DE3211522C1 - Device for the continuous heat treatment of workpieces such as crankshafts, gears, rings and the like. - Google Patents

Description

The invention relates to a device for the continuous heat treatment of workpieces, such as Crankshafts, gears, rings and the like., In a reversible pusher furnace with in a closed furnace chamber provided slideways for the intermittent feed of lined up baskets between a Loading station and an unloading station as well as deflection devices for transferring individual baskets from one to the other slide.

Such a reversible pusher furnace is known from DE-OS 28 04 338. The loading station is formed on one end of the furnace and the unloading station on the other side of the furnace. Two separate devices are therefore required for loading and unloading. On the unloading side, the hardening device belonging to the furnace is formed, consisting of two hardening baths and a tilting device, with which baskets taken over from the middle slide can be tilted 180 ° to one side or the other. The quenching tanks arranged below are provided with two different media, e.g. B. water and oil filled. The disadvantage of this reversible pusher furnace is that the technical furnace capacity is only used to ² Iz because a slide is reserved for the return transport of the empty baskets. Above all, however, it should be noted that parts such as crankshafts, gears, rings and the like cannot be subjected to heat treatment in this furnace, since workpieces of this type require extremely uniform cooling from all sides. Hardening machines are used for this purpose, which clamp the workpieces under high pressure and immerse them individually in the hardening bath with these pressure devices.

Workpieces intended for press hardening have so far been heat treated in box furnaces or rotary hearth furnaces, because the workpieces are removed from these individually by hand or with manipulators and transferred to the hardening machine

can be fed. The limited capacity of these ovens is therefore a disadvantage, as only a few parts are in can be prepared for press hardening in a relatively long time.

The invention is based on the object to provide an overall device with which a continuous Heat treatment of workpieces such as crankshafts, gears, rings and the like in a heat treatment furnace high throughput can be carried out, from which the parts are individually removed and a hardening machine can be supplied to perform press hardening. The others discussed above Disadvantages of the prior art are to be avoided. This is also the main disadvantage of Pusher oven with basket loading to be expected in which the baskets after leaving the oven cool and have to be reheated with the charge, so that large losses of heat and time develop.

The object is achieved according to the invention in that in alignment with the reversible pusher furnace the initially named type a holding chamber is arranged on the unloading side, to which a manipulator is assigned, with the individual removal of the workpieces and loading of one in the direction of movement of the manipulator arranged press hardening machine is feasible. The idea of the invention is therefore based on the combination of a reversible pusher furnace with a holding chamber and a manipulator for individual operation, see above that the continuously heat-treated crankshafts in the reversing pusher furnace, for example in the holding chamber kept at the material-dependent holding temperature, removed individually with the manipulator and can be fed in one movement path of the press hardening machine. Advantageously, has the reversible pusher furnace has three slideways arranged side by side in a horizontal plane with both sides in the area of the two ends provided deflection devices, the middle slide by a Transport device is connected to the holding chamber, which in combination with the manipulator as Loading and unloading station is designed. This way there is a maximization of the technical Oven capacity achieved even with a single removal, as both all three slideways are used at the same time Heat treatment of the workpieces can be used as well as continuous loading and Discharge can take place in the cycle of the reversing pusher furnace.

The holding chamber preferably consists of a refractory lined with heating elements to a temperature between 850 ⁰ C and 900 ° C heatable oven chamber that is connected by a common raisable and lowerable door with the turning pusher furnace and has a further door for loading and / or unloading , whereby a forward and backward pressure chain is provided for transport between the reversible pusher furnace and the holding chamber. The holding chamber can be provided with a fan for improved atmospheric circulation. For heating, gas-heated radiant tubes are advantageously arranged on both sides in the longitudinal direction in the holding chamber.

According to an advantageous embodiment of the invention, the manipulator has a front and rear telescopic gripper arm and is arranged on a turntable so that it can be pivoted through 180 ° on both sides. It is usually in alignment coaxially with the reversible pusher furnace and the holding chamber, but it can also arranged laterally to the holding chamber in particular in the embodiment described below be. The telescopic gripper arms make it possible to move the manipulator into the holding chamber to lengthen and shorten it in order to simplify and space-saving the individual loading and To be able to carry out removal.

It may be necessary for various applications of the device combination according to the invention not only to treat workpieces that are to be subjected to a press hardening process, but also Small parts, such as screws. In this case, a quenching bath is provided below the holding chamber to be arranged, which in particular consists of two containers optionally filled with oil and water consists and out of the holding chamber via a tilting device arranged therein and a Chute can be loaded. The tilting device can be fitted with a pull-out device that can be retracted into the furnace chamber be combined for incoming baskets that can be moved back and forth from a lengthways Push and pull rod with a driver pivotably articulated at its free end in the direction of movement consists. The push and pull rod can be rotated with the tilting device. That way it is possible to carry out the loading and unloading of the holding chamber from the reversible pusher furnace and then either the loading of the quenching bath arranged below using the tilting movement make or the individual removal and loading of the press hardening machine by using the manipulator perform.

Further details, features and advantages of the subject matter of the invention emerge from the Subclaims and the following description of the drawing, in which schematically different Embodiments of the invention are shown. In the drawing shows

F i g. 1 a reversible pusher furnace with holding chamber and manipulator in side view,

F i g. 2 the device of FIG. 1 partly in section, partly in plan view,

F i g. 3 shows a modified embodiment of a reversible pusher furnace with holding chamber and manipulator in FIG two side views,

4 shows two sectional views of the device of Fig. 3,

5 is a sectional view of a reversible pusher furnace Holding chamber and additional quenching bath as per line I-L

F i g. 6 shows a sectional view along the line II-II according to FIG F i g. 5 and

7 shows a sectional view along the line III-III according to FIG. 6th

The in F i g. 1 of the drawing shown device is for the continuous heat treatment of workpieces, like crankshafts. It consists of a reversible pusher furnace 1 with a closed one Furnace chamber 2 arranged slideways, which are shown in accordance with below Embodiments are provided with the reference numerals 12, 13, 14, on which in intermittent feed Baskets 4 in a row can be transported between a loading station and an unloading station. the The loading and unloading stations are combined on the right-hand side of the furnace by a holding chamber 6 formed into which a manipulator 7 can intervene. The transport of the baskets 4 in the oven chamber 2 of

Slideway to slideway is made by means of deflection devices 24, which are arranged on opposite sides of the reversible pusher furnace. An associated press hardening machine 8 of a design known per se and therefore not described in detail can be loaded and unloaded from the manipulator 7. The loading takes place directly from the warming chamber 6, in which the crankshafts are held by heating elements 9 in a heated atmosphere at a material-dependent temperature of approximately 900 ^° C., the atmosphere being circulated by means of a fan 57

The in the F i g. The device shown in FIGS. 3 and 4 of the drawing differs from that just described solely because the manipulator 7 is not in alignment with the reversible pusher furnace and its holding chamber is arranged, but is to the side, so that for loading and unloading of the holding chamber 6 a side door 3 with a lifting cylinder drive is provided. This training is necessary because at the in the F i g. 3 and 4 shown reversing pusher furnace below the holding chamber 6, a quenching chamber 5 of the type described in more detail below is provided with an oil bath and water bath, which is provided by an in the holding chamber arranged tilting device can be charged. This embodiment of the device enables both the treatment of individual parts, such as crankshafts, which the press hardening machine 8 must be supplied, as well as the treatment of small parts, whose hardening takes place in the quenching bath.

The in the F i g. 5, 6 and 7 illustrated embodiment of the combination of a reversible impact furnace with one Holding chamber, a quenching chamber, a manipulator and a press hardening machine, not shown is structured as follows. The reversible pusher furnace has a in the usual way Refractory material existing housing 10 on with a vault designed as a furnace chamber 1, in which three slideways 12, 13, 14 made of ceramic material are arranged next to one another on one level. The slideways 12, 13, 14, the ends of the correspondingly shaped operating pieces with each other are connected, serve the intermittent feed of strung together baskets 15, which with the Thermally treated goods are filled, which consists of larger parts, such as crankshafts for press hardening, as well as small parts such as screws for oil / water bath hardening. The middle slide 13 is preferably to protect the charge from direct and excessive heat from a muffle 16 surrounded by refractory material. In the ceiling area of the muffle 16 openings 17 are formed which together with the fans 18 arranged above, ensure that the furnace atmosphere is circulated evenly. The furnace chamber 11 is heated with the aid of radiant tubes 19 through which the fire and flue gases and in this embodiment in the longitudinal direction, preferably on both sides of each slide 12,13,14 extend.

The baskets 15 are advanced with the aid of pneumatically or hydraulically operated piston-cylinder units 20,21,22, which are arranged at the front ends outside of the housing 10 and each with one of the slideways 12, 13, 14 are aligned. Designed as a slide 23 free piston ends of the Units engage in the furnace chamber 11. At the level of the ends of the slideways are also at the Long sides outside of the housing 10 are opposite in pairs and each consist of a piston-cylinder unit existing deflection devices 24 are provided. The free piston ends of these units are also designed as a slide 25 and engage laterally in the furnace chamber 11 to the individual baskets in to move from one slide to another in a manner yet to be described.

Located on the end face of the housing 10 facing away from the piston-cylinder unit 22 is FIG Extension of the middle slide 13 an unloading station 25 in the form of a holding chamber 6, the is connected gas-tight to the furnace chamber 11 and with this via a hydraulic or pneumatic operable inner door 27 is in communication. The unloading station 26 is provided with a tilting device 28 provided, which essentially consists of a rotatably mounted push and pull rod 29, one on this fixed tilt mount 30 and a piston-cylinder unit 31 designed as a drive, which by means of racks 32 and pinion 33 drives the push and pull rod 20 about its longitudinal axis. the Tilt mount 30 is equipped with two parallel holding rails 34 at a distance, which are aligned so that they cooperate with a correspondingly undercut foot part of the basket 15 and one in the Tilt mount 30 hold the retracted basket during the tilting movement by essentially 180 °. In In addition, the tilt mount 30 becomes its horizontal receiving position by a locking device 35 held, the pin 36 in a correspondingly formed longitudinal groove in the push and pull rod 29 intervenes.

The pull and push rod 29 is also part of an extraction device that has a further drive 37 for the push and pull rod 29 in the longitudinal direction, a guide carriage 41 and a driver 39 on the free End of the push and pull rod 29 includes. The one which is essentially fork-shaped at one end Driver 39 is rotatably seated on a shaft 40 which, in the rest position of the tilt mount 30, is horizontal and is aligned at right angles to the central axis of the push and pull rod 29. The other in relation to the axis of rotation The end of the driver 39 points to the front in a horizontal position and is heavier than the fork-shaped end, so that the driver 39 from the horizontal as a result of the one-sided weight load automatically in an im essential vertical working position tilts.

In the area of its free end, the push and pull rod 29 is also provided with a guide carriage 41 provided, on the one hand, the stabilization and guidance of the reciprocating pull and push rod 29 and on the other hand the weight-loaded end of the driver 39 in its essentially vertical Working position serves as a stop.

The provided for the push and pull rod 29 drive 37 comprises a motor 42, the one below the push and pull rod drives endlessly circulating chain 43, which is connected to the push and pull rod via a driver Pull rod 29 is engaged (see F i g. 5).

The pull-out device described above and the tilting device 28 are arranged as one about the longitudinal axis rotatable unit formed. For this purpose, the two drive members 31 and 42 by means of a Bracket 44 attached to a mounting plate 45 which rotates together with the push and pull rod 29.

The unloading station 26 is also on a

Running channel 46 with the interior of the housing 10 in connection, which is located below the inner door 27 and the

Levels of the slideways 12,13,14 extends and through the end of the push and pull rod 29 provided with the driver 39 and the guide carriage 41 arrives at least up to the level of the first basket 15 on the middle slide 13. The amount of the Running channel 46 is held so that the driver 39 during the forward movement, the in F i g. 6 shown Assumes position from which he tilts into the vertical working position at the moment in which he is below of the first basket 15 has reached the free space 47.

A quenching bath is provided below the unloading station 26, which can be made up of the two optionally with oil and There is water-filled containers 48, 49 and in which the filled baskets via a chute 50 optionally can be emptied.

Above the unloading station 26 is the filling station 51 for small parts, which have a horizontal sliding loading door 52 and a funnel-shaped loading shaft 53 with the unloading station 26 is connected. The shaft opening of the loading shaft 53 is thus at a distance above a basket 15 retracted into the tilt mount 30.

The loading and unloading of items such as crankshafts takes place by means of the manipulator 7 the side door 3 of the holding chamber is held by moving it up and into the open position Telescopic gripper 58 of the manipulator 7 with the workpiece in the holding chamber through the Door opening is retracted through and there the crankshaft stores in an existing basket. The removal takes place accordingly, the manipulator 7 according to the arrows in FIG Drawing is pivoted by 90 ° by means of the turntable 60 for loading the press hardening machine 8.

With the aid of the further telescopic gripper arm 59, the loading and unloading process can be carried out accordingly both the hardening machine and the holding chamber can be combined.

The based on the F i g. 5 to 7, the reversible pusher furnace itself works as follows (example for small parts):
For the following functional sequence it is assumed that all three slideways are equipped with filled baskets, as in FIG. 1 shown. After the end of the cycle time, the pull-out device with the driver 39 is retracted into the interior of the furnace until the driver has reached its end position below the basket A. After opening the inner door 27, the basket A is pulled in front of the tilt mount 30 into an intermediate position and then the inner door is closed again. The pull-out device with the driver then moves a little further forwards to approximately below the inner door, in order to then grasp the basket A on the front side and pull it completely into the tilting socket until it actuates a cylinder switch 54 attached to the mounting plate 45. By actuating the cylinder switch 54, the locking device 35 is activated, which removes the locking of the tilting device. After the piston rod of the cylinder switch 54 is fully retracted, the piston-cylinder unit 31 sets the push and pull rod 29 in motion and rotates the tilting socket together with the basket A, the contents of which are either emptied into the water or oil bath depending on the program. The tilt mount is then turned back into its horizontal starting position and fixed in this position.
The basket can now be reloaded by opening the loading door 52 of the filling station 51. After filling, the loading door is closed again and the inner door 27 is opened. The fuse puller now pushes the filled basket A by means of the pressure and pull rod 29, which is provided for this purpose with a correspondingly formed stop 55, in the position X. After closing of the inner door, the cage A using one of the deflecting means 24 in the position ^ pressed. The deflection device is moved back, and then also the pull-out device, until it has returned to the position shown.

Now the piston-cylinder unit 22 presses the basket B onto the middle slide 13 until a new basket has assumed position A. The basket in position C is then pressed into position B with the aid of the associated deflection device 24, whereupon the deflection device immediately moves back into its initial position as shown. This creates space for actuation of the piston-cylinder unit 20, which now pushes the basket A and thus all the baskets until one basket has assumed position C again.

As soon as the cycle time has ended, the next basket is emptied and filled, but it then runs through the path specified by the positions XZDB.

List of reference symbols

1 reversible pusher furnace

2 furnace chamber

3 door

4 baskets

5 quenching chamber

6 holding chamber

7 manipulator

8 press hardening machine

9 heating elements

10 housing

11 oven chamber

12 slideway

13 slideway

14 slideway

15 baskets

16 muffle

17 openings

18 fans

19 nozzles

20 piston-cylinder unit

21 piston-cylinder unit

22 piston-cylinder unit

23 slider

24 deflection device

25 sliders

26 unloading station

27 interior door

28 Tilting device

29 Push and pull rod

30 tilt mount

31 piston-cylinder unit

32 racks

33 pinions

Support rails

35 locking device

Cones

drive

Carrier

wave

Guide carriage

9

42 Motor 52 Loading door

43 chain 53 feed chute

44 Bracket 54 Cylinder switch

45 mounting plate 55 stop

46 channel ₅ 56 door

47 free space 57 fan

48 container 58 telescopic gripper arm

49 Container 59 Telescopic arm

50 chute 60 turntable

51 filling station ₁₀

For this purpose 4 sheets of drawings

Claims (13)

Patent claims: 1. Device for the continuous heat treatment of workpieces such as crankshafts, Gears, rings and the like., In a reversible pusher furnace with in a closed furnace chamber provided slideways for the intermittent feed of lined up baskets between a loading station and an unloading station as well as deflection devices for translating individual Baskets from one to the other slideway, characterized in that in alignment with the Reversible pusher furnace (1) on the unloading side a holding chamber (6) is arranged, which is a Manipulator (7) is assigned, with which an individual removal of the workpieces and loading a press hardening machine (8) arranged in the direction of movement of the manipulator (7) is. 2. Apparatus according to claim 1, characterized in that the reversible pusher furnace (1). three in horizontal plane juxtaposed slide ways (12,13,14) with both sides in the area of having deflection devices (24) provided at both ends, the middle slide (13) through a transport device is connected to the holding chamber (6), which in combination with the Manipulator (7) is designed as a loading and unloading station. 3. Apparatus according to claim 1 and 2, characterized in that the holding chamber (6) consists of a refractory lined with heating elements (9) to a temperature between 850 ⁰ C and 900 ⁰ C heatable furnace chamber, which can be raised and lowered by a common Door (27) is connected to the reversible pusher furnace (1) and has a further door (56) for loading and / or unloading, a forward and backward pressure chain being provided for transport between the reversible pusher furnace (1) and the holding chamber (6). 4. Device according to one of claims 1 to 3, characterized in that the holding chamber (6) is provided with a fan (57) for the circulation of the atmosphere. 5. Device according to one of claims 1 to 4, characterized in that the holding chamber Has gas-heated radiant tubes as heating elements (9), which on both sides in the longitudinal direction in the Holding chamber are arranged distributed. 6. Device according to one of claims 1 to 5, characterized in that the manipulator (7) a front and rear telescopic gripper arm (58, 59) and on a turntable (60) by 180 ° Is arranged pivotable on both sides. 7. Device according to one of claims 1 to 6, characterized in that the manipulator (7) in Aligned coaxially to the reversible pusher furnace (1) and the holding chamber (6) or to the side of the latter is arranged. 8. Device according to one of claims 1 to 7, characterized in that below the holding chamber (6) a quenching bath is arranged, which in particular consists of two optionally with oil and Water-filled containers (48, 49) and out of the holding chamber (6) via one therein arranged tilting device (28) and a chute (50) can be charged. 9. Apparatus according to claim 8, characterized in that the tilting device (28) with an in the furnace chamber (11) combined retractable pull-out device for the incoming baskets (15) is made up of a push and pull rod (29) that can be pushed back and forth in the longitudinal direction its free end is pivotably articulated in the direction of movement driver (39). 10. The device according to claim 9, characterized in that the driver (39) from the horizontal by weight loading a forward-facing end into a vertical working position is tiltable. 11. The device according to claim 9 and 10, characterized in that the push and pull rod (29) is provided with a guide carriage (41) in the area of its free end. 12. Device according to one of claims 9 to 11, characterized in that the pressure and The pull rod (29) can be actuated by means of a motor-driven chain (43) which, in particular, has a rotatable driver with the push and pull rod (29) is in engagement. 13. Device according to one of claims 9 to 12, characterized in that a piston-cylinder unit is used to actuate the tilting device (28) (31) is provided.