CN212443052U

CN212443052U - Cold upsetting and extruding die for small step shaft

Info

Publication number: CN212443052U
Application number: CN202020613147.9U
Authority: CN
Inventors: 伍太宾
Original assignee: Chongqing University of Arts and Sciences
Current assignee: Chongqing University of Arts and Sciences
Priority date: 2020-04-22
Filing date: 2020-04-22
Publication date: 2021-02-02
Anticipated expiration: 2030-04-22

Abstract

The utility model discloses a cold-heading extrusion mould of small-size step axle in mould processing field, this kind of cold-heading extrusion mould include upper die and lower mould, and the upper die includes cope match-plate pattern and upper die overcoat, the middle part of upper die overcoat is equipped with first step hole, the aperture in first step hole is embedded to be equipped with the upper die core, the middle part of upper die core is equipped with axial upper die cavity, the upper die cavity is located upper die core axis department, and the cross section of upper die cavity is involute tooth form splined hole, is equipped with the upper die core pad in the macropore in first step hole, the lower terminal surface of upper die core pad and the up end looks butt of upper die core, and the both sides of upper die overcoat are equipped with 2 first through-holes of symmetric distribution, 2 first through-holes are equipped with 2 pilot pins in; compared with the prior art adopting a hot die forging die, the simple cold heading extrusion die adopting the guide pins and the guide holes as the guide mechanism in the technical scheme has the advantages of simple and compact structure, few parts, low manufacturing cost, convenience in disassembly and assembly, high guide precision, long service life and the like.

Description

Cold upsetting and extruding die for small step shaft

Technical Field

The utility model belongs to the mould processing field specifically is an crowded mould of cold-heading of small-size step axle.

Background

The step shaft is a mechanical basic part which is widely used and has a large quantity in mechanical equipment industries such as automobiles, motorcycles, bicycles, motors, engineering machinery, general machinery, national defense and military industries and the like.

The step shaft has two main purposes: firstly, parts with different inner diameters, such as gears, bearings and the like are installed and positioned by utilizing shaft shoulders of steps on a step shaft, so that the positioning and installation functions are realized; the shaft shoulders with different heights can limit the movement or the movement trend of the parts arranged on the shaft along the axial direction, prevent the arranged parts from sliding in work and reduce the influence of axial pressure generated by some parts on other parts in work. And the other end of the power is transmitted to the other end by using a key groove, a rectangular spline or an involute tooth-shaped spline on the step shaft, so that the effect of power transmission is achieved.

The manufacturing requirements of the step shaft mainly aim at saving materials, reducing processing time and reducing production cost as much as possible on the premise of meeting the requirements on strength and service life.

Small stepped shafts are typically manufactured using two methods: one is cutting, and the other is hot die forging and subsequent cutting.

When the cutting machining method is adopted to produce the small-sized step shaft, the problems of large material waste, long machining time, low production efficiency, high manufacturing cost and the like exist, and the method is not suitable for large-batch industrial production.

The method for producing the small-sized step shaft part by adopting the hot die forging and subsequent cutting processing method is the most common manufacturing method at present. When the hot die forging die is used for hot die forging forming, the cavity of the hot die forging die has to adopt a larger fillet radius and a larger drawing inclination due to oxidation and burning loss of the hot and high-temperature metal blank, the guide precision of the hot die forging die is not high, the surface of the cavity is easy to be damaged, and the direct contact between the hot and high-temperature metal blank and the cavity of the hot die forging die during hot die forging causes the plastic deformation and fatigue damage of the cavity, so that the service life of the hot die forging die is shortened.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems, the present invention provides a cold heading and extruding forming mold with guide pin guide hole mechanism as guide, simple and compact structure, low manufacturing cost, easy dismounting, high guide precision and long service life.

In order to achieve the above purpose, the technical solution of the present invention is as follows: a cold heading and extruding die for a small step shaft comprises an upper die and a lower die, wherein the upper die comprises an upper die plate and an upper die outer sleeve, a first step hole with a large upper part and a small lower part is formed in the middle of the upper die outer sleeve, an upper die core is embedded in a small hole of the first step hole, an axial upper die cavity is formed in the middle of the upper die core and is positioned in the central axis of the upper die core, the cross section of the upper die cavity is an involute tooth-shaped spline hole, an upper die core pad is arranged in a large hole of the first step hole, the lower end face of the upper die core pad is abutted to the upper end face of the upper die core, 2 first through holes which are symmetrically distributed are formed in two sides of the large hole of the upper die outer sleeve, and 2 guide pins; the lower mould includes from supreme fixed connection's lower bolster, lower mould liner and lower mould overcoat in proper order down, and the middle part of lower mould liner is equipped with big-end-up's third step hole, the downthehole liftout pole that can gliding big-end-up is equipped with down in the third step, the middle part of lower mould overcoat is inlayed and is equipped with down the mold core, the middle part of lower mold core is equipped with down the die cavity, the die cavity is big-end-up's shoulder hole down, the both sides of lower mould overcoat are equipped with 2 guide holes coaxial with 2 guide pins and shape adaptation, and the middle part of lower bolster is equipped with the second through-hole, wears to be equipped with down the ejector pin in the second through-hole, the ejector pin is.

After the scheme is adopted, the following beneficial effects are realized:

1. compared with the prior art adopting a hot die forging die, the cold heading and extruding die adopting the metal blank to perform plastic deformation in a cold state in the technical scheme avoids the problems of plastic deformation and fatigue damage of the hot die forging die, prolongs the service life of the die and reduces die loss.

2. Compared with the prior art adopting a hot die forging die with low guiding precision, the technical scheme adopts a guide pin guide hole mechanism with high guiding precision to guide, so that the upper die cavity and the lower die cavity are ensured to have high coaxiality, and the centering performance of the die is improved.

Furthermore, the lower die sequentially comprises a lower die outer sleeve, a lower die liner and a lower die plate from top to bottom, 4 fourth stepped holes with small top and large bottom are formed in the lower die plate, and the 4 fourth stepped holes are symmetrically distributed along the axis of the lower die cavity; the lower die liner is internally provided with 4 third through holes which are coaxial with the small holes of the 4 fourth step holes and are adaptive to the shape of the small holes, and the lower die outer sleeve is internally provided with 4 first screw holes which are coaxial with the small holes of the 4 fourth step holes and are adaptive to the shape of the small holes; and 4 socket head cap screws are inserted into the 4 fourth stepped holes, the third through hole and the first screw hole, so that the lower template, the lower die liner and the lower die outer sleeve are fastened together.

Through the arrangement, the lower die outer sleeve, the lower die liner and the lower die plate in the lower die are well positioned and fastened, and the lower die is simple in structure, few in parts, easy to manufacture, and convenient to disassemble, assemble and replace.

Furthermore, the upper die comprises an upper die plate and an upper die outer sleeve which are sequentially connected from top to bottom, 4 second step holes with large top and small bottom are formed in the upper die plate, and the 4 second step holes are symmetrically distributed along the axis of the upper die cavity; the upper die outer sleeve is provided with 4 second screw holes which are coaxial with the small holes of the second stepped holes and are adaptive in shape, and 4 socket head cap screws are inserted into the 4 second stepped holes and the second screw holes, so that the upper die plate and the upper die outer sleeve can be fastened together.

Through the arrangement, the upper die outer sleeve and the upper die plate in the upper die are well positioned and fastened, and the upper die is simple in structure, few in parts, easy to manufacture and convenient to disassemble, assemble and replace.

Further, the middle part of the lower die outer sleeve is embedded with a lower die core which is in taper interference fit and cold press fit, the middle part of the lower die core is provided with a lower die cavity, and the lower die cavity is a stepped hole with a large upper part and a small lower part.

Through the arrangement, under the action of the assembling pressure applied by the lower die outer sleeve, the lower die cavity surface of the lower die core is in a compressive stress state, and the compressive stress can partially offset or completely offset the tensile stress generated on the lower die cavity surface of the lower die core under the action of the cold upsetting-extruding deformation force when the lower die core is in cold upsetting-extruding formation, so that the generation of microcracks on the lower die cavity surface of the lower die core can be avoided or delayed, and the service life of the lower die core can be prolonged.

Further, the middle part of going up the mould overcoat is equipped with first step hole, the aperture in first step hole is embedded to be equipped with through the last mould core of tapering interference fit, cold pressure equipment, the die cavity has been seted up at the middle part of going up the mould core, the cross section of going up the die cavity is involute tooth form splined hole.

Through the arrangement, under the action of the assembling pressure applied by the upper die outer sleeve, the surface of the upper die cavity of the upper die core is in a compressive stress state, and the compressive stress can partially offset or completely offset the tensile stress generated on the surface of the upper die cavity of the upper die core under the action of the cold upsetting and extruding deformation force when the cold upsetting and extruding forming is carried out on the upper die core, so that the generation of microcracks on the surface of the upper die cavity of the upper die core can be avoided or delayed, and the service life of the upper die core can be prolonged.

Drawings

Fig. 1 is an assembly view of a cold-heading extrusion die according to an embodiment of the present invention;

FIG. 2 is a full cross-sectional view of the upper die of FIG. 1;

FIG. 3 is a full cross-sectional view of the lower die of FIG. 1.

Detailed Description

The following is further detailed by way of specific embodiments:

reference numerals in the drawings of the specification include: the die comprises an upper die plate 1, an upper die outer sleeve, a lower die 2, a first step hole 3, an upper die core 4, an upper die cavity 5, an upper die core pad 6, a first through hole 7, a guide pin 8, a second step hole 9, a lower die plate 10, a lower die liner 11, a lower die outer sleeve 12, a third step hole 13, an ejector rod 14, a lower die core 15, a lower die cavity 16, a guide hole 17, a second through hole 18, a lower ejector rod 19, a fourth step hole 20, a third through hole 21, a first screw hole 22 and a second screw hole 23.

The embodiment is basically as shown in the attached figure 1: a cold-heading extruding die for a small step shaft comprises an upper die and a lower die, wherein the upper die comprises an upper die plate 1 and an upper die jacket 2, a first step hole 3 with a large upper part and a small lower part is formed in the middle of the upper die jacket 2, an upper die core 4 is embedded in a small hole of the first step hole 3, an axial upper die cavity 5 is formed in the middle of the upper die core 4, the upper die cavity 5 is located at the central axis of the upper die core 4, the cross section of the upper die cavity 5 is an involute tooth spline hole, an upper die core pad 6 is arranged in a large hole of the first step hole 3, the lower end face of the upper die core pad 6 is abutted to the upper end face of the upper die core 4, 2 first through holes 7 which are symmetrically distributed are formed in two sides of the large hole of the upper die jacket 2, and 2 guide pins 8 are; the lower mould includes from supreme fixed connection's lower bolster 10, lower mould liner 11 and lower mould overcoat 12 in proper order down, and the middle part of lower mould liner 11 is equipped with big-end-up's third step hole 13, gliding, big-end-up's ejector pin 14 about can be equipped with in the third step hole 13, the middle part of lower mould overcoat 12 inlays and is equipped with down mold core 15, the middle part of lower mold core 15 is equipped with down die cavity 16, die cavity 16 is big-end-up's shoulder hole down, the both sides of lower mould overcoat 12 are equipped with 2 guide holes 17 coaxial and the shape adaptation with 2 guide pins 8, the middle part of lower bolster 10 is equipped with second through-hole 18, wear to be equipped with down ejector pin 19 in the second through-hole 18, ejector pin 19 is used for controlling the upper and lower slip of ejector pin 14 down.

Referring to fig. 2, the upper die includes an upper die plate 1 and an upper die outer sleeve 2 connected in sequence from top to bottom, 4 second stepped holes 9 with a large top and a small bottom are formed in the upper die plate 1, and the 4 second stepped holes 9 are symmetrically distributed along the axis of the upper die cavity 5; go up mould overcoat 2 and open 4 second screw 23 that have 4 coaxial and shape adaptation with the aperture of second stepped hole 9, insert 4 socket head cap screws into in 4 second stepped hole 9 and the second screw 23, just can be with cope match-plate pattern 1 and last mould overcoat 2 fastening are in the same place.

Referring to fig. 3, the lower die sequentially includes a lower die outer sleeve 12, a lower die liner 11 and a lower die plate 10 from top to bottom, 4 fourth stepped holes 20 with a small top and a large bottom are formed in the lower die plate 10, and the 4 fourth stepped holes 20 are symmetrically distributed along an axis of a lower die cavity 16; the lower die liner 11 is internally provided with 4 third through holes 21 which are coaxial with the small holes of the 4 fourth stepped holes 20 and are adaptive in shape, and the lower die outer sleeve 12 is internally provided with 4 first screw holes 22 which are coaxial with the small holes of the 4 fourth stepped holes 20 and are adaptive in shape; the lower die plate 10, the lower die liner 11 and the lower die outer sleeve 12 can be fastened together by inserting 4 socket head cap screws into the 4 fourth stepped holes 20, the third through holes 21 and the first screw holes 22.

An operator inserts the cold metal blank subjected to surface lubrication treatment into a lower die cavity 16 of a cold upsetting extrusion die arranged on a press machine, starts the press machine, presses a pressing switch of the press machine, and drives an upper die to move downwards; when the upper mold moves down to 2 guide pins 8 in the upper mold outer sleeve and is inserted into 2 guide holes 17 in the lower mold outer sleeve 12, the guiding of the upper mold and the lower mold 2 is effected, and the high coaxiality of the upper mold cavity 5 and the lower mold cavity 16 is ensured; when the upper die continues to move downwards until the lower end face of the upper die cavity 5 is contacted with the upper end face of the metal blank, upsetting-extruding deformation force is applied to the metal blank, the metal begins to generate plastic deformation, and cold upsetting-extruding forming is started; as the upper die continues to move downwards, the upper end of the metal blank gradually enters the upper die cavity 5, at the moment, the metal at the upper end part of the metal blank is gradually extruded into the upper die cavity 5, and the metal at the lower end part of the metal blank is gradually extruded into the lower die cavity 16; when the upper die cavity 5 is completely filled with metal, as the upper die continues to move downwards, part of the metal in the metal blank flows along the axial direction and part of the metal flows along the radial direction, the metal flowing along the radial direction forms a section of flange, and the metal flowing along the axial direction continues to be extruded into the lower die cavity 16;

when the lower die cavity 16 is completely filled with metal, the small step shaft forging is completely filled, at the moment, a pressing switch of the press machine is loosened, a return switch of the press machine is pressed, and the press machine drives the upper die to move upwards; when the upper die moves upwards to a certain specified position, a return switch of the press is loosened, an ejection switch of the press is pressed, an ejection system of the press drives a lower ejector rod 19 to enable an ejector rod 14 to move upwards, and the small-sized step shaft forging formed by cold heading extrusion is gradually ejected out of the lower die cavity 16 by the upward ejector rod 14 until the small-sized step shaft forging is completely ejected out of the lower die cavity 16; and then the operator takes out the small step shaft forging to obtain the small step shaft forging.

The above description is only an example of the present invention, and the common general knowledge of the known specific structures and characteristics of the embodiments is not described herein. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims

1. The utility model provides a cold-heading crowded mould of small-size step axle which characterized in that: the die comprises an upper die and a lower die, wherein the upper die comprises an upper die plate and an upper die outer sleeve, a first step hole is formed in the middle of the upper die outer sleeve, an upper die core is embedded in a small hole of the first step hole, an axial upper die cavity is formed in the middle of the upper die core and is positioned in the central axis of the upper die core, the cross section of the upper die cavity is an involute tooth spline hole, an upper die core pad is arranged in a large hole of the first step hole, the lower end face of the upper die core pad is abutted against the upper end face of the upper die core, 2 first through holes which are symmetrically distributed are formed in two sides of the upper die outer sleeve, and 2 guide pins are arranged in the 2 first through holes; the lower mould includes from supreme fixed connection's lower bolster, lower mould liner and lower mould overcoat in proper order down, and the middle part of lower mould liner is equipped with the third step hole, gliding ejector pin about can being equipped with in the third step hole, the middle part of lower mould overcoat is inlayed and is equipped with down the mold core, the middle part of lower mold core is equipped with down the die cavity, the die cavity is the step hole down, the both sides of lower mould overcoat are equipped with 2 guide holes with the coaxial and shape adaptation of 2 guide pins, the middle part of lower bolster is equipped with the second through-hole, wear to be equipped with down the ejector pin in the second through-hole, the ejector pin is used for controlling the upper and lower slip of ejector pin.

2. The cold-heading extrusion die for the small-sized stepped shaft according to claim 1, wherein: 4 fourth step holes which are axially small at the top and big at the bottom are formed in the lower template, and the 4 fourth step holes are symmetrically distributed along the axis of the lower die cavity; the lower die liner is internally provided with 4 axial third through holes which are coaxial with the small holes in the 4 fourth stepped holes and are adaptive to the shapes of the small holes, and the lower die outer sleeve is internally provided with 4 axial first screw holes which are coaxial with the small holes in the 4 fourth stepped holes and are adaptive to the shapes of the small holes; and 4 socket head cap screws are inserted into the 4 fourth stepped holes, the third through hole and the first screw hole, and the lower die plate, the lower die liner and the lower die outer sleeve are fastened together.

3. The cold-heading extrusion die for the small-sized stepped shaft according to claim 2, wherein: the lower die comprises a lower die outer sleeve, a lower die liner and a lower die plate from top to bottom in sequence, a lower die core which is in taper interference fit and cold press fit is embedded in the middle of the lower die outer sleeve, a lower die cavity is formed in the middle of the lower die core, and the lower die cavity is a stepped hole with a large upper part and a small lower part.

4. The cold-heading extrusion die for the small-sized stepped shaft according to claim 3, wherein: axial 2 guide holes are formed in two sides of the lower die outer sleeve, the 2 guide holes are located between the lower die core and the first screw hole, and the 2 guide holes are symmetrically distributed along the axis of the lower die cavity.

5. The cold-heading extrusion die for the small-sized stepped shaft according to claim 4, wherein: the middle part of the lower die liner is provided with an axial third stepped hole with a large upper part and a small lower part, and the third stepped hole is connected with a material ejecting rod with a small upper part and a large lower part in a sliding way; the middle part of the lower template is provided with an axial second through hole, a lower ejector rod penetrates through the second through hole, and the lower ejector rod is in sliding fit with the second through hole.

6. The cold-heading extrusion die for the small-sized stepped shaft according to claim 5, wherein: the upper die comprises an upper die plate and an upper die outer sleeve which are sequentially connected from top to bottom, wherein 4 second step holes which are axial and big-end-up are formed in the upper die plate, and the 4 second step holes are symmetrically distributed along the axis of the upper die cavity.

7. The cold-heading extrusion die for the small-sized stepped shaft according to claim 6, wherein: the middle part of the upper die outer sleeve is provided with a first step hole with a large upper part and a small lower part, an upper die core which is in taper interference fit and cold press fit is embedded in a small hole of the first step hole, the middle part of the upper die core is provided with an upper die cavity, and the cross section of the upper die cavity is an involute tooth-shaped spline hole; the macropore both sides in first step hole are equipped with 2 first through-holes coaxial and the shape adaptation with 2 guide holes, 2 first through-holes along the axis symmetric distribution of last die cavity, and 2 first through-holes are built-in to be equipped with 2 guide pins, be tight clearance fit between 2 guide pins and 2 first through-holes, and the lower extreme of 2 guide pins stretches out the lower terminal surface of last mould overcoat.

8. The cold-heading extrusion die for the small-sized stepped shaft according to claim 7, wherein: an upper mold core pad is arranged at the central axis of the large hole of the upper mold jacket, the lower end surface of the upper mold core pad is abutted with the upper end surface of the upper mold core, and the upper end surface of the upper mold core pad is abutted with the lower end surface of the upper mold plate; the upper die outer sleeve is provided with 4 second screw holes which are coaxial with small holes in the second stepped holes and are adaptive in shape, and 4 socket head cap screws are inserted into the 4 second stepped holes and the second screw holes to fasten the upper die plate and the upper die outer sleeve together.