JP3538280B2 - Crosshead type two-stroke internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a crosshead type 2
An engine frame box mounted on top of a bed plate, comprising a bed plate having a top surface, a lateral stiffener and a vertical guide for a crosshead mounted on the lateral stiffener. When a cylinder segment with a cylinder liner, the <br/> cylinder section and front and said engine frame box
Serial and a stay bolt for attachment to the bed plate, the engine frame box having a substantially vertical stay bolts stiffeners extending from the top of the stay bolt surrounds and the engine frame box to the bottom, the main bearings for the crankshaft the beds <br/> de plate, the upper surface of the bed plate
Of is attached to the lower position, the lower end of the stay bolt, the main Beari and the upper surface of the bed plate
Between the mounting height position of the bed and the bed plate
The invention relates to a two-stroke internal combustion engine mounted on a vehicle.

[0002]

Such an engine is known from the applicant's International Patent Publication No. WO 94/12784, in which a vertical staybolt stiffener is provided with a crosshead guide plane and an outwardly facing guide plane support. A guide plane stiffener extending between the body and the lateral stiffener of the engine frame box. This document describes the use of double stay bolts, i.e. providing two pairs of two stay bolts on each of the internal lateral stiffeners. Due to the double stay bolts, a frame box with extremely high lateral rigidity can be designed. This is the way to stiffen the lateral stiffener through-going plate wall
It is because it can be manufactured as.

This structure has drawbacks in the design of the bed plate. In particular , there are drawbacks in the cast transverse wall, which includes the fixed housing part of the main bearing and extends to the upper surface of the bed plate. This is because the dimensions of these walls must be large in the longitudinal direction of the engine, so that the lower ends of the two pairs of stay bolts are mounted side by side. The longitudinal dimension of the side wall of the bed plate
The law also size Kunar. This means that the lateral stiffener in the engine frame box passes between the two stay bolts.
That's because. As a result, the lower end of the stay bolt is located at a predetermined distance behind and in front of the intermediate length position of the main bearing . This results in an inappropriate stress distribution on the lateral walls of the bed plate.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an engine having a design which solves the above-mentioned problems.

[0005]

SUMMARY OF THE INVENTION In view of the above object, a two-stroke internal combustion engine according to claim 1 is a tube in which a stay bolt stiffener is incorporated in a lateral stiffener of a frame box. Extends through the center of the tube and the lower end of the stay bolt is in the middle of the lateral stiffener
On each side of the main bearing
An engine mounted on the top of the rate .

Looking exclusively at the path of the staybolts in the engine frame box, this design of the staybolt tube allows only one staybolt on each side of each main bearing.
The design with the engine frame is achieved
Below, the stay bolt is positioned at the center of the lateral stiffener.
, Is fixed to the top of the bed plate.

[0007] Since the force acts on the plane of symmetry, distortion deformation such as twisting of the lateral wall caused by fastening of the stay bolt is reduced. Even in the event of an unsuitable small deformation of the associated main bearing operating condition, both reliability and ease of engine assembly and disassembly work are reduced by the prior art construction of mounting two stay bolts on the upper surface of the bed plate. It is improved compared to.

In a preferred embodiment, the staybolt tube is integrated into the lateral stiffener of the frame box and is remote from the crosshead guide in the lateral direction of the engine. This moves the stay bolt mounting point at the top of the bed plate away from the midplane of the engine and thus away from the main bearing, which is not affected by the stay bolt tightening. And provide space for the main bearing components. This improvement in spatial conditions is particularly important when removing the upper part of the main bearing housing. This means that the guide plane terminates at some distance above the engine frame box and the upper part is lifted a certain distance above the upper surface of the bedplate before moving away from the longitudinal direction of the engine. In order to provide space for them.

The staybolt tube is a circular tube incorporated into the single-layer plate wall, but may have a square cross section or may be a part of a double-walled lateral stiffener.

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
1 shows one half of a bed plate 1 for a large crosshead engine such as a marine propulsion engine or a stationary power generation engine having an output of about 5000 kW. An engine frame box 2 and a cylinder section 3 are mounted on the upper surface of the bed plate. The three main components 1, 2, and 3 are symmetric about a longitudinal symmetry plane 4 of the engine. For cylinder classification,
A cylinder liner (not shown) is mounted in a conventional manner, and the cylinder section is fitted with connecting rods, crossheads, piston rods, and pistons, and the cylinder section is covered with cover studs threaded into the top of the cylinder section. Cover is clamped. These components are very well known and are not relevant to the present invention and are not shown in the drawings for clarity.

The engine frame box is reinforced by lateral stiffeners 5 between the cylinders. This stiffener may be a single-layer plate wall or a double-walled frame. The lateral stiffener supports a guide 6 for the crosshead. On the outwardly facing backs of these guides, stiffeners are provided which transmit lateral forces from the crosshead to the lateral stiffeners 5. The crosshead guide 6 terminates further above the bottom flange 7 of the engine frame box, so that above the main bearing 8 there is a gap defining a good space for handling the upper part 9 of the bearing housing. The bearing stud 10 can be removed by lifting the upper part of the bearing housing.

The bed plate 1 has a lateral wall 11 below the lateral stiffener 5. The lower part 12 of the main bearing housing is formed integrally with the wall 11. Upper housing
The main bearer is above the height position where the
The integration of the ring and the wall 11 has been completed . When manufacturing a bed plate, a main bearing is boring to a predetermined size by a general boring operation. Therefore, in order to make the alignment of the engine as good as possible, it is desirable to minimize the deformation of the bed plate in the area around the lower part 12 during engine assembly. These components are clamped together by stay bolts 13 attached to the top of the bed plate so that the deformation caused by clamping the bed plate, engine frame box, and cylinder clamp to each other is not applied to the bed plate. You. The path of the stay bolt is clearly shown in FIG. 1 by a partial section along the longitudinal axis of the stay bolt.

The stay bolts 13 pass through holes in the cylinder section 3 and extend further downward through stay bolt tubes 14 of the engine frame box. The lower end 15 of the stay bolt is screwed into an upward female screw hole of the bed plate. Instead of screwing the area below the stay bolt into the screw hole, a recess communicating with the upwardly opened through hole may be provided in the bed plate. In this case, the lower end of the stay bolt is attached by a nut inserted into the recess. The upper end of the stay bolt is threaded,
A nut 17 is screwed onto this thread and is tightened downward against the upper surface of the cylinder section, at the same time the stay bolt is elastically extended.

In the embodiment shown, the stay bolt consists of two parts joined by a bush 16 with internal threads. The bush contacts the inside of the bore of the cylinder section and supports the stay bolt laterally. This design is particularly advantageous for large engines with stay bolts up to 9 m. Furthermore, the stay bolt can be manufactured in one piece.

The stay bolt tube 14 is configured such that the lower end of the stay bolt has a main bearing in the longitudinal direction of the engine.
So that it can be mounted substantially opposite the center of the
That is, it is attached to the lateral stiffener 5 so that it is attached to the top of the bed plate at the center of the lateral wall 11 but at a laterally offset position with respect to the main bearing. This installation state is considerably omitted
This is shown in FIG .

Depending on the size of the engine, the length of the stay bolt is 3 m to about 9 m, and the length of the stay bolt tube 14 extending from the upper flange to the lower flange of the engine frame box is 1.5 m to about 5 m. It is.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a half of an engine according to the present invention.

FIG. 2 is a horizontal cross-sectional view of the lateral stiffener of FIG. 1 along the line II-II.

[Explanation of symbols]

Reference Signs List 1 Bed plate 2 Frame box 3 Cylinder section 5 Stiffener 6 Crosshead guide 8 Main bearing 13 Stay bolt 14 Stay bolt tube

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-50514 (JP, A) JP 6-48137 (JP, Y2) WO 94/012784 (WO, A1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F02F 1/00-11/00 F16C 5/00

Claims (4)

(57) [Claims] 1. A crosshead type two-stroke internal combustion engine.
Bed plate (1) with top surface
Directional stiffener (5) and clamps attached to the lateral stiffener
Said bed having a vertical guide (6) for a loss head;
Engine frame box mounted on top of rate
(2) and cylinder classification with cylinder liner
(3) the cylinder section and the engine frame
A box for attaching a box to the bed plate
A tapered bolt (13);
Box (2) surrounds the stay bolt and
Substantially extending from the top to the bottom of the engine frame box
With a vertically vertical stay bolt stiffener
In the bed plate, the main bearing for
Attached to a position below the upper surface of the bed plate.
And the lower end of the stay bolt is
Mounting height position of the upper surface of the seat and the main bearing
Between and attached to the bed plate,
In a two-stroke internal combustion engine, The stay bolt stiffener is located next to the frame box.
Tube (14) incorporated in the directional stiffener (5)
Ri, The stay bolt (13) extends in the center of the tube.
AndThe bed plate is located below the lateral stiffener (5).
Has a side wall (11), At the top of the bed plate, the side wall (11)
A fixing hole is provided in the center, The lower end (15) of the stay bolt is attached to the fixing hole.
And the force of the stay bolt is applied to the plane of symmetry of the lateral wall.
Worked Two-stroke internal combustion
engine. 2. A stay bolt tube (14) is incorporated in the lateral stiffener (5) of the frame box,
2. The engine according to claim 1, wherein the crosshead guide is spaced laterally from the engine.
Stroke internal combustion engine. 3. A two-piece fastener according to claim 1, wherein the stay bolt tube has a circular cross section and is incorporated in a lateral stiffener in the form of a single-layer plate wall.
Stroke internal combustion engine. 4. The two-stroke internal combustion engine according to claim 1, wherein the stay bolt tube has a rectangular cross section and is incorporated in a double-walled lateral stiffener.