EP1186361A2 - Method and device for lubricating forming tools, in particular hot forging tools - Google Patents

Abstract

Lubricating hot forging tools comprises electrically and/or electrostatically applying a graphite or graphite-containing powder as lubricant to the surface of the tool before or continuously during its operation. An Independent claim is also included for a device for carrying out the process comprising a powder container (2) connected to a spraying line (3) to a spraying device (1). Preferred Features: The graphite powder is mixed with one or more other powders or granulates before being applied.

Description

The invention relates to a method for lubricating forming and primary forming tools, of molds for pressure, automatic and continuous casting and briquetting, especially for the lubrication of hot forging tools.

Furthermore, the invention relates to a device for performing the invention Process.

Forming and primary forming tools are known to be lubricated to them on the one hand to cool them, but on the other hand to prevent them from becoming excessive Protect wear and make it easier to shape the workpiece.

Lubrication with carbon, in particular with carbon black and graphite, is known Form of suspensions and pastes, but these substances are often included other substances are mixed (cf. EP 0 403 306 A1; EP 0 507 449 A1; EP 0 590 959 A2 and US 5,468,401).

Lubrication of tools with graphite in the form of suspensions and Paste has the disadvantage that the lubricant does not usually adhere there, where it is most needed, especially on edges and vertical or for Forming direction approximately vertical and inclined surfaces. This is where drips the lubricant or cannot be applied at all. Another disadvantage consists in the considerably unclean work and the pollution of the workplace and thus the environment, so that such lubricants are not in all Have cases and apply to all forming processes, especially in some Countries have relatively high requirements for the use of lubricants on forming tools gives the workers handling the health damage to preserve, but also to protect the environment. So tend to Example some of the carbon or graphite based lubricants, especially when mixed with oils and fats, to significant smoke, which is particularly annoying when hot forging, quite apart from Health damage that the workers handling it can incur. Therefore, as can be seen from the publications cited above, one also has already proposed to use graphite and other substances in the form of batches, to counteract the development of smoke and smell. To this For example, the purpose has been to drastically reduce carbon in part and for that significantly increased the percentage of these mixtures of other substances, so that the smoke and smell nuisance should be limited. Some of these batches consist of a large number of components, whereby It should not be forgotten that some of the components are also health-related Can cause damage to workers, especially if they do used in hot forging.

The invention is based on the object, a method for lubrication of forming and master forming tools of the required type to improve that with low environmental impact otherwise difficult to access or tool surfaces that are difficult to lubricate, such as edge areas surfaces that run almost vertically or at an angle are well and permanently lubricated can be used with careful and thus effective use of the Lubricant.

Furthermore, the invention has for its object a device for To carry out the method according to the invention.

This object is achieved by the features described in claim 1 or by the features described in one of claims 2 to 7 .

Surprisingly, it has been shown that by applying different Potentials, on the one hand to the forming tool or to the original tool, on the other hand to the lubricant itself, the lubricant also in powder form is specifically reflected on the tool parts to be lubricated. To the Example can be applied to the tool in the manner of a falling electrode plus voltage be while the lubricant particles are negatively charged and to Example sprayed onto the tool walls to be lubricated by ionized air become. This also leads to the adherence of powdery Lubricant on otherwise difficult to access or not lubricable at all Wall areas, such as edging areas, vertical or oblique Walls. Because the powder particles without polluting the environment Precisely targeting the wall areas to be lubricated is also given a low consumption of powdered lubricant, the Environment is protected in that it does not become polluted as usual suspensions or pastes.

In this way it is also possible, for example, to use graphite-containing powder as a lubricant (claim 1). In the same way, it is possible to use phosphate-containing powder as a lubricant (claim 2), or powder containing boron nitride (claim 3). Glass powder (claim 4) can also be sprayed on as a lubricant in this way, as can powder containing molybdenum sulfite (claim 5), or PTFE (claim 6) or organic lubricants (claim 7).

So that, for example, graphite can be charged, it is expedient to use it with others electrically chargeable granular substances blended which are considered as lubricants come, so that the once otherwise not easily rechargeable Lubricant parts are encased or enclosed by other particles that can be charged electrically be so that they are targeted to the different pole tool surface hike and knock down and cling here. Although this type of Charging of various substances also known from painting processes, however surprisingly from this basic thought when lubricating Forming tools, especially in hot forging, have never been used made. The experts have presumably looked at this more superficially Let considerations keep you from doing so, because they believed that pure Graphite is not easily electrically chargeable and therefore supposedly the Method known from painting technology for spraying paints Surfaces are not applicable to the lubrication of forming tools.

In the claims 8 to 14 further inventive procedures are described as an inventive embodiment.

It is particularly advantageous if, in accordance with patent claim 15, the respective powder is fluidized before it is charged.

For this purpose, the powder can be fluidized according to claim 16 by vibrations or by introducing gas, for example by compressed air.

This object is achieved by the device described in claim 17 .

The device according to the invention is of relatively simple construction, since only for this purpose a spray gun, a container for the powder to be sprayed and charged or powder batch and a hose line and optionally an electrical one Cables need to be used. Such devices are suitable therefore also under rough operating conditions, as for example in Hot forging prevail to be used.

Further inventive configurations are described in claims 18 to 25 .

The compressed air line is used to convey the carrier air (claim 18).

The spray device, in particular a spray gun, can also be assigned to a manipulator, which can program the individual contours or surfaces of the relevant tool, for example a forging tool, after program control (claim 19).

However, it is also possible to connect several devices in parallel - claim 20. For this purpose, can be coated as great tools in a very short time with the lubricant.

Claim 21 describes a particularly advantageous embodiment of the invention. The fluidization device can be designed as a vibration device and / or as a compressed air device which introduces air brought under pressure into the powdered lubricant in order to loosen it up and thereby make it more transportable.

Advantageously, the spray gun is encapsulated to suit the forge - claim 22. This protects it particularly well against flying sparks, but also against impact and shock loads and thermal stress.

According to claim 23 , the amount of lubricant can be changed during the forming process or forging process, for example increased or decreased.

According to claim 24 , the lubricant is also arranged on vertical contours and edge areas.

If an embodiment according to claim 25 is used, for example, particularly endangered contours or high wear during the forming process, wall areas and edge areas exposed to a larger amount of lubricant can be sprayed in order to particularly lubricate these areas and thereby protect them.

In the drawing, the invention is schematic of an embodiment illustrated.

From the drawing, a device can be seen, as with special Advantage for the lubrication of hot forming tools, for example when forging, can be used.

Reference numeral 1 denotes a spray device designed as a spray gun, who manipulated in a suitable way, for example back and forth, but also moved up and down, or otherwise manipulated in a spatial manner can be. For example, it is possible to manually close this device handle, or a manipulator, not shown, which is preferably program-controlled is to assign. The double arrow under the spray gun 1 should generally indicate the mobility of the spray gun 1.

Reference number 2 denotes a powder container in which a suitable one Lubricant in powder form, for example a mixture of different powder components, for example made of graphite and electrically chargeable components or z. B. only made of graphite. However, it is also possible for the individual Store components in various containers, not shown and only before or in the spray gun 1 during the conveying process mix and there electrostatically by high voltage coils, not shown charge. The rest of the electrical charging device with electrical or electronic components is usually assigned to the spray gun 1 and is not shown. It can consist of electrical lines, controls, electronic Components, for example strong electromagnets, coils and the like, consist. On the powder container 2 is a conveyor hose 3 for below Pressure gas, in particular compressed air and powder, indicated.

Reference numeral 4 designates a supply hose for purging gas, in particular for purge air. This supply hose 4 is on the one hand to the powder container 2 on the other connected to the spray gun 1.

5 shows a compressed gas line, in particular a compressed air line, due to the pressurized gas, especially compressed air, the powder container 2 is supplied. Suitable control and regulation devices and a Pressurized gas source, e.g. B. a compressor are for simplification also not shown.

An electrical line designed as a mains connection bears the reference symbol 6, through the electrical energy for the appropriate motors, but also for the electrical charging, etc., is introduced. 7 denotes a line, via which a control signal for the spray gun 1 can be forwarded, while 8 represents an electrical connection for the spray gun 1. A band generator, over which, for example, a voltage of 30,000 volts and high-voltage cascades, For example, 70000 volts are available for reasons of Simplification also not shown. For example, the tools 9 and 10, which can be designed as hot forging tools, with a High voltage source to be charged and coated with powder. The tool is connected to the positive pole while the Spray gun 1 negatively charges the powdered lubricant to be sprayed and over the ionized air on the surfaces of the tools to be sprayed 9 and 10 sprayed on. This will reduce the proportion of spray material sprayed too much considerably reduced, which is possible due to oppositely charged electrodes is.

Instead of a mixture of graphite or other powder components, you can use suitable high voltages even with pure graphite or other lubricants, for example with phosphate powder, with boron nitride, glass powder, molybdenum sulfite powder or PTFE. All of these powders can be used suitable high tensions on the surfaces of the tools to be lubricated Apply 9 and 10 and form even on otherwise difficult to access areas thin and dry solid lubricant layers.

If necessary, the surfaces to be lubricated can also be added be wetted beforehand with water or the like to avoid spraying with powder To facilitate lubrication.

The in the summary, in the claims and in the description Features described and apparent from the drawing can both individually as well as in any combination for the implementation of the invention be essential.

LIST OF REFERENCE NUMBERS

1

Spray gun with high voltage coils for negative charging of the spraying powder as a lubricant; sprayer

2

Powder container with fluidization device and feed device if necessary

3

Delivery hose for air and powder

4

Supply hose for purge air, purge gas

5

Compressed gas line, compressed air line

6

Mains connection, electrical line

7

Line for control signal for spray gun 1

8th

Electrical connection for the spray gun 1

9

Tool

10

"

Claims (25)

Process for the lubrication of forming and primary forming tools, of molds for pressure, automatic and continuous casting and briquetting, in particular for the lubrication of hot forging tools, in which the lubricant is applied to the surface in question before or continuously during the forming or before the primary forming process , characterized in that a powder made of graphite or a graphite powder is electrically or electrostatically charged before being applied to the surface of the tools (9, 10) to be lubricated and then sprayed or sprayed onto the opposite pole surface of the tool (9, 10) is deposited by different electrical potentials between the powder to be sprayed and the surfaces of the tools (9, 10) in the form of a thin layer or a film. Process for the lubrication of forming and primary forming tools, of molds for pressure, automatic and continuous casting and briquetting, in particular for the lubrication of hot forging tools, in which the lubricant is applied to the surface in question before or continuously during the forming or before the primary forming process , characterized in that a powder consisting of phosphate or a phosphate-containing powder is electrically or electrostatically charged before being applied to the surface of the tools (9, 10) to be lubricated and then sprayed or sprayed onto the opposite pole surface of the tool (9. 10) is deposited by different electrical potentials between the powder to be sprayed and the surfaces of the tools (9, 10) in the form of a thin layer or a film. Process for the lubrication of forming and primary forming tools, of molds for pressure, automatic and continuous casting and briquetting, in particular for the lubrication of hot forging tools, in which the lubricant is applied to the surface in question before or continuously during the forming or before the primary forming process characterized in that a powder consisting of boron nitride or a powder containing boron nitride is electrically or electrostatically charged before being applied to the surface of the tools (9, 10) to be lubricated and then sprayed or sprayed onto the opposite pole surface of the tool (9, 10) is deposited by different electrical potentials between the powder to be sprayed and the surfaces of the tools (9, 10) in the form of a thin layer or a film. Process for the lubrication of forming and primary forming tools, of molds for pressure, automatic and continuous casting and briquetting, in particular for the lubrication of hot forging tools, in which the lubricant is applied to the surface in question before or continuously during the forming or before the primary forming process , characterized in that a powder consisting of glass or a glass-containing powder is electrically or electrostatically charged before being applied to the surface of the tools (9, 10) to be lubricated and then sprayed or sprayed onto the opposite pole surface of the tool (9, 10) is deposited by different electrical potentials between the powder to be sprayed and the surfaces of the tools (9, 10) in the form of a thin layer or a film. Process for the lubrication of forming and primary forming tools, of molds for pressure, automatic and continuous casting and briquetting, in particular for the lubrication of hot forging tools, in which the lubricant is applied to the surface in question before or continuously during the forming or before the primary forming process , characterized in that a powder consisting of molybdenum sulfite or a powder containing molybdenum sulfite is electrically or electrostatically charged before being applied to the surface of the tools (9, 10) to be lubricated and then sprayed or sprayed onto the opposite pole surface of the relevant tool (9, 10) is deposited by different electrical potentials between the powder to be sprayed and the surfaces of the tools (9, 10) in the form of a thin layer or a film. Process for the lubrication of forming and primary forming tools, of molds for pressure, automatic and continuous casting and briquetting, in particular for the lubrication of hot forging tools, in which the lubricant is applied to the surface in question before or continuously during the forming or before the primary forming process , characterized in that a polytetrafluoroethylene powder (PTFE) or a PTFE-containing powder is electrically or electrostatically charged before it is applied to the surface of the tools (9, 10) to be lubricated and then onto the opposite pole surface of the tool (9, 10) sprayed or deposited by different electrical potentials between the powder to be sprayed and the surfaces of the tools (9, 10) in the form of a thin layer or a film. Process for the lubrication of forming and primary forming tools, of molds for pressure, automatic and continuous casting and briquetting, in particular for the lubrication of hot forging tools, in which the lubricant is applied to the surface in question before or continuously during the forming or before the primary forming process , characterized in that organic lubricants in powder form, for. B. granular fats, powdered fats, before it is applied to the surface of the tools (9, 10) to be lubricated electrically or electrostatically charged and then sprayed onto the opposite surface of the tool (9, 10) or by different electrical potentials between the powder to be sprayed and the surfaces of the tools (9, 10) are deposited in the form of a thin layer or a film. Method according to Claim 1 or one of the subsequent claims, characterized in that the graphite powder is mixed with one or more other powders or grains before it is charged and then electrically or electrostatically charged in opposite polarity to the material surfaces to be sprayed and then onto the relevant surfaces of the tools ( 9, 10) is sprayed on. Method according to Claim 1 or one of the subsequent claims, characterized in that the phosphate-containing powder is mixed with one or more other powder or grains of other substance before it is charged and then charged with the opposite polarity to the material surfaces to be sprayed, electrically and electrostatically and then onto the relevant surfaces of the tools (9, 10) is sprayed on. Method according to Claim 1 or one of the subsequent claims, characterized in that the boron nitride-containing powder is mixed with one or more other powder or grains of other substance before it is charged and then electrically or electrostatically charged in opposite polarity to the material surfaces to be sprayed and then onto the relevant surfaces of the tools (9, 10) is sprayed on. Method according to Claim 1 or one of the subsequent claims, characterized in that the glass powder is mixed with one or more other powders or grains before it is charged and then charged with the opposite polarity to the material surfaces to be sprayed, electrically and electrostatically and then onto the relevant surfaces of the tools ( 9, 10) is sprayed on. Method according to Claim 1 or one of the subsequent claims, characterized in that the powder containing molybdenum sulfite is mixed with one or more other powder or grains of other substance before it is charged and then electrically or electrostatically charged in opposite polarity to the material surfaces to be sprayed and then onto the relevant surfaces of the tools (9, 10) is sprayed on. Method according to Claim 1 or one of the subsequent claims, characterized in that the polytetrafluoroethylene powder is mixed with one or more other powders or grains before it is charged and then electrically or electrostatically charged in opposite polarity to the material surfaces to be sprayed and then onto the relevant surfaces of the tools ( 9, 10) is sprayed on. Method according to claim 1 or one of the subsequent claims, characterized in that organic lubricants in powder form, e.g. B. granular fats, powdered fats, mixed before being charged with one or more other powders or grains and then charged with the opposite polarity to the material surfaces to be sprayed electrically or electrostatically and then sprayed onto the relevant surfaces of the tools (9, 10). Method according to claim 1 or one of the subsequent claims, characterized in that the powder is fluidized before it is charged, for example by introducing compressed air. Method according to claim 1 or one of the subsequent claims, characterized in that the powder is fluidized by vibrations. Device for carrying out the method according to claim 1 or one of the subsequent claims, characterized in that the powder or powder mixture held in a powder container (2) can be fed via at least one hose line (3) to a spray device (1), in particular a spray gun, in which an electrical or electronic charging device for static charging of the powder or powder mixture is arranged, and that the spray device (1) has at least one spray nozzle through which the electrically charged powder can be sprayed onto the surface of tools (9, 10) to be sprayed. Apparatus according to claim 17, characterized in that the spray device (1) or the spray gun is connected to a compressed air line. Apparatus according to claim 17 or 18, characterized in that the spray device (1) is arranged on a manipulator which travels the tool contour. Apparatus according to claim 17, characterized in that several spray devices (1) are connected in parallel and are arranged together on a supporting structure. Device according to claim 17 or one of the subsequent claims, characterized in that the powder container (2) is assigned a fluidization device for the flowable loosening of the powder or powder mixture. Device according to claim 17 or one of the subsequent claims, characterized in that the spraying device (1) is encapsulated in a housing in a manner suitable for forging and has air or water cooling. Device according to claim 17 or one of the subsequent claims, characterized in that the amount of lubricant can be changed continuously or intermittently during the forming process. Device according to claim 17 or one of the subsequent claims, characterized in that the lubricant can also be sprayed on the vertical and edge regions of the tools (9, 10) to be lubricated. Device according to claim 17 or one of the subsequent claims, characterized in that especially edges can be wetted with a thicker layer of lubricant.

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