JPH02528Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an overload warning device for an agricultural working machine such as a combine harvester.

Conventionally, agricultural working machines such as combines and harvesters have been equipped with torque limiters to cut off the transmission of power to the grain transport section in the event that the grain culms become abnormally stagnant during the grain culm movement route. Further, there is known an overload warning device which is provided with a detection switch linked to the operating mechanism of the torque limiter and which activates an alarm such as a horn or a lamp in the event of an overload.

However, with the overload warning device of this type of conventional agricultural work equipment, the alarm is only issued when there is an overload condition, regardless of the magnitude of the load applied to the torque limiter. Regarding the mode and degree of overload, whether it is okay to continue work with caution even under load, or whether it is overloaded and the machine must be stopped immediately and work interrupted. Not only is this inconvenient for work, but it also makes it impossible to respond appropriately and quickly depending on the type of overload.

Therefore, the present invention uses a torque limiter cam to adapt the detection switch to the load condition, opening and closing the switch only once in the event of a temporary overload, keeping it closed in the event of a slight overload, and repeatedly opening and closing the switch in the event of an overload. and an alarm circuit equipped with a retrigger monostable multivibrator that activates the alarm only once in the case of temporary overload or slight overload, and continuously in the case of overload, depending on the above-mentioned opening and closing modes of the detection switch. By installing this system, during work, when there is a temporary overload condition or a slight overload condition, an alarm is issued only once to call attention to each case, and also to prevent the occurrence of an overload condition. If this happens, a continuous alarm will be issued to ensure that the abnormal state is notified, and the system will be able to detect cases such as a temporary overload such as a temporary large bundle of grain passing through the culm, or when the grain culm supply is slightly higher than normal. Even if the work is slightly overloaded (e.g., by reducing the reaping speed, i.e., reducing the grain culm supply amount), the work can be continued as is, and in other cases, the work can be continued as is, even if the work is slightly overloaded (e.g., by reducing the reaping speed, i.e., by reducing the amount of grain culm supplied). This makes it possible to identify cases in which the machine must be immediately stopped and the work interrupted due to a failure, and in many cases, the work can be continued without interruption, which unnecessarily reduces work efficiency. To provide an overload warning device for an agricultural working machine that can prevent damage to equipment, prevent damage to equipment, and ensure safety by taking appropriate measures immediately in case of overload. That is.

The configuration of the present invention will be described with reference to an embodiment shown in the drawings.

FIG. 1 shows the power transmission mechanism of a combine harvester. Reference numeral 1 denotes a power drive section thereof, and a drive cam 2 extending from the power drive section 1 via a drive camshaft 2' has a driven A driven cam 3, which is provided on the camshaft 2' and is movable in the direction of the shaft 2' under load, is engaged with a predetermined pressing force via a spring _S1 .
Both cams 2 and 3 are designed to mesh and rotate in the direction of the arrow, thereby forming a torque limiter 4. Also, on one side of a case 4' of the torque limiter 4, a detection switch 5 and a torque limiter cam 6 are installed. The torque limiter cams 6 are arranged vertically opposite each other, and are configured to swing about a fulcrum shaft 6' in relation to the axial movement of the driven camshaft 3'. The detection switch 5 is actuated by the swinging of the torque limiter cam 6. To explain this in detail, the driving cam 2 and the driven cam 3 have engaging pawls 2a, 3a similar to a known pawl clutch, and each engaging pawl 2a, 3a has an inclined joint surface 2' on both left and right sides. a, 3'a, and has a mountain shape when viewed from the front. Also, in the case 4' of the torque limiter cam 4, a bevel gear _G1 engaged with the driven camshaft 3'
and bevel gear _G2 fixed to the output shaft are always in mesh. Note that the bevel gear _G1 is fixed in position, and the driven camshaft 3' is slidably engaged with the bevel gear _G1 only in the axial direction.

The power introduced into the power drive unit 1 from the engine side (not shown) via the input shaft 13 is transmitted to the drive camshaft 2', the drive cam 2, the driven cam 3, the driven camshaft 3', and the bevel gears _G1 , G. ₂ to the output shaft 14 to drive working parts not shown, such as grain culm conveying parts such as feed chains and reed removal chains.

On the other hand, on the driven cam shaft 3', a truncated conical inclined cam K having a larger diameter on the side closer to the driven cam 3 is fixed concentrically with the shaft 3', and is attached to the inclined outer peripheral surface of the inclined cam K. The free end side of an operating arm P fixed perpendicularly to the fulcrum shaft 6' of the torque limiter cam 6 is pressed into contact with the fulcrum shaft _6' via a spring S2. With this configuration, when the driven cam 3 and its shaft 3' move in the axial direction due to a load, the inclined cam K also moves in the same direction, and the cam diameter at the contact point of the actuating arm P changes, so that the actuating arm P and the torque Limiter cam shaft 6'
rotates, thereby causing the torque limiter cam 6 to rotate (swing). Note that the driven cam 3 may not be fixed to the shaft 3' as in the illustrated example, but may be slidably fitted to the shaft 3' only in the axial direction. In this case, the shaft 3' itself is not moved, but the torque limiter cam 6 is configured to swing in relation to the movement of the driven cam 3 in the axial direction.

Now, the driving cam 2 and the driven cam 3 that constitute the torque limiter 4 are operated under normal load, for example.
Normal amount of waste culm (grain culm after threshing process) in waste straw chain
As shown in FIG. 1, when the two parts are continuously supplied, the two parts are completely engaged and rotate as shown in FIG. In this state, the torque limiter cam 6 is maintained in a state separated from the detection switch 5, as shown in FIG. 6A, and the detection switch 5 remains in the OFF state.

In addition, in the case of temporary overload, for example, when a large bundle of waste culm is temporarily supplied to a straw removal chain, etc. (after the large bundle of waste culm passes through the straw removal chain, the load returns to the normal load state), The inclined joint surface 3'a of the pawl 3a of the driven cam 3 meshing with the driving cam 2 is connected to the spring S ₁
As shown in FIG. 3, the driven cam 3 moves largely in the direction away from the driving cam 2 (the driven cam shaft 3' and the inclined cam K are also displaced by the same amount). Therefore, the torque limiter cam 6
also rotates from the A state to the B state and then to the C state in FIG. Then, the claw 3a on the driven cam 3 side
The upper surface 3'b is the upper surface 2'b of the claw 2a on the drive cam 2 side.
(The driving cam 2 rides on the claw upper surface 3' of the driven cam 3.)
b), the driving cam 2 of the driven cam 3
Since the meshing with the drive cam 3 is once released, the power transmission is temporarily cut off, but when the overload disappears, the driven cam 3 is pushed back toward the drive cam 2 by the spring _S1 , and the driven cam 3 is brought into mesh again. Therefore, since the torque limiter cam 6 rotates in the opposite direction from the C state to the B state and then to the A state, the detection switch 5 is turned ON and OFF only once in the event of a temporary overload. .

Next, in a slightly overloaded state, for example, when the supply of waste culm to the waste straw chain continues to be slightly higher than usual, the driven cam 3 separates from the drive cam 2 as shown in FIG. (the driven cam shaft 3' and the inclined cam P are also moved and displaced by the same amount), and if the torques are balanced in this half-meshing state, the driving cam 2 and the driven cam 3 rotate together. In this state, the torque limiter cam 6 rotates slightly in the direction of the arrow as shown in FIG. 6B, and the detection switch 5
It is designed to maintain the ON state.

In addition, when overloaded, for example, when the grain culm is clogged in the grain culm transport section, or during manual handling (when the machine is stopped and the grain culm bundle is continuously fed to the feed chain by hand to thresh), In the case of a harvester, only manual handling is required.
(In the case of a combine harvester, the parts that cannot be cut mechanically are cut by hand in advance and then handled later.) In the case where a large bundle of waste culms is continuously fed to the straw removal chain, as shown in Figure 3. As the driven cam 3 moves greatly in the axial direction, the claws 2a of the driving cam 2 and the driven cam 3,
3a ride on each other (disengagement) and repeat the engagement (since the drive cam 2 is constantly rotating, the engagement and disengagement of both cams 2 and 3 are determined by the relationship between the claw shape and the elastic force of the spring _S1 . (times and times), the torque limiter cam 6 swings at high speed, causing the detection switch 5 to repeatedly turn on and off.

FIG. 9 shows an alarm circuit A, in which 7 is a battery, 8 is a main switch, 9 is an alarm lamp, 10 is a horn, and 11 is a retrigger monostable multivibrator constituting a timer. This retrigger monostable multivibrator 1
1 is interposed between the alarm lamp 9 and horn 10 of the alarm circuit A and the detection switch 5;
As shown in the figure and FIG. 12, the detection switch 5
When it is turned on and one trigger t is generated as input S, it operates to continue sending out a signal for a preset time T, and as shown in Figure 11, during that set operation time. retrigger t
When input, the output of the signal is continued. 12 (Tr) is a switching transistor.

Note that agricultural working machines generally have the characteristic that the load on the working part always fluctuates, and therefore, the present invention can be applied to agricultural working machines other than combines and harvesters.

In the device configured as described above, in the normal load state (FIG. 1), the torque limiter cam 6 of the torque limiter 4 switches to the detection switch 5 as described above.
Since the alarm circuit A is kept in a state where it is not turned on (see Fig. 6A), the alarm circuit A does not operate, and therefore no alarm is issued. On the other hand, it is slightly overloaded (Fig. 2)
, the torque limiter cam 6 maintains the ON state of the detection switch 5 (see FIG. 6B), but in this case, as shown in FIG. Since only one trigger is input, one alarm is issued for a preset time T. In addition, if an overload condition occurs and the condition continues (Fig. 3),
Torque limiter cam 6 detects detection switch 5 at high speed.
Since ON and OFF are repeated, as shown in Fig. 11, the retrigger monostable multivibrator 11
will be re-triggered and the alarm will continue to be issued. However, if an overload condition occurs temporarily and is resolved, the detection switch 5 is activated only once.
Since it is only turned on, one trigger t is input as shown in FIG. 10, and the alarm is issued only once.

Therefore, during work, the operator must check whether a warning is given, whether the load is normal, a temporary overload, a slight overload, or an overload. It can be reliably determined by

For this reason, in combine harvesters and harvesters, it is necessary to check whether the amount of grain culm supplied is appropriate and the working conditions are good, or even if it is slightly excessive, it is possible to reduce the amount of grain culm supplied without interrupting the operation. Either the grain culms are stagnant in large quantities and it is necessary to immediately stop the operation and take necessary measures, or even if a large bundle of grain culms has just passed through temporarily and it is left as is. This allows the operator to accurately understand when it is acceptable to overload, minimize work interruptions, and eliminate the inconvenience of unnecessarily decreasing work efficiency.In addition, the operator can immediately take appropriate measures in the event of an overload. This will prevent equipment damage and ensure safety.

In this way, the present invention configures the driven cam provided on the driven cam shaft to be movable in the axial direction by a load,
In a torque limiter that operates a detection switch by swinging a torque limiter cam in relation to the axial movement of a driven cam, the torque limiter cam temporarily operates the detection switch in response to a load condition. When the load is overloaded, it opens and closes only once, and when the load is slightly overloaded, it remains closed continuously.
It is configured to open and close repeatedly when overloaded,
The alarm circuit is equipped with a retrigger monostable multivibrator that activates the alarm only once in the case of temporary overload or slight overload, and continuously in the case of overload, depending on the above-mentioned opening and closing modes of the detection switch. Therefore, during work, when a temporary overload condition occurs or a slight overload condition occurs, an alarm is issued only once each to alert the operator and prevent the overload condition from occurring. If a problem occurs, a continuous alarm will be issued to ensure that the abnormal condition is notified, and even if there is a temporary overload or a slight overload, it will not be enough to interrupt the work. There are cases in which you can continue working as is, and cases in which you have to immediately stop work due to overload.
Operators are able to quickly and reliably identify the type of alarm being issued, which in many cases avoids unnecessary interruptions and reduces work efficiency. Moreover, it is possible to immediately take appropriate measures in the event of an overload, prevent equipment damage, and ensure safety. Extremely effective practical effects can be obtained as a device.

[Brief explanation of the drawing]

The drawings show an embodiment of the overload warning device for agricultural working machines according to the present invention, in which FIG. 1 is a perspective view of a power drive section and a torque limiter section of a combine harvester, and FIGS. 2 and 3 are respectively Fig. 4 is a side view showing the relationship between the torque limiter cam and the detection switch, Fig. 5 is a perspective view of the drive cam, and Fig. 6 shows the operating state of the torque limiter drive cam and driven cam. These are side views showing the positional relationship between the torque limiter cam and the detection switch depending on the mode. Figure A is a side view showing the positional relationship under normal load, Figure B is a side view showing the positional relationship under slightly overload, and Figure C is a side view showing the positional relationship under overload. , FIG. 7 is a schematic diagram showing the operating mechanism of the torque limiter cam, FIG. 8 is a side view showing the relationship between the tilt cam and the operating arm, FIG. 9 is an alarm circuit diagram, and FIG.
11 and 12 are time charts showing the operation mode, respectively. In the figure, 1 is a power drive unit, 2 is a drive cam, 3 is a driven cam, 3' is a driven camshaft, 4 is a torque limiter,
5 is a detection switch, 6 is a torque limiter cam,
6' is the fulcrum shaft of the torque limiter cam, 9 is a warning lamp, 10 is a horn, 11 is a re-trigger monostable multivibrator, 13 is an input shaft, 14 is an output shaft, and A is an alarm circuit.

Claims (1)

[Scope of utility model registration request] A torque limiter in which a driven cam provided on a driven cam shaft is movable in the axial direction by a load, and a detection switch is actuated by swinging the torque limiter cam in relation to the axial movement of the driven cam. The torque limiter cam is configured to cause the detection switch to respond to load conditions, opening and closing only once in the case of a temporary overload, remaining closed in the case of a slight overload, and repeatedly opening and closing the switch in the case of an overload; The alarm circuit is equipped with a retrigger monostable multivibrator that activates the alarm only once in the case of temporary overload or slight overload, and continuously in the case of overload, depending on the above-mentioned opening and closing modes of the detection switch. An overload warning device for agricultural working machines, which is characterized by: