WO1995002723A1

WO1995002723A1 - Material processing device, for example for wood, metal or textiles, in particular smoothing iron

Info

Publication number: WO1995002723A1
Application number: PCT/DE1994/000815
Authority: WO
Inventors: Josef Schiefer
Original assignee: Kennametal Hertel Ag Werkzeuge + Hartstoffe
Priority date: 1993-07-15
Filing date: 1994-07-15
Publication date: 1995-01-26

Abstract

A device for processing workpieces made of materials such as wood, metal or textiles, in particular a smoothing iron, has a processing arrangement for the workpiece, for example a milling arrangement, or a temperature generating arrangement, as well as a slide surface in flat contact with a flat surface of the workpiece to be processed. The slide surface may be moved relatively to the flat surface of the workpiece, in a parallel direction thereto, in order to process the workpiece or to supply the workpiece to the processing arrangement. The slide surface is formed by the surface of at least one ceramic body (5, 15).

Description

Device for processing materials such as wood, metal or textiles, especially irons.

The invention relates generally to processing machines with which materials such as wood, metal or textiles e.g. be worked by mechanical or thermal influence. In such machines there is a sliding surface which forms a sliding pairing with the material to be machined. The sliding surface and the material to be machined or the workpiece perform a relative movement to one another. The relative movement serves to change the location of the machining on a workpiece to be machined or to feed the workpiece to a machining device. An example of this is a thickness milling machine for processing wooden workpieces with a metal feed table. In order to be able to achieve appropriate machining accuracy, such tables are aligned very precisely and have a smooth surface. Experience has shown that the coefficient of friction of the iron-wood pairing is relatively high. For devices with no automatic feed, relatively high forces must therefore be used for the feed of the workpiece for the feed movement. Another disadvantage is that wear of metallic feed tables is relatively high. This also applies to machines with automatic feeding of the workpiece to be machined. These disadvantages can be avoided in that the feed table or at least the surface areas of the table facing the workpiece consist of a ceramic material which on the one hand has a low coefficient of friction compared to wood. As a result, the wooden workpieces are much easier to move on the feed table than is the case with metal feed tables. For example, silicon nitride or silicon carbide can be used as the ceramic material. These materials also show that they are very wear-resistant.

According to claim 3, a feed table can be designed so that its sliding surface is formed by the surfaces of several ceramic bodies. This could be done by inserting ceramic bodies protruding from the surface, for example in the manner of cams, into the surface of a conventional metallic feed table, the surfaces of which add up to form an overall sliding surface. Another example of a device according to the invention are irons used for smoothing textiles. Depending on the type of textile and the prevailing temperatures, the sliding pairing of metal and textile may have relatively high coefficients of friction. In industrial use in particular, this means a not inconsiderable burden on the operators over the duration of a working day. Another disadvantage is the weight of the materials previously used, such as steel, cast iron or aluminum die casting for the production of sole plates. The weight is also disadvantageous in the case of manual processing machines such as, for example, hand planing or hand milling.

The primary object of the invention is to reduce the sliding behavior of sliding or bearing surfaces of machines and devices and to increase their wear resistance. Another object is to additionally reduce the weight of manual processing machines.

This object is achieved by the combination of features of claim 1. After that, the sliding surfaces are the surfaces of ceramic bodies. Specifically, this means that the feed or support tables or the support plates that can be placed on the material to be processed, for example the iron soleplate, are made of ceramic material. Such a device is, for example, as specified in claim 2, a wood thickness milling machine. The feed table of this machine is a one-piece or multi-part ceramic plate that is attached to the machine frame in the usual way. In the case of such machines and devices, however, it is also conceivable for raised areas on a conventional feed table to be made of ceramic material and the entirety of the surfaces of these projecting partial areas to be the sliding surface for the workpiece to be machined.

The further claims 4-17 relate to an iron with an iron soleplate made of ceramic material and an associated heating part carrying a heating element. The use of ceramic materials for the soleplate improves the sliding properties compared to the previous steel soleplate. The effort required for the smoothing movements on the textile is correspondingly reduced. Another advantage of a ceramic soleplate is that it is much more wear-resistant. This is particularly noticeable when processing garments with buttons, zippers or the like. In particular, zippers or certain types of buttons often have sharp edges, which leads to scratching of the sole surface. This is particularly disadvantageous in the case of sole plates which are coated with tetrafluoropolyethylene to improve their lubricity. This coating is in the processing of the above Garments are naturally exposed to increased wear. Another advantage of ceramic soles is that they are less likely to get dirty than conventional metal soles. The pollution of the soleplate has different causes. On the one hand, it stems from ironing aids that are applied to the textiles before or during ironing. Above all, these substances can easily adhere to the soleplate at higher temperatures. However, the pollution can also result from substances present in the textiles from home or from the textile material itself. In the case of ceramic soles, this soiling effect only occurs to a reduced extent.

Another advantage of the irons according to the invention is that their ceramic soleplate has less heat radiation to the environment than steel. The energy loss due to continuous heat transfer from the edges of the soleplate and, during handling-related breaks and during the lifting movement of the iron from the textile, from the soleplate to the surroundings is less.

In addition to the complete replacement of previous steel ball soles with ceramic soles, it is also conceivable to connect a conventional steel sole with a ceramic plate, for example in a "sandwich construction", which is reduced in thickness.

As ceramic materials, carbides, nitrides and borides of subgroups IV, V and VI of the PSE and of main groups III and IV, for example Al and Si, are advantageously considered. These materials are particularly light, wear-resistant and have a relatively good thermal conductivity. Properties that are not available to the same extent in oxide ceramics, for example zirconium oxide. Si3N4 has proven to be particularly advantageous because of its low weight, high wear resistance and low wettability. The low wettability has an advantageous effect on the soiling of the soleplate, e.g. through ironing aids.

Irons usually have a heating element which carries a heating element and is connected to the soleplate. In conventional irons, the soleplate is integrally connected to the heating part in the form of an aluminum die-cast part. The heating elements must be insulated from the electrically conductive heating part. The heating parts are therefore usually equipped with heating elements which are constructed as follows: They have a metallic outer jacket in which a resistance heating wire is arranged centrally. Between the resistance heating wire and the tubular sheathing, for example quartz sand, is arranged. Such heating elements can only be bent to a certain extent. The result is that the surface of the heating part covering the soleplate surface cannot be covered tightly with the heating element. Rather, relatively large areas remain between opposing turns of the heating element. This results in a corresponding temperature uneven distribution on the sliding surface of the soleplate. In conventional steel soleplates, temperature differences of approximately 35 ° C. to 40 ° C. occur between the area near the tip of the soleplate and the middle area of the sliding surface. Although this does not play a major role in many areas of application, the temperature unequal distribution is nevertheless disadvantageous for some applications. For example, this is the case with textiles such as silk, where a narrow temperature range has to be observed. Since, above all, the tip area of the soleplate is only slightly supplied by heating coils arranged appropriately on the heating part, there can be a considerable temperature difference from the remaining sole area. The result is that the tip of the iron can no longer be used for smoothing due to the operating temperature being too low. If the temperature of the tip area is increased accordingly, on the other hand, the middle area can become too hot and destroy a sensitive textile material.

Surprisingly, when using ceramic sole plates, this temperature uneven distribution is lower than with conventional steel soles. A further reduction in the temperature uneven distribution can be achieved if, as stated in claim 7, the heating part also consists of ceramic material. This eliminates the need to insulate the heating element from the heating part. It is therefore possible to lay a bare resistance heating wire with turns on the heating part, which naturally can have tight bending radii. As a result, almost the entire area of the heating part that overlaps the sliding surface of the soleplate can be covered with a resistance heating wire. The result is a very homogeneous temperature distribution in the heating part and thus in the soleplate and on its sliding surface.

The properties of the ceramic material for the heating part do not have to meet the high requirements as for the soleplate itself. Cordierite or steatite ceramics are therefore advantageously used for the heating part. Claim 9 relates to the fixing of the heating elements in the heating part. The heating elements are advantageously embedded therein. This means that separate fastening elements can be dispensed with. The assembly effort is reduced accordingly. According to claim 10 the heating elements advantageously lie in recesses on the upper side of the heating part facing away from the soleplate. The recesses are simple to manufacture due to the manufacturing process of the ceramic heating part, namely by designing the molds for the ceramic powder blanks accordingly. Claim 11 relates to the fixation of the heating elements in the recesses. This is advantageously done by pouring or filling the recesses with a fixing compound. The heating elements are embedded in the fixing compound. Fixing compositions which are self-curing or hardenable and which hold the heating elements securely in the recesses after hardening are advantageously used. Advantageously, conventional insulation cements are used as casting compounds in electrical engineering.

Another possible solution to reduce the temperature uneven distribution on the underside of the soleplate, that is to say the sliding surface of the soleplate, consists in that, according to claim 14, an intermediate plate made of a metal with high thermal conductivity is interposed between the heating part and the soleplate is. The intermediate plate acts as a temperature distributor and ensures that the soleplate temperature is leveled. In order that it can fulfill this purpose, the intermediate plate only has to be a few millimeters thick. The materials for the intermediate plate according to claim 15 are in particular the metals copper and aluminum with their known high thermal conductivity. The intermediate plate is preferably dimensioned such that it covers the entire separating surface between the heating part and the soleplate.

Claims 16 and 17 relate to an embodiment of an iron according to the invention, which permits the generation of steam.

The invention will now be explained in more detail with reference to exemplary embodiments shown in the figures.

Show it:

1 shows a thickness milling machine as an example of a device according to the invention, a further exemplary embodiment of a FIG. 2, the perspective view of the device according to the invention, namely one

Fig. 3 shows a cross section along the line III-III Fig. 2, Fig. 4 shows a further exemplary embodiment of an iron according to the invention

Cross section according to line IV-IV in Fig. 2, 5 shows the lower part, consisting of the heating part and soleplate, of a further embodiment of an iron according to the invention in longitudinal section,

6 shows a plan view of the upper side of the heating part facing away from the soleplate according to FIG. 5,

7 shows a further embodiment of an iron according to the invention in cross section along line VII-VII in FIG. 2, in which an intermediate plate is arranged between the heating part and the soleplate and

8 shows a plan view of the sliding surface of an iron soleplate, which shows the arrangement of temperature measuring points.

A device according to the invention will first be described by way of example using a thickness milling machine. Thickness milling machines essentially comprise a machine frame 1 with a machine table arranged on its upper side and a milling device 3. The milling device 3 is arranged on the machine table and comprises an adjusting device 4 for setting the desired thickness of the wood to be processed. A feed table 5 is arranged on the machine table 2, the surface of which facing the milling device is a sliding surface 6 for a wooden workpiece lying thereon and to be fed to the milling device. The platen 5 is made of ceramic. An insertion gap 7 is arranged between its sliding surface 6 and the milling device 3, into which the workpiece to be machined can be inserted. Si3N4 serves as the ceramic material for the support plate 5.

It is also conceivable that the support plate 5 consists only partially of ceramic material. For example, only the plate area 9 arranged above the dashed line 8 in FIG. 1 could consist of ceramic material and the area 10 below it made of metal. Another possibility would be to have areas made of ceramic material on the sliding surface 6. These areas could either be flat or also cam-like protruding structures which are inserted into corresponding recesses on the sliding surface 6 and fastened there.

2 shows a further example of a device according to the invention, it is an iron. For reasons of clarity, the temperature control device, the cover housing and the handle attached to it are omitted in FIG. 2 and the other drawings. Only the soleplate 15 made of Si3N4 and a heating part 16 connected to it are shown. The heating part of the embodiment shown in Fig.2 consists of die-cast aluminum and is glued to the soleplate 15. The parting line or the Separation joint 17 between heating part 16 and soleplate 15 runs in a plane parallel to the plane of the soleplate.

The heating part has on its upper side 18 facing away from the soleplate 15 a molded bead 19 protruding therefrom. This extends from the rear third of the heating part 16, starting at the point designated by the reference number 20 in FIG. 2, approximately parallel to the edge of the heating part. On the side opposite the point 20, the molded bead 19 runs in the manner of a hairpin curve and extends on the inside of the molded bead section 21 near the edge in a counterclockwise direction to the starting point 20. A heating element 22 is embedded in the molded bead. The heating element 22 consists of a resistance heating wire 23, which is surrounded by a tubular outer shell 24. The space between the outer sheath 24 and the resistance heating wire is filled with quartz sand 25 (FIGS. 3 and 4). Steam channels 26 are arranged within the heating part 16. The steam channels are connected to an external or internal water reservoir. The steam developed in the steam channels 26 exits via outlet openings 28, as in the exemplary embodiment according to FIG. 5 are present, reaching the outside and reaching the underside of the soleplate 15 serving as sliding surface 29 (FIG. 3). The heating part 16 shown in FIGS. 2, 3 and 4 is an aluminum die-cast part. The heating element must therefore be insulated from this part. Therefore, practically only the heating elements 22 described above are used, which due to their tubular configuration can only be bent to a certain extent. For this reason, the top 18 of the heating part 16 cannot be covered with heating coils or heating elements 22 lying close together. Rather, relatively large areas remain, namely an edge area 30, a central area 31 and heel area 32. The consequence of this uneven distribution of the heating element 22 on the upper side 18 of the heating part 16 is a corresponding temperature uneven distribution on the sliding surface 29 of the soleplate 15.

This temperature uneven distribution is also present in conventional irons, the iron sole 15 of which is made of steel, for example of V2A steel. Diagram 1 shows the temperature profile of the sliding surface 29 of a conventional iron with a V2A sole during heating at three different measuring points. The position of the measuring points is shown in Fig.8. Measuring point 1 (MP1) is located near the tip 33 of the soleplate 15, specifically at a position which lies within the edge region 30 of the heating part 16. Measuring point 2 (MP2) is arranged on the sliding surface 29 in an area corresponding to the central area 31. Measuring point 3 (MP3) is finally in one with the heel area 32 overlapping sliding surface area. The measuring points 1-3 lie approximately on a line corresponding to the central longitudinal axis 34 of the soleplate 15.

As can be seen in diagram 1, the sliding surface temperature assymptotically approaches a constant final temperature after a heating period of a few minutes. Both this final temperature, which is reached after about 10-15 minutes, and the previously measured temperature values differ from one another in the various measuring points. The temperature difference between measuring point 1 and measuring point 2 is about 35 ° C. after 15 minutes. Diagram 2 shows the temperature profile on the sliding surface 29 of an iron according to the invention according to FIGS. 2-4. In this iron, a conventional heating part 16 made of die-cast aluminum is connected to an Si3N4 soleplate 15. It can be clearly seen that, compared to a steel soleplate, the temperature uneven distribution on the sliding surface 29 is no longer present to the extent. The temperature difference between MP1 and MP2 and between MP2 and MP3 is only 20 ° C after 15 minutes.

In Figure 4 an embodiment of an iron according to the invention is shown, which differs from the gem. Fig.1 -2 shown differs in that the heating part 16 lies in a recess 40 of the soleplate 15. The parting line 39 between the soleplate 15 and the heating part 16 therefore has a U-shaped profile when viewed in cross section. It is advantageous in this embodiment that the heating part 16 lies positively in the soleplate 15 and is therefore very well fixed in the lateral direction. The heating part 16 is additionally integrally connected to the soleplate 15. It is also advantageous that the parting line is not visible from the outside.

5 shows a further embodiment of an iron according to the invention. Like the embodiments already described, it includes a soleplate 15 and a heating part 16 connected to it. A recess 42 is arranged in the upper side 41 of the heating part 16 facing away from the soleplate 15. The recess 42 runs, as can be seen from FIG. 6, essentially in a serpentine shape on the upper side 41. A resistance heating wire 43 is located in the recess 42. To fix the resistance heating wire in the recess, it is filled with an electric cement 44. In the hardened state, this connects both to the wall of the recess 42 and to the surface of the resistance heating wire. In the final assembly state, the resistance heating wire is arranged so that it is embedded in the electrical cement 44. In this embodiment, there are also steam channels 45 in the heating part 16, which extend both in the transverse and in the longitudinal direction 27 and which are connected to one another. A steam collection space 46 is arranged in the heating part 16 near the tip 33 of the soleplate 15 and communicates with the environment via outlet openings 28. The steam generated in the steam channels 45 and in the steam collection space 46 passes through the outlet openings onto the sliding surface 29 or onto the textile surface (not shown). The steam channels 45 and the steam collection space 46 are recesses in the underside 47 of the heating part 16 facing the iron soleplate 15. The connection between the heating part 16 and the iron soleplate 15 is an adhesive connection.

Due to the fact that the heating part 16 is made of ceramic material, it is no longer necessary to insulate the heating elements from the heating part 16. The outer shell 24 and the insulating layer consisting of quartz sand 25 can thus be omitted. The result is that the resistance heating wire 43 can be arranged in closely coiled serpentine turns, as shown in Fig.6. In the absence of areas not covered by a heating element, as in the exemplary embodiment according to FIGS. 2-4, a practically homogeneous temperature distribution on the sliding surface 29 is achieved.

7 shows another exemplary embodiment of an iron according to the invention. The parts relevant to the invention are also an iron soleplate 15 and a heating part 16. The heating part 16 is a conventional die-cast aluminum part, which has on its top 18 a molded bead 19 enclosing a conventional heating element 22. The underside 47 of the heating part 16 facing the soleplate 15 has recesses which form steam channels 45. The steam channels do not necessarily have to be formed in the form of recesses. Mold cavities, such as in FIG. 3, can also be arranged completely within the heating part 16. An intermediate plate 48 made of a metal with high thermal conductivity is arranged between the heating part 16 and the soleplate 15. Aluminum and copper are the most suitable metals here. The intermediate plate is only about 2-6 mm thick. It has the task of compensating for the temperature unequal distribution caused on the heating part 16 due to the uneven arrangement of the heating element 22.

Diagram 3 shows the temperature profile on the sliding surface 29 during the heating phase in the case of an iron with an aluminum intermediate plate 48. How From this it can be seen that there are significant temperature differences between the measuring points 1-3 only during the heating phase which lasts about 10 minutes. Thereafter, constant temperature values are set, a value of 5 ° C. between MP1 and MP2 being measured as the greatest temperature difference.

The temperature curve in the case of a copper intermediate plate 48 is shown graphically in diagram 4. Here, the temperature values of the individual measuring points are so close to one another even in the heating phase that there is practically only a single line in the graph of diagram 4. From about 6 minutes, a final temperature is reached, which is practically the same in the three measuring points. A value of 3 ° C. was the largest temperature difference between measuring point 1 and measuring point 3. measured.

46 steam collection room

47 underside

48 Intermediate plate MP1 measuring point 1 MP2 measuring point 2 MP3 measuring point 2

Diagram 1

REPLACEMENT LEAF Chart 2

REPLACEMENT LEAF Diagram 3

REPLACEMENT LEAF Diagram 4

REPLACEMENT LEAF

Claims

Expectations

1. Device for processing workpieces made of materials such as wood, metal or textiles, especially irons, with

- A processing device for the workpiece, and

- A sliding surface, which is in flat contact with a flat surface of the workpiece to be machined and is movable relative to and parallel to the plane of the workpiece for machining the workpiece or for feeding the workpiece to the machining device, characterized in that the sliding surface from the surface of at least one Ceramic body (platen (5), soleplate (15)) is formed.

2. Device according to claim 1,

- with a machine frame,

- a machine table arranged on its top,

- a wood milling device arranged on the machine table, and

- A feed table arranged on the machine table with a sliding surface on which a wooden workpiece can be placed and fed to the milling device, the feed table consisting at least partially of ceramic material.

3. Device according to claim 2, characterized in that the sliding surface is formed by the surfaces of several ceramic bodies.

4. The device according to claim 1, wherein the device is an iron which comprises an iron soleplate (15) made of ceramic material and a heating part (16) connected to the iron soleplate and carrying at least one heating element (22).

5. The device according to claim 4, characterized in that the ceramic material consists of nitrides, carbides or borides of elements belonging to the subgroup IV, V or VI or the main group III or IV of the periodic table of the elements.

6. The device according to claim 5, characterized in that the ceramic material is Si3N4.

7. Device according to one of claims 4-6, characterized in that the heating part (16) consists of ceramic material.

8. The device according to claim 7, characterized in that the heating part (16) consists of a cordierite or steatite ceramic.

9. The device according to claim 8, characterized in that the heating element (22) in the heating part (16) is embedded.

10. The device according to claim 9, characterized in that the heating element (22) in a recess (42) on the soleplate (15) facing away from the top (41) of the heating part (16).

11. The device according to claim 10, characterized in that the heating element (22) are embedded in a fixing compound filling the recess and adhering therein.

12. The apparatus according to claim 11, characterized in that the fixing compound is a self-curing or hardenable casting compound.

13. The apparatus according to claim 12, characterized in that the casting compound is an electrical cement (44).

14. Device according to one of claims 4-6, characterized in that an intermediate plate (48) made of a metal with high thermal conductivity is arranged between the heating part (16) of the soleplate (15).

15. The apparatus according to claim 14, characterized in that the metal is copper or aluminum.

16. Device according to one of claims 4-15, characterized in that in the heating part (16) steam channels for generating water vapor are arranged, which are connected to outlet openings (28) for the water vapor-forming passage openings in the soleplate (15) .

17. The apparatus according to claim (16), characterized in that the steam channels (45) are formed by recesses in the soleplate (15) facing underside (47) of the heating part (16).