Background
When thin-wall parts are machined, the rigidity of the parts is insufficient, so that the clamping force during clamping can cause the parts to elastically deform during machining, and the size, the precision and the like cannot be controlled. In particular, when a material such as an aluminum alloy is processed, since the material itself has low hardness and is easily deformed, the accuracy and the like are more likely to be out of tolerance. When the outer diameter of the part is processed, the part is usually directly supported in an inner hole of the part by the three-jaw chuck, and when the thin-wall aluminum alloy part is processed, the BC type pneumatic chuck is adopted to enlarge the contact area with the workpiece, so that the part is pressed more uniformly to reduce the deformation. But the joint degree of the BC type chuck and the part can not be guaranteed, concentricity error is easy to cause, and the pressure of the air pressure clamp can not be accurately adjusted in a small range. Therefore, the size and the precision of the machined part cannot be guaranteed, and the chuck can leave scratches on the inner hole to influence the surface quality.
The invention with the application number of 201710010625.X discloses a mechanical tensioning device, which comprises a tensioning seat, a first fixed end cover, a screw, a boss, an internal thread, a nut seat, a cone, a guide pillar, a transverse connecting block, a fixed block, a connecting shaft, a fixed piece, a spring, a second fixed end cover, an external thread, a connecting sleeve, a groove clamping block and an operating piece; the fixing block is arranged, the top of the fixing block is provided with the T-shaped groove, and the bottom of the fixing block is provided with the T-shaped block, so that the fixing blocks can be effectively overlapped for use, and the tensioning requirements of cylinders with different sizes are met; the connecting sleeve is additionally arranged, when the length of the cylinder body is long, the connecting sleeve can effectively convey the tensioning device into a required position, and then the cylinder body can be tensioned by rotating the operating part, so that the use of workers is facilitated. However, the above patent is complicated in structure and high in cost.
SUMMERY OF THE UTILITY MODEL
The utility model discloses a solution is provided to present thin wall class parts machining deformation problem, promptly the part in the course of working not with three-jaw chuck direct contact, and play location and fixed effect through the frock. After the tensioning sleeve is opened, the tool can be attached to a reference surface of a workpiece, and the contact surface of the tool is enlarged, and the clamping force is manually screwed, so that the clamping force can be finely adjusted to ensure that the tool is clamped under the condition of applying the minimum force. Meanwhile, due to the fact that the contact surface of the tool and the part is increased, the friction force between the workpiece and the tool is increased, and the tool can be fixed through smaller pretightening force.
According to the utility model provides a pair of process large-scale thin wall class part tight formula device that rises, include: dabber, tight cover, apron and nut rise, wherein:
the outer cylindrical surface of the tensioning sleeve is in clearance fit with the workpiece, the inner hole of the tensioning sleeve is a tapered hole, and the tapered hole is matched with the tapered part of the mandrel;
the cover plate is sleeved on the mandrel, and one end face of the tensioning sleeve is tightly pressed by the nut and the cover plate.
Preferably, the mandrel is a four-section stepped shaft and comprises a threaded portion, a tapered shaft portion, a boss portion and a reference shaft portion which are sequentially arranged.
Preferably, the inner bore of the tensioning sleeve is matched with the conical shaft part of the mandrel.
Preferably, the cover plate is fitted over the threaded portion of the mandrel and contacts the end surface of the tension sleeve, and the nut is screwed onto the cover plate in cooperation with the threaded portion of the mandrel, the cover plate transmitting the tightening force of the nut.
Preferably, the outer diameter of the cover plate is smaller than the outer diameter of the tensioning sleeve, and the size of the through hole in the central part of the cover plate is larger than the outer diameter of the thread of the mandrel.
Preferably, the taper parts of the mandrel and the tensioning sleeve are in Morse taper, and the Morse taper is determined according to the size of the machined part.
Preferably, the morse taper of the tapered portion of the mandrel is complementary to the morse taper of the tapered portion of the tensioning sleeve.
Preferably, the tensioning sleeve is slit by wire cutting and can be fully expanded.
Preferably, the nut is tightened by a torque wrench.
Preferably, the tightening torque of the torque wrench is 7.5-12.5 N.m.
Compared with the prior art, the utility model discloses following beneficial effect has:
1. compared with the traditional three-jaw chuck for directly clamping workpieces, the clamping device can increase the contact area through the tensioning sleeve contact tool and reduce the deformation caused by stress;
2. compared with the traditional mandrel type tool, the addition of the tension sleeve reduces the concentricity error of the part and the tool, thereby improving the processing precision;
3. the utility model can adjust the tightening force of the nut through the torque wrench, so that the over pressure of the workpiece is reduced to the minimum;
4. former BC type chuck is maintained and is just unable to be used and scrap after reaching certain number of times, the utility model discloses only need maintain tight cover size that rises or change tight cover that rises and can reach used repeatedly's purpose, practiced thrift the processing cost.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.
As shown in figure 1, according to the utility model, the processing tool is largeThe tension type device for the thin-wall parts comprises a
mandrel 1, a
tension sleeve 2, a
cover plate 3 and a
nut 4, wherein the outer diameter of the
tension sleeve 2 is about the same as that of the tension sleeve
The length is about 120mm, the taper part of the
mandrel 1 and the taper hole of the
tensioning sleeve 2 are Mohs 5#, the
cover plate 3 is arranged on one side of the
tensioning sleeve 2, and the
tensioning sleeve 2 is expanded and fixed with the tool and the workpiece through the screwing force of the
nut 4. The
mandrel 1, the
tensioning sleeve 2 and the
cover plate 3 are made of aluminum alloy materials. The
mandrel 1 is a four-section stepped shaft and comprises a thread part, a conical shaft part, a boss part and a reference shaft part which are sequentially arranged. The inner hole of the
tensioning sleeve 2 is matched with the conical shaft part of the
mandrel 1. The
cover plate 3 is sleeved on the threaded part of the
mandrel 1 and contacts the end face of the
tensioning sleeve 2, the
nut 4 is matched with the threaded part of the
mandrel 1 to screw the
cover plate 3, and the
cover plate 3 transmits the screwing force of the
nut 4. The outer diameter of the
cover plate 3 is smaller than the outer diameter of the
tensioning sleeve 2, and the size of the through hole in the central part of the
cover plate 3 is larger than the outer diameter of the thread of the
mandrel 1.
Further, the tensioning sleeve 2 and the mandrel 1 are matched by Morse taper. The tensioning sleeve 2 is slotted through wire cutting, so that the tensioning sleeve can be fully expanded. The nut 4 is tightened with a torque wrench with a tightening torque of 9N · m.
This example is through tight formula frock internal diameter that rises
The outer spherical surface of the part is processed, and the spherical surface has the size
After the mode is adopted, the spherical precision of the part is improved by about 40 percent, the tool is simple in structure and convenient to disassemble and assemble, the size is flexible and adjustable after expansion, the processing difficulty is reduced, and the processing precision is improved.
According to another preferred embodiment of the present invention, the outer diameter of the
expansion sleeve 2 is about
The length is about 145mm, and the conical part and the tensioning sleeve of the mandrel 1The taper hole of the
nut 2 is Morse 5#, the
cover plate 3 is arranged on one side of the
tensioning sleeve 2, and the
tensioning sleeve 2 is opened and the tool and the workpiece are fixed through the screwing force of the
nut 4.
The tensioning sleeve 2 is matched with the mandrel 1 by Morse taper. The tensioning sleeve 2 is grooved by wire cutting, so that the tensioning sleeve can be fully expanded. The nut 4 is tightened with a torque wrench with a tightening torque of 12.5N · m.
This example is through tight formula frock internal diameter that rises
The outer spherical surface of the part is processed, and the spherical surface has the size
When the original BC type chuck is used for machining, in order to meet the precision requirement, the tool needs to be repeatedly trimmed according to the coaxiality of products, time and labor are consumed, and tool loss is increased. After using above-mentioned frock structure, the part machining precision promotes about 30%, only needs once to maintain the dabber axiality after frock and lathe clamping location simultaneously and can process whole batch part, has practiced thrift a large amount of costs and process time.
The utility model can increase the contact area through the tensioning sleeve contact tool and reduce the deformation caused by stress; compared with the traditional mandrel type tool, the concentricity error of the part and the tool is reduced by adding the tension sleeve, so that the machining precision is improved.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.