Injection molding machine having a transport device disposed on a baseplate

An injection molding machine for producing molded parts has a machine table with a base frame on which three supporting elements with a baseplate disposed thereon are arranged. The base plate has a temperature-control element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claimes benefit of priority from German (DE) Patent Application Nos. 10 2010 048 657.4 and 10 2010 048 658.2, both filed Oct. 15, 2010, and PCT No. PCT/EP2011/005203, filed Oct. 17, 2011, all of which are herein incorporated by reference in their entirety.

BACKGROUND

The invention relates to an injection molding machine for manufacturing molded parts.

Such an injection molding machine is known from DE 298 04 085 U1. It comprises a base-plate on which a plurality of machine parts are disposed; i.e. a plasticizing and injection mechanism, a multi-part molding tool and a mechanism to open, close and turn a mold half of the molding tool. The temperature of the baseplate changes during operation, whereby a movement of material occurs due to which the machine parts disposed on the baseplate change position. This is disadvantageous since the machine parts can thereby no longer be precisely aligned to one another, which can further result in functional impairment or malfunction.

It is the object of the invention to design an injection molding machine of the type cited at the outset such that it has a low temperature drift.

SUMMARY OF THE INVENTION

In accordance with the invention, this object is accomplished by the baseplate comprising a temperature control element. The possibility thereby exists of selectively changing the temperature of the baseplate. Should the temperature of the baseplate drop for example due to external influences, the temperature control element will supply heat to it; i.e. the baseplate will be heated. Should the temperature of the baseplate rise due to external influences, the temperature control element will withdraw heat from it; i.e. the baseplate will be cooled. The temperature control element prevents thermal stress in the baseplate and the machine parts disposed on same.

Being able to keep the baseplate at a specific temperature prevents a thermal-based material movement of the baseplate. A material movement of the affixed components and handling devices mounted to the baseplate can additionally be prevented. Thus, the precisely aligned mounting of the affixed components relative one another will be maintained during operation of the respective mechanism. The baseplate can moreover for example warm or cool its environment. Thus, a baseplate designed in accordance with the invention can for example cool the interior of a housing in which said baseplate is arranged.

In one preferred embodiment of the invention, the baseplate comprises at least one sensor to detect the plate temperature. The temperature of the baseplate can thereby be regulated to a constant predetermined value by means of a regulating device.

The temperature control element is advantageously formed by channels through which a heat transfer medium can be channeled. The temperature control element can thereby be of a simple construction. A temperature control element formed in this way is moreover very effective and sturdy.

The channels advantageously run parallel to the plane of the baseplate. This allows a very effective influencing of the baseplate temperature. For example, specific areas of the baseplate can be subject to greater cooling and/or heating by a specific routing of the channels. This is then particularly advantageous when certain areas of the baseplate are exposed to greater thermal influences than other areas.

It is very advantageous for the channels to be arranged such that the neutral axis of the channels is consistent with the neutral axis of the baseplate. To this end, the channels run substantially at the center of the plate thickness. This is on the one hand advantageous in terms of the baseplate stability and on the other hand allows channels of greatest possible cross section to be manufactured.

This is particularly applicable when the channels are formed in bores realized in the end faces of the baseplate, as a further particular embodiment of the invention provides. This allows a very easy and economical manufacturing of the channels.

A further particular embodiment of the invention provides for the channel inlets/outlets to be connected in part via connecting elements. Doing so thereby allows readily influencing the rate of the heat transfer medium through the channels.

A further particular embodiment of the invention moreover provides for a pump, by means of which the heat transfer medium can be intermittently pumped through the channels. Having the heat transfer medium being pumped through the channels in intervals achieves the heat transfer medium also flowing through remote areas of the channels. To this end, the pump only needs to be operated in full-load operation during the intervals.

A further particular embodiment of the invention furthermore provides for the baseplate to have air passage openings. Doing so increases the baseplate's thermal influencing of the environment of said baseplate. In other words, the baseplate can better cool or, if needed, warm the baseplate's environment.

In one preferred embodiment of the invention, the injection molding machine comprises a machine table having a base frame on which three supporting elements with a baseplate disposed thereon are affixed.

The baseplate is thus affixed to the base frame without tension. Since three points of support always span a flat surface, it is no longer necessary to mill off the elements of the frame on which the plate rests so they will span a flat surface. The fact that milling no longer needs to be performed is very advantageous in terms of costs. Moreover, there is no longer any risk of the milling not being precise enough, which could then otherwise lead to the baseplate not being disposed on the base frame without tension.

The base frame advantageously comprises a lower frame disposed on three feet. This advantageously achieves likewise arranging the base frame so as to be without tension on an uneven support. When the feet are height-adjustable, as is the case in a particular embodiment of the invention, this allows the horizontal disposing of the lower frame, or a baseplate arranged on the lower frame respectively.

The feet preferably comprise rubber mount elements. This thereby achieves being able to easily isolate the baseplate from vibrations introduced into the ground surface due to e.g. harsh environmental conditions.

In a further particular embodiment of the invention, the base frame comprises an upper frame which is connected to the lower frame by means of supports. This thereby allows the base-plate to be disposed at a greater distance from the ground surface.

The supporting elements are advantageously affixed to the upper frame. This thereby allows the baseplate to be directly affixed to the supporting elements.

To affix the baseplate to the supporting elements, the latter advantageously have a conical recess in which a hemispherically configured support engages. This thereby achieves the baseplate being able to be flatly connected to the support which thereby prevents tension from developing when e.g. screwing the baseplate onto the supporting elements, which could lead to warping of the baseplate.

In one preferred embodiment of the invention, the injection molding machine comprises an injection station on the baseplate in which melt can be introduced into the cavity of a molding tool which corresponds to the molded part and has at least one first mold part and one second mold part and is able to be brought into an open and closed position, wherein the first mold part has at least one runner and the cavity is at least partially arranged in the second mold part; arranged on the baseplate is a cooling station as well as a separating station to separate and remove the sprue; an ejection station to eject the molded part and a transport device arranged on the baseplate which comprises at least one transport route connecting the stations on which the second mold part can be transported from one station to another station with a molded part in the cavity where applicable; the first mold part being arranged stationary on a machine nozzle and the second mold part being moved along the transport route separate from the first mold part; the first mold part exhibiting a heat-dissipating area made from a material which is of good thermal conductivity; and the heat-dissipating area being able to be brought into thermal contact with a cooling area of the cooling station such that the cooling area is distanced from the molded part. It is thereby advantageously possible to open the mold after the injection molding process is finished but yet prior to the complete solidification of the melt and then only transport the second mold part together with the molded part situated therein to the cooling station. At the cooling station, the heat-dissipating area of the second mold part is brought into thermal contact with the cooling area of the cooling station in order to cool the second mold part and the molded part situated therein. Since the molded part is still relatively soft and malleable at the start of the cooling procedure, direct contact between the cooling station, the cooling area respectively, and the molded part is prevented. The first mold part remains on the machine nozzle and is not cooled. The injection molding machine according to the invention enables rapidly cooling the molded part so that it can thereafter be removed from the second mold part. Since only the second mold part of the mold is cooled, the injection molding machine enables energy-saving operation. The injection molding machine moreover saves space.

Because the transport device comprises a transport route connecting the stations on which the molded part can be moved from one station to another station, a plurality of molded parts can be transported at the same time. Thus, for example, one molded part can be transported from the injection station to a cooling station and one molded part can be transported from the cooling station to a demolding station at the same time. By the baseplate having a temperature-control element, the moving second mold part can thereby be exactly positioned at the individual stations.

In one preferred embodiment of the invention, the cooling area exhibits a cooling element able to be moved toward and away from the heat-dissipating area which can be brought into thermal contact with the heat-dissipating area to directly cool the second mold part. The cooling element can thereby be in planarly contact with the heat-dissipating area so that the second mold part with the molded part situated therein can be accordingly cooled rapidly. The cooling element is preferably designed as a cooling plate.

It is advantageous to dispose a heating station as a further station on the transport route. The heating station is thereby arranged after the cooling station in the transport direction such that the second mold part can be preheated before being positioned at the injection station. Warming the second mold part has the advantage of the melt injected into the cavity only cooling very slowly during the injection procedure. This thereby allows the manufacturing of very delicate and intricate molded parts. Because the slower the melt cools during the injection molding, the better the molded part can be molded. In the further station designed as a heating station, the relevant tool, the relevant second mold part respectively, can be heated in two stages by means of induction. To this end, the mold part only need be arranged in front of the inductor and the induction started. Additional elements are essentially no longer necessary. Because the mold part is warmed in two stages, it can be preheated in the first stage and heated to its desired final temperature in the second stage. Heating the mold parts to their final temperature can thus occur within a considerably shortened cycle time.

It is expedient to actively cool the cooling element. The second tool part can thereby be cooled faster. In addition, the cooling element can be of correspondingly compact size.

In one preferred embodiment of the invention, the cooling element comprises at least one coolant channel through which a cooling fluid can flow. Water is thereby preferably used as the cooling fluid. The mold half can thereby advantageously be cooled by a water-cooled aluminum plate being pressed against the surface of the mold half by means of a pneumatic cylinder, which thereby produces contact cooling.

In one apt design of the invention, the cooling element can be moved toward and away from the mold part transverse to the latter's direction of transport. The injection molding machine thereby enables a simple structuring.

The injection molding machine advantageously comprises a pressing mechanism by means of which the cooling element can be pressed planarly against the second mold part. Heat can thereby be conveyed even faster from the second mold part to the cooling area of the cooling station.

In another advantageous design of the invention, the cooling station comprises at least one gas outlet in the cooling area from which a cooling gas can flow directly onto the heat-dissipating area. The heat-dissipating area can thereby be cooled without contacting the cooling station. To prevent deformation of the molded part, the gas outlets are designed so as to prevent cooling gas from blowing directly onto the molded part.

When the transport route forms a closed loop, as a particular embodiment of the invention provides, then the mold-tool preheated in the heating station can moreover be re-transported back to the injection station again. Simultaneously transporting the tool between the stations considerably reduces the cycle time of the injection molding machine. It is only limited by the longest dwell time the tool spends in a station.

The transport route advantageously comprises linear conveyors which are connected together at 90 degree rotation at their ends. The connection of the linear conveyors at their ends is advantageously realized by rotary actuators. Instead of linear conveyors, the transport route could also be formed as a conveyor belt extending through the processing stations, or running along the processing stations respectively. Because the transport route consists of linear conveyors which form a closed loop, the essential parts of the injection molding machine can be arranged within the transport route. This is very advantageous in terms of the space required for the injection molding machine.

The inventive injection molding machine allows the manufacturing of a molded part as follows: A molding tool situated in the injection station is closed. Melt is then injected into the cavity of the molding tool. The molding tool is then subsequently opened. The actual injection molding process is thereby finished.

At the same time as the injection molding process, in the cooling station which is disposed outside of the injection station a molded part respectively the corresponding second mold part, can be cooled. Likewise simultaneous to the injection molding process, a molded part situated in a station also disposed outside of the injection station can be ejected from the sprue and the sprue expelled. In addition simultaneous to the injection molding process, a molded part situated in a station also disposed outside of the injection station can be ejected from the mold part arranged in the respective station. Lastly, a mold part situated in a heating station can be heated at the same time as the injection molding process.

After the injection molding process is finished, the molded part, or the second mold part in which the molded part is situated respectively, can be transported from the injection station to the cooling station in the course of a transport step. The mold part situated in the cooling station can be transported from the cooling station to the station at which the molded part is extracted from the sprue during the course of the transport step. Moreover, the second mold part situated in the station in which the molded part is extracted from the sprue can at the same time during the course of the transport step be transported from that station to the station in which the molded part is ejected from the second mold part. In addition, the mold part situated in the station in which the molded part is expelled can at the same time during the course of the transport step be transported from that station to the heating station. Lastly, the mold part situated in the heating station can be transported from the heating station to the injection station during the course of the transport step.

During the transport step, all respective second mold parts can thus be simultaneously transported from one station to the next station. Therefore, not only can the different sub-processes realized in manufacturing a molded part take place substantially simultaneously with the inventive injection molding machine but also the transporting of the molded part to the various processing stations as well. This is very advantageous in terms of the injection molding machine's cycle time.

Because a cooling station is provided, the time required for the molded part to cool down enough to be demolded is greatly reduced. This particularly becomes apparent when the molded part and/or the sprue is of voluminous design.

A further specific embodiment of the invention provides for the injection station to comprise a centering element to center the second mold part introduced into the injection station. Doing so advantageously achieves the transport device not needing to position the second mold part with absolute precise positioning. The transport device can thus be of correspondingly simple and thus economical construction.

DETAILED DESCRIPTION OF THE INVENTION

As can be noted fromFIG. 1, a molding tool is disposed in an injection station1of an injection molding machine100which comprises a stationary first mold part28connected to a machine nozzle29and an moveable second mold part6. The mold parts6,28are designed as respective mold halves. They can be moved toward and away from one another and can be brought into an open position as depicted inFIG. 1as well as a closed position.

The moveable second mold part6exhibits a recess in which a mold cavity6acomprising a cavity7bis disposed. The second mold part6is adjusted by means of a ball screw spindle13powered by a drive12. The ball screw spindle13displaces a pressure plate15which is connected to a movable mold clamping plate14via thrust pin18. A slide rail8aon which the second mold part6is arranged to be laterally movable is disposed on the movable mold clamping plate14on the opposite side from the thrust pin18.

The first non-moveable mold part28is disposed on a likewise non-moveable mold clamping plate26opposite the second mold part6. The non-moveable first mold part28comprises a runner27into the center of which the machine nozzle29can introduce melt.

When the ball screw spindle13presses the second mold part6against the first mold part28, the cavity7bformed in mold cavity6ais closed. The melt flowing through runner27can then fill the entire space of cavity7bunder pressure.

A first pivotable slide rail8bis disposed to the right next to the first slide rail8ainFIG. 1, same being pivotable by 90 degrees about an axis8c&prime; by means of a rotary actuator8c. This allows the first pivotable slide rail8bto be brought from the position depicted inFIG. 1, in which it is aligned with the first slide rail8a, into a position in which it is aligned with a second slide rail9aarranged at an approximate 90 degree angle to the first slide rail8a. A second mold part6disposed on the first slide rail8acan thus be transported by first moving on the first pivotable slide rail8band, subsequent pivoting of the first pivotable slide rail8b, on the second slide rail9a.

A further station designed as a cooling station2is disposed on the second slide rail9a. The cooling station2comprises a water-cooled aluminum plate2awhich can be pressed by a pneumatic cylinder2bagainst a second mold part6situated in the cooling station2. The contact cooling thereby produced cools the moveable second mold part6and in particular the molded part7together with sprue7asituated in said second mold part6.

A second pivotable slide rail9bis disposed underneath second slide rail9ainFIG. 1, same being pivotable by 90 degrees about an axis9c&prime; by means of a rotary actuator9c. This allows the second pivotable slide rail9bto be brought from the position depicted inFIG. 1, in which it is aligned with the second slide rail9a, into a position in which it is aligned with a third slide rail10aarranged at an approximate 90 degree angle to the second slide rail9a. A second mold part6disposed on the second slide rail9acan thus be transported by first moving on the second pivotable slide rail9band, subsequent pivoting of the second pivotable slide rail9b, on the third slide rail10a.

A further station3designed as a separating station3is disposed on the second pivotable slide rail9bin which the sprue7aof the molded part7is separated from the latter and expelled. The expelling occurs by means of a tappet3adisplaced by a pneumatic cylinder3b.

As can moreover be noted fromFIG. 1, a fourth slide rail11ais disposed to the left of the third slide rail10aand extends at an approximate 90 degrees angle to the third slide rail10a. A third pivotable slide rail10bis disposed at the lower end of the fourth slide rail11ainFIG. 1, same being pivotable by 90 degrees about an axis10c&prime; by means of a rotary actuator10c. This allows the third pivotable slide rail10bto be brought from the position depicted inFIG. 1, in which it is aligned with the fourth slide rail11a, into a position in which it is aligned with the third slide rail10a. A second mold part6disposed on the third slide rail10acan thus be transported by first moving on the third pivotable slide rail10band, subsequent pivoting of the third pivotable slide rail10b, on the fourth slide rail11a.

An ejection station4is disposed on the third pivotable slide rail10bas a further station in which a molded part7still situated in the cavity7bof a mold part6located in station4can be expelled from the cavity7b. The expelling occurs by means of a tappet4adisplaced by a pneumatic cylinder4b.

A further station designed as a heating station5is disposed on the fourth slide rail11a. The heating station5comprises an inductor by means of which a second mold part6situated in a first part5aof the heating station5can be preheated to a first temperature. In a second part5bof the heating station5, a second mold part6situated in the second part5bof the heating station5is heated to its desired final temperature.

A fourth pivotable slide rail11bis disposed above the fourth slide rail11ainFIG. 1, same being pivotable by 90 degrees about an axis11c&prime; by means of a rotary actuator11c. This allows the fourth pivotable slide rail11bto be brought from the position depicted inFIG. 1, in which it is aligned with the fourth slide rail11a, into a position in which it is aligned with the first slide rail8aarranged at an approximate 90 degree angle to the fourth slide rail11a. A second mold part6disposed on the fourth slide rail11acan thus be transported by first moving on the fourth pivotable slide rail11band, subsequent pivoting of the fourth pivotable slide rail11b, on the first slide rail8a.

The respective second mold part6can be transported into the injection station1on the first slide rail8a. When the second mold part6reaches its position in the injection station1, a centering pin21arranged in an opening21aof the second mold part6is drawn into an opening21aformed in the slide rail8a. This thereby ensures that the second mold part6is in a required exact position in the injection station1for performing the injection molding process. The centering pin21is arranged on a second ball screw spindle19which is driven by a ball bearing drive16. The second ball screw spindle19is supported in the movable mold clamping plate14by means of a bearing17. The structure of the centering mechanism is depicted more clearly inFIGS. 2 and 3.

As can be noted fromFIG. 2, the centering pin21is arranged in the opening21aof the second mold part6in which a tappet to eject the molded part is usually disposed. The centering pin21exhibits a T-groove-shaped recess20ain which a corresponding T-shaped head20of the ball screw spindle19is disposed. The ball screw spindle19is arranged such that the head20enters the T-groove-shaped recess20aof the centering pin21upon the second mold part6being moved.

The centering pin21further comprises a recess formed on its periphery in which a ball22engages. This thereby holds the centering pin21in its position when the second mold part6is not on a slide rail. Ball22is pressed into the recess by the force generated by a spring22a.

To facilitate the introducing of the centering pin21into the opening21of the first slide rail8a, the centering pin21comprises corresponding chamfers at its end facing opening21b.

InFIG. 3, the centering pin21is partially disposed in opening21b. The second mold part6is thereby in an accurate position. In all other respects,FIG. 3corresponds toFIG. 2. For this reason, the reference numerals have been omitted.

Guide elements23are arranged on the first slide rail8awhich engage in correspondingly formed guide grooves of the second mold part6. The first slide rail8afurthermore comprises a bearing groove24a, the walls of which are abutted by consecutively arranged rollers24,25affixed to the second mold part6. The rollers24,25support the second mold part6in the first slide rail8a.

As can particularly be noted fromFIG. 4, to improve the bearing, the roller25arranged between two outer rollers24are affixed to a slider25awhich is subjected to the force of two springs25b. The spring action is such that the center roller25is pressed to the upper wall of the groove24aand the outer rollers24are pressed against the lower wall of the groove24a.

The remaining slide rails8b,9a,9b,10a,10b,11a,11bhave substantially the same structure such that a detailed description of these slide rails can be dispensed with.

The lateral displacing of the second mold part6ensues by means of rodless pneumatic cylinders8,9,10,11, wherein the first pneumatic cylinder8effects the transport of the second mold parts6arranged on the first slide rail8a, the second pneumatic cylinder9effects the transport of the second mold parts6arranged on the second slide rail9a, the third pneumatic cylinder10effects the transport of the second mold parts6arranged on the third slide rail10a, and the fourth pneumatic cylinder11effects the transport of the second mold parts6arranged on the fourth slide rail11a. The lateral displacing function will be described using the example of the arrangement of the second pneumatic cylinder9and the second slide rail9adepicted inFIG. 5.

As can be noted fromFIG. 5, a short-stroke cylinder9eis arranged on the actuator of the second pneumatic cylinder9, the plunger of which is connected to a rail9d. The rail9dexhibits recesses in which the protrusions6bdisposed on the second mold part6engage. When the protrusions6bare situated in the recesses of the rail9d, the respective second mold parts6are laterally displaceable by means of the rodless second pneumatic cylinder9.

In the position depicted inFIG. 5, the second mold part6disposed on the left inFIG. 5is situated in station3in which the sprue7ais expelled and the second mold part6depicted on the right inFIG. 5is in the cooling station2. Stations2and3are not depicted for reasons of clarity.

As the second mold parts6are situated in stations2and3, the short-stroke cylinder9ecan preferably be actuated during the time the processes are being performed in stations2and3such that rail9dis lowered, whereby the protrusions6bof the second mold part6are no longer engaged with the rail9d. The second pneumatic cylinder9is thereupon actuated such that the short-stroke cylinder9e, and thus rail9d, are moved to the right.

Prior or simultaneous to the second pneumatic cylinder9being actuated, the first pivotable slide rail8bis actuated such that it is aligned with the second slide rail9a. In so doing, a second mold part6situated on the first pivotable slide rail8bcomes into a position in which the recess of the rail9dto the right inFIG. 5is below the protrusion6bof the respective second mold part6. The left recess of the rail9dinFIG. 5is then situated below the protrusion6bof the second mold part6situated in the cooling station2.

Actuating the short-stroke cylinder9emoves rail9dupward so that the protrusions6bof the two respective second mold parts6enter the recesses of the rail9d.

After the sprue7ain station3has been expelled, the second pivotable slide rail9dis pivoted such that it is aligned with the third slide rail10a. If this is the case, the second mold part6situated on the second pivotable slide rail9bis pushed from the second pivotable slide rail9bto the third slide rail10aand the second pivotable slide rail9bpivots back into its initial position.

After this being the case and the relevant second mold part6being cooled in the cooling station2, the second pneumatic cylinder9is actuated such that the second mold part6situated in the cooling station2is shifted into station3in which the sprue7ais expelled as well as the second mold part6situated on the first pivotable slide rail8bbeing shifted into the cooling station2. The operations to be performed in stations2and3as well as the above-described process are thereupon repeated.

The above-described transport also occurs in virtually identical manner with the first slide rail8aand the fourth slide rail11a. The transport of the second mold part6on the third slide rail10aonly differs from the above-described transport in that only one second mold part6is transported in each case. Meaning that an element corresponding to rail9dis not needed in the transport of the second mold part6on the third slide rail10. After being correspondingly shifted, the actuator10eof the third pneumatic cylinder10is in direct operative connection with the protrusion6bof the relevant second mold part6. A second mold part6disposed on the second pivotable slide rail9bcan thereby be moved over the third slide rail9adirectly to the third pivotable slide rail10bby actuation of the third pneumatic cylinder10.

The arrangement of the slide rails8a,8b,9a,9b,10a,10b,11a,11bdepicted inFIG. 1forms a closed loop in which the second mold part6can be continuously transported. It is hereby very advantageous for the essential components of the injection molding machine100, such as for example the clamping unit, to be able to be arranged within the closed loop. Doing so achieves a very compact structure only needing little space.

The injection molding machine100comprises the baseplate101schematically depicted inFIG. 6on which the injection station1, the cooling station2, the separating station3, the ejection station4and the transport device with transport routes8a,8b,9a,9b,10a,10b,11a,11bare arranged. As can be noted fromFIGS. 6 and 7, the baseplate101exhibits channels102which run parallel to the plane of the baseplate101. The channels102are designed as bores102bdrilled into the end faces101bof the baseplate101. The bores102bare disposed at the center of the plate's thickness. Their neutral axes thereby follow a course consistent with the neutral axis of the baseplate101.

The baseplate101further comprises openings108through which air can flow. The air passage openings108can serve to fix machine elements to be arranged on the baseplate101. The baseplate101also further comprises cut-outs109for positioning machine elements.

As can be noted fromFIG. 7, the inlets/outlets of channels102are sealed in part by means of blind plugs105. The inlets/outlets of channels102are moreover partly connected together by means of connecting elements104. The connecting elements104can be conventional tubes comprising screw caps on their ends by means of which the tubes can be screwed into the openings of the bores102b. The blind plugs105as well as the connecting elements104are connected to the bores102bin standard fashion such a more detailed description thereof can be dispensed with.

Two of the openings102bof the channels102disposed on the left inFIG. 7are connected to a pump106. The pump106pumps a coolant into the respective channels102. The pump106draws the coolant from a heat exchanger107which for its part is connected to two of the openings102bof the channels102disposed on the right inFIG. 7. The heat exchanger107allows the heating or cooling of the heat transfer medium to a predetermined temperature.

The controller106aof the pump106is connected to a temperature sensor103arranged at plate101. According to the plate temperature determined by the temperature sensor103, the controller106atriggers the pump106to pump heat transfer medium into the channels102at maximum output at more or less long intervals.

As can particularly be noted fromFIG. 8, the baseplate101is arranged on a base frame110which together with the baseplate101forms a machine table. The base frame110consists of a lower frame110aand an upper frame110bwhich are welded together of square-end box spars. The upper frame110bis connected to the lower frame110avia supports111,112,113,114which likewise consist of square-end box spars.

As can particularly be noted fromFIG. 9, supporting elements115,116,117comprised of metal blocks are affixed (preferably welded) to the upper frame110b, on top of which the baseplate101rests. Screws115a,116a,117aextend through the supporting elements115,116,117, by means of which the baseplate101can be screwed to the supporting elements115,116,117. This is particularly discernible fromFIG. 10.

The lower frame110aexhibits machine feet118,119,120comprising rubber mount elements118a,119a,120a. The lower frame110a, and thus the entire machine table as a whole, is thereby cushioned against vibrations.

As can particularly be noted fromFIGS. 10 and 11, disks121are arranged on the supporting elements115,116,117, same comprising a bore through which the screws115a,116a,117aextend. The bores are countersunk on their side facing the baseplate101so as to form a conical recess. A hemispherical element122having a flat side on its side facing away from the recess engages into the conical recess. The recess and the element122form a conic joint such that the baseplate101always has a flat support. This achieves not warping the baseplate101when it's screwed to the supporting elements115,116,117.

A combination consisting of one of the disks121and the element122is also arranged between the head of the screws115a,116a,117aand the supporting elements115,116,117. This is particularly discernible fromFIG. 11.

The baseplate101further comprises recesses as well as threaded holes which serve in the arranging, respectively affixing, of machine elements.