CN204108206U - Is furnished with the closed-type cold-extruding mould of counterpressure forming structure - Google Patents

Abstract

The utility model discloses a closed cold extrusion die equipped with a back pressure forming structure, which is composed of a lower die and an upper die. The lower mold backing plate is installed on the workbench of the lower mold, the tooth mandrel is inserted in the hole of the lower mold backing plate, the tooth mandrel is covered with the tooth mold and the insert, and the lower mold backing plate is located under the insert, between the two The floating support structure of the lower die is composed of evenly distributed springs between the opposite end faces. The bottom end surface of the mold base of the upper mold is positioned to install the die head through the upper mold backing plate, and the gas spring is installed in the axial inner hole in the center of the mold base. The coaxial through hole in the die head and the backing plate of the upper die is equipped with an upper ejector rod, and the upper ejector rod is pushed by a gas spring to form a back pressure forming structure of the upper die. The utility model realizes the forming process of the parking lock plate gear in the closed mold cavity by organically adding the floating support structure of the lower mold and the back pressure forming structure of the upper mold in the cold extrusion mold, ensuring the nearly rectangular tooth shape The parking lock gear is formed by one-time cold extrusion, which effectively reduces the forming pressure and the internal stress of the mold. Because the cold finish process is reduced and the production efficiency is greatly improved, the utility model is especially suitable for mass production.

Description

Closed cold extrusion die with back pressure forming structure

technical field

The utility model relates to a structural design of a metal forging die, in particular to a closed cold extrusion die equipped with a back pressure forming structure.

Background technique

The parking lock gear in the car parking mechanism belongs to the category of spur gears, and the industry usually adopts warm and hot forging plus finishing forming process to achieve mass production. The tooth shape of the parking lock gear is nearly rectangular, and its structural feature is that the tooth portion is relatively long. In addition, the quality of the tooth surface is relatively high, so the draft angle of the matching forging die cannot be too large. Due to the limitations of these conditions, it is more difficult to design the matching forging die structure. At present, hot forging dies with conventional structures are generally used in actual production in this industry, which can achieve the expected quality. However, during the production process, problems such as early plastic deformation of the forging die, roughening of the teeth, and insufficient filling of the teeth of the forging are prone to occur. These obvious defects directly affect the processing quality of the subsequent cold finishing process.

Utility model content

The utility model mainly aims at the deficiencies of the prior art, and proposes a closed cold extrusion die equipped with a back pressure forming structure. The die adopts a floating and split forging forming structure, which significantly reduces the internal stress of the die, thereby realizing one-time forging Forming, forging teeth can meet the design requirements without cold finishing.

The utility model realizes the technical goal through the following technical solutions.

A closed cold extrusion die equipped with a back pressure forming structure, which consists of a lower die and an upper die on the same axis. The lower mold includes a spring, a tooth core mold, a lower ejector rod, an insert, a tooth mold, a lower mold backing plate and a workbench. The upper mold includes a die head, an upper ejector pin, a gas spring, a mold base and an upper mold backing plate. The improvement is that: the lower die backing plate is installed in the middle of the upper end face of the lower die, the vertical tooth mandrel is inserted into the hole facing upward on the lower die backing plate, and the tooth mandrel is coaxially matched with the tooth mandrel and the tooth mandrel. The inserting sleeve, the backing plate of the lower mold is located under the inserting sleeve, and the floating support structure of the lower mold is composed of evenly distributed springs between the opposite end faces of the two. The lower ejector rod is installed in the inner cavity of the tooth mandrel, and the rod end exposed from the bottom of the tooth mandrel runs through the backing plate of the lower die and the workbench. The mold base of the upper mold is a plate, the bottom end surface of the upper mold base is positioned to install the die head through the upper mold backing plate, and the gas spring is installed in the axial inner hole in the center of the mold base. The upper ejector rod is a slender rod, and the coaxial through hole built in the die head and the upper die backing plate is equipped with the upper ejector rod. The top end of the upper ejector rod contacts the bottom end of the gas spring. Upper mold back pressure forming structure.

The spring in the above structure is a compression spring. The gas spring is a nitrogen gas spring. The tooth mold is an internal tooth mold structure, the tooth core mold is an external tooth mold structure, and the working belt tooth parameters of the tooth mold and the tooth mandrel are the same.

Compared with the prior art, the utility model has the following positive effects:

1. There is a floating structure in the upper and lower molds, which can significantly reduce the internal stress of the mold when the mold is closed, and effectively improve the service life of the mold;

2. In the closed mold cavity, the nitrogen spring provides power to drive the upper ejector pin, and the back pressure generated by the upper ejector pin increases the metal flow, which is beneficial to tooth filling;

3. In the cold extrusion stage, the upper and lower dies are not opened under the action of the spring, and the closed die cavity is conducive to improving the forming quality of the forging.

Description of drawings

Fig. 1 is a schematic cross-sectional view of the structure of the utility model.

Fig. 2 is a schematic diagram of the planar structure of the forging of the embodiment.

Detailed ways

Below according to accompanying drawing and in conjunction with embodiment, the utility model is further described.

The closed cold extrusion die equipped with back pressure forming structure shown in Figure 1 consists of a lower die and an upper die on the same axis. The lower mold is based on the workbench 1.7 to install a spring 1.1, a tooth mandrel 1.2, a lower ejector rod 1.3, an insert 1.4, a tooth mold 1.5 and a backing plate of the lower mold. The upper mold is located above the lower mold, and the upper mold slides up and down with the supporting press. The upper die includes a die head 2.1, an upper ejector pin 2.2, an air spring 2.3, a die base 2.4 and an upper die backing plate 2.5. The workbench 1.7 of the lower mold is in a static state, and the lower mold backing plate 1.6 is installed in the middle of the upper end face of the workbench 1.7, and the vertical tooth mandrel 1.2 is inserted into the upward hole of the lower mold backing plate 1.6, and the upper part of the tooth mandrel 1.2 The coaxial gear mold 1.5 and the insert 1.4 of the overcoat. Tooth mandrel 1.2 is an external tooth mold structure, tooth mold 1.5 is an internal tooth mold structure, tooth mold 1.5 and tooth mandrel 1.2 work with the same tooth parameters, and the two have clearance fit. The tooth shapes of the tooth mold 1.5 and the tooth mandrel mold 1.2 in this embodiment are shown in FIG. 2 , the tooth shape is nearly rectangular, and the included angles α and β of the two tooth surfaces are different. The backing plate 1.6 of the lower die is located under the insert 1.4, and springs 1.1 are uniformly distributed between the two opposite end faces. In this embodiment, the spring 1.1 is a pressure spring, and the spring 1.1 between the two forms the floating support of the lower die. structure. The lower ejector rod 1.3 is installed in the cavity of the tooth mandrel 1.2, and the rod end exposed from the bottom of the tooth mandrel 1.2 runs through the lower die backing plate 1.6 and the workbench 1.7. The mold base 2.4 of the upper mold is a plate, and the bottom end surface of the upper mold base 2.4 is positioned and installed with the die head 2.1 through the upper mold backing plate 2.5. During cold extrusion, the die head 2.1 presses down with the die base 2.4, and the die head 2.1 cooperates with the upper end surface of the tooth die 1.5 of the lower die to form a closed die cavity. In order to provide the forming back pressure of the upper mold, the utility model installs a gas spring 2.3 in the axial inner hole of the mold base 2.4, and the gas spring 2.3 pushes the displacement of the upper ejector rod 2.2. The upper ejector rod 2.2 is a slender rod, which cooperates with the coaxial through hole built in the mold base 2.1 and the upper die backing plate 2.5. The top end of the upper ejector rod 2.2 contacts the bottom end of the gas spring 2.3 to form a follow-up upper die back pressure forming structure. The gas spring 2.3 used in the present embodiment is a nitrogen gas spring.

When the utility model is actually used, the blank is first placed in the inner cavity of the tooth mold 1.5, and the supporting press is started to drive the upper mold downward until the die head 2.1 of the upper mold and the tooth mold 1.5 of the lower mold are closed. The spring 1.1 in the box is a pressure spring, which produces a reverse elastic force when under pressure, so as to ensure that the upper and lower molds do not open when forming, and maintain a closed cavity. The blank is subjected to compressive stress in three directions in the closed cavity. The first is the compressive stress applied by the press through the die head 2.1, the second is the reaction force of the compressed spring 1.1, and the third force is the constraint of the metal flow of the blank by the tooth die 1.5 Force, the blank is easy to form under the action of compressive stress in three directions. In addition, the utility model aims at the problem of insufficient filling of the tooth part when the near-rectangular tooth is formed, and the gas spring 2.3 pushes the upper ejector rod 2.2 to displace, so as to provide back pressure for the blank forming, and promote the flow of the blank metal to the tooth part located at the edge of the mold cavity. Conducive to tooth filling.

The utility model organically adds the floating support structure of the lower mold and the back pressure forming structure of the upper mold in the cold extrusion mold, realizes the forming process of the parking lock plate gear in the closed mold cavity, and ensures that the tooth shape is nearly rectangular The unique parking lock gear is cold extruded at one time, and the forming pressure and internal stress of the mold are effectively reduced. Because the cold finishing process is reduced and the production efficiency is greatly improved, the utility model is particularly suitable for mass production.

Claims (4)

1. A closed cold extrusion die equipped with a back pressure forming structure, which consists of a lower die and an upper die on the same axis; the lower die includes a spring (1.1), a tooth core die (1.2), Lower ejector rod (1.3), insert (1.4), tooth mold (1.5), lower die backing plate (1.6) and workbench (1.7); said upper die includes die head (2.1), upper ejector rod (2.2) , gas spring (2.3), mold base (2.4) and upper mold backing plate (2.5); it is characterized in that: the lower mold backing plate (1.6) is installed in the middle of the upper end surface of the working table (1.7) of the lower mold, and the vertical The tooth mandrel (1.2) is inserted into the upward hole of the lower mold backing plate (1.6), the tooth mandrel (1.2) is covered with the tooth mold (1.5) and insert (1.4) coaxially matched, and the lower mold backing plate (1.6) Located under the insert (1.4), the floating support structure of the lower mold is composed of evenly distributed springs (1.1) between the two opposite end faces; the lower ejector rod (1.3) is installed in the inner cavity of the tooth mandrel (1.2) , the rod end exposed from the bottom of the tooth mandrel (1.2) runs through the backing plate (1.6) and the workbench (1.7); The die head (2.1) is positioned and installed on the end face through the backing plate (2.5) of the upper die, and the gas spring (2.3) is installed in the axial inner hole in the center of the die base (2.4); the upper ejector rod (2.2) is a slender rod, The coaxial through hole built in the head (2.1) and the upper mold backing plate (2.5) is equipped with the upper ejector rod (2.2), and the top of the upper ejector rod (2.2) contacts the bottom end of the gas spring (2.3). When molding, the gas spring (2.3 ) to push the displacement of the upper ejector rod (2.2) to form the back pressure forming structure of the upper die. 2. The closed cold extrusion die equipped with a back pressure forming structure according to claim 1, characterized in that: the spring (1.1) is a compression spring. 3. The closed cold extrusion die equipped with a back pressure forming structure according to claim 1, characterized in that: the gas spring (2.3) is a nitrogen gas spring. 4. The closed cold extrusion die equipped with a back pressure forming structure according to claim 1, characterized in that: the tooth mold (1.5) is an internal tooth mold structure, and the tooth mandrel (1.2) is an external tooth mold The structure, tooth mold (1.5) and tooth mandrel (1.2) have the same parameters of the working belt teeth.