CN205362667U - Powder metallurgy forming die - Google Patents

Abstract

The utility model discloses a powder metallurgy forming die, which belongs to the field of forming dies, and is used to solve the problem that the traditional method of taking compacted compacts by ejecting them leads to low compacted compacts, and it is difficult to form the aspect ratio (h/D) Larger compacts. It includes an upper mold, a cavity below the upper mold, and a lower mold below the cavity. The upper mold includes an upper template and an upper die punch. The upper template is rectangular, and the upper die punch is cylindrical. The upper die punch is fixed on the lower end surface of the upper template; the cavity includes a die, a die cavity set on the outside of the die, the die has a taper, the upper and lower surfaces of the die are circular, and the die A circular through hole matched with the upper die punch is opened in the middle, the die is divided into three lobes, and the inside of the die cavity matches the outside of the die. This technical scheme adopts the form of flapping, which avoids the influence of friction when taking the compact, and can form a compact with a large length-to-diameter ratio, which improves the success rate of pressing and the quality of the compact, and is suitable for one-way hydraulic presses, with high production efficiency. low cost.

Description

A powder metallurgy forming die

technical field

The utility model belongs to the field of forming dies, in particular to a powder metallurgy forming die.

Background technique

One of the basic processes in powder metallurgy production, the purpose is to make loose powder into semi-finished or finished products with predetermined geometry, size, density and strength. Molding (steel mold) forming is the most widely used forming method in powder metallurgy production. In the second half of the 18th century and the first half of the 19th century, Spain, Russia and the United Kingdom used similar powder metallurgy processes to manufacture platinum products. At that time, Sobolevsky in Russia used steel molds and screw presses. Wollaston in the United Kingdom, using a higher-pressure tie-rod press and higher-purity platinum powder, produced dense platinum with almost no residual pores. Later, the molding method was gradually improved and used to manufacture various shapes of copper-based oil-impregnated bearings and other products. Since the 1930s, in the industrial production process of powder metallurgy parts, press equipment, mold design and other aspects have been continuously improved, the molding method has been greatly developed, and mechanization and automation have reached a higher level. In order to expand the size and shape range of products, especially in order to increase the density of products and improve the uniformity of density, various forming methods have appeared and developed successively. In the early stage, there were powder rolling, cold isostatic pressing, extrusion, hot pressing, etc.; since the 1950s, hot forming methods such as hot isostatic pressing, hot extrusion, and hot forging have appeared. These methods facilitate the production of fully dense, high-performance powder metal materials.

Compression molding puts metal powder into a steel mold cavity, and presses the powder through a die punch to form it.

Pressing pressure and compact density distribution In the molding process, the pressing pressure is mainly consumed in the following two parts:

① Overcome the friction between powder particles (called internal friction) and the deformation resistance of powder particles;

② Overcome the friction of powder particles on the mold wall (called external friction). Due to the existence of external friction, the density distribution of the green compact formed by compression molding is actually non-uniform.

In summary, the existing powder metallurgy compression molding has the following characteristics:

1) Ordinary low-priced presses only have one-way pressure from the top to the bottom. Therefore, the mold is required to be suitable for this type of press.

2) In the traditional pressing process, the compact is ejected, and factors such as friction during the ejection process will affect its quality.

3) It is difficult to form a compact with a large aspect ratio (h/D).

Utility model content

The purpose of the utility model is to provide a powder metallurgy forming die with high success rate, high forming quality and suitable for one-way hydraulic press.

For realizing above-mentioned technical purpose, the technical scheme that the utility model adopts is as follows:

A powder metallurgy forming die, comprising an upper mold, a cavity below the upper mold, and a lower mold located below the cavity, the upper mold includes an upper template and an upper die punch, the upper template is rectangular, and the upper mold The punch is cylindrical, and the upper die punch is fixed on the lower end surface of the upper template; the cavity includes a die and a die cavity set on the outside of the die, the die has a taper, and the upper and lower surfaces of the die are round In the middle of the die, there is a circular through hole matching the punching of the upper die. The die is divided into three parts. The inside of the die cavity matches the outside of the die. The lower end of the die cavity is provided with threads hole; the lower mold includes a base, a lower die punch positioned above the base, and support blocks positioned at both sides of the lower die punch; There is a lower die punching fixing plate over the joint between the protrusion and the lower die punch; the lower die punch is matched with the circular through hole, there is an interval between the lower die punch and the upper die punch, and the lower die punch is covered with Push tube, the upper end of the push tube is sleeved in the die cavity, the lower end of the push tube is provided with a push tube fixing plate, and the push tube fixing plate and the upper template are connected by a tie rod; the support block is a hollow cavity, The lower end of the support block is connected to the base, the upper end of the support block is connected to the cavity of the die through a guide post, the upper end of the guide post matches the threaded hole, the guide post is covered with a spring, and there are at least two guide posts.

In the utility model adopting the above-mentioned technical solution, the concave mold has a taper, and when the upper platen is pressed to the upper top of the concave mold, a horizontal pressure can be formed, so that the green compact receives a horizontal pressure while receiving a vertical pressure. The die is divided into three parts. When taking out the green compact, you don’t need to eject it up and down. You can take out the die directly. Separate the die and you can take out the parts, so as to avoid the quality of the green compact being affected by friction during the ejection process. The success rate of pressing and the quality of compact are improved. The guide post is covered with a spring, which can make the die be at the highest point without pressure, which is beneficial to add more powder, and can separate the lower die punch and the die under the elastic force of the spring. There is a push tube on the outer cover of the lower die punch, and the push tube plays the role of pushing out the die and strengthening the lower die punch.

Further defined, the taper is 3°-6°.

In the range of 3 degrees to 6 degrees, the quality of the pressed compact is good, and the success rate is also higher.

It is further defined that a spiral groove is formed on the inner side of the die cavity.

After the pressing is completed, when the die is to be taken out, the spiral groove can be injected with lubricating oil, which makes it easier to take out the die.

Further defined, there are four guide posts.

Since the guide posts are covered with springs, the resistance generated by the springs on the four guide posts will not be too large during pressing. Within the working range of the one-way hydraulic press, the elastic force of the springs can be more easily released when the one-way hydraulic press releases the pressure. Separate the lower die punch from the die.

A method of using a powder metallurgy forming die is as follows:

Close the die, put it into the cavity of the die, add metal powder into the die, press down the upper die, complete the closing of the die punch and the die, and complete the powder pressing process. After the powder metallurgy test piece is pressed, the upper template rises, which drives the pull rod to rise. After the pull rod rises to a certain position, it drives the push tube fixing plate and the push tube to rise. When the push tube pushes to the die, push the die from the die cavity Take out, take out the die, separate the die and take out the green compact.

Compared with the prior art, the utility model can form compacts with larger length-to-diameter ratio (h/D), has high pressing success rate and high compact quality, is suitable for one-way hydraulic presses, and has high production efficiency and low cost.

Description of drawings

The utility model can be further illustrated by the non-limitative embodiments provided by the accompanying drawings;

Fig. 1 is the front view of a kind of powder metallurgy forming mold of the present utility model;

Fig. 2 is the top view of a kind of powder metallurgy forming mold of the present utility model;

Fig. 3 is the sectional view of A-A in Fig. 2;

Fig. 4 is the structural representation of die;

The main component symbols are explained as follows:

Upper die 1, cavity 2, lower die 3, upper die plate 4, upper die punch 5, die 6, die cavity 7, circular through hole 8, threaded hole 9, base 10, lower die punch 11, support block 12, protrusion 13, lower punching fixed plate 14, push tube 15, push tube fixed plate 16, pull bar 17, guide post 18, spring 19, spiral groove 20.

detailed description

In order to enable those skilled in the art to better understand the utility model, the technical solution of the utility model will be further described below in conjunction with the drawings and embodiments.

Embodiment one,

As shown in Figure 1, Figure 2, Figure 3, and Figure 4, a powder metallurgy forming mold includes an upper mold 1, a cavity 2 located below the upper mold 1, a lower mold 3 located below the cavity 2, and an upper mold 1 It includes an upper template 4 and an upper punch 5, the upper template 4 is rectangular, the upper punch 5 is cylindrical, and the upper punch 5 is fixed on the lower end surface of the upper template 4; the cavity 2 includes a die 6, which is set outside the die 6 The cavity 7 of the die, the die 6 has a taper, the upper and lower surfaces of the die 6 are circular, the middle of the die 6 has a circular through hole 8 matching the upper die punch 5, the die 6 is divided into three lobes, the die The inner side of the cavity 7 matches the outer side of the die 6, and the lower end of the die cavity 7 is provided with a threaded hole 9; the lower die 3 includes a base 10, a lower die punch 11 positioned above the base 10, and support blocks 12 positioned on both sides of the lower die punch 11, A protrusion 13 is provided on the upper end surface of the base 10, and the upper end surface of the protrusion 13 is connected to the lower die punch 11, and the joint between the protrusion 13 and the lower die punch 11 is covered with a lower die punch fixing plate 14; the lower die punch 11 and the circular through hole 8 matching, there is a gap between the lower die punch 11 and the upper die punch 5, the lower die punch 5 is covered with a push tube 15, the upper end of the push tube 15 is sleeved in the die cavity 7, and the lower end of the push tube 15 is provided with a push tube fixing plate 6 , the push tube fixing plate 6 and the upper template 4 are connected by a pull rod 17; the support block 12 is a hollow cavity, the lower end of the support block 12 is connected to the base 10, and the upper end of the support block 12 is connected to the die cavity 7 through a guide post 18, and the guide post 18 upper ends are matched with threaded hole 9, and guide post 18 is overcoated with spring 19, and there are at least two guide posts 18.

Preferably, the taper is 3°-6°.

Embodiment two,

As shown in Figure 1, Figure 2, Figure 3, and Figure 4, a powder metallurgy forming mold includes an upper mold 1, a cavity 2 located below the upper mold 1, a lower mold 3 located below the cavity 2, and an upper mold 1 It includes an upper template 4 and an upper punch 5, the upper template 4 is rectangular, the upper punch 5 is cylindrical, and the upper punch 5 is fixed on the lower end surface of the upper template 4; the cavity 2 includes a die 6, which is set outside the die 6 The cavity 7 of the die, the die 6 has a taper, the upper and lower surfaces of the die 6 are circular, the middle of the die 6 has a circular through hole 8 matching the upper die punch 5, the die 6 is divided into three lobes, the die The inner side of the cavity 7 matches the outer side of the die 6, and the lower end of the die cavity 7 is provided with a threaded hole 9; the lower die 3 includes a base 10, a lower die punch 11 positioned above the base 10, and support blocks 12 positioned on both sides of the lower die punch 11, A protrusion 13 is provided on the upper end surface of the base 10, and the upper end surface of the protrusion 13 is connected to the lower die punch 11, and the joint between the protrusion 13 and the lower die punch 11 is covered with a lower die punch fixing plate 14; the lower die punch 11 and the circular through hole 8 matching, there is a gap between the lower die punch 11 and the upper die punch 5, the lower die punch 5 is covered with a push tube 15, the upper end of the push tube 15 is sleeved in the die cavity 7, and the lower end of the push tube 15 is provided with a push tube fixing plate 6 , the push tube fixing plate 6 and the upper template 4 are connected by a pull rod 17; the support block 12 is a hollow cavity, the lower end of the support block 12 is connected to the base 10, and the upper end of the support block 12 is connected to the die cavity 7 through a guide post 18, and the guide post 18 upper ends are matched with threaded hole 9, and guide post 18 is overcoated with spring 19, and there are at least two guide posts 18.

Preferably, the taper is 3°-6°.

The inner side of the die cavity 7 is provided with a spiral groove 20 .

Optimally, there are four guide posts 18 .

The difference between the above embodiments is that compared with the first embodiment, the second embodiment provides a spiral groove 20 inside the die cavity 7, and lubricating oil can be added to the spiral groove 20, which reduces the number of the die 6 and the die cavity 7. The frictional force between makes it easier for the die 6 to be taken out.

A powder metallurgy forming die provided by the utility model has been introduced in detail above. The description of specific embodiments is only used to help understand the method and core idea of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made to the utility model, and these improvements and modifications also fall into the protection of the claims of the utility model. within range.

Claims (4)

1. a powder metallurgy forming mold, including upper mould, it is positioned at the cavity below upper mould, is positioned at the counterdie below cavity, it is characterised in that: described upper mould includes cope match-plate pattern and upper punch, and described cope match-plate pattern is rectangle, described upper punch is cylindrical, and described upper punch is fixed on cope match-plate pattern lower surface；Described cavity includes die, is placed on the matrix cavity outside die, described die is tapered, described die upper and lower surface is circular, the manhole mated with upper punch is had in the middle of described die, described die divide into three lobes, mating with outside die inside described matrix cavity, described matrix cavity lower end is provided with screwed hole；Described counterdie includes base, be positioned at the bottom punch above base, be positioned at a bracer of bottom punch both sides, and described base upper surface is provided with projection, and described protruding upper surface is connected to bottom punch, described projection and be cased with the fixing plate of bottom punch outside bottom punch junction；Described bottom punch and manhole coupling, there is interval between described bottom punch and upper punch, be cased with ejector sleeve outside described bottom punch, in described ejector sleeve upper end, be placed on matrix cavity, described ejector sleeve lower end is provided with the fixing plate of ejector sleeve, and the fixing plate of described ejector sleeve and cope match-plate pattern are connected by pull bar；Described bracer is the cavity of hollow, and described bracer lower surface connects base, and described bracer upper end is connected to matrix cavity by guide pillar, and described guide pillar upper end is mated with screwed hole, is cased with spring outside described guide pillar, and described guide pillar has at least 2.

2. a kind of powder metallurgy forming mold according to claim 1, it is characterised in that: described tapering is 3 degree to 6 degree.

3. a kind of powder metallurgy forming mold according to claim 2, it is characterised in that: have helicla flute inside described matrix cavity.

4. a kind of powder metallurgy forming mold according to claim 3, it is characterised in that: described guide pillar has 4.