JPS6221743Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting valve for supplying starting air to the combustion chamber of a diesel engine.

Conventionally, this type of starter valve is installed with almost the entire part inside the cylinder head, with the inlet side air passage in the cylinder head connected to an external air tank and the outlet side air passage in the cylinder head connected to the combustion chamber. The function is to allow the passages to communicate with each other during engine starting operations. However, the conventional structure described above has the problem that the structure of the cylinder head becomes large and complicated because almost the entire starter valve is embedded in the cylinder head and an inlet air passage is provided in the cylinder head. In addition, in the conventional product, the spring seat of the return spring for the pilot piston incorporated in the starter valve is molded separately from the valve body, so there is a problem that the number of parts is large. Furthermore, the starter valve is fixed in the cylinder head by pressing the end wall of the valve body with a retaining plate, but in order to maintain airtightness, it is necessary to align the pressing direction with the center line of the starter valve. For this purpose, in the conventional product, a partially spherical convex surface is formed on the pressing surface of the presser plate, and the apex of the convex surface presses the center of the end wall. However, forming a convex surface on the presser plate requires a forging process, which requires time and effort to manufacture the presser plate.

In order to solve the above-mentioned conventional problems, this invention
An air passage is formed inside the generally cylindrical valve body,
The outlet of the air passage formed at one end of the valve body is connected to the starting air supply passage inside the cylinder head, the valve body supports the valve body for opening and closing the outlet, and the valve body is moved in the opening direction. A pilot air pressurizing chamber for biasing the valve body and a spring for biasing the valve in the closing direction are provided inside the valve body, and the outlet end of the valve body is fitted into the hole in the cylinder head in a concentric position. , a portion of the valve body other than the outlet side end protrudes to the outside of the cylinder head, the air passage and the inlet of the pressurizing chamber are formed in the protruding portion of the valve body, and the inlet of the air passage is connected to an external air supply. The inlet of the pressurizing chamber is connected to an external pilot air supply pipe.

Further, in the present invention, an end wall separate from the valve body is fitted to the end opposite to the outlet of the valve body, and the outer surface of the end wall opposite to the outlet is formed with a partially spherical convex surface, and the convex surface Another feature is that the apex of the valve body is aligned with the center line of the hole and the valve body, a presser plate is seated on the apex, and the presser plate is fixed to the cylinder head around the apex with a plurality of bolts.

In FIG. 1, which is a longitudinal cross-sectional view, 1 is a cylinder block, 2 is a combustion chamber, 3 is a cylinder head,
An air supply passage 4 communicating with the combustion chamber 2 is provided within the cylinder head 3. 5 is a generally cylindrical starting valve body, and the end 7 on the outlet 6 side is connected to the cylinder head 3.
The body 5 as a whole extends generally parallel to the radial direction of the cylinder block 1. The outlet 6 is a valve body 10 of a poppet valve.
It is designed to be opened and closed by the two-dot chain line 10'.
When the valve body 10 moves into the passage 4 as shown in FIG.
communicates with passage 4. The hole 9 and the valve body 5 are concentric (center line 0-0), and the inner peripheral surface of the hole 9 has a center line 0-0.
An annular step 11 is formed at right angles to the end 7.
An annular stepped portion 12 provided on the outer circumferential surface of the tip and perpendicular to the center line 0-0 is pressed against the stepped portion 11 via a packing.

A stem 13 extending from the valve element 10 into the valve body 5
is provided with a flange 15 that is slidably fitted to the inner peripheral surface of the end portion 7, and connects the outlet 6 and the longitudinally intermediate portion of the valve body 5 through a groove 16 parallel to the stem 13 formed on the outer periphery of the flange 15. A passage 17 is in communication. A generally cylindrical downward flange 18 is integrally formed in the longitudinally intermediate portion of the valve body 5 , and the passage 17 communicates with a passage 19 within the flange 18 . An external air supply pipe 22 is connected to the lower end surface of the flange 18 using an annular packing 20 and a joint member 21. The outlet of the supply pipe 22 communicates with the passage 19, and the inlet (not shown) is connected to the air supply pipe 22. connected to the tank.

A cylindrical flange 23 is formed on the lower surface of the right end (end opposite to the outlet end 7) of the valve body 5 in FIG. 1, and the outlet end of the pilot air supply pipe 25 is fixed to the flange 23. has been done. Supply pipe 25
The inlet (not shown) is connected via a distribution valve to a source of pressurized air, and the outlet communicates via a passage 26 in the flange 23 to a pressurized chamber 27 in the end of the valve body 5. A pilot piston 29 facing the pressurizing chamber 27 from the outlet 6 side is slidably fitted on the inner peripheral surface of the valve body 5. The tip of the stem 13 protrudes into the pressurizing chamber 27 through the center hole of the piston 29, and the piston 29 is connected to the stem 1 by a nut 30 attached to the protruding tip of the stem 13.
It is fixed at 3. The piston 29 has a pressurizing chamber 2
One end of the return spring 31 (compression coil spring) is pressed from the opposite side to the spring 3.
An annular spring seat 32 supporting the other end of the passage 17
The valve body 5 is formed integrally with the valve body 5 adjacent to the valve body 5 .

A disk-shaped end wall 36 is pressed against the end surface of the valve body 5 opposite to the outlet 6 via an annular packing 35.
The small diameter portion 37 of the end wall 36 fits into the inner peripheral surface of the end portion of the valve body 5. The outer surface 39 (the surface opposite to the outlet 6) of the end wall 36 has a relatively flat partially spherical shape having an apex 40 on the center line 0-0 of the valve body 5, in other words, on the center line 0-0 of the hole 9. It forms a convex surface, with apex 4
A press plate 41 is in pressure contact with 0. The pressing surface 42 and other surfaces of the holding plate 41 are flat, and the overall shape is an elongated rectangle as shown in FIG.
and is fixed to the cylinder head 3 by a nut 44 as shown in FIG. Each bolt 43 is parallel to the center line 0-0, one end is fixed to a screw hole in the cylinder head 3, and a nut 44 is screwed into the other end protruding from a hole (not shown) in the holding plate 41. are doing. By appropriately tightening both nuts 44, the pressing surface 42 can be brought into pressure contact with the apex 40 in a position perpendicular to the center line 0-0. 3
6 and the valve body 5 are applied with a force concentric with and in the same direction as the center line 0-0, so that the stepped portion 12 is pressed against the seal and the stepped portion 11 with an even force over the entire circumference, and the end portion 7 and the cylinder Sufficient airtightness is maintained between the heads 3.

Explain the action. When a starting operation is performed, the supply pipe 25 is opened at a predetermined timing from a distribution valve (not shown).
Pressurized air is supplied to the pressurizing chamber 27 through the passage 26, and the piston 29 is pushed by the pressurized air to move toward the outlet 6, and the valve body 10 together with the stem 13 moves from the closed position shown by the solid line to the dashed double-dashed line. 10' to the open position. This operation causes the starting air sent from the supply pipe 22 to the passage 17 via the passage 19 to the outlet 6.
The air is supplied to the combustion chamber 2 through the passage 4, and the piston is pushed down by the air to provide starting rotation. After the start is completed, the intermittent supply of pilot air pressure to the pressurizing chamber 27 is stopped, the piston 29 returns to its original position and remains stationary due to the action of the spring 31, and the valve body 10 also remains stationary at the closed position.

As explained above, the present invention has a pilot air pressurizing chamber 27 inside the valve body 5, in addition to the starting air passage 19, for urging the valve body 10 in the opening direction. Spring for 3
The target is a structure with 1.

This structure is suitable for multi-cylinder engines, and compared to starting valves that are mainly used in single-cylinder engines, which open and close the valve using only starting air without using pilot air. Piping structures, etc. can be made smaller and simpler.

In the present invention, the end of the valve body 5 on the outlet side is fitted into the hole 9 of the cylinder head 3 in a concentric positional relationship, and the portion of the valve body 10 other than the end on the outlet side protrudes to the outside of the cylinder head 3. , an internal air passage 19 and a pressurizing chamber 27 are provided in the protruding portion of the valve body 10.
The inlets are connected to an external air supply pipe 22 and a pilot air supply pipe 25, respectively.
The structure is connected to the

In this way, only the outlet end of the valve body 5 enters the cylinder head 3, and there is no need to provide an air passage on the inlet side for starting air or pilot air in the cylinder head 3. This has the advantage that the structure can be made smaller and simpler, and manufacturing costs can be reduced.

Furthermore, if the starting valve is made to protrude significantly from the cylinder head 3 as described above, there is a risk that the mounting accuracy and mounting strength of the starting valve to the cylinder head 3 will be reduced, but the present invention is designed to prevent such problems. The following structure is adopted.

That is, in the present invention, in order to attach the starter valve to the cylinder head 3, the outer surface 39 of the end wall 36 fitted to the end of the valve body 5 opposite to the outlet 6 is formed with a partially spherical convex surface. A structure is adopted in which the apex 40 is aligned with the center line 0-0 of the valve body 5, a presser plate 41 is seated on the apex 40, and the presser plate 41 is fixed to the cylinder head 3 around the apex 41 with a plurality of bolts 43. ing.

According to this structure, since a force is applied from the holding plate 41 that is coaxial with and in the same direction as the center line 0-0 of the end wall 36 and the valve body 5, the valve body 5 is moved toward the cylinder head 3.
It can be securely fixed in the hole 9 in an airtight state.

Furthermore, in the above structure, since the flat presser plate 41 can be used, the presser plate 41 can be manufactured at low cost by sheet metal processing. Further, since the end wall 36 is a part that conventionally requires machining in order to form, for example, the small diameter portion 37, the manufacturing cost does not substantially increase even if the end wall is provided with the convex surface 36. Therefore, it is also possible to prevent the cost of the mounting structure from increasing.

In this way, the present invention improves each part of the starting valve to simplify the overall structure of the starting valve device.
Cost reduction can be achieved.

In the illustrated embodiment, the spring seat 32 of the pilot piston return spring 31 is connected to the valve body 5.
Since it is formed integrally with the main body, the number of parts can be reduced and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the embodiment, and FIG. 2 is a view taken along the - arrow in FIG. 1. 3... Cylinder head, 4... Passage, 5... Valve body, 6... Outlet, 7... Outlet end, 9...
Hole, 10... Valve body, 17... Passage, 22... Air supply pipe, 29... Pilot piston, 31...
Return spring, 32... Spring seat, 36...
End wall, 39... convex surface, 40... apex, 41... presser plate, 0-0... center line.

Claims (1)

[Scope of utility model registration request] An air passage is formed inside a generally cylindrical valve body, and an outlet of the air passage formed at one end of the valve body is connected to a starting air supply passage inside the cylinder head to open and close the outlet. The valve body supports the valve body, and a pilot air pressurizing chamber for biasing the valve disc in the opening direction and a spring for biasing the valve disc in the closing direction are provided inside the valve body. The end portion is fitted into the hole of the cylinder head in a concentric positional relationship, and the portion of the valve body other than the outlet side end protrudes to the outside of the cylinder head, and the air passage and pressurizing chamber are connected to the protruding portion of the valve body. forming an inlet, connecting the inlet of the air passage to an external air supply pipe, connecting the inlet of the pressurizing chamber to an external pilot air supply pipe, and connecting the valve body to an end opposite to the outlet of the valve body. Insert an end wall separate from the
The outer surface of the end wall opposite to the outlet is formed with a partially spherical convex surface, the apex of the convex surface is aligned with the center line of the hole and the valve body, a presser plate is seated at the apex, and the area around the apex is A starting valve for a diesel engine characterized by a holding plate fixed to a cylinder head with a plurality of bolts.