DE3010416A1 - Measuring system for blades gap of harvesting machine - uses non-contact acoustic or optical sensor located underneath fixed blade - Google Patents

Abstract

A crop-harvesting machine is equipped with a system for continuous measurement of the working gap between the moving blades and a fixed blade. The system provides a facility for early correction if the gap lies outside of specified limits. The stalks of the crop are drawn through guide rollers (5a,5b,5c) that are fitted with prongs. A final set of rollers (6a,6b) compress the stalks and direct them against a fixed blade (3) and a moving set of blades mounted on a rotor (2). The gap between the fixed and moving set of blades is monitored by either an acoustic or optical non-contact sensor (1) that is mounted directly underneath the fixed blade.

Description

Device for monitoring the distance between the cutting edges

Harvesting machines The invention relates to a device for monitoring the distance between corresponding cutting edges on knives of harvesting machines, especially forage harvesters.

For the best possible preparation of the crop and production the lowest possible cutting forces, it is necessary that with forage harvesters the distance between the cutting edges of the corresponding knives as possible is kept low.

Wear and tear increases the distance between the corresponding cutting edges during operation. This has to As a result, the operator controls the distance and readjusts it from time to time got to. Both the control and the necessary readjustment are omitted in many cases. This leads to a reduction in throughput.

The invention is based on the object of providing a device of the initially described mentioned type to create with the help of the distance between the cutting of interacting knives can be constantly monitored, so that the operating personnel is made aware of the conditions in the cutting unit at an early stage, in those on readjustment of the knife, for example because of grinding or that the distance is too great.

This object is achieved according to the invention in that at least a sensor arranged in the harvesting machine is provided which determines the distance the cutting edge of a movable knife measures from the given reference point.

It has proven to be expedient for the measuring sensor to be stationary is arranged. The cutting edge of a stationary one can be the preferred place of attachment Select counter knife.

In a preferred embodiment, an induction proximity sensor is used as the measuring sensor intended.

Finally, it is also proposed according to the invention that when exceeded A signal is generated after a predetermined limit value for the distance.

In the case of the high-frequency induction proximity sensors known per se eddy currents are generated when electrically conductive objects are approached, which change the electrical properties of an excitation coil of the sensor or a phase shift of the measuring current resp.

cause of the measuring voltage. With such a probe, which can give a signal or a switching pulse, the response point can be very precise can be set. It is possible with a stationary attachment of the sensor to scan very small deviations from the specified cutting edge distance and at If a limit value is exceeded, a pulse is triggered which sends a signal to the operating personnel generated for a necessary correction of the knife setting.

So far, the use of proximity sensors in harvesting machines is for the task described above is not known.

The advantages of such a solution are in particular one simple checking of important operating values of the harvesting machine with the possibility of correct the settings immediately if necessary. This way the performance and Cutting losses of the harvesting machine are always kept very low.

A preferred embodiment of the invention is illustrated below described in detail in the drawing. They show: FIG. 1 - a longitudinal section through the intake and knife area of a forage harvester, Figure 2 - the conditions in Knife area in an enlarged view.

The forage harvester has the usual feed rollers 5a, 5b and 5c, which promote the picked crop to the press rollers 6a and 6b. Behind the A stationary knife 3 with a cutting edge 3a is provided for the press rolls. The fixed one Knife 3 extends parallel to the axis of rotation 7 of the knife drum 8, which on has its circumference distributed rotating knife 2, one after the other with their cutting edges 2a run off the cutting edges 3a of the stationary knife 3.

The sensor 1 is attached to the stationary knife 3 below it.

The sensor 1 is set so that when it exceeds a predetermined limit value for the distance a between the cutting edges 3a and 2a a signal caused. This can be, for example, an acoustic or optical signal. It is also possible to use this signal to switch off the forage harvester to take advantage of.

L e r s e i t e

Claims (5)

Claims: Device for monitoring the distance between one another Corresponding cutting edges on the knives of harvesting machines, especially forage harvesters, d u r c h g e k e n n -z e i c h n e t, there! 3 at least one in the harvesting machine arranged sensor (1) is voreshen the distance (2a) of a movable Measures knife (2) from a predetermined reference point. 2. Apparatus according to claim 1, d a d u r c h g e k e n n -z e i c h n e t that the measuring sensor (1) is arranged in a stationary manner 3. Device according to claim 1 or 2 ', which means that the sensor (1) denotes the Distance (a) from the cutting edge (3a) of a stationary counter knife (3) measures. 4. Device according to one or more of claims 1 to 3, d a it is indicated that the sensor is an induction proximity sensor is. 5. Device according to one or more of claims 1 to 4, d a d u r c h e k e n n n z e i c h n e t that when a predetermined value is exceeded Limit value for the distance a signal is generated.