JPH0127263B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air motor for starting internal combustion engines, in particular small gas turbines.

Traditionally, starting devices for internal combustion engines include systems in which a pinion rotates at high speed and meshes with the engine's ring gear during startup, and after the engine starts, the pinion retreats and disengages from the ring gear. There was a system in which a high-speed rotating shaft with a spline cut into it was inserted into the end of the rotating shaft, and the tip of the spline retreated after the engine started, but in any case, unless special measures were taken, the starting device and internal combustion Large impact damage often occurs when meshing with the engine. For example, in an internal combustion engine starting device using an electrically driven starter motor, the speed at which the device's pinion rotates is set in advance to mesh with a ring gear while rotating at a low speed, and then the engine is started at a high speed based on a sensor. , which avoids impact damage and this method is widely known.

However, this electric starting device requires a battery, charging pressure regulator, etc., and in particular, in large internal combustion engines directly connected to emergency work equipment, a small internal combustion engine for auxiliary equipment is attached, and even with this, large internal combustion engines are required. Although an attempt was made to start this small internal combustion engine using an electric starter, the electric starter would not turn on in an emergency, which was inconvenient.

For this reason, starting devices for internal combustion engines that use air motors have begun to become popular.In order to prevent shock damage, even this starter device rotates at a low speed when the pinion and ring gear are engaged, and once they are engaged, it stops and then rotates at high speed. A device has been proposed for starting the engine.
In this proposal, when the pinion and ring gear mesh, the pinion is pushed out only by the piston, so even if the pinion is engaged at a low speed, it will still rotate at a considerable speed due to the characteristics of the air motor. There was a risk of damage.

The above example is a solution to the problem of meshing, but the present invention is a starting device for an internal combustion engine using an air motor. The present invention provides a highly reliable starting device for an internal combustion engine that focuses on preventing impact damage when a member and engine suddenly separate from each other.

Hereinafter, the structure of the present invention will be described in detail based on embodiments shown in the accompanying drawings. FIG. 1 is an overall schematic diagram, FIG. 2 is a sectional view of the air motor with the air control valve omitted, and FIG. 3 is an enlarged sectional view of the air control valve.

[Summary of configuration]

In FIG. 1, 1 is an air tank that stores air compressed by a compressor (not shown);
3 is a gate valve, 3 is a filter that removes foreign matter from the compressed air, 4 is an oiler for mixing lubricating oil to supply lubricating oil to the air motor, 5 is an air control valve, 6 is the air motor body, 7 is a silencer, 8 is a pinion ,
9 is a ring gear of the internal combustion engine that meshes with the pinion;
Reference numeral 10 denotes a start valve, which communicates with the air motor main body 6 through supply/discharge control tubes 10', 10'.

The outline of the operation of this device is as follows:
By manually pressing , the air control valve 5 is actuated, the air motor is started, and the pinion 8 is jumped out, that is, moved forward to mesh with the ring gear 9 and start the internal combustion engine.

[Configuration of air valve and air motor]

In this embodiment, the air valve 5 and the air motor have the following configuration.

In FIG. 2, the air motor is a vane type motor, and a rotor 12 which is eccentric with respect to the cylinder 11 is housed in a cylinder 11. Ball bearings 17 to 15 and 16
and is rotatably supported via roller bearings 18. A plurality of blades 19 are provided on the rotor 12 so as to be slidable radially with respect to the center of the rotor 12, and the outer ends of these blades 19 are always inscribed in the cylinder 11. The cylinder 11
is provided with a plurality of air inflow passage grooves 20 on the inlet side and a plurality of air outflow passage grooves 21 on the outlet side, the inlet side communicates with the oiler 4 side explained in FIG. 1, and the outlet side communicates with the silencer 7. ing. These mechanisms are well known (Japanese Unexamined Patent Publication No. 57-91375).

Next, regarding the speed reduction mechanism connected to the air motor, a pinion 23 is carved into the extending end of the rotor shaft 14, and the pinion 23 is connected to the internal gear 22.
The rotation of the rotor 12 is reduced by the internal gear 22, and a drive shaft 30, which will be described later, is rotated. The internal gear 2
2 is integrally extended with a cylindrical body 24 having a smaller diameter than the cylindrical body 24 to serve as a transmission shaft, and these internal gears 22 and the cylindrical body 24
are ball bearing 25 and roller bearing 2
It is supported by 6. The ball bearing 25 is supported by the side housing 16, the roller bearing 26 is supported by the intermediate cylinder 28, and the base of the intermediate cylinder 28 is supported by the casing 2.
7 is fitted. A threaded spline 29 is carved on the inner circumference of the cylindrical body 24 in the front, and the threaded spline 2
9 meshes with a threaded spline formed on the drive shaft 30. This threaded spline 29 functions to move the driven shaft forward when the rotation of the driven shaft is stopped. A stopper 31 is fixed to the end of the drive shaft 30 on the threaded spline 29 side, and the pinion 8 explained in FIG. 1 is fixed to the other end. A roller bearing 32 that also receives thrust is provided between the pinion 8 and the threaded spline 29, and the drive shaft 30 is supported by the roller bearing 32 and the stopper 31. Further, in the ring-shaped space formed by the intermediate cylinder 28 and the casing 27, a piston 33 is slidably provided, and the roller bearing 32 is built in the extension portion 34 of the piston 33. 33 causes the drive shaft 30 to move forward together with the roller bearing 32.

A working chamber 35 is provided on the head side of the piston 33.
A communication port 36 is provided on the skirt side, and the piston 33 is always urged toward the working chamber 35 by a spring 38.

[Air control valve configuration]

Next, regarding the air control valve 5, in FIG.
A main valve main body 39 is mounted and fixed on the inlet side of the main valve body 39, and an air control valve 5 is attached to the main valve main body 39.

The main valve body 39 is approximately a valve 40 and a valve spring 4.
1 and a valve stem 42, the valve stem 42 is guided vertically by an intermediate frame 43 of the valve body 39 and slides thereon. A piston 44 is fixed to the upper end of the valve stem 42, and the back of the piston 44 and the intermediate frame 4
3 forms a working chamber 45. 39' indicates an opening communicating with the oiler 4 side.

The air control valve 5 is approximately an upper spool valve 47,
Consisting of a lower conical valve 48, a barrel 49, and a valve seat 50, a protruding rod 52 of the lower conical valve 48 fits into a central hole 51 of the upper spool valve 47, and is coupled so that they can be joined and separated, and both move up and down inside the barrel 49. to slide. Both the upper spool valve 47 and the lower conical valve 48 have compression-biased valve springs 53 and 54 and are biased upward.

Regarding the port of the air control valve 5,
The first port 55 communicates with the control tube 10' described in FIG. 1, and the control tube 10' communicates with the air tank 1 via the start valve 10. The first port 55 is connected to the conical valve chamber 5 in which the lower conical valve 48 is built.
It is temporarily set up on 6th. The second port 57 communicates with the working chamber 35 described in FIG. 2 and is provided adjacent to the conical valve chamber 56. The third port 58 has a narrow pore and communicates with the second port 57, and is provided on the inlet side of the cylinder 11. The fourth port 59 communicates with the working chamber 45 and is provided in an outer peripheral notch 60 of the barrel 49 . The outer periphery notch 60 communicates with the center hole 61 of the protruding rod 52 and also communicates with the conical valve chamber 56 via an on-off valve consisting of a small land 62 of the barrel 49 and an O-ring 63 of the upper spool valve 47. The fifth port 64 communicates with the communication port 36 described in FIG. 2 and is provided adjacent to the upper spool valve chamber 65.

[Operation at the start of meshing between pinion and ring gear]

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

First, when the start valve 10 is opened, compressed air is introduced from the air tank 1 into the first port 55, and the compressed air is discharged from between the lower conical valve 48 lifted by the valve spring 54 and the valve seat 50. The water is divided into a second port 57 and a third port 58 and flows out. The compressed air flowing out from the second port 57 is introduced into the working chamber 35 shown in FIG. 2, and causes the piston 33 to slide in the direction in which the pieon 8 pops out. On the other hand, the compressed air that is throttled and flows out from the third port 58 is introduced into the cylinder 11 and rotates the rotor 12 at a low speed. As a result, code 23→
22→24, the drive shaft 30 rotates via the threaded spline 29, and the drive shaft 30 attempts to be pulled out via the roller bearing 32 by the sliding movement of the piston 33 in the protruding direction, that is, in the forward direction. However, since the threaded spline 29 is threaded so that it moves forward when the rotating drive shaft 30 is stopped, if the piston 33 attempts to move the drive shaft 30 forward, the drive shaft 30 will instead be reversed. As a result, the pinion 8 rotates even more slowly, and then engages the ring gear 9 slightly. And once,
When the pinion 8 and ring gear 9 begin to engage,
This time, the rotation preventing force on the drive shaft 30 by the ring gear 9 acts on the threaded spline 29, and becomes faster than the forward speed of the piston 33, causing the drive shaft 30 to
It moves forward quickly, that is, the piston fits into the pinion 8 and the ring gear 9 completely mesh with each other. At this position, the stopper 31 of the drive shaft 30 comes into contact with the stepped portion 66 of the cylindrical body 24, and the forward movement of the drive shaft 30 is thereby stopped. Moreover, at the same position, the piston 33 moves and connects the working chamber 35 and the communication port 3.
This is also the position where compressed air is introduced into the upper spool valve chamber 65 from the communication port 36.

[Opening operation of the main valve body]

As described above, the movement of the piston 33 brings the working chamber 35 into communication with the communication port 36, and compressed air is introduced into the upper spool valve chamber 65 from the fifth port 64, pushes the upper spool valve 47 downward, and causes the lower conical While seating the valve 48 on the valve seat 50,
The small land 62 of the barrel 49 and the O-ring 63 of the upper spool valve 47, which had been closed until now, are now opened.
The conical valve chamber 56 and the outer peripheral notch 60 communicate with each other. Therefore, compressed air enters the working chamber 4 from the fourth port 59.
5, pushing up the piston 44 and opening the valve 40 of the main valve. As a result, air tank 1
A large amount of compressed air is introduced into the cylinder 11 and rotates the rotor 12 at high speed. At this time, since the lower conical valve 48 is seated on the valve seat 50, compressed air is introduced from the third port 58 in the opposite manner to the previous one, and is introduced into the working chamber 35 via the second port 57. and continues to push the piston 33.

[Closing operation of the main valve body]

The internal combustion engine starts with the high-speed rotation of the rotor 12, but when the internal combustion engine starts, the ring gear 9 rotates faster than the pinion 8, and a force acts to rotate the drive shaft 30 faster, so the spline 29 As a result, the drive shaft 30 moves backward, and the pinion 8 and ring gear 9 disengage.
As the drive shaft 30 retreats, the piston 33 also retreats against the compressed air in the working chamber 35, and the communication port 36
Close.

Here, the stopper 31 is fixed to the rear end of the drive shaft 30 as described above, and the stopper 31 and the rear end surface of the drive shaft 30 act as a piston, and this piston forms a bowl-shaped cylinder. It slides in an air chamber 68 formed by a body 69, and this air chamber 68 functions as a shock absorber. Therefore, when the internal combustion engine, in this case a small gas turbine, starts rotating at high speed (300,000 rpm), the drive shaft 3, which has a large mass,
0 is blown away, but the compressed air in the working chamber 35 and the air in the air chamber 68 stop the drive shaft 30 from rapidly retreating. Note that the air chamber 68 is not completely sealed, and air is gradually released outside through a throttle hole (not shown).
The elasticity of the air chamber 68 is attenuated.

As a result of closing the communication port 36, the compressed air introduced into the upper spool valve chamber 65 is gradually discharged through a labyrinth formed on the outer periphery of the piston 33, and the pressure is reduced. As a result, the upper spool valve 4
7 is pushed up by the pressure in the conical valve chamber 65, the small land 62 and the O-ring 63 are closed again, and the outer peripheral notch 60 and the conical valve chamber 56 are no longer in communication. Therefore, compressed air drips into the working chamber 45. On the other hand, since the upper spool valve 47 is retracted, the air in the working chamber 45 flows through the center hole 61 and the port 6.
7 to the atmosphere, while the valve spring 41 closes the valve 40 and the rotor 12 stops rotating.

At this time, compressed air continues to be supplied to the first port 55, so the conical valve chamber 56 is pressurized, the lower conical valve 48 remains seated against the valve spring 54, and the start is started. Even if the valve 10 is not closed, the pinion 8 will not pop out again inadvertently and is locked, so to speak.

When the start valve 10 is then closed, the lower conical valve 48 is raised by the valve spring 54 and returns to its initial state.

In summary, since the present invention adopts the structure described in the claims, the inertial force of the large mass drive shaft having a threaded spline that retreats when the engine starts is absorbed by the working chamber of the shock absorber and the piston. Therefore, even if there is a sudden retreat,
Impact damage can be avoided and a highly reliable starting device can be achieved. Moreover, there is no intervening measure to prevent damage due to increased drive speed, such as an overclutch, between the drive shaft and the mechanical coupling member, and the mechanism works together with a simple shock absorber and the working chamber of the piston for advancing the drive shaft. Therefore, a starting device with a simple structure and low cost can be provided.

[Brief explanation of drawings]

FIG. 1 is an overall schematic diagram, FIG. 2 is a sectional view of the air motor with the main valve body and air control valve omitted, and FIG. 3 is a sectional view of the main valve body and the air control valve. 8... Pinion, 9... Ring gear, 29... Screw spline, 30... Drive shaft, 33... Piston, 35
...Working chamber, 68...Air chamber.

Claims (1)

[Claims] 1. In an air motor for starting an internal combustion engine, if an attempt is made to stop the rotation of the driven side of the air motor, the shaft moves forward through a threaded spline.
A drive shaft to be driven is provided, a mechanical coupling member is provided at the tip of the drive shaft, a shock absorber is provided at the rear end, and compressed air for the air motor is divided,
The drive shaft is advanced by the piston pressed by the shunted compressed air, the engine is engaged with the engine to start the engine, and the drive shaft and the piston are moved back by the rotational force of the engine. An air motor for starting an internal combustion engine, characterized in that the retraction is stopped by compressed air operating the shock absorber and the piston.