JP5032906B2 - How to install a waterjet propulsion device on the hull - Google Patents

Description

  The present invention relates to a method for attaching a water jet propulsion device to a hull of a water jet propulsion type ship.

  In a ship equipped with a water jet propulsion device at the rear of the hull, such as a water jet type aluminum ship, an engine is arranged at the rear or center of the hull, and from this engine to the impeller that constitutes the stern propulsion device A method of driving the gap using a drive shaft is employed.

  For example, in a water jet propulsion ship, the distance between the main engine provided in the center of the hull and the impeller provided in the water conduit arranged at the rear of the hull is long, and the rotation speed of the main engine is too high. Therefore, a bearing and a reduction gear are provided between the main engine and the impeller, these devices are connected by a first power transmission shaft, and a first power transmission shaft is connected between the reduction gear and the impeller. Proposed is a device that is connected by two power transmission shafts, prevents bending of the first power transmission shaft by the bearing, and makes the second power transmission shaft thicker than the first power transmission shaft according to the transmission torque (Patent Document 1).

Moreover, the structure which connects the hull transom of a water jet propulsion ship and a transom flange with a volt | bolt is proposed (patent document 2).
JP 2003-146291 A JP 2003-112690 A

  The invention described in Patent Document 1 proposes a structure for preventing the deflection of the first power transmission shaft by disposing a bearing and a speed reducer between a main engine and an impeller in a water jet propulsion ship. Means for aligning a series of shaft centers of the first power transmission shaft from the main engine to the speed reducer via the bearing and the second power transmission shaft connecting the speed reducer and the impeller of the pump device. Is not taught at all.

  Further, Patent Document 2 describes a mounting structure between a hull transom and a transom flange. However, in the invention described in this patent document, a method for mounting a transom flange by processing a flange surface of a hull transom is disclosed. It has only been done. Therefore, in this processing method, a special cutting device must be prepared and processed, and the construction cost of the water jet propulsion ship must be expensive.

  FIG. 2 shows the main part of a water jet type aluminum ship. The suction port 3a of the water guide pipe 3 is opened toward the front of the bottom of the hull 1, and the impeller 4 and the nozzle 5 of the pump device are provided at the rear part thereof. Further, the steering device 6 is arranged at the rear part thereof. The impeller 4 and the engine 2 are connected by a drive shaft 7.

  As shown in FIG. 4, the impeller casing 9 is arranged so that the shaft core (line of sight L) of the transom short pipe 8 attached to the stern end 1 a is aligned with the impeller casing 9 while being accommodated in the impeller casing 9. Inserted and fixed.

  FIG. 3 shows a state in which the transom short pipe 8 is fixed to the stern flange 11 provided at the stern end 1a and the rear end portion of the water guide pipe 3 and the cylindrical portion of the transom short pipe 8 are connected by a flange. . As shown in FIG. 4, the transom short pipe 8 is integrally formed with a water jet propulsion device 10 including a steering device 6, a nozzle 5, an impeller casing 9 for housing the impeller 4, and the like. The impeller casing 9 is fitted and fixed to the pipe 8.

  As shown in FIGS. 2 and 4, the impeller 4 is accommodated in the impeller casing 9, and a slight gap is formed between the tip of the blade and the inner peripheral surface of the impeller casing 9. Although this gap differs depending on the model and size, generally, if the mounting angle of the transom short tube deviates by “± 0.1 to 0.15 degrees” with respect to the shaft center, the impeller 4 and the impeller casing 9 come into contact with each other, resulting in large vibrations. There is a problem that a predetermined pump performance cannot be exhibited.

  Therefore, as shown in FIG. 4, the impeller 4 is mounted so that the rotational surface of the impeller 4 is orthogonal to the drive shaft 7, and the surface of the flange 9a of the impeller casing 9 and the surface of the flange 8a of the transom short tube 8 are parallel. Face to face and need to be fixed accurately.

  However, in reality, there is an eccentricity error in the positional relationship between the inner surface of the impeller casing 9 and the impeller 4, and it is often impossible to assemble correctly. Therefore, normally, as shown in FIG. 5, the inclination adjustment margin “A” is provided to adjust (correct) the inclination of the attachment surface 11a of the stern flange 11 fixed directly to the stern end 1a.

  When the stern flange 11 is fixed to the stern end 1a, it is necessary to adjust the mounting surface 11a by boring the error of the stern flange 11 within the range of the inclination adjustment margin A.

  However, in order to accurately drill the inclination of the mounting surface 11a of the stern flange 11 fixed to the stern end 1a, the position measured over the entire circumference of the rear part of the stern flange 11 in the preparation stage corresponds to the position. It is necessary to use a special boring device capable of cutting the surface standing in the vertical direction based on the data after measuring the inclination and the like, and to perform the cutting process for a considerable time.

  Therefore, for example, when the stern flange 11 having a diameter of about 1 m is processed on site, there is a problem that it requires a cost of at least 5 million yen or more and working time.

  An object of the present invention is to solve the problem of requiring a great deal of time and cost for adjusting the mounting surface of the stern flange in the prior art.

  The present invention for solving the above-described problems is configured as follows.

1) Connect the suction port of the water conduit to the opening at the bottom of the hull, and connect the rear end of this water conduit to the transom short tube fixed to the stern, and connect it to a drive device such as an engine provided in the hull. In the construction process of the water jet type ship in which the drive shaft is extended into the transom short tube and the impeller accommodated in the transom short tube is fixed to the drive shaft.
A step of measuring an inclination error of the surface of the stern flange fixed to the stern portion of the hull with respect to the axis of the drive shaft; and a face of the transom short tube fixed to the stern flange is fixed to face the stern flange. A step of cutting the surface of the flange in accordance with the inclination error; and the transom short tube is fixed to the stern flange.

  2) A value obtained by measuring an error in the thickness direction of the stern flange and a plane perpendicular to the axis of the drive shaft passing through the center of the stern flange fixed to the stern portion at an interval of at least 90 degrees of the stern flange. It is characterized by a gradient error.

  3) When measuring the tilt error of the stern flange with respect to the axis of the drive shaft, the axis is formed by a laser beam or a piano wire.

  4) The inclination error in the thickness direction of the stern flange is measured at the hull construction site, and the data is communicated to the factory that processes the transom short tube, and the flange surface of the transom short tube is cut using this data. It is a feature.

  5) The rough material of the transom short pipe fixed to the stern flange provided at the stern part of the water jet propulsion type ship has a thickness compared with the normal thickness of the flange forming the short pipe. It is characterized in that it can be adjusted by cutting the inclination error of the stern flange by this thickness.

  In the present invention, the flange of the transom short pipe is characterized in that it is formed thicker by the amount of inclination adjustment.

  An error with respect to the axis of the drive shaft (line of sight) has occurred in the circumferential direction on the mounting surface of the stern flange fixed to the stern of the water jet hull. In consideration of the gradient error, the gradient error is corrected at the factory by using the adjustment allowance of the transom short tube, so that the processing can be performed accurately and easily. It can be installed at low cost.

  FIG. 1 is a side view of a transom short tube 80 according to an embodiment of the present invention. A flange 81 of the transom short tube 80 is added with a normal thickness “F” and a transom short tube inclination adjustment allowance “A1”. It is characterized in that it is formed with a thickness “T” or slightly thicker.

  In the first processing step, as shown in FIG. 3, the inclination of the mounting surface S of the stern flange 11 fixed to the stern end 1 a of the hull 1 with respect to the axis (line of sight L) is determined by the stern flange 11. The measurement is performed over the entire circumference, and the measured position and the error (error with respect to the line of sight L) at the location are measured to measure the “gradient error”. In addition, although the method using a laser beam is suitable for the measurement of the said line of sight L (measurement of an axial center), it is also possible to measure using a piano wire.

  In the next step, data (gradient) measured on the basis of the mounting surface S of the stern flange 11 fixed to the hull so as to cancel the “gradient error” using a milling machine or the like as the cutting equipment in the factory. Based on the error), the inclination adjustment margin “A1” of the flange 81 of the transom short tube 80 is cut.

  As described above, when the portion of the inclination adjustment allowance “A1” shown in FIG. 1 is cut by the machine equipment in the factory, the center line L1 of the transom short tube 80 becomes the proper place (the center of FIGS. 3 and 4). Corresponding to the line L).

  Accordingly, by attaching the transom short tube 80 whose inclination is adjusted as described above to the stern flange 11 depicted in FIG. 3, the center line L of the stern flange 11 and the center line of the transom short tube 80 are adjusted. L1 (FIG. 1) matches.

  In this state, as described above, the impeller casing 9 and the impeller 4 inside the impeller casing 9 are concentrically held, and the rotation surface at the tip of the impeller and the inner surface of the impeller casing 9 are A water jet propulsion device that can keep the gap constant and keep the pump performance to the maximum can be installed on the stern.

  In the present invention, by cutting the surface of the flange 81 of the transom short tube 80 (inclination adjustment allowance 82 of the transom short tube 80), the axis of the transom short tube 80 can be aligned with the axis of the drive shaft 7. It becomes possible.

  Therefore, in the conventional process, a process with difficulty in cutting the mounting surface 11a of the stern flange 11 (FIGS. 3 and 5) fixed in an upright state is required. Since the transom short tube 80 (coarse material), which is a product, can be handled as a single unit, the axis can be accurately aligned using a normal machine tool in the factory. Can be completed very easily and at a low cost (about one-tenth of the conventional one).

It is a side view of the transom short tube concerning the present invention. It is a schematic sectional drawing of the stern part of the aluminum ship equipped with the water jet propulsion apparatus. It is sectional drawing which shows a stern part structure. It is explanatory drawing which shows the state which fixes a water jet propulsion apparatus to a stern part. It is sectional drawing which shows the conventional stern flange and a transom short pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hull 1a Stern end 3 Water guide pipe 3a Water inlet 4 Impeller 5 Nozzle 6 Steering device 7 Drive shaft 8 Conventional transom short pipe 9 Impeller casing 10 Water jet propulsion apparatus 11 Stern flange 11a Mounting surface 80 Transom short pipe (of the present invention)
81 Flange 82 Transom short pipe inclination adjustment allowance

Claims (4)

The suction port of the water conduit was connected to the opening at the bottom of the hull, and the rear end of this water conduit was connected to a transom short tube fixed to the stern and connected to a driving device such as an engine provided in the hull. In the construction process of the water jet type ship in which the drive shaft is extended into the transom short tube and the impeller accommodated in the transom short tube is fixed to the drive shaft,
Measuring a tilt error of the surface of the stern flange fixed to the stern portion of the hull with respect to the axis of the drive shaft;
Cutting the surface of the flange of the transom short tube fixed to the stern flange facing the stern flange according to the inclination error, and fixing the transom short tube to the stern flange And a step of attaching the water jet propulsion device to the hull.   A value obtained by measuring an error in a thickness direction of the stern flange at least at an interval of 90 degrees with respect to a plane perpendicular to the axis of the drive shaft passing through the center of the stern flange fixed to the stern portion. 2. A method of attaching a water jet propulsion device to a hull according to claim 1, wherein the error is an error.   The water jet on the hull according to claim 1, wherein when measuring the tilt error of the stern flange with respect to the shaft axis of the drive shaft, the shaft core is formed by a laser beam or a piano wire. How to install the propulsion device.   The inclination error in the thickness direction of the stern flange is measured at the hull construction site, and the data is communicated to a factory for processing the transom short tube, and the flange surface of the transom short tube is cut by this data. A method for attaching a water jet propulsion device to a hull according to claim 1.

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