JPH037556Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an engine stop device for an agricultural working machine.

Conventionally, as a safety device for powered agricultural machinery, a torque limiter was installed between the engine and the working machine, and the engine was automatically stopped when the rotational speed of the transmission system passing through the torque limiter fell below a set value. The method is described in Japanese Utility Model Application Publication No. 160432/1983. In addition, there is a means to prevent the safety maintenance function from malfunctioning by not stopping the engine immediately when an overload is detected, but automatically stopping the engine after the overload condition continues for a certain period of time, and , pressure, temperature, and other safety devices are already known.

By the way, in agricultural working machines such as combine harvesters, for example, the amount of waste straw passing through varies from moment to moment during operation, so when conventional means are used to simply automatically stop the engine in the event of overload, it is difficult to stop the operation. Conditions occur frequently, making it impossible to work smoothly, and simply delaying the automatic engine stop when an overload is detected does not allow appropriate control to respond to load fluctuations, leading to unnecessary interruptions in work, or insufficient control. The reality is that safety cannot be guaranteed.

Therefore, the present invention consists of a drive cam on the input shaft side and a driven cam that meshes with this drive cam with a predetermined pressing force. Under normal loads, both cams mesh completely and drive according to the magnitude of overload. a torque limiter configured to change the meshing state of the driven cam with the cam and release the meshing when an overload is applied;
In conjunction with the operating mechanism of the torque limiter, a torque limiter cam is provided that operates the sensor in different ways at normal loads, slightly overloads, and overloads.
A discrimination circuit is provided that discriminates between slightly overloaded and overloaded conditions and determines whether it is possible to continue work or not, and when the judgment result from the above discrimination circuit is that continued work is impossible, fuel is supplied to the engine. Alternatively, by cutting off the power and automatically stopping the engine, it can appropriately respond to load fluctuations specific to agricultural machinery, eliminate unnecessary interruptions in work, further improve work efficiency, and further improve work efficiency. An object of the present invention is to provide an engine stop device for an agricultural working machine that can ensure sufficient safety against loads.

The structure of the present invention will be described with reference to an embodiment shown in the drawings. 1 is a power drive unit of a combine harvester;
a is an input shaft, and 1b is an output shaft. Reference numeral 2 denotes a drive cam derived from the power drive section 1, and a driven cam 3 is engaged with this drive cam 2 with a predetermined pressing force, so that both cams 2 and 3 always rotate in the direction of the arrow. These constitute the torque limiter 4. A contact type sensor (detector) 5 consisting of a micro switch or the like is provided on one side of the case 4' of the torque limiter 4, and the sensor 5 sends an electric signal as the torque limiter cam 6 rotates. The torque limiter cam 6 is interlocked with the operating mechanism of the torque limiter 4 and performs a switching action according to the torque state. In other words, as shown in FIG. 1, under normal load when the driven cam 3 is rotating in a state in which the driven cam 3 is fully engaged with the driving cam 2, the torque limiter cam 6 is operated by the sensor. When the driven cam 3 stands still in a state separated from the torque limiter 4 and a torque slightly exceeding the action starting torque of the torque limiter 4 is applied, the driven cam 3 moves slightly in the axial direction as shown in FIG. If the torques are balanced, the driving cam 2 and the driven cam 3 will rotate together, but in this slightly overloaded state, the torque limiter cam 6 will rotate by a predetermined angle around the pivot shaft 6' as shown in Fig. 4. The sensor 5 is configured to be pressed continuously.

In addition, when an overload occurs, the driven cam 3 moves greatly in the axial direction as shown in Fig. 3, and is disengaged from the drive cam 2, cutting off the transmission of power to the driven cam 3. To repeat, in this state, the torque limiter cam 6 moves repeatedly in the left and right directions in FIG. 4 about the pivot shaft 6', turning the sensor 5 ON and OFF at high speed.

The sensor 5 is designed to emit different sensor signals depending on the normal load, slight overload, and overload applied to the torque limiter 4, and detects the sensor signal to determine whether or not continued work is possible. A discriminating circuit _C1 is provided to determine whether the circuit is in a possible state, and when the result of the determination is that continued work is not possible, the fuel supply or power to the engine (not shown) is cut off and the engine is automatically stopped. It is composed of

FIG. 5 is an example of the above-mentioned discrimination circuit, and the one shown is one in which the discrimination circuit _C1 is integrated into the alarm circuit _C2 .

In the figure, 7 is the battery, 8 is the starter switch, and 9 is the starter switch.
is a warning lamp, and 10 is a horn. 11 is a retriggerable monostable multivibrator (timer device), and this monostable multivibrator 11 is connected to the alarms 9 and 10 of the alarm circuit C ₂ and the sensor 5 described above.
When the sensor 5 is turned on, a pulse is generated from the monostable multivibrator 11, and the horn current and lamp current flow in the monostable multivibrator 11 for a preset time T. There is. 12 is a switching transistor, 13 and 14 are fuses, 15 is a switching transistor, 16 is a relay, and 17 is a relay contact. Reference numeral 18 denotes an engine stop unit which senses when the relay contact 17 is turned off and operates a solenoid 19 to cut off the fuel supply to the engine.

In the above embodiment, a contact type sensor such as a micro switch is used as the sensor 5, but a sensor 5' consisting of a non-contact type magnetic proximity switch as shown in FIGS. However, when using the sensor 5', which consists of such a magnetic proximity switch, the contacts are not exposed, so the contacts may be damaged due to moisture such as threshing wet materials, or due to the adhesion of straw, dirt, etc. In addition to preventing malfunctions, the switch itself has no mechanical parts such as rollers, arms, or springs, so responsiveness is even better. In the figure,
20 is a magnet, 21 is a torque limiter arm, 22
is the drive shaft of the torque limiter arm 21.

Next, the operation of the present invention will be explained. Under normal load conditions, the power from the power drive unit 1 is transmitted to the drive cam 2 and the driven cam 3, and is transmitted to the exhaust wall chain (not shown) via the output shaft 1b (the first
(see figure).

Incidentally, during manual handling work, etc., sometimes a large bundle enters. In such cases, the torque limiter 4 operates only when the large bundle passes through the waste straw chain, and at this time, the torque limiter cam 6
The sensor 5 is turned ON and OFF once in a while, but in this case, the output of the alarm circuit C ₂ will take the operating pattern shown in Figure 6, and the alarm will end in a short time, so the operator should be warned that the load is too large. I can do it. Also, in this state, the discrimination circuit _C1 does not output any output, so the engine continues to rotate.

Next, when the waste straw chain is clogged with waste straw, etc., in other words, when the load is overloaded (see Figure 3), the drive cam 2
The driven cam 3 has come off and the exhaust chain is stopped. In this case, the torque limiter cam 6 repeatedly turns the sensor 5 on and off at high speed, so the output of the alarm circuit _C2 is as shown in Fig. 7. As shown in the operation pattern, the alarm is output continuously and regularly, and the discrimination circuit _C1 senses the above sensor signal and outputs the switching transistor ( _Tr2 )1.
5 and relay 16, and relay contact 17 is activated.
Turn it off. and engine stop unit 18
detects that the relay contact 17 is turned off and drives the solenoid 19 to cut off the fuel supply to the engine, so the engine automatically stops. Therefore, transportation problems such as straw clogging can be quickly dealt with.

On the other hand, if, for example, a large amount of culm is continuously fed into the waste straw chain and the culm is on the verge of being overloaded (see Figures 2 and 4), the torque limiter cam 6
continues to press the sensor 5, so the sensor 5 remains ON continuously, but the output of the alarm circuit _C2 remains ON for a certain period of time set by the monostable multivibrator 11 ( Since the horn 10 and the lamp 9 only emit an alarm for a certain period of time, the operator can tell that the operating condition is on the verge of overload. However, in this case, the torque is balanced and it is still possible to continue the reaping operation, and the discrimination circuit C ₁ does not output an output, but it does, for example, reduce the amount of grain culm supplied in order to reduce the overload. Measures can be taken, such as slowing down the reaping speed of the combine.

As mentioned above, the present invention consists of a drive cam on the input shaft side and a driven cam that meshes with this drive cam with a predetermined pressing force.During normal loads, both cams fully mesh, and depending on the magnitude of overload. A torque limiter is configured such that the engagement state of the driven cam with respect to the drive cam changes, and the engagement is released in the event of an overload. A torque limiter cam is installed that operates the sensor in different ways depending on the time, and depending on the operation mode of the sensor, it can be determined whether it is under normal load, slightly overloaded, or overloaded, and whether it is possible to continue work or not. A discriminating circuit is provided to determine whether the agricultural working machine is in a state of By appropriately responding to load fluctuations unique to
Moreover, the effect of ensuring sufficient safety against excessive loads can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the drive unit, FIG. 2 is a front view showing the state of the drive cam and driven cam at medium load, and FIG. 3 is a front view showing the state of the drive cam and driven cam at overload. Figure 4 is a side view showing the relationship between the torque limiter cam and the sensor, Figure 5 is a discrimination circuit diagram, Figure 6 is a diagram of the output operation pattern when the sensor is turned on once, and Figure 7 is the sensor repeatedly Figure 8 is a diagram of the output operation pattern when the sensor is turned on and off. Figure 8 is a diagram of the output operation pattern when the sensor is in the ON state continuously. Figures 9 and 10 each use a sensor consisting of a non-contact magnetic switch. FIG. 2 is a perspective view of the drive unit and a partially cutaway side view of the torque limiter case in the case of the above-mentioned configuration. In the figure, 1 is a power drive unit, 1a is an input shaft, 1b is an output shaft, 2 is a drive cam, 3 is a driven cam, 4 is a torque limiter, 5 is a sensor, 6 is a torque limiter cam, and _C1 is a discrimination circuit.

Claims (1)

[Scope of utility model registration request] Consists of a drive cam on the input shaft side and a driven cam that meshes with this drive cam with a predetermined pressing force. Under normal loads, both cams mesh completely, and depending on the magnitude of overload, the driven cam engages with the drive cam. A torque limiter configured to be disengaged when the state changes and is overloaded, and a sensor that is linked to the operating mechanism of the torque limiter to operate in different ways at normal loads, slightly overloads, and overloads. A discrimination circuit is installed that operates a torque limiter cam and distinguishes between normal load, slight overload, and overload according to each operating mode of the sensor, and determines whether it is possible to continue work or not. An engine stop device for an agricultural working machine, characterized in that the engine is configured to automatically stop the engine by cutting off fuel supply or power to the engine when the discrimination result by the discrimination circuit indicates that the operation cannot be continued.