DE2608837A1 - Overload coupling mechanism with driving motor - has circuit responsive to angular displacement between driving and driven part providing signal when slip occurs - Google Patents

Abstract

Overload coupling has a driving rotor (1) supporting a small mark (6) for switching either of a pair of series-connected normally closed sensor relays (7, 8) provided on stationary structure at diametrically opposite points of the rotor. A driven rotor has a large mark (9) extending peripherally to either side of the small mark. The large mark switches either of a pair of normally open sensor relays (10, 11) arranged in parallel with the normally closed relays. In case of slip between two rotors one of the normally open relays is also open, and the resulting signal is used to stop the drive.

Description

Describing

Method with circuit for mechanical overload ~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ hedge or torque control The invention relates a procedure for safeguarding and controlling against overloads, e.g. B. at power and Work machines, especially against operationally not absolutely impossible massive shock loads, which in the form of blocking lead to destruction.

It can be used for lifting and conveying machines and systems can usually only exclude with a limited degree of certainty that a sudden, sudden overload occurs, which can endanger people and machines. Extensive gears upstream of the drive motors are also often used largely damaged; or tapes on conveyor systems can tear, etc.

In order to elastically absorb brief impacts to protect gear wheels, flexible couplings of various types are known. Furthermore, one knows also slip clutches for the same purpose, which also cope with massive overloads of blocking to the extent that they can secure by using the pre-set torque continuously slip through. The electrical protective devices are also in general use against overloads of the electrical drives, which to a limited extent also mechanical Can avert destruction.

For this purpose, the load-dependent increase in current is measured and then switched off or control, although the case of blocking associated with the Effects of the rotational energy cannot be compensated. Furthermore knows one also the ongoing monitoring of the torque it mainly to control and Control purposes, which at the same time include every overload case in the Involves control and helps prevent effects. This happens e.g. fl. means Strain gauges attached to the drive shafts with connected evaluation electronics; usually electronic bridge gauges.

On the one hand, these machine elements and processes are effective Prevention of such dangers is not sufficiently versatile, on the other hand however, such as B. in electronic monitoring, too complex and expensive than can be accepted for most practical applications.

The invention is based on the object of using a method which results in a largely versatile and simple application, as well offers maximum effectiveness against the overload cases that occur and thus as Safety device or can serve as a control for control purposes.

The method according to the invention is based on the fact that a slip clutch known constructions as a fuse element is used in such a way that the both coupling halves 1, 2 after the occurrence of an overload case the preset Do not transmit further torque, therefore shift their position to each other, because the drive-side half 1 slips and thus this position shift circuit-wise can be used for a delimiting signaling.

This is done according to Figs. 1 and 2 and the circuit diagram Fig. 3 in detail as follows: (For reasons of control, the clearer Representation and description and recognition of the logic in the example given electrical or electronic control selected.) The drive side 1 of the slip clutch carries the disc 3, the diameter of which appropriately corresponds to that of the clutch housing. This disk 3 sits on a centering collar and is to the coupling halves 1, 2 mounted so that it can be rotated completely and is mounted on a threaded attachment by means of a nut 4 5, which is led out on the drive-side coupling half 1, against the Flange on drive side pressed on for driving.

This disc 3 is used to accommodate the small switching mark 6, which on the reflex light barrier units 7, 8 (integrated transmitter and receiver), briefly called sensors 7, 8, work.

A switch mark can e.g. 13. through the most diverse possible reflectivity be given from the coloring against their surroundings and the two signal states corresponding to "light" or "dark", to the receiver by means of the emitted light spot reflect.

The large switching mark 9 is opposite in the same way applied to the housing part of the output side 2 and not in their position movable. It works accordingly on the sensors 10, 11 assigned to it. The two pairs of sensors 7, 10 and 8, 11 are optimally offset 1800 to one another on the circumference arranged. The large switching mark 9 must be smaller than 1800 for functional reasons. so that they do not simultaneously cover both associated sensors 10, 11 and their Can switch outputs.

The small switching mark 6 only requires a size that is sufficient under unfavorable conditions, e.g. fl. at maximum speed still safely the output the associated sensors 7, 8 to switch.

In order to function properly, the disk 3 must have the small switching mark 6 are placed within the scope of the large switching mark 9 and with the mother 4 be determined to take away; according to Fig. 1.

As a result, one remains during trouble-free operation, e.g. B. on the "on button" in the circuit Figure 3 made self-holding circuit received, since the opening of the sensors 7, 8 (switch outputs), actuated by the small switch mark 6, each from the closing of sensors 10, 11 (switch outputs), actuated by the large switch mark 9, is previously bridged in parallel.

In the event of an overload and thus a malfunction, the rushes due to slipping Drive side 1 ahead of the output side 2 with the coupling half attached to it 1 and the disk 3, which bears the small switching mark 6. Now the self-holding separated by opening the sensors 7, 8 according to the circuit illustration 3 and thus a signal closed circuit is switched because the small switching mark 6 has moved out of the circumference of the large switching mark 9 and not a parallel one The bridging takes place more. The signal circuit for its part can now be an electromagnetic one Switch the clutch or brake or other electromagnetic protection elements.

The second pair of sensors 7, 10 or 8, 11 offset by 180 required here to enable the interfering signaling if in the case of the Blocking no more rotation of the output side 1 takes place and therefore the large one Switching mark 9 can come to rest in front of one of the two associated sensors 10, 11 and keeps the output switched.

However, the drive side 1, which continues to run through, with the small one Switching mark 6 brings the interfering signal generation in each case by the next one The associated sensor (switch output) 7 or 8 opens, its (over-bridging) sensor 10 or 11 can therefore not be covered by the large switching mark 9. This Case can e.g. B. often at low speeds and small rotating masses or in the Start-up phase of a machine or system occur.

So it is for the perfect functioning of the procedure It is very important that the small switching mark 6 is on the driven side and not on the load side, which can block under certain circumstances.

With the length of the marks to each other, which can also be adjustable can also determine the sensitivity of the interference signal to certain criteria to change. Instead of the arrangement shown in the example using reflex light barriers, can also use simple roller tappet switches at correspondingly lower speeds used instead of the switching marks on analogue switching tracks or switching cams run.

For applications at high speeds, it is advisable to the sensor switch outputs contactless as transistor switches and more compatible Electronics for a subsequent control to be carried out.

After a false signal has been triggered, as well as possibly required by the application Eliminating the source of the error, the nut 4 is loosened in order to be ready for operation again and the disk 3 with the small switching mark 6 again within the circumferential area adjusted to the large switching mark 9 and tightened the nut 4 again. Maybe one The disadvantage to be seen here for the application of the method is, however, insignificant and the handling can be carried out by technical support staff due to the simplicity.

In addition, the predominant use cases are the Triggering of a safety process which is not a continuously recurring operation and should generally only occur relatively rarely.

Furthermore, from certain points of view, this is at least necessary Elimination of sources of error, in this handling also an additional safety precaution to see.

Claims (5)

Claims 1. Method with circuit for mechanical overload protection or torque control, characterized in that on a slip clutch the drive half (i) has a small switching mark (6) that can be adjusted against the circumference and on the output half (2) a large switching mark (9) is attached, which two pairs of sensors, offset by 1800 if possible, and assigned to these switching marks Operate (7, 10) and (8, 11) while turning so that the circuit is moderate sensors (7, 8) lying in a "row", actuated by the small switching mark (6), work as normally closed contacts and meanwhile from the respectively parallel-lying Sensors (10, 11), actuated by the large switch mark (9), must be bridged beforehand, so that the switching effects of opening one of the sensor output switches (7, 8), only take place and can be used in a control system if as a result a slipping through of the drive side (1) against the output side (2) the The small switching mark (6) carried along by the output side (1) moves in the direction of rotation rotates relatively out of the circumference or working area of the large switching mark (9). 2. Procedure and circuit for mechanical overload protection and Torque control according to Ansprltch 1., characterized in that the method in connection with the circuit shown in the example, the logic it contains and this switching logic also pneumatically, hydraulically or with each other medium to work analogously. able. 3. Procedure and circuit for mechanical overload protection and Torque control according to claim 1 and 2, characterized in that for the disk (3) with the small switching mark (6) inside the circumference of the large switching mark (9) must be readjusted manually. 4. Procedure and circuit for mechanical overload protection and Torque control according to claims 1, 2 and 3, characterized in that that on the circumference of the disc (3) and opposite on the circumference of the housing Identical pairs of numbers are applied as markings on the output side (2), which the Rinstell the disc (3) with the small switching mark (6) even with mostly concealed installation of the safety slip clutch in any position, by setting the same numbers opposite each other without changing the Needs to see circumferential positions of the switching marks to each other. 5. Procedure and circuit for mechanical overload protection and Torque control according to claims 1 to 4, characterized in that that the small switching mark (6) as well as the large switching mark (9) are adjustable can be within the limits imposed by the described effectiveness of the procedure lead to a desired adjustment of the switching sensitivity.