DE3032514A1 - Reversing pusher furnace with three parallel tracks - for goods in baskets charged and discharged at same end - Google Patents

Abstract

Furnace heat treats small items held in baskets which travel intermittently along three parallel tracks in the enclosed furnace. Baskets filled with the items at a filling station are moved away along the two outer tracks at whose far end they are alternately transferred to the central track, along which they move back to the end of the furnace where the filling occurred. At this end of the furnace the central track has an enclosed discharge station at which the returning baskets, now filled with heated items, automatically tip the items into a quenching bath immediately below the discharge station. As compared with similar known furnaces but with discharge at the other end from loading, all three tracks are used for heat treatment, which increases efficiency and enables a shorter furnace to be used. The atmos. in the furnace is more stable.

Description

Reversible pusher furnace

The invention relates to a reversible pusher furnace for the heat treatment of Small parts with three arranged side by side in a closed furnace chamber Slideways for the intermittent feed of lined up baskets, with one on both sides in the area of the two ends of the slideways provided deflection device for translation individual baskets from one slide to another as well as with a filling station and one aligned with the middle slide and gas-tight to the furnace chamber connected unloading station, into which the filled baskets can be inserted automatically and can be emptied into a quenching bath via a tilting device.

From DE-OS 28 04 338 a reversible pusher furnace with these features known, in which the filling station at the end of the remote from the unloading station Furnace chamber is arranged and thus one of the slideways for the return transport of the emptied Is reserved for baskets. As a result, only 2/3 of the technical furnace capacity is used, which has a detrimental effect on production output and thus on profitability of such a furnace.

The invention is based on the object of the production output a reversible pusher furnace of the generic type with at least constant thermal To increase conditions with the simplest possible means.

The object is achieved according to the invention in that the flushing station is arranged at the same end of the furnace chamber as the unloading station.

In this way, the technical furnace capacity is maximized achieved, since now all three slideways at the same time for heat treatment the workpieces can be used.

The heat treatment time allotted for the small parts increases thus theoretically by the throughput time for one furnace length compared to the known furnace, so that the length of the furnace chamber is shortened under the same thermal conditions.

Finally, the one-sided arrangement of the filling station and has an effect Unloading station also stabilizes the furnace atmosphere when the Inner door to the unloading station less due to the ingress of oil and / or water vapors being affected. Thanks to the new arrangement of filling and unloading stations on one The furnace side and gas ducting muffles between the transport tracks also results from the The advantage that the entire furnace is divided into a heating zone, carburizing zone and diffusion zone can be divided.

According to a preferred proposal of the invention is the filling station Arranged above the unloading station and with it through a loading door connected so that there is only one door opening to the furnace chamber, whereby the influence of the furnace atmosphere from the outside is reduced to a minimum a uniform temperature distribution in the furnace is achieved.

The furnace atmosphere can finally after a further suggestion of the invention are best used when the middle slide is used for return transport of the filled baskets is intended for the unloading station.

For the continuous operation of the furnace, it is useful if the unloading station with a retractable pull-out device for the incoming baskets is provided, which can be pushed back and forth from a longitudinal direction Push and pull rod with a pivotable at its free end in the direction of movement hinged driver exists.

The driver is preferably out of the horizontal as a result of weight loading its forward-facing end can be tilted into a vertical working position, to automatically detect the individual baskets.

To ensure safe guidance even at higher working speeds to ensure the pull-out device, it is also advantageous if the pressure and the pull rod is provided with a guide carriage in the area of its free end is.

The push and pull rod is preferably by means of a motor-driven one The chain can be operated via a rotatable driver with the push and pull rod is engaged.

To further reduce the downtime of the furnace during unloading, can according to a preferred embodiment, the pull and push rod together with the tilting device be rotatable, wherein a Piston-cylinder unit is provided, which has racks on the pressure and Pull rod attached pinions engaged.

The shape of the furnace chamber can be designed to be particularly favorable in terms of radiation if, according to a further proposal of the invention, the heating of the furnace chamber provided jet pipes are arranged on both sides of the middle slide.

However, the nozzles can also be attached to the respective outer sides of the be arranged on both outer conductor tracks, with a maximization of the Can reach furnace temperature when each slide is surrounded on both sides by radiant tubes is.

Several exemplary embodiments of the invention are based on the following the drawings explained in more detail. 1 shows a sectional view of a reversible pusher furnace according to the invention in a schematic representation along the line I-I, Fig. 2 a Sectional view along the line II-II according to FIG. 1, FIG. 3 along a sectional view the line III-III according to Fig. 2, 4 shows a further embodiment of the reversible pusher furnace according to the invention in a sectional view according to FIG. 3, and FIG. 5 shows a further embodiment of the reversible pusher furnace according to the invention in a sectional view according to Fig. 4.

The reversible pusher furnace shown in FIGS. 1 to 3 usually has a Housing 10 made of refractory material with a furnace chamber 11 formed vault in which on one level three slideways 12, 13, 14 made of ceramic Material are arranged side by side. The slideways 12, 13, 14, the end are connected to one another via appropriately shaped connecting pieces, serve the intermittent advancement of lined up baskets 15, which are to be heat treated with the Are well filled. The middle slide 13 is preferably to protect the load from direct and excessive heat from a muffle 16 made of refractory Surrounding material. Openings 17 are formed in the ceiling area of the muffle 16, which together with the fans 18 arranged above it for a uniform Ensure that the furnace atmosphere is circulated. The furnace chamber 11 is heated at the same time Help of jet pipes 19, through which the fire and smoke gases sweep and the in this embodiment, preferably on both sides of each slide in the longitudinal direction 12, 13, 14 extend.

The baskets 15 are advanced pneumatically or hydraulically operated piston-cylinder units 20, 21, 22, which at the front ends arranged outside the housing 10 and each with one of the slideways 12, 13, 14 are aligned. The free piston ends of the units, designed as slides 23 engage in the furnace chamber 11. At the level of the ends of the slideways are also on the long sides outside of the housing 10 in pairs and opposite one another Deflection devices 24 each consisting of a piston-cylinder unit intended. The free piston ends of these units are also designed as slides 25 and engage laterally in the oven chamber 11 to the individual baskets in a still descriptive way to move from one slideway to another.

On the end face of the housing facing away from the piston-cylinder unit 22 10 is an unloading station in extension of the middle slide 13 26, which is gas-tightly connected to the furnace chamber 11 and with this via a hydraulically or pneumatically operated inner door 27 is in connection. The unloading station 26 is provided with a tilting device 28, which is essentially rotatable mounted push and pull rod 29, a tilt mount 30 attached to this and a piston-cylinder unit 31 designed as a drive, which by means of tooth rods 32 and pinion 33 drives the push and pull rod 29 about its longitudinal axis. The tilt mount 30 is equipped with two holding rails 34 parallel at a distance, which are aligned in such a way that they are provided with a correspondingly undercut foot part of the basket 15 interact and a basket retracted into the tilting socket 30 Hold during the tilting movement by substantially 1800. In their horizontal The tilt mount 30 is also set to the receiving position by a locking device 35 locked, the pin 36 in a correspondingly designed longitudinal groove in the pressure and pull rod 29 engages.

The pull and push rod 29 is also part of an extraction device, another drive 37 for the push and pull rod 29 in the longitudinal direction, a guide carriage 41 and a driver 39 at the free end of the printing 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 Kippfasspng 30 aligned horizontally and at right angles to the central axis of the push and pull rod 29 is.

The other end of the driver 39 in relation to the axis of rotation is shown in FIG horizontal position forward and is heavier than the forked end, like this that the driver 39 from the horizontal as a result of the unilateral Weight loading automatically in an essentially vertical working position tilts.

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

The drive 37 intended for the push and pull rod 29 includes a motor 42, which is an endlessly revolving chain below the push and pull rod 43 drives which engage the push and pull rod 29 via a driver stands (see Figure 1).

The pull-out device and the tilting device described above 28 are designed as a unit rotatable about the longitudinal axis.

For this purpose, the two drive members 31 and 42 by means of a Bracket 44 attached to a mounting plate 45, which together with the pressure and pull rod 9 rotates.

The unloading station 26 is also used with a Latafkana 46 Inside the housing 10 in connection, which is located below the inner door 27 and the Levels of the glideways 12 * 13, 14 extends and through the with the driver 39 and the guide carriage 41 provided end of the push and pull rod 29 at least reaches the level of the first basket 15 on the middle slide 13. The height of the running channel 46 is so held. that the driver 39 during the forward movement assumes the position shown in Figure 2, from which he is at the moment in the vertical Working position tilts, in which he below the first basket 15 the free space 47 has reached.

A quenching bath is provided below the unloading station 26 consists of the two containers 48, ag, optionally filled with oil and water, and into which the filled baskets via a chute 50 optional can be emptied.

Above the unloading station 26 is the filling station 51, the via a horizontally displaceable loading door 52 and a funnel-shaped one Loading shaft 53 is connected to the unloading station 26. The shaft opening of the feed chute 53 is thus located at a distance above one basket 15 retracted into tilt mount 30.

The reversible pusher furnace described with reference to FIGS. 1 to 3 works as follows: For the following functional sequence it is assumed that all three Slideways are equipped with filled baskets, as shown in Figure 1. After completion the cycle time, the extractor with the driver 39 into the interior of the The furnace is retracted until the driver reaches its end position below basket A. Has. After opening the inner door 27, the basket A is in front of the tilting socket 30 in a Intermediate position pulled and then the inner door closed again. The extractor the driver then travels a little further forwards to approximately below the inner door in order to then grasp the basket A at the front and completely to pull into the tilt socket until it reaches a cylinder switch attached to the mounting plate 45 54 actuated. By actuating the cylinder switch 54, the locking device 35 controlled, which releases the locking of the tilting device. After the piston rod of the cylinder switch 54 is fully retracted, the piston-cylinder unit resets 31, the push and pull rod 29 in motion and rotates the tilt mount 30 together with basket A, the contents of which, depending on the program, either go to the water or the oil bath is emptied. The tilt socket is then back in its horizontal position Turned back to the starting position and fixed in this position.

Now the basket can be reloaded by opening the loading door 52 of the filling station 51 is opened. After filling will the loading door is closed again and the inner door 27 is opened. The extractor now presses the filled basket A with the help of the push and pull rod 29, which closes is provided for this purpose with a correspondingly designed stop 55 into which Position X. After closing the inner door, the basket A with the help of one of the deflection devices 24 pressed to the Y position. The deflection device is moved back and then also the extractor until it resumes the position shown Has.

Now the piston-cylinder unit 22 presses the basket B onto the middle one Slide 13 until a new basket has taken position A. After that, the in position C basket with the help of the associated deflection device 24 into the Position B pressed, whereupon the deflection device immediately returns to its drawn position Retracts the starting position. This creates space for actuation of the Piston-cylinder unit 20, which now pushes basket A and with it all the baskets, until a basket has returned to position C.

As soon as the cycle time has ended, the next basket is emptied and filled, which then, however, runs through the path specified by the positions X-Z-D-B.

The embodiment shown in Fig. 4 differs from that Reversible pusher furnace according to FIG. 1 initially in a modified shift sequence. How out the arrangement of the baskets for the intermittent feed of the baskets on the two outer ones Slideways 56, 57 provided piston-cylinder units 59, 60 can be seen, are the two outer tracks 56, 57 for transporting the filled baskets to the combined Unloading-filling station 61 is provided. Accordingly, they are fresh in the oven chamber Introduced baskets brought onto the middle slide 58, where they end up over the respective deflection devices alternately on one of the two outer slideways implemented. The extractor the unloading station is accordingly designed at the same time as a piercing device, so that on a additional piston-cylinder unit can be dispensed with. Finally are at In this embodiment, the radiant tubes provided for heating the furnace chamber 62 arranged exclusively on the two outer sides of the outer slideways 56, 57.

The embodiment shown in Fig. 5 again differs 4 only in the arrangement of the jet pipes 63, which are on both sides the middle slide 64 are aligned. The advantage of this arrangement is there essentially in the fact that the furnace chamber in particular in the area of the two outer Slideways 65, 66 have a lower overall height than the usual standard ovens can, which has a cost-saving effect on both construction costs and heating costs affects.

Reference symbols: 10 housing 11 furnace chamber 12, 13, 14 slideways 15 baskets 16 muffle 17 openings 18 fans 19 jet pipes 20, 21, 22 piston-cylinder units 23 Slider 24 Diverting device 25 Slider 26 Unloading station 27 Inner door 28 Tilting device 29 Push and pull rod 30 Tilt mount 31 Piston-cylinder unit 32 Gear racks 33 Pinion 34 Retaining rails 35 Locking device 36 Spigot 37 Drive 39 Carrier 40 Shaft 41 Guide carriage 42 Motor 43 Chain 44 Bracket 45 Mounting plate 46 Runway 47 free space 48, 49 container 50 chute 51 filling station 52 loading door 53 Feed chute 54 Cylinder switch 55 Stop 56,57 outer slideways (Fig. 4) 58 middle slide 59.60 piston-cylinder units 61 unloading-filling station 62 nozzles 63 nozzles (Fig. 5) 64 middle slide 65,66 outer slide Blank page

Claims (12)

P A T E N T A N S P R Ü C H E 1. Reversible pusher furnace wr heat treatment of small parts with three arranged side by side in a closed furnace chamber (11) Slideways (12, 13, 14) for the intermittent feed of lined up baskets (15), with one on both sides in the area of the two ends of the slideways (12, 13, 14) provided deflection device (24) for translating individual baskets (15) from one slide to the other and with a filling station (51) and one with the middle one Slideway (13) aligned and gas-tight connected to the furnace chamber (11) Unloading station (26) into which the filled baskets (15) can be automatically introduced and can be emptied into a quenching bath (48, 49) via a tilting device (28), d a it is indicated that the filling station (51) is at the same end the furnace chamber (11) is arranged like the unloading station (26). 2 Oven according to claim 1, d u r c h g e n n n n z e i c h n e t, that the filling station (51) is arranged above the unloading station (26) and with this is connected by a loading door (52). 3. Oven according to claim 1 or 2, d a d u r c h g e k e n n -z e i ne t that the middle slide (13) for the return transport of the filled baskets (15) is provided for the unloading station (26). 4. Oven according to claim 3, d a d u r c h g e k e n n z e i c h -n e t that the unloading station (26) with a pull-out device that can be retracted into the furnace chamber (11) is provided for the incoming baskets (15), which consist of a longitudinal and pushing and pulling rod (29) with one at its free end in Direction of movement pivotably linked driver (39) consists. 5. Oven according to claim 4, d a d u r c h g e k e n n z e i c h -n e t that the driver (39) from the horizontal due to the weight of his after the front end can be tilted into a vertical working position. 6. Oven according to claim 4 or 5, d a d u r c h g e k e n n -z e i c h n e t that the push and pull rod (29) in the region of its free end with a Guide slide (41) is provided. 7. Oven according to one of claims 4 to 6, d a d u r c h g e k e n n z e i c h n e t that the push and pull rod (29) by means of a motor-driven Chain (43) can be actuated, which via a particularly rotatable driver with the Push and pull rod (29) is engaged. 8. Oven according to one of claims 4 to 7, d a d u r c h g e k e n n z e i c h n e t that the push and pull rod (29) together with the tilting device (28) is rotatable. 9. Oven according to one of claims 4 to 8, d a d u r c h g e k e n n z e i c h n e t that a piston-cylinder unit is used to actuate the tilting device (28) (31) provided is, which has a rack (32) with one on the push and pull rod (29) attached pinion (33) is in engagement. 10. Oven according to one of claims 1 to 9, d a d u r c h g e k e n It is noted that the radiant tubes provided for heating the furnace chamber are arranged on both sides of the middle slide (13). 11. Oven according to one of claims 1 to 10, d a d u r c h g e k e n n z e i c h n e t that the jet pipes on the respective outer sides of the two outer slideways (12, 14) are arranged. 12. Oven according to one of claims 1 to 11, d a d u r c h g e k e It is noted that it is divided into a heating zone, carburizing zone and diffusion zone (Fig. 4) is divided.