JPH0324256Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mold with a lubricant reservoir groove, which is used in a forging die or the like for producing a molded product by supplying a lubricant.

[Conventional technology]

In conventional forging, the forged product usually has a structure with a large excess wall thickness compared to the final product. Therefore, in order to reduce costs by reducing the weight of input materials and the amount of machining required to finish the product, precision forging is desired because it can produce forged products with a shape close to that of the final product with less excess material. It is rare.
Such forging methods include, for example, high-temperature die forging technology for forging difficult-to-work and expensive titanium alloys and nickel-based superalloys by heating the die to a temperature slightly lower than, or approximately equal to, that of the workpiece material. Alternatively, there is constant temperature forging technology. In these forging technologies, lubricants reduce friction between the die and the workpiece, reduce the amount of force required for machining, prevent seizure between the product and the die,
It plays an important role in preventing oxidation of the workpiece, releasing the product from the mold, and improving the surface condition of the product. Glass-based lubricants, BN, and the like, which exhibit good lubricity at high temperatures, are used as the above-mentioned lubricants.

However, while the above-mentioned lubricant is stable even at high temperatures, as shown in FIG. Easy to form and impede flow and filling of workpiece material. For this reason, a lack of thickness 23a occurs in the forged product 23, resulting in the inconvenience that the required shape and dimensional accuracy cannot be obtained. Deposition of the lubricant is particularly likely to occur in the sealed area surrounded by the workpiece and the lower die 20 during the process of filling the workpiece. Therefore, in precision forging, which uses a forging die with a complicated shape and requires strict dimensional accuracy, it is even more difficult to obtain a stable product. Furthermore, in order to avoid such inconveniences, it is necessary to perform complicated maintenance of the mold to remove the accumulated lubricant, but on the other hand, the mold is heated to high temperatures during forging, making it difficult to perform maintenance. This leads to a decrease in workability. On the other hand, if you try to prevent excess lubricant from accumulating by reducing the amount of lubricant applied, it will be difficult to obtain the original lubricant properties.
There is a risk of burning, wear and tear of the mold. Additionally, in order to take advantage of the lubricant build-up, a mold was previously proposed in which grooves were provided to hold the lubricant and forging was performed continuously (U.S. Pat. No. 3,780,553). However, with such a structure, forging is limited to about 10 times in a row, and the above-mentioned drawbacks have not yet been fully resolved.

On the other hand, for example, in Japanese Patent Application Laid-open No. 58-20343,
A configuration is disclosed in which a mold for warm forming high-strength aluminum alloy is provided with a ventilation hole that communicates at least one location at the lower end of the internal molding space with the outside. In this case, the lower mold consists of a female mold and a middle mold that is located within this female mold and fits into the inner peripheral surface of the lower end of this female mold, and the above-mentioned ventilation hole is located in the direction in which the upper mold is pressed down. It has a shape that extends laterally in a direction perpendicular to , and communicates with the outside. The mold release material applied to the mold surface is discharged to the outside through the ventilation hole. This reduces the amount of lubricant residue deposited within the molding space and improves the shape accuracy of the molded product.

Further, Japanese Utility Model Application Publication No. 60-176844 discloses a configuration in which an extrusion forging die is provided with a lubricant escape passage similar to the above. In this case, since a relatively large amount of lubricant is sprayed onto the mold surface, if there is any lubricant left inside the molding space, which is sealed during molding, the water, oil, etc. contained in the lubricant will cause an explosion. The purpose of the lubricant escape passage is to prevent the explosion pressure from causing various problems. This relief passage includes a gap section provided between the ring die constituting the lower mold and the insert inside thereof, extending downward over the entire length of the insert, and a gap between the ring die and the insert. an annular groove formed on the mold base on which the upper die is placed and communicating with the lower end of the gap, and a pipe extending laterally from the annular groove in a direction perpendicular to the pressing direction of the upper mold, as above. It is formed by a structure in which these are connected in sequence.

[The problem that the idea aims to solve]

However, when performing high-temperature die forging by heating difficult-to-work titanium alloys, nickel-based superalloys, etc. to 700 to 1100°C, as in the conventional examples described above, the forming space is simply moved to the outside. Simply providing communication ventilation holes and lubricant escape passages in the mold will not work.
It is not possible to repeatedly mold a molded product with good shape accuracy. In other words, in high-speed extrusion forging and warm forging of high-strength aluminum alloys, a relatively large amount of oil-based or water-soluble lubricants that are fluid even at room temperature are used. The above-mentioned ventilation holes and lubricant escape passages are mainly constructed from the viewpoint of communication between Not talked about.
On the other hand, in the case of the above-mentioned high-temperature die forging, it is necessary to use glass-based lubricants, BN, etc. that are solid at room temperature, and such lubricants do not have sufficient fluidity. In this case, as in each of the conventional examples described above, for example, if the passage area extends in a direction perpendicular to the pressing direction of the upper mold, the pressing force from the upper mold is weakened and the discharge to the outside is not performed. If the gap is long, clogging will occur immediately. As a result, excess lubricant remains in the molding space, and the accumulation of this residual lubricant causes
The shape accuracy of the molded product will soon be impaired.

This invention was made in view of the above, and
The purpose of this is to maintain the accuracy of molded products over a longer period of time, especially in high-temperature die forging using lubricants that do not have much fluidity, as well as to reduce production costs and improve mold efficiency. It is an object of the present invention to provide a mold with a lubricant reservoir groove that can improve workability in maintenance.

[Means to solve the problem]

Therefore, the mold with a lubricant storage groove of the present invention uses an upper mold and a lower mold to form a molded product having an outer circumferential surface that is approximately parallel to the pressing direction of the upper mold and a lower end surface that is approximately perpendicular to the pressing direction. A mold with a lubricant storage groove for forming the molded product, the mold having an inner peripheral surface as a molding surface relative to the outer peripheral surface of the molded product, and an upper end surface serving as a molding surface relative to the lower end surface of the molded product. The lower mold is formed by fitting the intervening mold which can be freely fitted and removed onto the bottom side of the inner peripheral surface of the outer mold, and the outer peripheral surface of the intervening mold A space-shaped lubricant reservoir is formed between the outer mold and the inner peripheral surface of the outer mold, and a space-shaped lubricant reservoir is formed between the outer peripheral surface of the intermediate mold and the inner peripheral surface of the outer mold above the lubricant reservoir. The lubricant reservoir is characterized by being provided with a gap-shaped gap portion that communicates the molding space above the intervening mold with the lubricant storage portion.

[Effect]

According to the above configuration, the lubricant reservoir is provided between the outer peripheral surface of the interposed mold located below the molding space in the lower mold and the inner peripheral surface of the outer mold, and the lubricant reservoir has the following properties: The lower end of the molding space communicates through a gap formed between the outer peripheral surface of the interposed mold and the inner peripheral surface of the outer mold in parallel to the pressing direction of the upper mold. Therefore, by providing the lubricant reservoir as close as possible to the lower part of the molding space, it is possible to shorten the length of the gap in the shape of the gap as much as possible. Since the shape extends parallel to the pressing direction of the upper die, excess lubricant that conventionally accumulated on the lower end side of the molding space is removed by the pressing force acting directly on the upper die when the upper die is pressed down, and the excess lubricant that has conventionally accumulated on the lower end side of the molding space is The lubricant is forced out through the lubricant reservoir. As a result, surplus lubricant is quickly discharged from the molding space during each molding process, so that molding with high shape accuracy can be maintained for a longer period of time. Moreover, in the above, the above-mentioned lubricant reservoir is provided between the opposing surfaces between the outer mold and the intervening mold which is separate from the outer mold, and in this case, for example, The above-mentioned lubricant reservoir can be easily produced by providing locally spaced shaped portions on the opposing surfaces of the outer surface of the intermediate mold and the inner circumferential surface of the lower mold. Therefore, it can be manufactured at a lower cost than, for example, when a passage passing through the mold laterally is provided exclusively as in the conventional case. In addition, since the lubricant reservoir is provided between the facing surfaces of the intermediate mold and the outer mold as described above, when cleaning the mold, the sealed lubricant reservoir can be used. The accumulated lubricant can be easily removed by separating both molds from each other, so maintenance work can be easily performed.

[Example] An example of the present invention will be described based on FIG.

A lower mold 3 for forging a workpiece to form a forged product 2 having a predetermined shape is mounted on a flat mold base 1 provided at the bottom, and a lower mold 3 that fits into the lower mold 3 An upper die 4 is provided to do this. Lower mold 3
, an outer mold 5 disposed on the outer periphery, and a protruding middle mold 6 penetrating the mold base 1 and disposed in the center.
This is a composite mold consisting of three split molds: an intervening mold 7 which is disposed between the outer mold 5 and the middle mold 6 and faces the tip surface of the downwardly protruding portion 2a of the forged product 2. There is. These outer mold 5, middle mold 6 and interior mold 7 are
Each is provided so that it can be inserted and removed freely.

The outer circumferential shape of the forged product 2 above the protruding part 2a and the outer circumferential shape of the protruding part 2a are formed so as to follow the upper shape of the inner circumferential surface of the outer die 5, while the outer circumferential shape of the protruding part 2a The lower end surface is formed by the upper end surface of the intermediate mold 7. In the vicinity of the upper part of the intervening die 7 between the intervening die 7 and the outer die 5 and the middle die 6, the width of the intervening die 7 is formed to be narrower than the width of the tip surface of the protrusion 2a of the forged product 2. As a result, a gap-shaped gap portion 8 having a width δ is formed, and below this gap portion 8, the inner and outer surfaces of each mold 5, 6, and 7 are formed in a stepped shape, so that opposing surfaces are formed. Space-like lubricant reservoirs 9, 9 are formed which are locally spaced apart between them. The corners of the lower end of the molding space above the intermediate die 7 communicate with these lubricant reservoirs 9, 9 through the gaps 8, 8, respectively. The above lubricant reservoir 9
A groove 10 serving as a lubricant storage groove is formed by the gap portion 8 and the groove 8 .

In the above configuration, when manufacturing the forged product 2 using this die, lubricant is supplied to the die, the lower die 3 is filled with the workpiece material, and then the upper die 4 and the lower die 3 are The forged product 2 is formed by pressure fitting. The formed forged product 2 is then taken out by pushing up the middle die 6. By the way, the excess lubricant supplied during forging is
The lubricant flows into the lubricant reservoir 9 through the gap 8 without being deposited on the intervening mold 7, and is stored there.

Next, we will discuss the results of actual forging using this mold. When titanium alloy was forged with a high-temperature die at a temperature of approximately 900℃ using a glass-based lubricant with good lubrication properties, under-thickness occurred due to the accumulation of lubricant when forging with a conventional die without grooves 10. This problem was solved by completely filling the workpiece with the forging using this die, and a highly accurate forged product 2 was obtained. Furthermore, since the flow of the lubricant improved, the surface film thickness of the forged product 2 became uniform, and the surface condition was improved. At this time, it was possible to perform stable forging more than 100 times in a row without having to maintain the mold. Further, the prediction of the lubricant deposition location in the lower mold 3 was determined after conducting a model experiment and examining the flow state of the lubricant. The width δ of the gap 8 is determined in order to allow the lubricant to escape without creating unnecessary burrs at the tip of the protrusion 2a of the forged product 2 in the case of high-temperature forging of titanium alloy.
It is best to set δ to approximately 0.05 to 0.2 mm. Also,
In order to improve the flow of the workpiece and the lubricant, an appropriate slope may be formed toward the gap 8.

As described above, in the above embodiment, the outer mold 5
Lubricant reservoirs 9, 9 are provided between the opposing surfaces of the intermediate mold 7, and the intermediate mold 7 and the intermediate mold 6, respectively, and the lower end of the molding space is connected to these lubricant reservoirs 9, 9.
Gap portions 8, 8 formed between each of the above-mentioned opposing surfaces
It communicates through. Therefore, the length of the gap portions 8, 8 of the gap shape is short, and the upper die 4
Since the shape extends parallel to the pressing direction of the upper mold 9, the excess lubricant that has conventionally accumulated on the lower end side of the molding space is removed by the pressing force directly acting on the upper mold 9 when the upper mold 9 is pressed down. The lubricant is pushed out through the gap 8 into the lubricant reservoir 9. As a result, surplus lubricant is quickly discharged from the molding space during each molding process, so that molding with high shape accuracy can be continuously and stably obtained many times. In addition, in the above method, since there is no need to consider the accumulation of lubricant, it is possible to reduce the radius of the mold angle, and furthermore, it is possible to obtain a molded product without missing parts without providing radius. It is possible. Moreover, since the lower mold 3 is a composite mold, the above R
It is possible to alleviate stress concentration on the parts. Also,
Each of the lubricant reservoirs 9, 9 is provided between the opposing surfaces of the mutually divided outer mold 5, intermediate mold 7, and intermediate mold 6, so that, for example, the inner and outer surfaces of the intermediate mold 7 and the outer The above-mentioned lubricant reservoirs 9, 9 are easily produced by forming a step shape on the inner circumferential surface of the mold 5 and the outer circumferential surface of the medium mold 6, respectively, so that the opposing surfaces are locally separated. can do. Therefore,
For example, it can be manufactured at a lower cost than the conventional case where a dedicated groove for a lubricant escape passage or the like is formed to penetrate laterally inside the mold. In addition, since the lubricant storage parts 9, 9 are provided between the opposing surfaces of the molds that can be separated from each other as described above, when cleaning the molds, the lubricant storage parts 9, 9 can be kept in a sealed state. Since the lubricant accumulated in the parts 9, 9 can be easily removed by dividing each mold,
Maintenance work can also be done easily.

[Effect of idea]

As described above, the mold with a lubricant reservoir groove of the present invention has an outer mold having an inner peripheral surface as a molding surface for the outer peripheral surface of the molded product, and an upper end surface as the molding surface for the lower end surface of the molded product. A lower mold is formed by fitting the removable interlayer mold to the bottom side of the inner circumferential surface of the outer mold, and an outer peripheral surface of the interlayer mold. A space-shaped lubricant reservoir is formed between the inner peripheral surface of the outer mold and the outer peripheral surface of the interposed mold and the inner peripheral surface of the outer mold above the lubricant reservoir. , a gap portion is provided in the form of a gap that communicates the molding space above the intervening mold with the lubricant storage portion.

As a result, it is possible to make the length of the gap shaped gap for removing excess lubricant from the molding space as short as possible, and this gap has a shape that extends parallel to the direction in which the upper mold is pressed down. Therefore, when the upper mold is pressed down, the pressing force directly acts on the excess lubricant, and the excess lubricant is forced out through the gap into the lubricant reservoir. In this way, excess lubricant from within the molding space is quickly discharged during each molding process, so that molding with high shape accuracy can be maintained for a longer period of time. In addition, the above-mentioned lubricant reservoir can be easily formed by providing a locally spaced shaped portion on the surface where the outer surface of the interposed mold and the inner circumferential surface of the lower mold face each other. It can be manufactured at low cost. Furthermore, when cleaning the molds, by separating both molds from each other, the lubricant accumulated in the previously sealed lubricant reservoir can be easily removed. It has the effect of improving sexual performance.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of essential parts showing a conventional example. 1...Mold base, 2...Forged product (molded product),
2a...Protrusion part, 3...Lower mold, 4...Upper mold, 5...
. . . Outer mold, 6… Middle mold, 7… Intermediate mold, 8… Gap portion, 9… Lubricant storage portion, 10… Groove.

Claims (1)

[Scope of utility model registration request] A mold with a lubricant storage groove for forming a molded product by an upper mold and a lower mold, having an outer circumferential surface substantially parallel to the pressing direction of the upper mold and a lower end surface substantially perpendicular to the pressing direction. , an outer mold having an inner peripheral surface as a molding surface for the outer peripheral surface of the molded product, and an intervening mold having an upper end surface as a molding surface for the lower end surface of the molded product, and an inner mold for the outer mold. The lower mold is formed by fitting the removable intervening mold to the bottom side of the peripheral surface, and a space shape is formed between the outer peripheral surface of the intervening mold and the inner peripheral surface of the outer mold. A lubricant reservoir is formed, and a molding space above the interleaved mold is formed between the outer circumferential surface of the interlocking mold and the inner circumferential surface of the outer mold above the lubricant reservoir. A mold with a lubricant storage groove, characterized in that a gap portion having a gap shape is provided to communicate with the lubricant storage groove.