JPH0658170U - Emergency stop device for general-purpose engine - Google Patents

Abstract

(57) [Abstract] [Purpose] A float with a magnet that moves up and down according to the displacement of the oil level of the stored oil inside the engine, and a reed switch that is closed by the magnetic force of the magnet when the oil level falls below a specified level are provided. In the emergency stop device for a general-purpose engine, in which the engine operation is stopped in an emergency according to the closing operation of the reed switch, the circuit configuration is greatly simplified to save costs, improve productivity and reliability. . A reed switch L is provided as an opening / closing means of the earth circuit Es for directly grounding the primary side T ₁ of the ignition coil Ig, and the reed switch L withstands a current flowing through the earth circuit Es. Has the capacity to get.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention comprises a magnet-equipped float that moves up and down according to the displacement of the oil level of the stored oil inside the engine, and a lead switch that is closed by the magnetic force of the magnet when the oil level falls below a specified level. The present invention relates to an emergency stop device for a general-purpose engine that prevents engine seizure by stopping the operation of the engine in response to the closing operation.

[0002]

[Prior art]

 As shown in FIG. 3, the above-mentioned conventional apparatus has a circuit board including various elements such as a thyristor, and when the engine is in operation, the operation of the engine E is stopped to an emergency, and a warning is issued only for a short time until the engine is stopped. The control unit (oil alert unit U) that blinks the LED (light emitting diode) lamp is connected to the primary side T of the ignition coil Ig. ₁ The control unit U was connected to a signal generating circuit S including the reed switch L'to send an operation command signal to the control unit U when the oil level is lowered.

[0003]

[Problems to be solved by the device]

 In the above conventional device, since the capacity of the reed switch L'is small, it is indispensable to specially provide the control unit U having a relatively complicated circuit configuration, and the number of parts of the device is increased accordingly, and the cost increases. There was a problem that the reliability of the device was reduced.

The present invention has been proposed in view of the above, and an object thereof is to provide an emergency stop device for a general-purpose engine, which can solve the above problems of the conventional device.

[0005]

[Means for Solving the Problems]

 To achieve the above object, the present invention comprises a float with a magnet that moves up and down according to the displacement of the oil level of the stored oil inside the engine, and a reed switch that is closed by the magnetic force of the magnet when the oil level falls below a specified level. In a general-purpose engine emergency stop device in which the operation of the engine is stopped in response to the closing operation of the reed switch, an earth circuit that directly grounds the primary side of the ignition coil is used as an opening / closing means for the circuit. A reed switch is interposed, and the reed switch has a capacity capable of withstanding a current flowing through the ground circuit.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the general-purpose engine E employs a so-called "magnet generator ignition method" in which self-electromotive force is used as a power source for ignition, and the engine body around the flywheel F that rotates integrally with the crankshaft. An ignition coil Ig that cooperates with a permanent magnet M fixed to the outer peripheral portion of the flywheel F is disposed and fixed therein.

On the primary side T ₁ of the ignition coil Ig (that is, one end on the non-ground side of the primary coil), there is a disconnection circuit C having a primary current interrupting transistor unit TN, and one end is grounded, and the other end is the same. Is connected in parallel with a main earth circuit Em that is grounded. On the other hand, a spark plug P is connected to the secondary side T ₂ of the ignition coil Ig (that is, one end on the non-earth side of the secondary coil). . The main earth circuit Em is provided with a manually operated engine switch Sw capable of opening and closing the circuit. The other ends T ₀ of the primary and secondary coils are grounded.

To start the engine E, first, the engine switch Sw is opened, and a recoil (not shown) is pulled to crank the engine E. According to this cranking, the rotation of the flywheel F (and therefore the permanent magnet M) interlocked with this cranking induces a primary voltage in the primary coil of the ignition coil Ig, and when this voltage is maximum, the current is generated in the transistor unit TN. By shutting off, the high voltage is generated on the side of the secondary coil, which causes the ignition plug P to ignite and the engine E to start operating. Further, when it is desired to stop the running engine E at any time, the engine switch Sw may be closed. As a result, the primary side T ₁ of the ignition coil Ig is directly grounded via the main earth circuit Em. The mutual induction action of the primary and secondary coils, and eventually the ignition action of the spark plug P, cannot be obtained, and the engine E is stopped. The above is the conventional normal ignition structure and operation in a general-purpose engine having no ignition battery.

On the primary side T ₁ of the ignition coil Ig, one end side of a sub-earth circuit Es as the earth circuit of the present invention is connected in parallel with the main earth circuit Em. The other end side of the sub earth circuit Es is grounded, and a normally open reed switch L capable of opening and closing the sub earth circuit Es is interposed in the middle thereof. This reed switch L functions as a direct opening / closing means for the sub-earth circuit Es, and has a sufficient capacity to withstand the current flowing through the sub-earth circuit Es at the time of closing in order to achieve its function. That is, in the illustrated example, the maximum energizing current is 4 A (conventional product is 1 A) and the contact capacity is 150 VA (conventional product is 10 VA), which is larger than the reed switch L'of the conventional product shown in FIG. Has been done.

Further, as shown in FIG. 2, the reed switch L is fixed to the inner wall of the oil pan 1 of the engine E, and is housed and fixed in an oil-tight manner in a switch case 2 in which the stored oil in the oil pan can freely enter and leave. The switch case 2 also accommodates a float 4 with a magnet 3 that can move up and down according to the oil level displacement of the stored oil in the oil pan 1. When the oil level 5 of the stored oil in the oil pan 1 is equal to or higher than the specified level (immediately normal), the magnet 3 of the float 4 is relatively separated from the lead switch L as shown by the chain line in FIG. Therefore, the reed switch L is still open, but when the oil level 5 becomes lower than the specified level, the magnet 3 descends to approach the reed switch L as shown by the solid line in FIG. The switch L is closed and the sub-earth circuit Es can be made conductive.

Next, the operation of the above embodiment will be described. During operation of the engine E, in response to the rotation of the permanent magnet M integrated with the flywheel F, a high voltage is generated on the secondary coil side due to the mutual induction action of the primary coil and the secondary coil in the ignition coil Ig, and a spark plug is generated. Since P is ignited, the operation of the engine E is continued without any trouble. When it is desired to stop the running engine E at any time, the engine switch Sw only has to be closed, and the primary side T ₁ of the ignition coil Ig is directly grounded via the main grounding circuit Em. Also, the mutual induction action of the secondary coil and the ignition action of the spark plug P cannot be obtained, and the engine E is stopped.

By the way, when the amount of oil in the oil pan 1 is sufficient, since the magnet 3 of the float 4 is relatively separated from the reed switch L as described above, the reed switch L remains open and therefore the sub switch L Although the earth circuit Es is also kept in the cutoff state, the operation of the engine E is continued without any trouble, but when the oil level 5 becomes below the specified level due to the decrease in the oil storage amount, as described above, the float 4 As the reed switch L comes to be closed by the magnetic force of the magnet 3 as the magnet 3 descends, the primary side T ₁ of the ignition coil Ig is directly grounded via the sub-grounding circuit Es. Since the mutual induction effect of the above, and eventually the ignition effect of the spark plug P cannot be obtained, the operation of the engine E can be automatically stopped. Further, at that time, even if the primary current flowing through the sub-earth circuit Es directly passes through the reed switch L, since the reed switch L has sufficient capacity as described above, there is no risk of damage.

In this embodiment, there is no special means for warning the emergency stop of the engine as described above. Therefore, when the engine is automatically stopped, a display (for example, a seal) to check the oil amount is displayed. It is desirable to attach it on the engine body, and it is also desirable that one of the inspection items when the engine is stopped is to list "check of oil amount".

[0014]

[Effect of device]

 As described above, according to the present invention, when the oil level of the stored oil inside the engine falls below a specified level, the primary side of the ignition coil is directly grounded via the reed switch to stop the engine operation in an emergency. Since it is possible to do so, the control unit, which was previously required for the emergency stop, can be omitted, which simplifies the circuit configuration and greatly reduces costs, and simplifies the assembly work and improves productivity. To do. In addition, the elimination of extra circuit components reduces the occurrence of failures such as short circuits and disconnections, thus improving the reliability of the device.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an essential part showing an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing an oil level detecting means in an oil pan.

FIG. 3 is a circuit diagram of a main part similar to FIG. 1, showing a conventional example.

[Explanation of symbols]

Es ... Sub-ground circuit as a ground circuit Ig ... Ignition coil L ... Reed switch T ₁ ... Primary side of ignition coil 3 ... Magnet 4 ... Float 5 ... ‥Oil surface

Claims (1)

[Scope of utility model registration request] 1. A float (4) with a magnet (3) that moves up and down according to a displacement of an oil level (5) of stored oil inside an engine (E), and the magnet when the oil level (5) falls below a specified level. Reed switch (L) closed by the magnetic force of (3)
In the emergency stop device for a general-purpose engine, which has an emergency stop device for the engine (E) according to the closing operation of the reed switch (L), the primary side (T ₁ ) of the ignition coil (Ig) is The reed switch (L) is interposed as an opening / closing means of the circuit (Es) in the earth circuit (Es) for directly grounding, and the reed switch (L) can withstand a current flowing through the earth circuit (Es). An emergency stop device for a general-purpose engine, which has a capacity.