EP0574694B1 - Cutting tool for a machine for comminution of pasty substances - Google Patents

Description

The invention relates to a cutting set of a very fine comminution machine for doughy masses, in particular meat masses, with at least two rotating cutter heads, each individually assigned to a fixed perforated plate and arranged on a cutter shaft driven by a motor, and with an adjusting device for adjusting the axial position of the cutter heads relative to the pertaining perforated plates.

To achieve a good cutting effect, the cutting set must be set so that both cutter heads lie evenly on the perforated disks or are at a defined, even distance from the perforated disks. Wear and regrinding of the perforated plates and the knife blades can always result in different distances between the cutter head and the perforated plate.

EP-A-0 249 840 discloses a fine grinding machine of the generic type, on which two cutter heads arranged opposite a respective perforated plate can be adjusted together by displacing the cutter shaft in the axial direction. The different distances between the respective cutter head and the associated perforated plate resulting from different thicknesses of the perforated plates and from grinding the knife blades have previously been compensated for by an adjusting nut outside the machine in an adjusting device. After installing the cutting set in the machine, the distance from the cutter head to the perforated plate must be adjusted.

The known machine only allows a joint adjustment of the axial position of the cutter heads which is dependent on the load on the drive motor by means of adjustment of the cutter shaft.

During the shredding process, it may be necessary to adjust the position of the cutter heads depending on the temperature of the meat mass to be shredded or shredded. A temperature change occurs when the distance between the cutter head and the respective perforated plate is changed. A small distance between cutter head and perforated plate means high throughput and low Temperature increase, while a larger distance between cutter head and perforated plate results in a smaller throughput and a larger temperature increase.

It is consequently an object of the invention to provide a cutting set for a very fine comminution machine which can be adapted better and more extensively than before to changing operating conditions.

This task is solved according to the requirements.

According to an essential aspect of the invention, the adjusting device has separate adjusting elements for each cutter head, which adjust the axial positions of the cutter heads separately and automatically, depending on at least one operating parameter.

The main advantage of this is that the axial positions of the cutter heads in relation to the fixed perforated plates assigned to them can be carried out automatically in the machine even after the cutting set has been installed in the machine.

• Für jeden Messerkopf je eine koaxiale, um die Messerwelle angeordnete Verstellbüchse,
• je ein Axiallager für jede Verstellbüchse,
• mindestens eine Verstellspindel pro Verstellbüchse, und
• einen Verstellmotor für jede Verstellspindel, der mit den Verstellspindeln über ein Verstellgetriebe verbunden ist, wobei je nach Drehrichtung des Messereinstellmotors der Abstand zwischen dem jeweiligen Messerkopf und der zugehörigen Lochplatte vergrößert oder verkleinert wird.

The adjustment device preferably has:

• For each cutter head there is a coaxial adjustment sleeve arranged around the cutter shaft,
• one axial bearing for each adjusting bush,
• at least one adjusting spindle per adjusting sleeve, and
• an adjustment motor for each adjustment spindle, which is connected to the adjustment spindles via an adjustment gear, the distance between the respective cutter head and the associated perforated plate being increased or decreased depending on the direction of rotation of the blade adjustment motor.

A preferred embodiment has two cutter heads, two perforated plates and two adjusting bushes.

Preferably, two adjusting spindles running in parallel are provided per adjusting bushing, which bring about a more favorable force transmission to the adjusting bushes than would be possible with only one adjusting spindle.

In order to achieve a flexible and at the same time defined position adjustment of the cutter heads, the adjustment gear is equipped with a sliding hub with adjustable torque.

The adjustment gear is preferably designed as a toothed belt gear.

If the cutter heads fit snugly on the perforated plates assigned to them, the action of the knife adjustment motor should be stopped so that the slide hub is not subjected to excessive stress.

For this purpose, a rotary pulse generator is preferably connected to the adjusting spindles in a rotationally fixed manner, and the knife setting motor is switched off at the moment when the rotary pulse generator no longer emits pulses.

In order to achieve an exact adjustment of the cutter heads to the perforated plate, it is also necessary that the adjustment device has no axial play.

For this reason, the adjusting device preferably has an axial play compensation device which engages on bearing flanges of the adjusting bush axial bearings. The latter preferably has a spring assembly that generates a preload between a housing of the microfinishing machine and the bearing flanges of the axial bearings of the adjusting bushes.

Furthermore, the adjustment device preferably has a position encoder which indicates the axial position of the cutter heads, and an electronic control device is provided for controlling the adjustment device and is connected at least to the knife adjustment motor, the rotary pulse encoder and the travel encoder.

If, as preferred, the temperature in the outlet of the micro-shredder is recorded as an operating parameter for actuating the adjusting device, a temperature sensor is provided at least in the outlet area of the micro-shredder and the electronic control device is set up so that it depends on the distance between the cutter heads and the associated perforated plates of at least the temperature in the outlet area.

Another temperature sensor can preferably also detect the temperature in the inlet area, so that the difference between outlet temperature and inlet temperature can be determined by the electronic control device as an operating parameter for actuating the adjusting device.

Fig. 1

Eine teilweise aufgebrochene Schnittdarstellung einer Feinstzerkleinerungsmaschine im Aufriß mit dem erfindungsgemäßen Schneidsatz;

Fig. 2

ein bei dem in Fig. 1 dargestellten Schneidsatz verwendetes Zahnriemen-Verstellgetriebe; und

Fig. 3

eine vergrößerte Schnittdarstellung einer beim erfindungsgemäßen Schneidsatz gemäß Fig. 1 bevorzugt eingesetzten Axialspiel-Ausgleichsvorrichtung.

Further features, the mode of operation and advantages of a preferred embodiment of the invention are described in more detail below with reference to the drawing. Show it:

Fig. 1

A partially broken sectional view of a very fine comminution machine in elevation with the cutting set according to the invention;

Fig. 2

a toothed belt adjusting mechanism used in the cutting set shown in FIG. 1; and

Fig. 3

an enlarged sectional view of an axial play compensation device preferably used in the cutting set according to the invention according to FIG. 1.

1, a knife shaft 5 coupled to a motor shaft is located within a machine housing 9. The motor shaft is driven by a knife motor 6 (not shown).

According to the invention, the cutting set has a first cutter head 1 and a second cutter head 2, which, driven by the cutter shaft 5, are each arranged opposite fixed perforated plates 3 and 4. Furthermore, the cutting set for adjusting the cutter heads 1 and 2 has two adjusting bushes 11, 12 which are connected to the cutter shaft in a rotationally fixed manner but are axially displaceable coaxially to the cutter shaft 5. The adjusting bushes 11, 12 are each mounted in axial bearings 14 and 13, which are each held in bearing flanges 32 and 31. Two adjusting spindles 17, 18 jointly engage on the bearing flange 31 and two adjusting spindles 15, 16 jointly engage on the bearing flange 32. The adjustment spindles are driven by a knife adjustment motor 20 via an adjustment gear described below with reference to FIG. 2 for adjusting the cutting set.

Furthermore, the cutter heads 1, 2 and their associated fixed perforated plates 3, 4 are surrounded all around by an annular holder 48 which holds two baffle rings 46 and 47 serving as wipers. The cutter heads 1 and 2 are fixed on the adjusting bushes 11 and 12 by clamping nuts 42 and 43, respectively. By means of a clamping bracket 45, an outlet housing 8 is clamped onto the end of the cutting set opposite the first perforated disk 3 and tightened with a handwheel 44. A temperature sensor 41 is attached to an extension piece of the outlet housing 8 and measures the temperature of the outgoing, comminuted material to be cut. On the wall of an inlet housing 7, a further temperature sensor 40 is provided, which detects the temperature of the incoming material to be cut.

In order to achieve a very fine degree of comminution of the material to be cut, the first perforated plate 4 seen in the flow direction of the latter is coarse and the second perforated plate 3 is finely perforated. The thicknesses of the two perforated plates 3 and 4 can be different due to different wear or due to design. In Fig. 1, the second, fine perforated plate 3 is thinner than the first, rough perforated plate 4. Due to the inventive separate adjustability of the cutter heads 1 and 2, such a different thickness of the perforated plate can be automatically taken into account when adjusting the cutter heads.

2, the preferably used toothed belt transmission 21 is shown schematically. The four adjusting spindles 15 - 18 are each driven by the knife setting motor 20 via toothed belts 24, 26 and 27. The spindle axes are provided with slip hubs 22, not shown, which slip when the respective cutter head hits the associated perforated plate. As a result, a toothed belt 25, which is connected to the spindle axis 18 and drives a rotary pulse generator 23, comes to a standstill, whereupon the rotary pulse generator 23 no longer generates any pulses.

The setting procedure for the axial position of the knife blades is described in more detail below. A control device (not shown) is provided for controlling the adjustment device and is connected at least to the knife setting motor 20, the rotary pulse generator 23 and the temperature guides 40, 41 in the inlet and outlet housings 7 and 8. Furthermore, the axial actual position of the cutter heads 1 and 2 are provided, which is also connected to the control device. Furthermore, the control device has a keyboard, also not shown, for entering control commands.

The setting process is as follows:

Pressing a specific key on the keyboard initiates the setting. The knife setting motor is started. The four adjusting spindles 15-18 are driven via the slip hubs, which adjust the bearing flanges 32 and 31 with the adjusting bushes 11, 12 until the cutter heads 1, 2 abut the perforated plates 3, 4. As soon as a cutter head rests on the perforated plate and thus blocks the drive, the corresponding slip hub 22 slips. The second adjustment unit continues to run until the other cutter head also lies against the assigned perforated plate and the second slip hub slips. The rotary pulse generator 23 then no longer outputs pulses, the knife setting motor 20 switches off.

The control device takes this position, in which the distances between the two cutter heads 1, 2 from the associated perforated plates 3, 4 are assumed to be zero, and then moves to the preselected knife distance by reversing the direction of rotation of the knife setting motor.

The keyboard of the control device also has separate keys for forward and reverse operation of the knife setting motor.

A display unit then shows the knife distance. If the knives were still in the working position, the knife distance is displayed immediately. The keyboard has separate forward / backward keys for the knife setting motor. By pressing one of the two buttons, the knife spacing can also be changed by hand while the fine grinding machine is in operation.

The preferred temperature-dependent control of the position of the cutter heads is as follows:

When the meat is chopped, the aim is to achieve an outlet temperature that is as uniform as possible. The inlet temperature can be determined by the temperature sensor 40 in the inlet housing 7 and, in combination with the outlet temperature determined by the temperature sensor 41 in the outlet housing 8, the adjusting device can be actuated in order to automatically increase the distance of the cutter heads 1, 2 from their opposing perforated plates 3, 4 change that the outlet temperature reaches the desired value and then maintains. Of course, only an outlet temperature-dependent regulation of the knife distances can be achieved by detecting the outlet temperature.

It is clear to the person skilled in the art that the operating parameter outlet temperature influencing the knife adjustment is preferably used, but that the adjusting device of the cutting set designed according to the invention also allows other operating parameters, such as loading, due to the electronic control device of the knife motor, degree of fineness of the material to be shredded, throughput, etc. to be used alternatively or additionally for the regulated adjustment of the cutting set.

In order to achieve a precise adjustment of the distances between the cutter heads and the perforated plates, it is necessary that the adjusting device has no axial play and that an axial play compensation device shown in detail in FIG. 3 can absorb axial forces of such a strength that the cutter heads 1 and 2 can keep their set distance despite the back pressure exerted by the material to be cut. For this purpose, the axial play compensation device has four spring assemblies, of which one spring assembly is shown in FIG. 3, which comprises a compression spring 33 acting between the bearing flange 31 for the adjusting bush 12 and the machine housing 9 and one between the bearing flange 32 for the bearing bush 11 and the other bearing flange 31 acting second compression spring 34. The first-mentioned compression spring 33 has an approximately twice as high spring constant as the second compression spring 34, which is, for example, approximately 400 Newtons. Furthermore, the axial bearings 13 and 14 are designed as double angular contact ball bearings to absorb the axial forces.

The cutting set according to the invention and the adjusting device designed according to the invention have, in the preferred embodiment, two cutter heads and two perforated plates lying opposite them, the axial adjustment of the cutter heads being able to be effected separately by means of two adjusting bushes connected to the cutter shaft in a rotationally fixed manner. Of course, the invention is The cutting set is not limited to two cutting heads, but can also have a larger number of cutter heads and perforated plates. The cutting set according to the invention is preferably used in a very fine comminution machine with an essentially horizontal knife shaft. Instead, the principle of the invention can also be applied to an obliquely lying or vertical knife shaft.

Although the preferred adjustment of the adjusting bushes is carried out by a spindle drive which includes the adjusting spindles 15-18, the position of the cutter heads can also be adjusted by means of pneumatic and / or hydraulic adjusting drives via the adjusting bushes.

Claims (13)

1. Set of cutters for a fine pulverisation machine for doughy masses, in particular meat masses, with at least two rotating blade heads (1,2) which are allocated, individually, to a stationary perforated plate (3,4) in each case and are disposed on a blade driving shaft (5) driven by a motor (6) and an adjustment device (10) for adjusting the axial position of the blade heads (1,2) in relation to the perforated plates (3,4) which are associated therewith in each case, characterised in that the adjustment device (10) comprises separate setting members (11,12,13,14,15,16,17,18) allocated to each blade head (1,2) and in that the axial position of the cutter heads (1,2) can be set separately by means of the setting members (11,12,13,14,15,16,17,18).
2. Set of cutters according to Claim 1, characterised in that the setting members (11 - 18) set the axial position of the blade heads (1,2) automatically and in dependence on at least one operating parameter of the fine pulverisation machine.
3. Set of cutters according to Claim 1 or 2, characterised in that the adjustment device (10) comprises:

   - for each blade head (1,2), a sleeved adjustor (11,12) disposed axially about the blade drive shaft (5);

   - an axial bearing (13,14) for each sleeved adjustor (11,12);

   - at least one adjustment spindle (15,16 and 17, 18) which engages on the axial bearing for the adjustment of the sleeved adjustor (12,11) in each case, and

   - a blade setting motor (20) for driving the adjustment spindles (15 - 18), which is connected to the adjustment spindles via an adjustment gear (21) wherein, depending on the direction of rotation of the blade setting motor (20) the distance between the blade head (1,2) in each case and the associated perforated plate (3,4) is increased or reduced.
4. Set of cutters according to any one of Claims 1 to 3, characterised in that two blade heads (1,2) and two perforated plates (3,4) are disposed axially one below another.
5. Set of cutters according to one or more of Claims 1 to 4, characterised in that two adjustment spindles (15, 16 and 17, 18), extending in parallel, are provided per sleeved adjustor (11,12).
6. Set of cutters according to one or more of Claims 2 to 5, characterised in that the adjustment gearing (21) comprises, per sleeved adjustor, a sliding hub (22) with a settable rotational force.
7. Set of cutters according to one or more of Claims 2 to 6, characterised in that the adjustment gear (21) is a toothed belt gear.
8. Set of cutters according to one or more of Claims 2 to 7, characterised in that a rotational pulse generator (23) is connected in manner secure against rotation to the adjustment spindles and the blade setting motor is switched off if the rotational pulse generator (23) does not generate any pulses.
9. Set of cutters according to one or more of the preceding Claims, characterised in that the adjustment device (10) comprises an axial play equalisation device (30) which engages on bearing flanges (31,32) of the sleeved adjustor axial bearings (13,14).
10. Set of cutters according to Claim 9, characterised in that the axial play equalisation device (30) comprises a spring assembly (33,34) which generates a pretensioning between a machine casing (9) of the fine pulverisation machine and the bearing flanges (31,32) of the axial bearings (14,13) of the sleeved adjustors (11,12).
11. Set of cutters according to one or more of the preceding Claims, characterised in that a distance indicator, which indicates the axial positions of the cutter heads (1,2), is provided.
12. Set of cutters according to one or more of the preceding Claims, characterised in that an electronic control device is provided for controlling the adjustment device (10) and is connected at least to the blade setting motor (20), the rotational pulse generator (23) and the distance indicator.
13. Set of cutters according to one or more of the preceding Claims, characterised in that a thermometer probe (41) is provided at least in an outlet area (8) of the fine pulverisation machine, and in that the electronic control device is arranged such that it sets the axial position of the blade heads (1,2) in the outlet area (8) in a manner dependent on at least the temperature measured by the thermometer probe (41).

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