastic clamp body (1), so that the elastic expansion part of the elastic clamp body (1) is forced to uniformly contract inwards until the outer circle of the workpiece (7) is tightly held; the outer conical surface of the elastic clamp body (1) is attached to the inner cone of the rolling supporting block (2), the inner cone of the rolling supporting block (2) is coaxial with the outer circle of the rolling supporting block, the outer conical surface of the elastic clamp body (1) is coaxial with the inner hole of the elastic expansion clamp and coaxial with the outer circle of the workpiece (7), so that the outer circle of the workpiece (7) is coaxial with the outer circle of the rolling supporting block (2), and the workpiece (7) and a turning device are fixedly connected into a whole;

(3) finally, the other end of the workpiece (7) is clamped by a main shaft end of the machine tool, one end provided with the turning device is placed into a lathe center frame, and three ball frames of the lathe center frame are held in the middle of the excircle of the rolling supporting block (2); when the machine tool spindle drives the workpiece (7) to rotate, the workpiece drives the elastic clamp body (1) and the rolling bearing block (2) to synchronously rotate, so that the turning requirement is met.

Technical Field

The invention belongs to the field of machining, and relates to a method and a device for turning a high-precision inner hole of a long tube blank.

Background

In the automobile manufacturing industry, the weight of a vehicle body is reduced, material saving is a long-term target of manufacturing enterprises, and blank pipe materials are inevitably adopted in product design so as to reduce the consumption of materials caused by machining and the like as far as possible.

However, due to the assembly requirement, the inner hole of the blank tube material is always required to be processed into an inner hole with higher precision. If a lathe is adopted for processing, the short material can be turned at the main shaft end through clamping jaws, the long material can only hold the excircle of the blank through the center frame to turn the inner hole at the tail seat end, and due to the fact that the excircle of the blank is irregular, if the excircle of the blank is directly held by the frame to be processed, the processing size cannot meet the product quality requirement, and production cannot be achieved.

In addition, only a boring mode can be adopted for processing, but special boring equipment is required for boring, such as a horizontal boring machine, a horizontal processing center and the like; and the single piece processing time is long. Meanwhile, in each manufacturing enterprise, the boring equipment is far less widely used than a numerical control lathe, and the production energy restriction is obvious.

Under the active participation of the inventor, the applicant has proposed a plurality of related patent applications, such as CN201720664682.5 "a blank tube material excircle turning device" (yellow spring dragon; wude de), in which a main shaft end internal expansion clamp and a tailstock end internal expansion clamp are connected through a workpiece and are connected into a whole after being axially tightened, and since the clamping at both ends is formed by expanding and clamping the inner hole of the workpiece, the axis of the inner hole of the workpiece is collinear with the rotation center of the machine tool, so that the excircle of the turned workpiece is ensured to be coaxial with the inner hole of the workpiece, and the two end clamps are deformed to synchronously expand and clamp the inner holes at both ends of the workpiece through tightening the tailstock, thereby ensuring that the axis of the inner hole after the workpiece is clamped to be coaxial with the rotation center of the machine tool, and the operation is simple and reliable.

For example, CN201720664692.9 "a thin-walled blank tube inner hole turning device" (huang quan long; wu de jun) includes an elastic clamp body, the elastic clamp body includes a sleeve portion and a wedge-shaped elastic portion located at one side of the sleeve portion, the wedge-shaped elastic portion and the sleeve portion are hollow, and the device can directly process the blank tube. Namely, the blanked blank pipe material can be directly turned into the end face through the device to ensure the length and finish turning of the inner hole to ensure the size of the inner hole, and the end face turning process is not required to be additionally carried out by adopting a lathe before boring like boring, so that the processing efficiency is improved.

Through continuous innovation, the inventor can explore a device and a method for the high-precision inner hole of the long tube blank.

Disclosure of Invention

The invention aims to provide a device and a method for turning a high-precision inner hole of a long pipe blank, so that the product can be manufactured on a common lathe without being limited to a horizontal boring machine, a horizontal machining center and the like; meanwhile, the single-piece machining time is obviously reduced, and the production period is shortened.

One of the technical schemes of the invention is as follows:

a high-precision inner hole turning device for a long tube blank, a device clamp comprises,

the front end of the elastic clamp body is of an end face slotting elastic expansion clamp structure with an outer cone, the rear end of the elastic clamp body is provided with an external thread, a rolling limiting device is arranged in the middle guide cylinder area, and the outer cone and the external thread of the elastic clamp body as well as an inner hole of the elastic expansion clamp are coaxial with the excircle of the guide cylinder;

the rolling supporting block is of an annular inner cone structure, and a rolling limiting device is arranged in the rolling supporting block; the inner cone, the outer circle and the inner hole of the rolling supporting block are coaxial, and the inner hole of the rolling supporting block is in clearance fit movable connection with the guide cylinder of the elastic clamp body;

and

the nut is of an internal thread structure, more than three axial thread through holes are uniformly distributed on the end face of the nut, and the internal thread of the nut is coaxial with the external thread of the elastic clamp body;

the rolling supporting block is positioned at the front end of the elastic clamp body, and a rolling limiting device on the elastic clamp body is correspondingly connected with a rolling limiting device in the rolling supporting block; the nut is connected with the external thread at the rear end of the elastic clamp body and is fixed through the locking device, when the expansion clamp is used, the extrusion bolt is screwed in and penetrates through the axial threaded through hole of the nut to extrude the end face of the rolling supporting block, and the rolling supporting block generates axial movement to force the elastic expansion clamp part of the elastic clamp body to uniformly contract inwards until the outer circle of a workpiece is held tightly. The rolling limit device is a circumferential limit device.

Furthermore, the rolling limiting device on the elastic clamp body consists of more than two radial holes symmetrically arranged in the middle guide cylindrical area of the elastic clamp body and pull pins arranged on the radial holes; the rolling limiting device in the rolling supporting block is more than two through grooves symmetrically arranged in the rolling supporting block; the pull pins are correspondingly connected with the through grooves one by one; one end of the pulling pin is tightly matched and installed in a radial hole on the elastic clamp body, and the other end of the pulling pin is positioned in the through groove of the rolling supporting block and is in sliding connection with the through groove in the axial direction and is in limiting connection in the rolling direction.

Furthermore, the external conical part of the elastic clamp body is in contact with the internal conical surface of the rolling supporting block to form a wedge-shaped structure, and the wedge-shaped structure is wedged into the internal conical surface of the rolling supporting block under the action of axial external force.

Furthermore, three radial holes and three pull pins are symmetrically arranged in the middle guide cylindrical area of the elastic clamp body, and three through grooves are symmetrically arranged in the rolling bearing block.

Furthermore, the locking device of the nut and the elastic clamp body is composed of more than two radial internal thread through holes which are symmetrically arranged on the side edge of the nut and a fastening bolt connected with the radial internal thread through holes; the nut is connected with the external thread at the rear end of the elastic clamp body and is fixed by the fastening bolt.

Furthermore, four axial thread through holes are processed on the end face of the nut, and the four extrusion bolts simultaneously extrude the end face of the rolling supporting block.

Furthermore, the excircle of the rolling supporting block is a fine grinding cylindrical surface, the roundness of the cylindrical surface is within 0.005, and the inner cone is a grinding surface.

The second technical scheme of the invention is as follows:

the method for turning the inner hole by using the device comprises the following steps:

(1) firstly, sleeving the rolling supporting block from the rear end of the elastic clamp body, wherein a rolling limiting device on the elastic clamp body corresponds to a rolling limiting device in the rolling supporting block in position until an inner cone of the rolling limiting device is attached to an outer cone axial part of the elastic clamp body; when the nut is screwed into the rear end of the elastic clamp body until the full thread enters and is fixed by the locking device; then screwing in an extrusion bolt in the axial threaded hole uniformly arranged on the end face of the nut;

(2) after the turning device is sleeved on the outer circle of the workpiece and moves to a processing position, the extrusion bolts are symmetrically screwed to force the rolling supporting block to move downwards in the inner hole of the rolling supporting block and the guide cylinder of the elastic clamp body in a clearance fit guide way, the inner cone is axially extruded towards the outer conical surface of the elastic clamp body, and then the elastic expansion clamp part of the elastic clamp body is forced to uniformly contract inwards until the outer circle of the workpiece is tightly held; the outer conical surface of the elastic clamp body is attached to the inner cone of the rolling supporting block, the inner cone of the rolling supporting block is coaxial with the outer circle of the rolling supporting block, and the outer conical surface of the elastic clamp body is coaxial with the inner hole of the elastic expansion clamp and the outer circle of the workpiece, so that the outer circle of the workpiece is coaxial with the outer circle of the rolling supporting block, and the workpiece and the turning device are fixedly connected into a whole;

(3) finally, clamping the other end of the workpiece by a main shaft end of the machine tool, placing one end provided with the turning device into a lathe center frame, and enabling three ball frames of the lathe center frame to be held in the middle of the excircle of the rolling supporting block; when the main shaft of the machine tool drives the workpiece to rotate, the workpiece drives the elastic clamp body and the rolling bearing block to synchronously rotate, so that the turning requirement is met.

After the method is implemented, the high-precision inner hole of the long pipe blank can be directly turned by a lathe. Namely, the blanked blank pipe material can be directly turned into an end face and finish-turned into an inner hole through the device to ensure the size of the inner hole, and boring machining with low efficiency is not needed.

The invention is creatively realized by comparing with the CN201720664692.9 technology as follows:

1. the bearing mode of the cutting force of the workpiece is changed, and the cutting applicability is improved. The rotating force of the workpiece of CN201720664692.9 is realized by the friction force of related components on the clamp, so that the bearing capacity is small, the workpiece can only be used for processing at low rotating speed and light load, otherwise, the workpiece is easy to slip during cutting; according to the invention, the related components are related by adopting the pull pin, the cutting force is borne by utilizing the shearing force of the pull pin, the bearing capacity of the workpiece during cutting is greatly improved, and the application range of the method for machining is enlarged.

2. The clamping mode of the clamp is changed, and the operation convenience is improved. The pressing nut of CN201720664692.9 moves relative to the elastic clamp body, and rotates the pressing nut to generate relative displacement to axially press the related component, so as to force the wedge-shaped parts of the component to mutually wedge and generate elastic deformation to clamp the workpiece. The nut is contacted with the whole plane of the related component, the workpiece is easy to rotate and needs to be fixed firstly when being clamped, a specially-made large hexagonal wrench is needed for operation, and the operation is inconvenient; the extrusion nut does not move relative to the elastic clamp body. Four threaded holes are processed on the end face of the extrusion nut, bolts passing through the four threaded holes rotate to generate axial displacement to directly extrude related components, wedge-shaped parts of the components are forced to mutually wedge into elastic deformation to clamp a workpiece, and an operator can operate the extrusion nut by using a conventional inner hexagonal wrench.

The invention has greater applicability and advancement after being implemented. The machining allowance, the cutting depth during machining, the rotating speed of the main shaft and the like of the workpiece can meet the requirements of a conventional lathe, and the limited application range does not need to be additionally reduced; meanwhile, the clamping is convenient, and the invention is easy to popularize and implement.

Drawings

FIG. 1 is a schematic diagram of the use of example 1 of the present invention;

FIG. 2 is a schematic structural view of embodiment 1 of the present invention;

fig. 3 is a schematic structural view of the elastic clamp body 1 according to embodiment 1 of the present invention;

fig. 4 is a schematic structural view of a nut 4 according to embodiment 1 of the present invention;

fig. 5 is a schematic structural view of the roll bearing block 2 according to embodiment 1 of the present invention.

Detailed Description

The invention can be practiced according to the teachings of the present disclosure, and the following non-limiting examples further illustrate the practice.