CN201511053U

CN201511053U - Lower mandril eliminating stress by self for bevel-gear closed-type cold extruding die

Info

Publication number: CN201511053U
Application number: CN 200920232117
Authority: CN
Inventors: 陶立平; 申加圣; 赵军华; 石小荣; 赵红军
Original assignee: Jiangsu Pacific Precision Forging Co Ltd
Current assignee: Jiangsu Pacific Precision Forging Co Ltd
Priority date: 2009-09-18
Filing date: 2009-09-18
Publication date: 2010-06-23
Anticipated expiration: 2019-09-18

Abstract

The utility model discloses a lower mandirl eliminating stress by self for a bevel-gear closed-type cold extruding die. The lower mandirl includes an outer sleeve and an inner core rod which are in clearance fit with each other; a cone shaft is arranged at the top end of the inner core rod adopts and exposed out of the top end surface of the outer sleeve, the bottom end surfaces of the outer sleeve and the inner core rod are aligned, the diameter of the inner core rod body is equal to the diameter of the big end of the cone shaft at the top end; the lower mandril adopts a split structure; the interior stress generated during the cold extrusion of the inner core rod is eliminated at the clearance fit part, the inner core rod and the outer sleeve have no difference in the interior stress, and the conduction of generating annular cracks is lost; and in addition, the outer sleeve protects the inner core rod. Due to the adoption of the structure, the average service life of the lower is as long as the time for processing 30,000 pieces. The utility model is suitable for being used on bevel-gear closed-type cold extruding dies with different specifications and sizes.

Description

Bevel gear enclosed cold extruding die is from the lower push rod of stress-removal

Technical field

The utility model relates to a kind of cold extruding die, and specifically, the utility model relates to a kind of lower push rod structure of enclosed cold extruding die.

Background technology

Cold extrusion is the precision form processing that a kind of advanced forming and machining method in the modern mechanical processing industry, particularly enclosed cold-extrusion technology have been widely used in automobile gear.This technology is really accomplished few, the no machining of gear teeth face, has both saved material and machining period, has improved the workmanship of gear again.Make the enclosed cold extrusion die of bevel gear and mainly be made up of upper ejector pin, upper die and lower die and lower push rod, the lower push rod of prior art design is an overall structure, is arranged in the counterdie endoporus.Because enclosed cold extruding die design feature, lower push rod carries the die forming extruding force alone during cold-extrusion shaping, because of shaft-like lower push rod specific loading is very big, so service life is short, be no more than 2000 under the normal condition, the principal mode of damage is that the lower push rod top produces annular crack along the boss place.The lower push rod rapid wear has seriously restricted production efficiency, has increased production cost.

The utility model content

The utility model is primarily aimed at prior art lower push rod stress and concentrates the deficiency that easily causes damage, the lower push rod of a kind of bevel gear enclosed cold extruding die from stress-removal proposed, this is simple and reasonable for structure, and internal stress has the release channel, and lower push rod reaches more than 30000 service life.

The utility model is achieved through the following technical solutions technical goal.

Bevel gear enclosed cold extruding die is from the lower push rod of stress-removal, and it is nested by two of overcoat and internal core rod and sets up jointly.Its improvements are: described overcoat is a matched in clearance with cooperating of internal core rod, and the internal core rod top is the axis of cone and exposes the overcoat top end face, and two bottom faces are equal, and the internal core rod main diameter equals top axis of cone outside diameter.

The apex cone shaft size of internal core rod in the said structure equals to treat the bottom face shrinkage pool size of cold-extruded part.

The utility model compared with prior art has following good effect:

1, axle is simple in structure with the split that cover matches, making is easy;

2, split is rational in infrastructure, and internal core rod is different with the overcoat apex area, and the load of bearing is also different, and dividing body structure to constitute independently to bear separately should have load, between stress difference because of the fit clearance existence discharges elimination, do not produce the annular crackle;

3, the internal core rod that unit are load is big is is relatively protected and led by the less relatively overcoat of unit are load, thus divide the lower push rod of body structure not fragile, long service life.

Description of drawings

Fig. 1 is that the utility model structure is partly cutd open schematic diagram.

Fig. 2 is that prior art constructions is partly cutd open the contrast schematic diagram.

Fig. 3 is the utility model position view in the enclosed cold extruding die.

The specific embodiment

The utility model is described in further detail with reference to the accompanying drawings below.

The cold extruding die of bevel gear enclosed shown in the accompanying drawing 1 is from the lower push rod of stress-removal, and it is nested by 2 two of overcoat 1 and internal core rod and sets up jointly.Described overcoat 1 is a matched in clearance with cooperating of internal core rod 2, and internal core rod 2 tops are the axis of cone and expose overcoat 1 top end face, and two bottom faces are equal, and internal core rod 2 main diameters equal top axis of cone maximum gauge.The utility model practical application as shown in Figure 3, lower push rod places counterdie 3 endoporus, upper ejector pin 7 places patrix 6 endoporus, patrix 5 forms die cavity 5 with counterdie 3 enclosed matched moulds, the die cavity 5 mid-cold-stamped bevel gear blanks that remain, patrix 6 and counterdie 3 move downward jointly, implement extruding by static lower push rod, make the bevel gear cold-extrusion shaping.Bearing the cold-stamped lower push rod is the branch body structure, and internal core rod 2 is installed in overcoat 1 endoporus, and internal core rod 2 tops are the axis of cone, and this section shape and size correspondence are treated the bevel gear bottom face shrinkage pool of cold-extrusion shaping.Because of the area of axis of cone surface area, so the relative overcoat of the cold-extruded pressure of internal core rod 2 carryings 1 is big greater than axis of cone outside diameter circle.Internal core rod 2 is a matched in clearance with overcoat 1, and the internal stress that produces during internal core rod 2 cold extrusions terminates in this gap, makes internal core rod 2 and overcoat 1 not have the comparison of internal stress difference.Lose the condition that produces annular crack.In addition, 1 pair of internal core rod 2 of overcoat has the effect of protecting and leading.The utility model proves that in force said structure improves and to have significant beneficial effect, under equal conditions operation, and the utility model lower push rod average life is about 30,000.

Claims

1. a bevel gear enclosed cold extruding die is from the lower push rod of stress-removal, and it is nested by (2) two of overcoat (1) and internal core rod and sets up jointly; It is characterized in that: described overcoat (1) is a matched in clearance with cooperating of internal core rod (2), and internal core rod (2) top is the axis of cone and exposes overcoat (1) top end face, and two bottom faces are equal, and internal core rod (2) main diameter equals top axis of cone outside diameter.

2. bevel gear enclosed cold extruding die according to claim 1 is characterized in that from the lower push rod of stress-removal: described internal core rod (2) apex cone shaft size equals to treat cold-extruded part bottom shrinkage pool size.