阅读说明：本技术 一种零件磨削快换夹具及磨削方法 (Part grinding quick-change clamp and grinding method ) 是由 张玉环 田兵娃 许可 贾俊魁 周晓卫 吴春利 吕阿鹏 于 2019-08-30 设计创作，主要内容包括：本发明公开了一种零件磨削快换夹具及磨削方法,包括芯棒,所述芯棒设置有安装段和装夹段,安装段和装夹段连接形成一个阶梯轴；其中,装夹段为方头锥度芯棒结构,本发明采用的方头锥度芯棒结构,装夹段的大端靠近安装段；本发明所述装置定心定位精度较高,这种结构消除了装配间隙,定心精度可达0.005-0.01mm；夹具结构简单,无需设计专门夹紧装置,加工时可依靠方头及楔紧时产生的摩擦力提供扭矩,带动工件旋转；本夹具不需分组,对于所加工零件均可直接套入方头中楔紧后即可进行加工；降低了操作工人劳动强度,缩短了生产准备时间,能达到快速装夹零件的目的；设计加工工艺简单、操作方便、省力且制造成本低。(The invention discloses a part grinding quick-change clamp and a grinding method, wherein the part grinding quick-change clamp comprises a core rod, wherein the core rod is provided with an installation section and a clamping section, and the installation section and the clamping section are connected to form a stepped shaft; the clamping section is of a square-head taper core rod structure, and the large end of the clamping section is close to the mounting section; the device has higher centering and positioning precision, the structure eliminates assembly clearance, and the centering precision can reach 0.005-0.01 mm; the clamp has a simple structure, a special clamping device is not required to be designed, and torque can be provided by virtue of a square head and friction force generated during wedging during processing so as to drive a workpiece to rotate; the clamp does not need to be divided into groups, and the processed parts can be directly sleeved into the square head and wedged tightly to be processed; the labor intensity of operators is reduced, the production preparation time is shortened, and the purpose of quickly clamping parts can be achieved; the design and processing technology is simple, the operation is convenient, the labor is saved, and the manufacturing cost is low.)

1. A part grinding quick-change clamp is characterized by comprising a core rod, wherein the core rod is provided with an installation section (1) and a clamping section (2), and the installation section (1) and the clamping section (2) are connected to form a stepped shaft; wherein, the clamping section (2) is of a square-head taper core rod structure, and the large end of the clamping section (2) is close to the mounting section.

2. The quick-change jig for grinding parts as claimed in claim 1, characterized in that the mounting section (1) is a solid round shaft.

3. The part grinding quick-change clamp according to claim 1, wherein the end surfaces of both ends of the core rod are provided with tip holes.

4. The part grinding quick-change clamp according to claim 1, characterized in that the side length of the cross-sectional square of the clamping section (2) at a distance of 1mm from the end surface of the large end shaft shoulder is 0.12mm larger than that at a distance of 1mm from the end surface of the small end shaft shoulder.

5. The part grinding quick-change clamp according to claim 1, wherein the central runout of the mounting section (1) and the clamping section (2) is not more than 0.01 mm.

6. The part grinding quick-change clamp according to claim 1, characterized in that the roughness of the surface of the clamping section (2) is not lower than the roughness of the surface of an inner hole of the part to be machined.

7. The part grinding quick-change clamp according to claim 1, characterized in that a tool withdrawal groove is arranged at a transition shaft shoulder between the mounting section (1) and the clamping section (2), and the bottom surface of the tool withdrawal groove is an arc surface.

8. The quick-change fixture for grinding parts as claimed in claim 1, wherein the core rod is made of 20# steel and has a hardness of HRC 55-60.

9. The part grinding quick-change clamp according to claim 8, wherein the core rod is prepared by performing a quenching heat treatment process after the core rod is integrally carburized for 0.8-1.0 mm.

10. A method of grinding a quick change fixture for grinding parts as defined in claim 1, including the steps of:

step 1, pushing a clamping section (2) of a core rod into a part to be processed, and wedging the clamping section (2) with the part to be processed;

step 2, mounting an assembly consisting of the part to be processed and the core rod on a grinding machine, and respectively ejecting two apexes on the grinding machine into apex holes at two ends of the core rod;

step 3, mounting a heart-shaped chuck on the mounting section (1);

and 4, starting the grinding machine to grind the part to be processed.

Technical Field

The invention belongs to the technical field of machining, and particularly relates to a part grinding quick-change clamp and a grinding method.

Background

The part adjusting screw is assembled on a pressure regulating valve component of a certain machine, and has the effects that the adjusting screw is driven to rotate circumferentially and move axially at the same time under the action of external force on the inner four sides so as to change the space volume of a closed cavity of the component and achieve the purpose of adjusting the gas pressure in the inner cavity of the component, as shown in figures 1-1 and 1-2.

The part is provided with an external thread with higher precision, the tolerance of the pitch diameter of the thread is 0.08mm, the part is also provided with a full-length through square inner hole, the tolerance of the opposite side dimension of the square inner hole is 0.1mm, and the technical requirement that the pitch diameter of the external thread of the part cannot be larger than 0.05mm relative to the deflection of the center of a square hole of the part in the manufacturing process of the part is also met based on the requirement of assembly precision. In order to ensure that the processed threads meet the requirements, the technical scheme adopts a mode of finishing on a thread grinder by a special clamp, and the used special clamp needs to use a square hole as a positioning reference. The part positioning reference structure is special, different from a plane or a cylindrical surface which is commonly used in the past, and the positioning reference size tolerance is large, so that the positioning precision of the clamp is ensured to be extremely difficult, and therefore, the design of which structure type of the grinding machine clamp clamping part is the key for ensuring the processing precision of the external thread.

Aiming at the problem of how to clamp a part in the process of grinding a thread, the original grinding machine clamp takes the inner square of the part as a positioning surface and adopts a rigid spindle structure, and because the tolerance of the inner square is within 0.1mm, the tolerance of the inner square is larger as a positioning reference, in order to ensure the positioning precision, the grinding machine clamp usually makes the four dimensions of the spindle into various groups according to the tolerance of the inner square of the part and adopts a mode of clamping the part in groups. The original grinding machine clamps are divided into four groups, and the four-side size (side length of the section) B of the mandrel is respectively as follows: 8.09⁰ _-0.01、8.12⁰ _-0.01、 8.14⁰ _-0.01、8.17⁰ _-0.01As shown in fig. 2-1 and 2-2, the conventional grinding machine clamp has the following disadvantages:

before grinding the threads, operators need to spend a certain time to measure the sizes of the four sides in the parts and group the parts, and group and clamp the parts according to the size group marked on the mandrel.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a part grinding quick-change clamp and a grinding method, which can realize quick clamping of parts, reduce the technical requirements on workers, reduce the labor intensity of the workers and eliminate the problem of low production efficiency caused by the increase of production preparation time due to the use of the original grinding machine clamp.

In order to achieve the purpose, the invention adopts the technical scheme that the part grinding quick-change clamp comprises a core rod, wherein the core rod is provided with an installation section and a clamping section, and the installation section and the clamping section are connected to form a stepped shaft; the clamping section is of a square-head taper core rod structure, and the large end of the clamping section is close to the mounting section.

The mounting section is a solid round shaft.

The end surfaces of the two ends of the core rod are provided with tip holes.

The side length of the square with the section at the position 1mm away from the end face of the shaft shoulder at the large end of the clamping section is 0.12mm larger than that of the square with the section at the position 1mm away from the end face at the small end.

The central deflection of the mounting section and the clamping section is not more than 0.01 mm.

The roughness of the surface of the clamping section is not lower than the surface roughness of the inner hole of the part to be processed.

A tool withdrawal groove is arranged at the transition shaft shoulder between the mounting section and the clamping section, and the bottom surface of the tool withdrawal groove is an arc surface.

The core rod is made of 20# steel, and the hardness is HRC 55-60.

The core rod is prepared by performing quenching heat treatment after the whole carburization is 0.8-1.0 mm.

The grinding method for the part grinding quick-change clamp comprises the following steps:

step 1, pushing a clamping section of a core rod into a part to be machined, and wedging the clamping section with the part to be machined;

step 2, mounting an assembly consisting of the part to be processed and the core rod on a grinding machine, and respectively ejecting two apexes on the grinding machine into apex holes at two ends of the core rod;

step 3, mounting a chicken heart chuck on the mounting section;

and 4, starting the grinding machine to grind the part to be processed.

Compared with the prior art, the invention has at least the following beneficial effects: the square-head taper core rod structure adopted by the invention has high centering and positioning precision, the structure eliminates assembly clearance, and the centering precision can reach 0.005-0.01 mm; the clamp has a simple structure, a special clamping device is not required to be designed, and torque can be provided by virtue of a square head and friction force generated during wedging during processing so as to drive a workpiece to rotate; the clamp does not need to be divided into groups, and the processed parts can be directly sleeved into the square head and wedged tightly to be processed; the labor intensity of operators is reduced, the production preparation time is shortened, and the purpose of quickly clamping parts can be achieved; the design and processing technology is simple, the operation is convenient, the labor is saved, and the manufacturing cost is low.

Furthermore, when the inner hole of the part is filled, the clamping section and the part to be ground are guaranteed to be wedged tightly, so that the axial directions of the clamping section and the part to be ground are kept consistent.

Furthermore, the cost of the 20# steel is low, the 20# steel can meet the strength requirement of the clamp and is easy to process, the surface hardness of the steel can be improved through quenching heat treatment after carburization, the steel is more wear-resistant, and the service life of the steel is prolonged on the premise of keeping the clamping precision.

Furthermore, the central deflection of the mounting section and the clamping section is not more than 0.01mm, so that the mounting precision of the clamp and the machining precision of a part to be machined are ensured.

Drawings

FIG. 1-1 is a schematic front view of a part to be machined,

figure 1-2 is a view from direction a of figure 1-1,

figure 2-1 is a front view of a prior art grinder furniture,

FIG. 2-2 is a schematic sectional view taken along line C-C of FIG. 2-1,

figure 3-1 is a schematic front view of the clamp of the present invention,

figure 3-2 is a schematic sectional view taken along line a-a of figure 3-1,

fig. 3-3 is a schematic sectional view taken along line B-B of fig. 3-1.

Detailed Description

The invention is explained in detail below with reference to the figures and examples.

A part grinding quick-change clamp comprises a core rod, wherein the core rod is provided with an installation section and a clamping section, and the installation section and the clamping section are connected to form a stepped shaft; the clamping section is of a square-head taper core rod structure, and the large end of the clamping section is close to the mounting section; the mounting section is a solid round shaft; a tool withdrawal groove is arranged at the shaft shoulder of the mounting section and the clamping section.

The end surfaces of the two ends of the core rod are provided with tip holes.

The side length of the small end section of the clamping section square head taper core rod structure is 0.12mm smaller than that of the large end section of the clamping section square head taper core rod structure.

Preferably, the central deflection of the mounting section and the clamping section is not more than 0.01 mm.

The roughness of the surface of the clamping section is not lower than the surface roughness of the inner hole of the part to be processed.

As shown in fig. 3-1-3, the fixture of the invention designs a core rod into two step shaft forms according to the rigid taper mandrel centering and positioning principle, the mounting section 1 is a solid round shaft, the end head of the mounting section is provided with a tip hole for clamping a part on a grinding machine by a chicken heart chuck, the clamping section 2 is a square taper mandrel form, the end head of the clamping section is also provided with a tip hole, and the positioning and clamping of the part to be processed are realized by pushing the clamping section 2 of the core rod into the part to be processed and wedging the clamping section. In order to ensure the positioning accuracy of the square-head tapered core rod, the deflection of the center of the mounting section to the center of the clamping section is not more than 0.01mm, and the side length of the section of the small end of the square-head tapered core rod structure of the clamping section 2 is less than that of the section of the large end thereof by 0.12 mm; simultaneously, in order to guarantee that square head tapering plug uses lasting stand wear and tear, require simultaneously: the core rod material is 20# steel, and a heat treatment mode of quenching is adopted after the whole carburization is carried out for 0.8-1.0mm, and the surface hardness after the quenching treatment is HRC 55-60.

The clamping section 2 is chamfered at one end contacted with a part to be ground, chamfers are machined at two ends of the mounting section 1, and the bottom surface of the tool withdrawal groove at the shaft shoulder is an arc surface.