JPS623169A - Control of air motor for internal-combustion engine - Google Patents

Abstract

PURPOSE:To preclude damage in a control device where a main valve of an air motor is opened by compressed air according to an air piston's forward traved by making it possible to block re-supply of compressed air to the air piston in case the compressed air for opening the said valve is released into the atmosphere. CONSTITUTION:When a start command valve 102 of a starter is opened, the compressed air from an air tank 101 is supplied via a pilot valve 7 toa supply port A, and according to the forward travel of an air piston 3 a pinion 5 engages with a ring gear. Part of compressed air is supplied via a reverse check valve 9 to an air motor 1 to rotate it a low speed. When the supply port A and an outlet port B are communicated with each other in the course of forward travel of the air piston, compressed air is introduced via a passage 104 to a main valve 6 to open it, and as a result the air motor is rotated at a high speed. It is so constituted that the said pilot valve 7 is closed with throttled and compressed air in a part of the passage 104 and the closure is retained by means of compressed air of a passage 106.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for an air motor for an internal combustion engine.

[Conventional technology]

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A starting device consisting of an air motor for an internal combustion engine is known from the specification No. 4126113. Such a starter is a pinion installed at the end of the drive shaft.
-1 moves forward while rotating, meshes with the ring gear of the internal combustion engine, and starts the internal combustion engine,
Its operation is to supply compressed air to the air piston fitted to the drive shaft, advance the cough drive shaft as the air piston moves forward, and rotate the cough drive shaft at high speed using the air motor to start the internal combustion engine. It is something that makes you

2,' And the starting device consisting of a conventional air motor is
/"A solenoid valve is used for the start command, and after the internal combustion engine has been started, when the pinion of the starter is disengaged from the ring gear of the internal combustion engine, the solenoid valve is activated manually or automatically (for example, In the device disclosed in Japanese Patent Publication No. 58-21101, when the internal combustion engine is started, the exhaust gas pressure of the engine is used as a sensor to operate a solenoid valve and the valve is disconnected.

In such a case, if there is a delay in turning off the solenoid valve after the engine has started, the starting device will be accelerated by around 10 times due to engine rotation, and in the worst case, it will be damaged. A device or electrical protection circuit is provided.

However, in such measures, electrical protection circuits are expensive, and maintenance and inspection are difficult in places where internal combustion engines using air motors are used, such as in the mountains or at sea, and mechanical protection devices are difficult to use. It doesn't fulfill its function adequately.

[Means for solving problems]

Therefore, the present invention was created to solve these conventional problems, and particularly provides a control device that ensures the safety of the air motor after the engine is started.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

Fig. 1 is an overall sectional view of an embodiment of the present invention, Fig. 2 is an air circuit diagram used in the embodiment of Fig. 1, and Fig. 3 is an
An enlarged view of the section is shown.

The starting device for internal combustion engines of this embodiment has power outputs ranging from 50 horsepower to 2000 horsepower.
Although suitable for high horsepower diesel engines, it is also applicable to small gas turbines.

[Overview of configuration in example]

In the air circuit diagram of FIG. 2, an air motor l in the illustrated starting device is integrated with a piston housing 2 in which an air piston 3 is built.
A drive shaft 4 driven by the piston housing 2 is installed horizontally in the piston housing 2, and a pinion 5 (or spline) is provided at the tip of the drive shaft 4, and the pinion 5 engages and disengages with a ring gear (not shown) of the internal combustion engine. It is supposed to be done. The air motor 1 is rotated at high speed by compressed air from the air tank 101.
A main valve 6 is interposed between the main valve 01 and the main valve 6. Also,
The air piston 3 moves forward (moves to the right in FIG. 2) by compressed air from the air tank 101, but a start command valve 102 and a pilot pulp 7 are interposed between the air piston 3 and the air tank 101. These main pulp 6 and pilot valve 7 are
In the figure, it is surrounded by a two-dot chain line.

Regarding the operation of such an internal combustion engine starting device, first, when the start command valve 102 is opened, compressed air from the air tank 101 is supplied to the first passage 103 and then flows through the viroft pulp 7 to the second passage 106. Since it is supplied to the supply hole A drilled in the piston housing 2,
Air piston 3 moves forward. When the air piston 3 moves forward, the drive shaft 4 also moves forward, and the pinion 5 provided at its tip meshes with the ring gear.

On the other hand, after being supplied to the pilot valve 7, the branched compressed air is supplied to the air motor 1 while being throttled through the check valve 9 provided in the branch passage 107.
Rotate at low speed. Therefore, the pinion 5 rotates the ring gear at a low speed while moving forward.

Next, when the air piston 3 moves further forward, the supply hole A and the discharge port B will communicate with each other, and the third
Compressed air is supplied to the passage 104, and the main valve 6 is opened. As a result, a large amount of compressed air from the air tank 101 passes through the fourth passage 105 and is supplied to the air motor 1, causing the air motor 1 to rotate at high speed, causing the ring gear to rotate at high speed using the pinion 5, and starting the internal combustion engine. .

In addition, in FIG. 2, 108 is a compressor, 109 is a drain tank, 110 is a lubricator, 111 is an oil tank, and 112 is a diffuser.

[Air motor configuration]

The details of the air motor l in the above embodiment are configured as follows.

That is, in FIG. 1, an air motor 1 includes a rotor 10 having a plurality of blades, and the rotor 10 is housed in a main housing 11. As shown in FIG. The rotor lO has a rotor shaft 14 supported at both ends by bearings 12.12, and one of the rotor shafts 14 is protruded,
A pinion 15 is carved into its end. The pinion 15 is meshed with an internal gear 16° carved on the inner periphery of a cylindrical shaft 16. The internal gear 1 is disposed on the inner periphery of the cylindrical shaft 16.
A threaded spline 17 is formed parallel to the 6° angle, and the threaded spline 17 is meshed with a threaded spline 18 formed on the drive shaft 4 . These threaded splines 17.1
Reference numeral 8 is a screw that causes the drive shaft 4 to move forward when a force that prevents the rotation of the pinion 5 acts. Therefore, when a force that moves the drive shaft 4 forward acts, the drive shaft 4 moves forward. 4 is about to be reversed, and the rotation speed of pinion 5 becomes low. A needle bearing 1 is provided on the outer periphery of the cough shaft 16.
A cylinder 20 is fitted through 9, and the cylinder 2
An air piston 3 is slidably housed in an annular space formed by the air piston 0 and the piston housing 2. If the air piston 3 is connected to the piston spring 2 via the sleeve 23
1, it is always pressed in the backward direction. The sleeve 23 is integrated with the outer race of the bearing 13, and further includes:
Since the inner race of the bearing 13 is integrated with the drive shaft 4, the sleeve 23 and the drive shaft 4 move forward and backward together, but the rotation of the drive shaft 4 is not transmitted to the sleeve 23.

[Configuration of main pulp and viroft pulp] The details of the main pulp 6 and pilot pulp 7 in the above embodiment are configured as follows.

That is, in FIGS. 1 and 3, these pulps 6.7 are mounted on the main housing 11, and are located in the first passage 103, the second passage 106, the third passage 104, and the fourth passage 11. The passages 105 are connected to each other. The first passage 103 and the second passage 106 communicate with each other via the pilot valve 7. The main body 24 of the pilot valve 7 is constantly lifted from the valve seat 26 by a pilot pulp spring 25.
The first passage 103 and the second passage 106 are communicated with each other before starting the starter. A stem 27 is protruded from the top of the main body 24, and a small diameter portion 29 is formed in the middle of the stem 27, and a through hole 30 is formed in the small diameter portion 29 in the radial direction.
is drilled.

The through hole 30 communicates with a drill hole 31 further drilled on the axis of the stem 27, and the drill hole 31 is opened at the top of the stem 27. The tip of the leg 33 of the pilot piston 32 is brought into contact with the top of the stem 27, and the virofft piston 32 also has a drilled hole 34 formed in its axis, and the drilled hole 34 coincides with the drilled hole 31. It is communicated. The stem 27 is slidably supported by a stem support 35, and the stem support 35 is provided with a throttle hole 35° that communicates with the third passage 104, and the throttle hole 35° is connected to the small diameter portion 29. It communicates with the outer periphery. An O-ring 36 is provided below the opening of the throttle hole 35''.
6 blocks off the first passage 103 and the third passage.

The virofft piston 32 is always pressed upward by a pilot piston spring 37, and the spring 37 is inserted so that the leg 33 of the virofft piston 32 can slide freely.
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2. A branch passage 107 branched from the second passage 106 is bored in the valve seat 26, and the branch passage 107 is connected to the rotor 10 via the check valve 9.
° into the chamber.

It's communicating.

The third passage 104 passes around the outer periphery of the piston support 38 and communicates with the main pulp piston 39, which is connected to the main pulp body 40 by a pulp spindle 41. The main pulp body 40 is a main pulp piston spring 4
2 and the main pulp body spring 43, which are normally pressed against the valve seat 44.

Since the configuration of this embodiment is as described above, the following operations are performed.

[Operation to start meshing between pinion and ring gear] As mentioned above, the start command valve 102 (usually composed of a solenoid valve)
When opened, compressed air from the air tank 101 passes through the first passage 103 and is supplied to the outer periphery of the pilot valve 7. Since the pilot valve 7 is always lifted upward by the pilot valve spring 25, compressed air passes through the valve seat 26 and is supplied to the supply hole A from the second passage 106. Therefore, the air piston 3 moves forward against the piston spring 21.

As a result, the drive shaft 4, which is integral with the air piston 3, is also gradually advanced while being reversed by the action of the threaded splines 17, 18, and the pinion 5 comes into contact with the ring gear.

On the other hand, the compressed air branched from the valve seat 26 of the pilot pulp 7 is squeezed by the check valve 9 and sent to the rotor 10.
The rotor 10 is rotated at a low speed. The low speed rotation of the rotor 10 is controlled by the pinion 15 and the internal gear 16.
” and is transmitted to the screw spline 1 of the drive shaft 4, and by the action of the screw splines 17 and 18, the rotation speed is further reduced, causing the pinion 5 to rotate at an extremely low speed. Therefore, the pinion 5 is rotated at a very low speed. A slight engagement is made while searching for a good fit.

Once the pinion 5 and the ring gear + begin to engage, a force acts on the ring gear to prevent the rotation of the pinion 5, and this acts on the threaded spline 17, 18, causing the drive shaft to 4 advances more quickly than the forward speed of the air piston 3, and the pinion 5 and the ring gear are quickly engaged.

[Main valve opening operation]

At the position where the pinion 5 and the ring gear are completely engaged and the drive shaft 4 stops moving forward, the supply hole A and the discharge hole B are communicated with each other, and the compressed air is passed through the discharge hole B to the third passage 104. through which the main valve piston 39 is supplied. Therefore, the main valve body 40 is lifted and the air tank 1
A large amount of compressed air from 01 passes through the fourth passage 105,
The rotor 10 is supplied to the rotor 10, and the rotor 10 rotates at high speed.

At this time, the compressed air supplied to the main valve piston 39 seats the pilot pulp 7 on the valve seat 26, as will be described later.

[Closing operation of the main pulp 7] The internal combustion engine is started by the high speed rotation of the rotor 10, but
When the internal combustion engine starts, the ring gear rotates faster than the pinion 5, and as a result, a force acts on the drive shaft 4 to make it rotate faster, so the threaded spline 17.
18 causes the drive shaft 4 to move backward, but in addition to this, the biasing force of the piston spring 21 also acts, causing the drive shaft 4 to quickly move backward, and the pinion 5 and the ring gear are disengaged. As the drive shaft 4 moves backward, the air piston 5 also moves backward, but as a result, communication between the second passage 106 and the third passage 104 is cut off, and the compressed air in the third passage 104 is , Diffuser 4
5, the main valve piston 39 moves down, and the main pulp 6 closes. On the other hand, although the pilot pulp 7 and the main pulp 6 are closed as described above, the compressed air in the second passage 106 is prevented by its suction action because the air motor 1 is rotating due to inertia. It is sucked in through valve 9.

[Lock action of main pulp]

As mentioned above, compressed air is supplied to the third passage 104 in order to open the main pulp 6, but at the same time, a part of the compressed air passes through the throttle hole 35° and enters the pilot piston 3.
It is also supplied to the top 32° of No. 2 without being throttled. As a result, the pilot piston 32 is pushed down against the pilot piston spring 37, and the stem 27 is pushed down.

Therefore, although the pilot valve 7 is seated on the valve seat 26, the compressed air from the first passage 103 is no longer supplied to the second passage 106.

Note that the timing is the period before and after the rotation of the rotor lO starts normal high-speed rotation. On the other hand, since the stem 27 is pressed down, the compressed air in the first passage 104, which has a slightly higher pressure than the compressed air in the third passage 104 that bypasses the supply hole A and the discharge hole B,
Since the compressed air in the passage 103 is directly supplied to the main pulp piston 39 from the small diameter portion 29 of the stem 27, the main pulp 6 remains completely open, and
After the initial movement, the compressed air in the third passage 104 is released into the atmosphere at once by the backward movement of the air piston 3, and even if the main valve 6 is closed, the compressed air from the first passage 103 is released into the pilot valve. 7 is maintained seated on the valve seat 26. In other words, as long as compressed air is introduced into the first passage 103,
The pilot valve 7 is closed, so that the air piston 3 is not moved forward again, and the main valve 6 is not accidentally restarted. small amounts continue to be released into the atmosphere through

Since the present invention has the above-described configuration, it has the following effects.

〔Effect of the invention〕

■ The main valve for the air motor is opened and closed using the compressed air used in the air motor, making the air motor inexpensive and easy to maintain no matter where the starter is installed. .

■ After the engine starts, the main valve opens and the compressed air that is maintained is immediately released to the atmosphere, so the main valve closes quickly and does not apply unnecessary force to the air motor's rotor, pinion, drive shaft, etc. Moreover, unnecessary compressed air is not supplied to the rotor.

■ Even though the compressed air that keeps the main valve open is released all at once to the atmosphere, the pilot valve remains closed, so the compressed air in the first passage passes through the air piston to the second passage. Since the valve is locked in a state where it is not resupplied, the pinion etc. will not be moved forward again to engage the internal combustion engine, and the main valve will not be restarted.

[Brief explanation of drawings]

FIG. 1 is an overall sectional view of an embodiment of the present invention, FIG. 2 is an air circuit diagram used in FIG. 1, and FIG. 3 is an enlarged view of the X section in FIG. 1. 1...Air motor, 3...Air piston, 4...
Binion, 6... Main valve, 7... Pilot valve, 35゛... Throttle hole, 103... First passage, 104... Third passage, 106... Second passage .

Claims (1)

[Claims] An air piston is moved forward by compressed air supplied to a first passage and a second passage communicated with the first passage through a pilot valve, and is moved backward by a piston spring or the like, and is rotated by an air motor. It consists of a drive shaft and a pinion or spline provided at the tip of the drive shaft and engaged with the internal combustion engine, and as the air piston moves forward, the drive shaft moves forward and the air piston moves forward. The compressed air supplied to the second passage is
In the air motor for an internal combustion engine, which is operated to open the main valve of the air motor by being communicated with the third passage, the pilot valve is closed by compressed air that is partially throttled from the third passage, and the pilot valve is closed. The pilot valve is characterized in that the blockage is maintained by compressed air in the second passage, and the compressed air in the third passage is immediately discharged to the atmosphere as the air piston moves backward. Control device for air motor for internal combustion engine.