阅读说明：本技术 一种复杂支架类零件小装夹面低弯矩装夹定位方法 (Small clamping surface low-bending-moment clamping and positioning method for complex support parts ) 是由 李奔 张文明 谢新春 兰起洪 于 2019-11-05 设计创作，主要内容包括：本发明涉及一种复杂支架类零件小装夹面低弯矩装夹定位方法,实现了小装夹面的复杂支架类零件的低弯矩装夹,不仅提高了零件装夹的稳定性,并且可以有效降低装夹应力,提高定位精度,减小了零件由于装夹力造成的变形,保证了加工一致性。该发明的主要技术特征为(1)支架装夹面与工装平面均具有较高的平面度；(2)支架与工装通过销孔定位；(3)支架与工装的夹紧是通过反拉螺栓固定；该发明可用于一种复杂支架类零件小装夹面低弯矩装夹定位,用于零件立式转卧式加工。保证了零件精度,提高了合格率和一致性。(The invention relates to a low-bending-moment clamping and positioning method for a small clamping surface of a complex bracket part, which realizes low-bending-moment clamping of the complex bracket part with the small clamping surface, improves the stability of part clamping, can effectively reduce clamping stress, improves positioning accuracy, reduces the deformation of the part caused by clamping force, and ensures the processing consistency. The invention has the main technical characteristics that (1) the clamping surface of the bracket and the plane of the tool have higher planeness; (2) the bracket and the tool are positioned through the pin holes; (3) the support and the tool are clamped by a reverse pull bolt; the invention can be used for clamping and positioning small clamping surfaces of complex bracket parts with low bending moment and is used for vertical-to-horizontal machining of the parts. The precision of the parts is ensured, and the qualification rate and the consistency are improved.)

1. A low-bending-moment clamping and positioning method for small clamping surfaces of complex bracket parts is characterized by comprising the following steps:

step 1: two process handles are arranged at the far positions of two side edges of the part;

step 2: in the semi-finishing stage of the part, the plane of the process handle is finely milled, and the flatness is ensured to be 0.008; the process handle is provided with a positioning pin hole and a clamping threaded hole;

and step 3: the tool for processing the I-shaped structure is characterized in that the flatness of a mounting surface is 0.01, and a positioning pin hole and a clamping threaded hole are formed; the positions of the positioning pin holes are matched with the positions of the positioning pin holes on the process handle, the number of the positioning pin holes is matched with the number of the positioning pin holes on the process handle, and the position and the number of the clamping threaded holes of the tool are matched with those of the process handle;

and 4, step 4: in the finish machining stage, when the high-precision outer circle of the bottom surface of the boring is bored, a part is installed together with an I-shaped tool through a pin and a positioning hole, then a bolt upwards penetrates through clamping threaded holes in the tool and a process handle from a rib part on the side surface of the tool, the part and the tool are tensioned, and the positioning and clamping of the part and the tool are completed;

the installation order of bolt is angle first, and the tightening torque of the tightening in-process of bolt is by little and big: 2 N.M- >3 N.M- >4 N.M.

2. The complex bracket part small clamping surface low-bending-moment clamping and positioning method as claimed in claim 1, is characterized in that: the tool material is 2A 12-T4.

3. The complex bracket part small clamping surface low-bending-moment clamping and positioning method as claimed in claim 1, is characterized in that: the positioning pin hole is 2 multiplied by phi 3.

4. The complex bracket part small clamping surface low-bending-moment clamping and positioning method as claimed in claim 1, is characterized in that: the clamping screw holes 4 × M6, 2 on each side.

Technical Field

The invention belongs to the field of machine manufacturing, and relates to a low-bending-moment clamping and positioning method for a small clamping surface of a complex bracket part.

Background

Due to the weight reduction and the requirements on design aspects such as rigidity and strength, the complex support part lacks a reliable and stable clamping and positioning plane, so that the clamping and positioning are difficult during finish machining of the bottom surface outer circle of the boring machine. The clamping plane available is the facet of the technological shank (about 27 x 70, two places, span 112). The conventional clamping mode is pressing plate clamping, and the problems of unstable pressing point, high height, large bending moment and the like of the pressing plate exist. When cutting force is applied, vibration is easily generated, and machining accuracy and consistency are affected.

In order to solve the problems, the invention provides a clamping mode with low bending moment, which not only improves the stability of part clamping, but also can effectively reduce the clamping stress, improve the positioning precision, reduce the deformation of the part caused by the clamping force and improve the processing consistency.

Disclosure of Invention

Technical problem to be solved

In order to avoid the defects of the prior art, the invention provides a small clamping surface low-bending moment clamping and positioning method for complex bracket parts.

Technical scheme

A low-bending-moment clamping and positioning method for small clamping surfaces of complex bracket parts is characterized by comprising the following steps:

step 1: two process handles are arranged at the far positions of two side edges of the part;

step 2: in the semi-finishing stage of the part, the plane of the process handle is finely milled, and the flatness is ensured to be 0.008; the process handle is provided with a positioning pin hole and a clamping threaded hole;

and step 3: the tool for processing the I-shaped structure is characterized in that the flatness of a mounting surface is 0.01, and a positioning pin hole and a clamping threaded hole are formed; the positions of the positioning pin holes are matched with the positions of the positioning pin holes on the process handle, the number of the positioning pin holes is matched with the number of the positioning pin holes on the process handle, and the position and the number of the clamping threaded holes of the tool are matched with those of the process handle;

and 4, step 4: in the finish machining stage, when the high-precision outer circle of the bottom surface of the boring is bored, a part is installed together with an I-shaped tool through a pin and a positioning hole, then a bolt upwards penetrates through clamping threaded holes in the tool and a process handle from a rib part on the side surface of the tool, the part and the tool are tensioned, and the positioning and clamping of the part and the tool are completed;

the installation order of bolt is angle first, and the tightening torque of the tightening in-process of bolt is by little and big: 2 N.M- >3 N.M- >4 N.M.

The tool material is 2A 12-T4.

The positioning pin hole is 2 multiplied by phi 3.

The clamping screw holes 4 × M6, 2 on each side.

Advantageous effects

The small clamping surface low-bending-moment clamping and positioning method for the complex support part, provided by the invention, realizes low-bending-moment clamping of the complex support part with the small clamping surface, improves the stability of part clamping, can effectively reduce clamping stress, improves positioning accuracy, reduces the deformation of the part caused by clamping force, and ensures the machining consistency. The invention has the main technical characteristics that (1) the clamping surface of the bracket and the plane of the tool have higher planeness; (2) the bracket and the tool are positioned through the pin holes; (3) the support and the tool are clamped by a reverse pull bolt; the invention can be used for clamping and positioning small clamping surfaces of complex bracket parts with low bending moment and is used for vertical-to-horizontal machining of the parts. The precision of the parts is ensured, and the qualification rate and the consistency are improved.

The invention has the beneficial effects that:

1. the clamping is carried out by means of the process handle, so that the stability of the clamping is improved.

2. Compared with the clamping of a pressing plate, the bending moment of the clamping is reduced, and the mounting stress is reduced

3. The positioning pin hole is matched with the clamping bolt for use, so that the clamping is guaranteed, and the positioning precision is improved.

4. The technical requirements of the mounting surface and the plane of the craft handle are defined

5. The mounting sequence and the tightening torque of the bolts are determined, the consistency of mounting and clamping is improved, and the method has clear guidance.

Drawings

FIG. 1: front view of tool

FIG. 2: plan view of tool

FIG. 3: schematic diagram of low-bending-moment clamping, positioning and clamping method for bracket parts

① -Complex Stent parts, ② Process handles, ③ tension bolts, ④ positioning pins, ⑤ tooling

Detailed Description

The invention will now be further described with reference to the following examples and drawings:

the invention adopts a mode of pin hole positioning and bolt reverse pull type clamping to clamp the bracket part with the small clamping surface. The flatness requirement of the tool datum plane is 0.01. The flatness requirement of the tool mounting surface is 0.008; two groups of threaded holes 4 multiplied by M6 and two positioning pin holes 2 multiplied by phi 3 are arranged on the installation surface of the tool, and the flatness requirement of the small clamping surface of the technological handle of the part is 0.008. There are also two sets of threaded holes 4 x M6, two dowel holes 2 x Φ 3, respectively. After rough machining is conducted on the support type parts, the small clamping faces and the tool mounting faces are machined, and the flatness requirement is guaranteed. And then drilling a positioning pin hole. The positioning pin is installed firstly when the part and the tool are clamped, then the part is matched with the tool through the positioning pin, the part is reversely pulled and clamped through the screw from the through groove below the tool installation surface, and the low bending moment positioning and clamping of the small clamping surface support part are completed.

The embodiment of the invention comprises the following steps:

step one, according to the characteristics of the part, two process handles are arranged at far positions of two side edges of the part, and the process handles are not suitable to be too large in size in order to reduce machining stress generated when the process handles are removed to the greatest extent.

And step two, in the semi-finishing stage of the part, the plane of the process handle is subjected to finish milling, the flatness is ensured to be 0.008, a positioning pin hole 2 multiplied by phi 3 is drilled, and a clamping threaded hole 4 multiplied by M6 (two on each side) is clamped.

And step three, designing an I-shaped tool according to the position and the size of the process handle, wherein the tool is made of 2A 12-T4. And the flatness of the finish-milled mounting surface is guaranteed to be 0.01. And pilot pin holes 2 x Φ 3 are drilled to clamp threaded holes 4 x M6 (two on each side). As shown in fig. 1 and 2.

And step four, in the finish machining stage, when the high-precision outer circle of the bottom surface of the boring is bored, the part is installed together with the I-shaped tool through the pin and the positioning hole, then the M6 bolt is installed upwards from the rib part of the side surface of the tool, and the part and the tool are tensioned. Note that: proper downward pressure should be applied to the parts during the process of screwing the bolts to prevent the parts from moving. The installation sequence of the bolts is diagonal first and then other. The bolt is firstly applied with a small torque in the tightening process, then the torque is gradually increased until the bolt is tightened, and the torque can be referred to: 2 N.M- >3 N.M- >4 N.M. And the bolt is screwed in a diagonal sequence, and then the other bolts are screwed, so that the positioning and clamping of the part and the tool are finally completed. The final installation result is shown in fig. 3.