JPH07269553A - Crosshead type piston engine - Google Patents

Abstract

PURPOSE: To prevent a guide member or guide shoes of a crosshead from being damaged or fatigued. CONSTITUTION: A guide member has two sliding surfaces 9, 10 directing to the outside in an engine crossing direction and an auxiliary sliding surface 28 directing in an engine longitudinal direction. The guide member is arranged at an engine longitudinal direction center, is vertically extended in an engine height direction and is rotatably supported by a frame box. Upper end and lower end of the guide member can be adjusted in position in the engine cross direction by a supporting stay. A crosshead has U-shaped guide shoes provided with two sliding surfaces 37, 38 facing each other. The guide member is stored between these guide shoes and the sliding surfaces 37, 38 slide along the sliding surfaces 9, 10 directing to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosshead piston engine in which a guide shoe of a crosshead is guided in a transverse direction of an engine along a sliding surface of a guide member provided in an engine frame box.

[0002]

2. Description of the Related Art Generally, a crosshead is constructed by providing two guide members facing each other in the transverse direction of the engine and arranging a guide shoe between the sliding surfaces of both guide members. At this time, the guide member is formed with a sliding surface facing inward, while the guide shoe contacting with the guide member is formed with a sliding surface facing outward.

This guide member is usually fixed to a transverse wall in a frame box provided between the engine plate and the cylinder portion. Generally, since the transverse wall is produced by casting, the guide member is not separated but is formed integrally with the transverse wall, but it is often the case that the guide member is separately produced and fixed to the transverse wall by welding. Done. In the case of welding, the reinforcing member inclined from the free end of the guide member to the transverse wall is reinforced.

[0004]

However, in the method of forming the guide member together with the transverse wall in the frame box, the machining accuracy of the guide member is required to be extremely high, and it takes a lot of time to manufacture the guide member. It becomes very expensive. That is, in order to prevent the guide shoes that slide between the guide members from biting during engine operation,
The sliding surface of the guide member needs to maintain a high degree of parallelism, but it is not easy to process because the sliding surface is inside the frame box. Further, the guide member which is integrated with the transverse wall in the frame box is likely to be deformed or bent when receiving the compressive force of the stay bolt near the center of the transverse wall.

On the other hand, when the engine is started after a long stop period or when the engine load changes significantly, thermal expansion and contraction are not uniform, and the guide member supported by the transverse wall is distorted. It is easy to occur. Such deformation of the guide member causes a partial contact with the guide shoe that is in contact with the slip surface, and the guide shoe is locally heated and greatly expands. In the worst case, the local expansion of the guide shoe causes the guide shoe to be caught between the sliding surfaces.

Further, in the case of an engine installed on a ship, a small strain is repeatedly applied from the moving ship to the transverse wall and to the guide member, so that both the guide shoe and the guide member are exposed to fatigue.

It is therefore an object of the present invention to provide a crosshead piston engine in which the guide member or guide shoe is not damaged or exposed to fatigue.

[0008]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a guide member centered in the longitudinal direction of an engine so that a slip surface faces at least partly outward in a transverse direction of the engine, whereby a guide shoe of the guide shoe is provided. It is characterized in that the sliding surface is arranged so as to come into contact with the sliding surface on the opposite side apart from the guide member.

[0009]

According to the present invention, the guide member is provided at the center of the longitudinal direction of the engine. Since this reduces the displacement of the slip surface when the transverse wall is distorted, the influence of the distortion can be avoided. The guide shoe is provided outside the guide member or so as to surround the guide member. When the guide shoe expands, the sliding surface extends away from the sliding surface and can avoid being bitten.

Further, the guide member is provided at the center of the longitudinal direction of the engine in the frame box, and the displacement of the guide member can be minimized when the transverse wall supporting the guide member is distorted.

Further, when a difference in elongation due to thermal expansion occurs between the guide member and the frame box, the slip surface is distorted. In the present invention, however, the guide member is supported at only one point, and such distortion occurs. Prevent. Desirably, this fulcrum is provided substantially in the center of the guide member extending in the engine height direction. It also pivotally mounts on the frame box.

Further, the upper end and the lower end of the guide member can be fastened in the transverse direction of the engine. In this bearing method, since the guide member is not completely connected to the frame box, thermal stress is not transmitted. Further, since the guide member is fixed in the transverse direction of the engine, the guide member can be extended vertically in the height direction of the engine even when the temperature of the guide member is higher than that of the transverse wall during operation of the engine.

In allowing the guide member to freely extend with respect to the transverse wall, the position of the fulcrum is determined at the center of the guide member.
This has the advantage of being able to distribute an equal amount above and below when extending vertically.

According to the present invention, the guide member can be easily attached to the frame box, and the adjustment is extremely easy even when the sliding surface is accurately placed parallel to the cylinder axis. That is, the centering of the guide member can be easily performed after the upper and lower ends of the guide member are fastened to the frame box with stay bolts in the transverse direction of the engine.

The guide member, in particular, is simple in the form of a beam having two sliding surfaces facing outward in the transverse direction of the engine and an auxiliary sliding surface facing in the longitudinal direction of the engine. The beam is cast and has a relatively small size and is made separately from the transverse wall as a unit. It is easy to machine to the desired accuracy before it is installed in the engine.

Also, the guide member of the present invention achieves a thorough simplification in comparison with a conventional engine having two separate guide members each supporting a guide shoe. With one guide member that supports two sliding surfaces, it is necessary to pay close attention to center the guide member on the axis of the cylinder in the conventional one, but it is difficult to attach it. It is not forced and is advantageous.

Further, a feature different from the above is that in the crosshead piston engine, the guide shoe is formed with two opposed sliding surfaces for accommodating the guide member therebetween, and the guide shoe is provided along the sliding surface facing outward. The sliding surface is made to slide.

Normally, the heat generated between the sliding surface and the sliding surface is absorbed by both the guide portion and the guide shoe, so that the guide shoe having a short dimension in the moving direction results in a temperature rise higher than that of the guide member. Fierce.

This temperature difference is further increased by the fact that the guide shoes slide alternately from one of the slip surfaces to the other. According to the present invention, since the guide member is located between the two sliding surfaces, even if the temperature of the guide shoe rises, the guide shoe freely thermally expands in the transverse direction of the engine and does not cause biting.

Preferably, the guide shoe is provided with an auxiliary sliding surface which is oriented in the longitudinal direction of the engine and is transversely arranged at the center of the guide shoe.

The auxiliary sliding surface guides the guide shoe, and the connecting rod and the piston rod in the longitudinal direction of the engine.

The sliding surface according to the present invention is located at the center of the guide shoe in the longitudinal direction of the engine, and the guide shoe does not tilt due to lateral pressure.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a sectional view of a trapezoidal frame box 1 used in a large diesel engine for a marine propulsion engine. The frame box 1 is composed of a bottom plate 4 horizontally arranged at a lower part, a ceiling plate 5 horizontally arranged at an upper part, and two side plates 2 and 3 connecting the bottom plate 4 and the ceiling plate 5. To be done. Among these members, the bottom plate 4 is connected to an engine plate (not shown), and the ceiling plate 5 is connected to a cylinder portion (not shown). The cylinder portion, the frame box 1 and the engine plate are fastened together by stay bolts 6 as a single unit.

This frame box 1 has stay bolts 6
It has a transverse wall 7 which supports a guide member 8 which absorbs the tightening force and determines the position of the crosshead which will be described later.

This guide member 8 is formed as a long beam by casting, and has two parallel surfaces facing outward in the transverse direction when the engine is mounted. These two surfaces are precisely finished by machining to become the slip surfaces 9 and 10 for the guide shoes (described later).

The pivot 11 at the main fulcrum A is pushed into the pivot hole 12 of the guide member 8 shown in FIG. The pin of the pivot 11 is the guide member 8
It is provided so as to project from the rear side. Guide member 8
A protrusion 13 surrounding the pin of the pivot 11 is provided on the rear side, and the pivot 11 is inserted into the pin hole 15 formed in the transverse wall 7.
Is inserted, the protrusion 13 of the guide member 8
The tip of is hit and positioned there. At this time, the guide member 8 can rotate around the pivot 11.

A plurality of through holes 16 are formed in the transverse wall 7 around the pin hole 15 so as to be concentric with the hole 17 formed in the guide member 8. The through hole 16 has a larger diameter than the hole 17, and when a fixing member such as a bolt 18 (see FIG. 5) is passed through the through hole 16, a certain gap is maintained and the guide member 8 rotates about the pivot 11. You can move.

Two auxiliary fulcrums B are provided at a distance from the main fulcrum A for centering the guide member 8 in the longitudinal direction of the engine (see FIG. 1).

The auxiliary fulcrum B is formed on the guide member 8 by the protrusion 1
A flat surface 14 which forms 3'and has its tip formed on the transverse wall 7
It is configured by applying it to ‘(see FIG. 3).

As shown in FIGS. 1 and 4, the guide member 8 has upper and lower forks 19 having recesses 20 continuous in the transverse direction of the engine. A support stay 21 is inserted into the upper and lower forks 19.

FIG. 7 shows a state in which one end of the support stay 21 is attached to the yoke 22. The yoke 22 extends through the transverse wall 7 and is supported there.

A main shaft 23 having a thread fixed to the yoke 22 is provided at the tip of the support stay 21, the yoke 22 is fitted to the main shaft 23, and the support stay 21 is connected by using a coupling piece 24 and a nut 25. And the yoke 22 are connected.

When the frame box 1 is used, all machining of the guide member 8 is completed before it is assembled into the engine, and the guide member 8 is assembled after the welding of the frame box 1 is completed. In the assembling method, first, the pivot 11 is fixed to the pin hole 15, and the pivot 11 is used to lower the pivot wall 11 to the transverse wall 7. With one guide member 8 supported on one of the transverse walls 7, as shown in FIG. 5, this is fixed by passing a bolt or shaft 18 across both guide members 8. 2 by this method
The book guide member 8 can be attached at the same time. At this time, the two guide members 8 are accurately centered in the longitudinal direction of the engine by shims (not shown) interposed between the protrusions 13 and 13 'and the flat surfaces 14 and 14'. The shim is made of a low friction material such as a copper-zinc alloy to act as a sliding bearing that slides along planes 14 and 14 '. Furthermore, this material is preferable also because the thermal expansion of the transverse wall 7 is easy. Further, in order to maintain the parallelism with the cylinder axis, the centering of the final guide member 8 is performed using the nut 27 attached to the holding stay 21.

Finally, the bolt or shaft 18 is tightened so as to absorb the torque provided by the guide shoe 33. At this time, the auxiliary slip surface 28 is placed in the center of the engine with a gap maintained in the longitudinal direction of the engine. The auxiliary sliding surface 28 determines the position of the crosshead, the piston rod and the connecting rod in the longitudinal direction of the engine together with the sliding surface of the crosshead which will be described later. The support stay 21 has a sufficient length so as not to restrain the extension when the guide member 8 thermally expands in the vertical direction.

Further, during the downward piston stroke operation, the shank portion of the support stay 21 which receives compression has a larger diameter than other portions.

5 and 6 show a crosshead 29 having a bearing connected to the connecting rod 30 and a crosshead pin 31 connected to a piston rod (not shown). The crosshead pin 31 has a guide shoe 33 that fits with two pins 32 protruding in the axial direction.

The guide shoe 33 is inserted into the recess 34 of the crosshead pin 31 in order to shorten the length of the crosshead 29 in the longitudinal direction of the engine. Guide shoe 3
The shape of 3 is U-shaped, and the guide member 8 is accommodated inside thereof. A thin plate 36 covered with a bearing metal such as white metal is fixed to the inner surface of the guide shoe 33 with bolts 35.

In this embodiment, when the sliding surface is worn, the entire thin plate 36 is replaced, but it is also possible to cast white metal integrally on the guide shoe 33. While the engine is running, the sliding surfaces 37, 38 of the guide shoe 33 are the sliding surfaces 9, 10 of the guide member 8.
Slide along.

For lubrication of the crosshead pin 31, lubricating oil is supplied from the communication hole 40 communicating with the oil hole formed in the pin 32 through the oil supply port 39.

Further, a thin plate 41 having an auxiliary sliding surface 42 facing the longitudinal direction of the engine is provided on the upper surface and the lower surface of the guide shoe 33. This thin plate 41 is also covered with bearing metal.
The auxiliary sliding surface 42 slides along the auxiliary sliding surface 28 while the crosshead 29 moves in the longitudinal direction of the guide member 8. As a result, the crosshead 29 can be accurately centered in the longitudinal direction of the engine.

Since the auxiliary sliding surface 42 for centering with respect to the center of the engine is formed, the crosshead 29 does not tilt due to lateral pressure. Of course, it is possible to use only one thin plate 41, but two thin plates are used as the cross head 2
It is preferable to provide as far away from the center of 9 as possible in order to reduce the lateral pressure. The thin plate 41 is fixed to the concave groove of the guide shoe 33 by the bolt 43 together with the joining member.

For lubrication of the auxiliary sliding surface 42, lubricating oil is supplied through the oil hole 44.

As described above, the centering of the guide member 8 is performed by slipping surfaces 9 and 10 when torsion is applied during engine operation.
The stay bolt 6 is to keep the displacement of the sliding surfaces 37 and 38 to a minimum and to mount the guide member 8.
After tightening, the guide member 8 can be centered when the transverse wall 7 is not deformed, which greatly affects the accuracy.

Although the sliding surface of the guide member 8 is a flat surface, it can be formed as a cylindrical surface. A guide member having a sliding surface formed in a cylindrical shape is used, and a guide shoe having at least one segment having a circular sliding surface is combined therewith. This embodiment applies to smaller engines.

[0045]

As described above, according to the present invention, the guide member is provided at the center of the longitudinal direction of the engine so that the sliding surface faces outward in the transverse direction of the engine, and the sliding surfaces of the guide shoes face each other apart from the guide member. Since it is arranged so that it contacts the sliding surface on the side, the sliding surface extends in the direction away from the sliding surface even when the guide shoe thermally expands, and the guide shoe or guide member is damaged without both sides getting caught. Can be prevented.

[Brief description of drawings]

FIG. 1 is an elevation view showing an embodiment of a frame box provided with a guide member according to the present invention.

FIG. 2 is a sectional view showing a main fulcrum portion of the guide member shown in FIG.

3 is a cross-sectional view showing an auxiliary fulcrum portion of the guide member shown in FIG.

FIG. 4 is a side view showing an end portion of the guide member shown in FIG.

FIG. 5 is a sectional view showing an embodiment of a piston engine according to the present invention.

FIG. 6 is a side view showing an embodiment of a guide shoe according to the present invention.

FIG. 7 is a detailed view showing a connecting portion between the support stay and the yoke shown in FIG.

[Explanation of symbols]

 1 frame box 8 guide member 9,10 sliding surface 21 support stay 28 auxiliary sliding surface 29 crosshead 31 crosshead pin 33 guide shoe 37,38 sliding surface 42 auxiliary sliding surface A main fulcrum B auxiliary fulcrum

Claims (9)

[Claims] 1. A piston rod and a connecting rod are connected to each other,
A piston engine having a crosshead guided by at least one guide shoe in the transverse direction of the engine, the guide member extending in a frame box in parallel with a cylinder axis, and a sliding surface of the guide member. A guide shoe having at least one sliding surface that slides along the guide member, wherein the guide member is provided at the center of the longitudinal direction of the engine so that the sliding surface faces at least partially outward in the transverse direction of the engine. A crosshead piston engine, wherein the sliding surface of the guide shoe is arranged so as to at least partially come into contact with the sliding surface on opposite sides away from the guide member. 2. A crosshead piston engine according to claim 1, wherein the guide member is provided on the frame box so as to be aligned with the center of the engine in the longitudinal direction. 3. The crosshead piston engine according to claim 2, wherein the guide member is supported at a point substantially in the middle of the guide member extending in the engine height direction in the frame box. 4. The upper and lower ends of the guide member are individually adjustable and fixable without restraining the guide member from substantially freely displacing in the engine height direction. The crosshead piston engine according to claim 3. 5. The beam according to claim 1, wherein the guide member is formed as a beam having two sliding surfaces facing outward in the transverse direction of the engine and an auxiliary sliding surface facing in the longitudinal direction of the engine. Crosshead piston engine described in. 6. A guide member provided on one of the transverse walls of the frame box is rotatably supported by at least one pivot, and the guide member is connected to the guide member through the transverse wall through a fixing means. The crosshead type piston engine according to any one of claims 3 to 5, characterized in that. 7. The crosshead piston engine according to claim 6, wherein a shim made of a low friction material is interposed between the guide member and the transverse wall. 8. A piston rod and a connecting rod are connected to each other,
A piston engine having a crosshead guided by at least one guide shoe in the transverse direction of the engine, the guide member extending in a frame box in parallel with a cylinder axis, and a sliding surface of the guide member. A guide shoe having at least one sliding surface that slides along the guide shoe, wherein the guide shoe is formed with two opposing sliding surfaces for accommodating the guide member therebetween, and a sliding surface that faces the outside of the guide member. A crosshead piston engine characterized in that the sliding surface is made to slide along the surface. 9. The guide shoe according to claim 5, wherein the guide shoe is provided with at least one auxiliary sliding surface which is oriented in the longitudinal direction of the engine and is transversely disposed at the center of the guide shoe. Crosshead piston engine.