JP3139596B2 - Model engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a model engine for a model airplane or the like used for practical purposes such as spraying a fertilizer, a fire extinguisher, and the like in the air and for games.

[0002]

2. Description of the Related Art A model airplane capable of flying in the air is used not only for practical purposes such as spraying fertilizer and fire extinguisher in the air, but also for games.

[0003] In such a flightable model airplane, the driving force of the engine is directly transmitted to the propeller, and the model airplane flies by rotation of the propeller. Therefore, the rotation speed of the propeller needs to be changed by adjusting the output of the engine. For this reason, when flying a model airplane, it is necessary to adjust the output of the engine according to flight conditions such as wind power, wind direction, and the amount of loaded fuel.

In order to adjust the engine output, it is necessary to accurately detect the engine output. However, a model airplane is not usually provided with a means for directly detecting the engine output, and detects the rotation of the propeller shaft or the rotation of the propeller shaft by an optical sensor in a non-contact manner.

[0005]

However, in the method of detecting the engine output based on the rotation sound of the engine, it is necessary to rely on experience, and even a skilled person can detect the engine output with high accuracy. Can not. Therefore, it is not easy to fine-tune the engine output.

[0006] In the method for detecting the rotation of profile peller shaft without contact by the optical sensor always an optical sensor, it is necessary to carry. Since the optical sensor is separate from the model airplane, it is not always easy to carry it. Moreover, without the optical sensor, the engine output cannot be detected.

The present invention has been made to solve such a conventional problem, and its object is to provide an engine speed (output).
It is an object of the present invention to provide a model engine that can accurately detect a model.

[0008]

In the model engine of the present invention, a linear motion of a piston reciprocating in a cylinder is connected to a connecting rod and the connecting rod via a crankpin.
A model engine that is transmitted to an output shaft via a crank and the output shaft is driven to rotate,
At least one end of the crankpin is hollow.
A magnetic material is fitted into the hollow part of the
The position of the magnetic body is detected at the location facing the rotation area.
Magnetic sensor, and the output
Engine output based on engine speed
It is characterized by the following.

[0009]

In the model engine of the present invention, the linear motion of the piston reciprocating in the cylinder is transmitted to the output shaft via the connecting rod and the crank, and when the output shaft rotates, the member rotates integrally with the output shaft. The magnetic body attached to the shaft rotates integrally with the output shaft. Then, the magnetic sensor disposed opposite to the orbital movement area of the magnetic body outputs a pulse signal when the magnetic body approaches, and the rotation speed of the output shaft is detected based on this signal.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a partially cutaway front view of a model airplane engine which is a model engine of the present invention, and FIG. 2 is a side view thereof.

The engine for a model airplane has a cylinder 11 and a piston 12 arranged reciprocally in the cylinder 11. The inside of the cylinder 11 is a horizontal cylindrical crank chamber 1 provided therebelow.
3 communicates with the inside. The inside of the piston 12 is hollow, and a piston pin 14 is installed in the piston 12 in a horizontal state. The piston pin 14 has
The upper end of the connecting rod 15 is attached. Connecting rod 15
Has a lower end extending into the crank chamber 13, and is connected to a tip end of a fan-shaped crank 16 arranged in the crank chamber 13 in the crank chamber 13.

In the crank chamber 13, there is disposed a base end portion 17a of an output shaft 17 which is in a horizontal state perpendicular to the axis of the cylinder 11, and the output shaft 17
The other end portion 17b has a slightly smaller diameter than the base end portion 17a and extends from the crank chamber 13. And
A drive washer 22 that rotates integrally with the output shaft 17 is attached to a tip end portion 17b of the output shaft 17 extending from the crank chamber 13, and a propeller is attached to the drive washer 22.

A central portion of a fan-shaped crank 16 is fitted to a base end portion 17a of the output shaft 17 located in the crank chamber 13 in a fitted state.
Rotates together with the crank 13. The crank chamber 13 is provided with an opening 13a on the side opposite to the side where the output shaft 17 is inserted.
3 a is closed by the cover plate 19. Cover plate 19
Are fixed by cover plate fastening bolts 21 screwed to the four corners of the periphery of the opening 13a.

The fan-shaped crank 16 has a tapered tip end, and a lower end of the connecting rod 15 is rotatably connected by a crank pin 18. Connecting rod 15
Transmits the reciprocating movement of the piston 12 to the crank 16 via the crank pin 18 to rotate the crank 16. The rotation of the crank 16 causes the crank pin 18 to
The orbit moves in the crank chamber 13. Crank pin 18
Has a hollow end facing the cover plate 19 covering the opening 13a of the crank chamber 13, and a cylindrical magnetic body 31 is fitted into the hollow portion.

A wide portion of the crank 16 attached to the lower end of the connecting rod 15 by a crank pin 18 on the opposite side to the tip end of the crank 16 with respect to the axis is sandwiched between the balance weight 1
6a.

A cover plate 19 that covers the opening 13a of the crank chamber 13 extends into the crank chamber 13 by fitting the flange 19a into contact with the periphery of the opening 13a of the crank chamber 13 and fitting into the opening 13a. And a protrusion 19b protruding in a cylindrical shape so as to protrude. Further, cover plate fastening bolts 21 for fixing the cover plate 19 are inserted through the four corners of the flange portion 19a of the cover plate 19, respectively.

A magnetoresistive element 32 as a magnetic sensor is provided outside the crankcase 13 and inside a protrusion 19b of the cover plate 19 fitted into the opening 13a of the crankcase 13.
Is provided. The magneto-resistive element 32 is provided above the top of the orbital movement area of the crank pin 18 orbiting in the crank chamber 13 so as to oppose the cover plate 19 with the cover plate 19 interposed therebetween.
Attached to. The magnetoresistive element 32 has four lead wires 32a.

The resistance of the magnetoresistive element 32 changes when the magnetic body 31 provided in the crankpin 18 approaches, so that the current flowing therethrough changes. Therefore, the magnetoresistive element 32 rotates the magnetic body 3 by one rotation of the crank 16, ie, one rotation of the output shaft 17.
A signal of one pulse is generated by the proximity of one, and a continuous pulse signal is output by continuous rotation of the output shaft 17. As a result, the magneto-resistive element 32 is connected to the output shaft 17.
And outputs a pulse signal corresponding to the number of rotations.

The lead wire 32a of the magnetoresistive element 32 is connected to, for example, a rotation speed indicator (not shown) which is mounted at an appropriate position on the main body of the model airplane and digitally displays the rotation speed.

The rotational speed indicator does not need to be attached to the model airplane main body. For example, when the terminal of the lead wire 32a of the magnetoresistive element 32 is exposed on the surface, the rotational speed indicator is displayed on the terminal. The meter may be configured to be detachable.

The magnetoresistive element 32 is provided with, for example, an auxiliary magnet (not shown) on the far side of the crank chamber 13 so that a large magnetic flux density is formed when the magnetic body 31 approaches. With such a configuration, the magnetoresistive element 32
Detects reliably that the magnetic body 31 has approached.

In the engine of the model airplane having such a configuration, when the piston 12 linearly reciprocates in the cylinder 11, the linear motion is transmitted to the crank 16 by the connecting rod 15, and the crank 16 is rotated. . The rotation of the crank 16 causes the crank 16 to rotate.
The output shaft 17 attached to the center of the shaft rotates.

When the crank 16 rotates in this way, the magnetic material 31 disposed in the crank pin 18 connecting the lower end of the connecting rod 15 at the tip of the crank 16.
Moves around the output shaft 17 and approaches the magnetoresistive element 32 attached to the cover plate 19, a predetermined pulse signal is output from the magnetoresistive element 32. Then, the number of revolutions of the output shaft 17 per unit time is measured based on the output pulse signal of the magnetoresistive element 32 per unit time, and the measurement result is displayed on, for example, a revolution number indicator.

In the above embodiment, a model airplane engine having one cylinder 11 has been described. However, the present invention can be applied to an engine having a plurality of cylinders. Even in the case where a plurality of cylinders are provided, the magnetic body is attached to the crankpin of the crank connected to the end of the output shaft, and the magnetoresistive element is opposed to the orbital movement area of the crankpin. Installed outside the room.

[0026]

Further, in the above-described embodiment, the magnetoresistive element is used as the magnetic sensor, but another magnetic sensor such as a Hall element may be used.

[0028]

As described above, the model engine of the present invention is configured such that the orbital movement of the magnetic material attached to the crankpin which rotates integrally with the output shaft is detected by the magnetic sensor. The output can be accurately detected. Moreover, a small magnetic material attached to the crankpin that rotates integrally with the output shaft ,
Since the rotation speed can be detected by a small component called a magnetic sensor provided at a position facing the orbital movement area of the magnetic material, it is not necessary to increase the size of a model such as a model airplane, There is little risk of weight increase.

[Brief description of the drawings]

FIG. 1 is a partially broken front view of a model airplane engine which is an example of the model engine of the present invention.

FIG. 2 is a partially broken side view of the model airplane engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Cylinder 12 Piston 13 Crank chamber 14 Piston pin 15 Connecting rod 16 Crank 17 Output shaft 18 Crank pin 19 Cover plate 21 Cover plate fastening bolt 31 Magnetic body 32 Magnetoresistive element

Claims (1)

(57) [Claims] 1. A linear motion of a piston reciprocating in a cylinder is transmitted via a connecting rod, the connecting rod and a crank pin.
A model engine that is transmitted to an output shaft via a connected crank and the output shaft is driven to rotate, wherein the crank pin has at least one end hollow, and
Of which magnetic material mounted fitted to the hollow portion, the positions opposing the circumferential moving range of the magnetic material, contact of the magnetic body
A magnetic sensor for detecting separation is provided;
Engine power is detected based on the output shaft speed.
A model engine characterized by being made to be able to be done .