DE20319600U1 - Workpiece support made from fibre reinforced ceramic, used for thermal treatment of metal goods, has workpiece holders releasably secured to base plate - Google Patents

Abstract

The workpiece holders (5) are releasably secured to the base plate (2) via a clamp-fit joint. At least two workpiece holders are mounted on the base plate and ensure that the workpieces (1) are kept spaced apart during thermal treatment. The only holes (4) present in the base plate are for the mounting the workpiece holders.

Description

The invention relates to a a base plate and at least two workpiece holders Workpiece carrier consisting from a temperature resistant fiber reinforced Ceramics for heat treatment from it at intervals arranged workpieces.

In the manufacture of metallic Components are steps for heat treatment of these components required. The heat treatments include, for example Glow, hardening, Soldering or Coating. So that the components are as uniform and as possible all-round heat treatment in appropriate ovens they will find out - mostly at regular intervals - arranged on workpiece carriers. However, metallic workpiece carriers are known since the mid-90s of the last century also workpiece carriers fiber reinforced Ceramics.

The terms in the text below are to understand like this:

• - Under the temperature resistant fiber reinforced Ceramics fall carbon fiber reinforced carbon with the abbreviation CFC, carbon fiber reinforced Silicon carbide with the abbreviation CSiC and fiber reinforced Ceramics with the English abbreviation CMC for Ceramic matrix composite.
• - The The central element of the workpiece carrier is the Base plate whose length and width (main level) is large in relation to to the thickness.
• - The central axes of the workpiece holder are essentially perpendicular to the main plane of the base plate and are easy to solve Clamp fastener attached to this.
• - The Workpiece holder have identical hook-like projections.
• - The hook-like projections the workpiece holder can into the openings with mutually identical dimensions for the clamp closures in the Intervene in the base plate.
• - Several Workpiece carriers can with Spacers assembled to a (charging frame or system with the base plates either horizontal or substantially vertical are oriented., For vertically oriented base plates, the Workpiece holder axes - starting on the base plate - either aligned at a right angle or rising slightly upwards.

In the German patent application DE 197 37 212 , filed on August 27, 1997, describes a workpiece carrier made of fiber-reinforced ceramic, which is either in one piece or is assembled from one-piece elements and support profiles in such a way that one element engages in the bores of another element. It is not the aim to lock the individual parts of the system against each other in a detachable manner.

In the German utility model DE 295 12 569 , registered on August 4, 1995, describes a workpiece carrier made of CFC, which is particularly simple and at the same time filigree. It serves as a holder for drills during hardening. There is no detachable closure corresponding to the present registration document, with which the individual parts of the workpiece carrier can be locked against one another.

In the European patent specification EP 0770 155 with French priority dated April 13, 1995, a process for the production of complex CFC components is described. These complex components are derived from a flat semi-finished product containing carbon fiber, which is converted into CFC sheets or angled CFC blanks. The CFC plates or angled CFC blanks are machined to size and then put together to form the complex CFC components. No detachable closure corresponding to the present application is provided, with which the individual machined CFC components can be locked against one another.

In the specialist journal Härterei-technische Mitteilungen HTM 55 (2000) 5, pages 281 to 284 are frames made of CFC or CSiC described. The elements mostly made of slabs become too put the racks together. It will not be one of these filings corresponding more detachable Closure described with which the individual parts of a frame can be locked against each other.

In the American patent US 6,401,941 , submitted as PCT application on May 4th, 2000, describes a multi-part workpiece carrier made of a temperature-resistant composite material (CFC or CMC). Starting from a vertical middle plate of the workpiece carrier, support arms extend symmetrically to both sides of the plate. The metal components to be treated are attached to the support arms or removed after a furnace trip.

Although the individual parts of the workpiece carrier so are constructed so that they can be inserted into each other no detachable closures corresponding to the present application document are provided, with which the individual parts of the workpiece carrier are locked against each other can be.

Describe the cited writings Workpiece carrier CFC, CSiC or CMC or from individual CFC, CSiC or CMC elements pluggable systems used for heat treatment in manufacturing of metallic components. Some systems remain unchanged in their constellation others are for disassembly and assembly. None of the systems is for a repeated and at the same time changeable assembly provided.

The task therefore consisted of temperature-resistant fiber reinforced Ceramic a workpiece carrier or to create a system that can be put together from individual elements, with the individual parts of a workpiece carrier or a system Help releasable Connections can be locked against each other.

The task is solved in that individual parts by means of a clamp closure on other parts are attachable and interchangeable.

The advantage of the task solved in this way is that z. B. the base plate of a workpiece carrier in succession with different workpiece holders stocked can be. For any oven trip or batch can the optimal workpiece holder in one for the workpieces best Distribution on the base plate can be selected.

In contrast to joining metallic Parts can only be made from CFC and CSiC materials add limited scope, for example is soldering possible. But it is also known that solder connections are usually not thermally highly resilient. This is one of the causes which is why it is practical in the prior art documents described above only simple plug connections are described to get out of the CMC materials or get systems. Another reason for using the simple Plug connections are in the few types of semi-finished products - such as panels, bands Poles - too see; the production of other types of semi-finished products - such as threaded rods, angles, Bowls - is unusual expensive and is therefore avoided.

To the task under the given Boundary conditions - restricted joining techniques, simple types of semi-finished products - too to solve, workpiece carriers were made temperature-resistant fiber reinforced Ceramic created, with workpiece holder attachable to a base plate using a clamp and are interchangeable.

Both parts to be connected made from simple semi-finished panels. Because of this lies it suggests that in the base plate used except the openings for the clamp closures of the workpiece holder no further or additional recesses are included. A closed base plate only becomes relative small ovens use in which the upheaval of the hot Medium is problem-free. For larger ovens the upheaval of the hot Medium is only guaranteed if the flow resistances are not are too big. A closed base plate of a workpiece carrier would look like a bulkhead. For this reason, they are large format Base plates except from the openings for the clamp closures the workpiece holder of additional Openings cut out.

Metallic heat treatment Parts are usually processed in series. So there are many identical parts annealed hardened, soldered or coated. To be as possible Obtaining identical identical parts is treatment that is as identical as possible to ensure the parts. Also includes also that the parts are washed in the same way by the medium in the ovens. Appropriately are the openings for the clamp closures the workpiece holder at regular intervals arranged the base plate. In exceptional cases and with large distances between the components on the base plate the openings for the clamp closures the workpiece holder on closed or with additional Recesses provided base plates can also be distributed irregularly.

In most cases, a charging rack so in the ovens used that a base plate arranged horizontally in the oven and that the axes of the workpiece holders - starting at the base plate - essentially arranged vertically upwards on the main plane of the base plate are. However, if the main plane of a base plate is vertical, it results in yourself the opportunity that the workpiece holder on both sides are arranged on this plate. The workpieces can then safely open for a furnace trip the workpiece holders be positioned if the axes of the workpiece holders are perpendicular to the main plane of the base plate. The workpieces are positioned even more securely, when the axes of the workpiece holders - starting on the base plate - light rise to the top.

Frequently become several workpiece carriers with spacers assembled into a (charging) frame or a system, the base plates being either substantially horizontal or are oriented essentially vertically.

Should the metallic Parts with different geometries should then also be used Various workpiece holders Have geometries. It is therefore important that the workpiece holder are interchangeable. So that the exchange can be done easily and quickly, have the for used a workpiece carrier Workpiece holder with different geometry always hook-like projections the same Dimensions.

The two parts of a workpiece holder according to the invention are made of relatively inexpensive plate material and on simply put into each other. The top view has a workpiece holder the contour of an isosceles cross, the arms of each at an angle of 90 ° to each other stand. When assembling a workpiece holder, the hook-like grip Projections of the Workpiece holder pushed into the extension until it stops an opening for the clamp lock in a base plate. By rotating the workpiece holder about 90 ° around its longitudinal axis it is clamped against the base plate. The clamping can done in two ways:

On the one hand, the clamping takes place between hook-like projection of the workpiece holder and collar of the opening for the clamping lock in the base plate. First of all, the width of the opening for the clamping lock in the base plate is wider than the maximum width of the hook-like projections of the workpiece holder without taking the collar into account; the width of the opening has a circular or any course. The width of the opening does not play a role in this clamping. It is crucial that the thickness of the collar perpendicular to the main plane of the base plate - starting with the widening of the opening and ending again after a rotation of almost 180 ° - increases with a clockwise or counter-clockwise screwing movement around the longitudinal axis of a workpiece holder. The collar then clamps in the mouth width of the hook-like projection of the workpiece holder between the stop and the inner pressing surface.

On the other hand, the clamping takes place between the hook-like projections of the workpiece holder and the elliptical course of the large width of the opening for the clamp closure in the base plate.

The width of the collar not considered. The size The axis of the ellipse coincides with the widening of the opening in the area of the collar together and the small axis of this ellipse in the main plane of the Base plate is perpendicular to the major axis of this ellipse. The Length of small axis of this ellipse is smaller than the maximum width of the hook-like projections of the workpiece holder. On this way clamp after a screwing movement of the workpiece holder around its longitudinal axis the outer press surfaces of the hook-like projections of the Workpiece holder at the elliptical or oval opening for the Clamp lock in the base plate.

Warp metallic workpiece carriers after use with a large number of batches and are therefore for the further use unusable. This is out with workpiece carriers CMC is not the case, which is why new aspects arise from multiple use become important. For example, you may want an item one of a CMC workpiece carriers low heat conduction should have or that the surface wear particularly should be low. That is why you sometimes become different types of materials for base plate and select workpiece holder. According to the invention however workpiece holder and base plate made of temperature-resistant, fiber-reinforced ceramic. A particularly inexpensive version The diversity of the material types is when the hook-like projections the workpiece holder by post-treatment - for example through a SiC coating - are wear-resistant.

Through the following figures the invention further exemplified. Show it:

1 a workpiece carrier,

1a a partial enlargement according to section Ia in 1 .

2a a plan view of an opening 1 a in a first embodiment,

2 B a section along the line IIb-IIb in 2a .

2c a perspective view, partially cut opening according to the 2a and 2 B with the workpiece holder clamped therein in the axial direction of the workpiece holder,

3a a plan view of an opening 1a in a second embodiment, 3b a section along the line IIIb-IIIb in 3a .

3c a perspective view, partially cut opening according to the 3a and 3b with the workpiece holder clamped therein in the radial direction of the workpiece holder and

4 a perspective exploded view of the individual parts of a workpiece holder over an opening 4 ,

The workpiece carrier 1 to 1 consists of workpiece holders 5 and from a base plate 2 , the recesses regularly arranged in the present case 3 Has. At regular intervals are on the base plate 2 the workpiece holders 5 arranged whose axes are perpendicular to the main plane of the base plate 2 stand. With the help of the workpiece holder 5 become workpieces 6 held securely in the desired position during an oven trip. Two or more workpiece carriers 1 can with the help of spacers 7 can be put together to form a (charging) frame or system. The spacers 7 have to fix the position of stacked workpiece carriers 1 openings at the end 7a on which spigot 7b of the respective subsequent workpiece carrier 1 can intervene.

The 2 to 4 show details of the openings 4 for clamp locks in the base plate 2 of the workpiece carrier 1 and to the workpiece holders 5 ,

The openings 4 are on the workpiece holders 5 facing side narrower than on the workpiece holders 5 opposite side. This is done by a two-piece collar 9 causing each of the two parts of the collar 9 almost 180 ° of the essentially round opening 4 covers. The two parts of the collar 9 are through an expansion 10 the opening 4 separated from each other. With a first in the 2a to 2c The configuration shown is the width of the opening 4 on that of the workpiece holders 5 facing away from the lateral surface of a cylinder whose diameter is at least as large as the extension 10 in the area of the two-part collar 9 , Any extended - also differently shaped, deviating from the cylindrical shape - surface of the opening is permissible for this configuration.

The workpiece holder 5 are according to the 4 formed such that they are in the openings 4 the base plate 2 to clamp and can be released again if necessary. For this purpose, the workpiece holder 5 on that of the base plate 2 facing end hook-like, diametrically opposite with respect to the longitudinal axis of the workpiece holder, projections 8th on. To the 2a and 2c it can be seen that the outermost ends of the diametrically opposite, hook-like projections 8th of a workpiece holder a maximum width 20 have that is smaller than the extension 10 the opening 4 in the base plate 2 ,

The hook-like projections 8th the workpiece holder 5 can - from the surface side 14 the base plate 2 coming here - through the expansion 10 the opening 4 in one - based on the workpiece holder 5 - Drive through axial movement and after a rotation of the workpiece holder 5 around its longitudinal axis behind the two-part collar 9 the opening 4 grip and thus form-fitting connections between workpiece holders 5 and base plate 2 produce.

Securing the workpiece holder 5 in the rotated position - as in the 2a to 2c represented - by a frictional clamping between the inner pressing surface 11 of the hook-like projection 8th with the clamping surface 12 of the collar 9 or the contact surface 13 of the workpiece holder 5 with the surface 14 the base plate 2 brought about. The clamping is due to an increasing thickness of the collar 9 accomplished in the direction of rotation, for example by a clockwise rotation about the axis of the workpiece holder 5 , Based on the extensions 10 the opening 4 the thickness of the collar increases 9 continuously on, ie each of the two parts of the collar 9 is as of an extension 10 to the other extension 10 Ramp rising in the direction of rotation with the clamping surface 12 educated. The maximum thickness of the collar 9 exceeds the mouth width 15 the hook-like projections 8th or exceeds the distance between the inner pressing surface 11 and the contact surface 13 of the workpiece holder 5 , The minimum thickness of each collar part 9 is smaller than the distance between the inner pressing surface 11 and the contact surface 13 of the workpiece holder 5 ,

A second embodiment of securing the workpiece holder 5 is in a rotated position in the 3a to 3c shown. Here is the frictional jamming through the diametrically opposite outer pressing surfaces 16 the hook-shaped projections 8th of the workpiece holder 5 with the inner wall 17 the opening 4 brought about, the inner wall of the opening 4 on the the workpiece holder 5 opposite side has an elliptical or oval shape.

The cross section of this side of the opening 4 has a particularly advantageous through the extensions 10 running large ellipse axis, whose length 18 is greater than the maximum width 20 the outer press surfaces 16 the hook-like projections 8th , The length of the small ellipse axis 19 is smaller than the maximum width 20 the outer press surfaces 16 the hook-like projections 8th ,

4 shows the two cut-to-size plates of the workpiece holder, which make up a complete workpiece holder. The simpler plate 22 is without a hook-like projection, the more complicated plate 21 has two hook-like projections on one end. Both plates are over central, axially limited slots 23 . 24 assembled into a cross-shaped structure, the bearing surfaces 13 come to lie in one plane.

1

Workpiece carrier

2

baseplate

3

recess

4

opening

5

Workpiece holder

6

workpiece

7

spacer

7a

opening

7b

spigot

8th

hook-like head Start

9

collar

10

extension

11

Press area

12

clamping surface

13

bearing surface

14

surface

15

mouth width

16

outer pressing surface

17

inner wall

18

Length of huge elliptical axis

19

Length of small ellipse axis

20

maximum width

21

plate with a hook-like projection

22

plate without a hook-like projection

23

slot

24

slot

Claims (10)

From a base plate ( 2 ) and at least two workpiece holders ( 5 ) assembled workpiece carrier ( 1 ) consisting of a temperature-resistant fiber-reinforced ceramic for the heat treatment of workpieces arranged at intervals ( 6 ) characterized in that the workpiece holder ( 5 ) by means of a clamp lock on the base plate ( 2 ) are attachable and interchangeable. Base plate ( 2 ) according to claim 1, characterized in that in addition to the openings ( 4 ) for the clamp locks of the workpiece holder ( 5 ) in the base plate ( 2 ) no further or additional recesses ( 3 ) are included. Base plate ( 2 ) according to claims 1 and 2, characterized in that the openings ( 4 ) For the clamp locks of the workpiece holder ( 5 ) of the closed or with additional recesses ( 3 } provided base plate ( 2 ) are arranged at irregular or regular intervals. Base plate ( 2 ) according to claims 1 to 3, characterized in that the openings ( 4 ) for the clamp locks of the workpiece holder ( 5 ) so in the base plate ( 2 ) are arranged so that the axes of the assembled workpiece holders ( 5 ) essentially perpendicular to the main plane of the base plate ( 2 ) are either arranged on one or both sides. Workpiece holder ( 5 ) according to one or more of claims 1 to 4, characterized in that the for a workpiece carrier ( 1 ) used workpiece holder ( 5 ) with a different geometry always a hook-like projection ( 8th ) have the same dimensions. Openings ( 4 ) for the clamp locks of the workpiece holder ( 5 ) in the base plate ( 2 ) according to claims 1 to 5, characterized in that the width of the opening ( 4 ) for the clamp lock in the base plate ( 2 ) without considering the collar ( 9 ) is wider than the maximum width ( 20 ) the hook-like projections ( 8th ) of the workpiece holder ( 5 ) and has a circular or any course and that the thickness of the collar ( 9 ) essentially perpendicular to the main plane of the base plate ( 2 ) - starting with the expansion ( 10 ) the opening and after a rotation of almost 180 ° it ends again - increases with a right or left screwing movement. Openings ( 4 ) for the clamp locks of the workpiece holder ( 5 ) in the base plate ( 2 ) according to claims 1 to 5, characterized in that the width of the inner wall ( 17 ) the opening ( 4 ) for the clamp lock in the base plate ( 2 ) without considering the collar ( 9 ) has an elliptical course, the major axis of this ellipse ( 18 ) with the extension ( 10 ) in the area of the collar ( 9 ) coincides, the small axis of this ellipse ( 19 ) in the main plane of the base plate ( 2 ) perpendicular to the major axis of this ellipse ( 18 ) stands and the length of the small axis ( 19 ) this ellipse is smaller than the maximum width ( 20 ) the hook-like projections ( 8th ) a workpiece holder ( 5 ). Clamping closure according to one or more of claims 1 to 7, characterized in that the workpiece holder ( 5 ) and the base plate ( 2 ) consist of the same or different types of temperature-resistant, fiber-reinforced ceramic. Workpiece holder ( 5 ) according to claim 8, characterized in that the hook-like projections ( 8th ) the workpiece holder ( 5 ) are wear-resistant due to post-treatment. Workpiece carrier ( 1 ) according to one or more of claims 1 to 9, characterized in that a plurality of workpiece carriers ( 1 ) with spacers ( 7 ) are assembled into a (charging) frame or system, the base plates ( 2 ) are oriented either essentially horizontally or essentially vertically.