CN214165338U

CN214165338U - A crowbar formula flywheel separation instrument for DA42NG aircraft

Info

Publication number: CN214165338U
Application number: CN202120254563.9U
Authority: CN
Inventors: 孟现召; 熊良建
Original assignee: Civil Aviation Flight University of China
Current assignee: Civil Aviation Flight University of China
Priority date: 2021-01-29
Filing date: 2021-01-29
Publication date: 2021-09-10
Anticipated expiration: 2031-01-29

Abstract

The utility model provides a crow bar formula flywheel separation instrument for DA42NG aircraft, characterized by: the T-shaped head base plate is welded with the extension bar vertically to form a whole; the T-shaped head base plate comprises an arc-shaped top and a semicircular bottom, and the arc-shaped top protrudes outwards and is used for being attached to the inner side surface of the outer edge of the hub mounting seat; the semicircle at the bottom of the semicircle is recessed inwards to stop the mounting seat rivet. After the utility model is used, the operation is convenient and fast, the working time is saved, and the maintenance efficiency is improved; the damage to the machine parts can be avoided to the maximum extent, and the material cost is reduced; when the hub is separated from the mounting seat, one side of the oval positioning pin hole with relatively small friction force between the hole and the pin does not need to be selected for separation in advance, and only the operation is considered to be executed according to the correct separation sequence, so that the problems of deformation of the hub mounting seat at the circular pin hole position, pulling-out of the positioning pin at the circular pin hole position from the hub mounting seat and the like are effectively reduced.

Description

A crowbar formula flywheel separation instrument for DA42NG aircraft

Technical Field

The utility model relates to an aircraft maintenance field technique, especially a crowbar formula flywheel separation tool for DA42NG aircraft.

Background

The DA42NG aircraft employs a compression ignition aviation piston engine fueled by aviation kerosene, the engine having a dual mass flywheel mounted on the crankshaft for increasing the crankshaft rotational inertia. And a hub plate is arranged on the double-mass flywheel. The dual-mass flywheel is installed on the end face of the crankshaft through 8 bolts, the hub is installed on a hub installation seat of the end face of the flywheel through another 8 bolts, and an axial key groove is formed in the inner wall of a hub central cylinder and used for being connected with the speed reducer, so that the dual-mass flywheel and the hub achieve connection and torque force transmission between the crankshaft of the engine and the speed reducer. The hub plate shields 8 fixing bolts of the dual-mass flywheel on the end face of the crankshaft after being installed, the fixing bolts can be prevented from completely falling off in vibration after being loosened, and safety is improved. In the maintenance work, the dual-mass flywheel needs to be periodically detached for function check, and the hub is separated from the dual-mass flywheel to become indispensable work.

Two positioning pins are embedded on the hub plate mounting seat on the dual-mass flywheel and are respectively arranged on two sides of the periphery of the mounting surface of the hub plate mounting seat facing to the hub plate, but the two positioning pins are not 180-degree symmetrical, the positioning pins are kept on the hub plate mounting seat under the normal condition, and the dual-mass flywheel is integrally scrapped if the positioning pins are loosened from the hub plate mounting seat. The hub plate is provided with two positioning pin holes, the hub plate is required to be circumferentially positioned through the positioning pins/the positioning pin holes when the hub plate is installed on the hub plate installation seat, and the two positioning pins are asymmetric in position, so that the hub plate has a unique installation position on the hub plate seat. The design allows the hub to be separated from the mounting seat in advance from one side of the circular positioning pin hole; on the contrary, because the circular positioning pin hole generates hole/pin axial deflection limitation within the range of 360 degrees to the positioning pin in interference fit, when one side of the elliptical hole is separated, the axial deflection trend generated between the circular pin hole/pin cannot be avoided, the hub mounting seat at the position of the circular pin hole is easy to deform, and the dual-mass flywheel is scrapped integrally; and because the locating pin hole and the locating pin are in interference fit, if the hub is separated from the mounting seat on one side of the oval locating pin hole in advance, the axial deflection trend generated between the round pin hole and the round pin tends to further increase the friction force between the round locating pin hole and the round pin, the locating pin is easy to be pulled out of the hub mounting seat, and the dual-mass flywheel is also scrapped integrally.

Due to the lack of a dedicated tool for separating the hub from the mounting plate, operators in aircraft maintenance work tend to separate the hub from the mounting plate from the side of the elliptical dowel hole where the friction between the dowel pin and the hub is relatively small, and then rotate the hub left and right to separate the hub from the circular dowel hole. The separation method is contrary to the above-mentioned correct separation method, and the deformation of the hub mounting seat at the position of the circular pin hole and the pulling-out of the positioning pin at the position of the circular pin hole from the hub mounting seat are more frequently caused in the maintenance practice, so that the integral rejection rate of the dual-mass flywheel is higher, the dual-mass flywheel is expensive, the maintenance operation efficiency is low, and higher material cost is brought. Therefore, a special separation tool capable of avoiding the defects is required in engineering practice.

Disclosure of Invention

The utility model aims to solve the technical problem that a crow bar formula flywheel separation instrument for DA42NG aircraft is provided, adopt the T shape head through accurate design to stretch into the separation from the flywheel with lever principle between hub and the flywheel from the dual mass flywheel in front, can accomplish in a few seconds, it is laborsaving to save time, it just causes the flywheel to go up hub mount pad deformation or the whole condemned drawback of dual mass flywheel of locating pin pine takes off easily to have avoidd when traditional separation method consumes labour time, manpower and materials loss has been reduced, efficiency is improved.

In order to realize the purpose of solving the technical problem, the utility model adopts the following technical scheme:

the utility model discloses a crowbar type flywheel separation tool for DA42NG airplane, which comprises a T-shaped head base plate and an extension bar, wherein the extension bar is vertically welded on the T-shaped head base plate to form a whole; the T-shaped head base plate comprises an arc-shaped top and a semicircular bottom, and the arc-shaped top protrudes outwards and is used for being attached to the inner side surface of the outer edge of the hub mounting seat; the semicircle at the bottom of the semicircle is recessed inwards to stop the mounting seat rivet.

More particularly, the maximum width of the top of the base plate of the T-shaped head is smaller than the maximum width of a specific access hole on the hub.

More specifically, the prying type flywheel separation tool is made of stainless steel or high-carbon steel.

The utility model relates to a prying bar formula flywheel separation instrument for DA42NG aircraft can be as the separation instrument of dual mass flywheel and hub, stretches into between hub and the flywheel through the preceding specific hole of being close to of dual mass flywheel through the T shape head of accurate design and utilizes lever principle to separate the hub from the flywheel.

The specific operation steps are as follows:

1. the 8 connecting bolts between the flywheel/hub were removed and the access hole closest to the circular locating pin hole was found.

2. The top of the T-head of the tool is tilted forward and downward to slide the T-head into the access hole closest to the circular locator pin hole.

3. The top of the T-shaped head of the tool is inclined upwards and the T-shaped head is retracted, so that the semicircular opening at the bottom of the T-shaped head is stopped on the rivet on the mounting seat below the hub.

4. Visual observation of the upper part of the approach hole confirms that the top of the T-shaped head of the tool is attached to the inner side surface of the mounting seat below the hub, and the tool cannot extend into the lower part of the outer edge of the mounting seat, otherwise the outer edge of the mounting seat is deformed when the extension rod of the tool is wrenched; after the tool is confirmed to be correct, the extension rod of the tool is pulled backwards, and the hub can be separated from the positioning pin by utilizing the lever principle.

5. The hub can be completely separated from the flywheel by performing the same steps on one side of the oval dowel hole in the same way.

By adopting the technical scheme, the utility model discloses following beneficial effect has:

1) the method is convenient and quick, saves working hours and improves maintenance efficiency;

before the tool is published, a special hub/flywheel separating tool is lacked when the disassembling and assembling work of an engine of a DA42NG airplane or a dual-mass flywheel with the same design is carried out in the industry field, a combination surface between a hub and a mounting seat is very flat, a combination gap is basically invisible, an operator has no need to start, the time and labor are wasted when the hub is separated from the mounting seat, and the practical effect is poor.

Use the utility model discloses an behind the instrument, adopt lever structural design because of the instrument, and simple to operate, laborsaving saving time can reach the purpose of practicing thrift man-hour, improving maintenance efficiency.

2) The damage of machine parts is avoided to the maximum extent, and the material cost is reduced;

before the publication of this fixing tool, when the dismounting work of the engine of the DA42NG airplane or the dual mass flywheel with the same design is performed in the industry field, the operator tends to adopt a method of separating the hub from the mounting seat from one side of the oval positioning pin hole with relatively small friction force between the hole and the pin, and then rotating the hub left and right to separate the hub from the circular positioning pin hole.

Use the utility model discloses an after the instrument, because of this instrument can easily accomplish the separation work of hub disc circular location pinhole one side, needn't select hole/round pin relatively less oval location pinhole one side of frictional force to separate in advance when separating the hub disc from the mount pad from this again, and only consider to carry out the operation according to the exact separation order, circular pin hole position hub disc mount pad deformation that has effectively reduced the reverse order operation and brought and the trouble case that circular pin hole position locating pin extracted from the hub disc mount pad, can furthest avoid parts damage, reduce material resources cost.

Drawings

Fig. 1 and 2 are schematic views of the mounting relationship of the hub and the flywheel of a DA42NG aircraft.

FIG. 3 is an overall view of a pry bar type flywheel separation tool for a DA42NG aircraft.

FIGS. 4-6 are schematic three-view illustrations of a crowbar flywheel separation tool for a DA42NG aircraft; fig. 4 is a front view, fig. 5 is a left side view, and fig. 6 is a plan view.

Fig. 7-9 are schematic views illustrating the operation of separating the hub from the flywheel using the tool of the present invention.

1-flywheel, 2-hub plate, 3-round pin hole, 4-rivet, 5-oval pin hole; 7-positioning pin, 8-pry type flywheel separation tool, 9-T-shaped head base plate, 10-extension bar, 11-arc top and 12-semicircular bottom.

Detailed Description

The patent is further explained below with reference to the drawings. The scope of protection of the patent is not limited to the specific embodiments.

Example 1

As shown in fig. 3-6, the pry type flywheel separation tool 8 for the DA42NG airplane comprises a T-shaped head base plate 9 and an extension bar 10, wherein the extension bar 10 is vertically welded on the T-shaped head base plate 9 to form a whole; the T-shaped head base plate 9 comprises an arc-shaped top part 11 and a semicircular bottom part 12, wherein the arc-shaped top part 11 protrudes outwards and is used for being attached to the inner side surface of the outer edge of the mounting seat of the hub 2; the semi-circle of the semi-circular bottom 12 is recessed inwardly for stopping against the mount rivet 4.

The T-shaped head base plate 9 is precisely dimensioned to include an arcuate top portion 11 of radius R =76mm for engaging the inside of the outer edge of the hub 2 and a semi-circular bottom portion 12 of radius R =5mm for stopping against the rivet head of the hub, and the maximum width L =24mm of the top portion of the T-shaped head base plate 9 that can pass through a particular access hole in the hub 2. The prying type flywheel separation tool 8 is made of stainless steel or high-carbon steel.

As described in fig. 7-9, the operation steps are:

1. the 8 connecting bolts between the flywheel 1 and the hub 2 are removed and the closest hole to the circular dowel hole 3 is found.

2. The top of the T-head of the tool is tilted forward and downward so that the T-head slides into the access hole closest to the location of the circular dowel hole 3.

3. The top of the T-head of the tool is tilted upwards and the T-head is retracted so that the semicircular opening at the bottom of the T-head is stopped on the rivet 4 on the mounting base below the hub 2.

4. Visual observation of the upper part of the approach hole confirms that the top of the T-shaped head of the tool is attached to the inner side surface of the mounting seat below the hub 2, and the tool cannot extend into the lower part of the outer edge of the mounting seat, otherwise the outer edge of the mounting seat is deformed when the extension rod of the tool is wrenched; after the tool is confirmed to be correct, the extension rod of the tool is pulled backwards, and the hub 2 can be separated from the positioning pin 7 by utilizing the lever principle.

5. By performing the same steps on the side of the elliptical dowel hole 5 in the same manner, the hub 2 can be completely separated from the freewheel 1.

Claims

1. A pry type flywheel separation tool for a DA42NG aircraft is characterized in that: the T-shaped head base plate is welded with the extension bar vertically to form a whole; the T-shaped head base plate comprises an arc-shaped top and a semicircular bottom, and the arc-shaped top protrudes outwards and is used for being attached to the inner side surface of the outer edge of the hub mounting seat; the semicircle at the bottom of the semicircle is recessed inwards to stop the mounting seat rivet.

2. The pry bar type flywheel separation tool for a DA42NG aircraft according to claim 1, wherein: the maximum width of the top of the base plate of the T-shaped head is smaller than the maximum width of a specific access hole on the hub.

3. The pry bar type flywheel separation tool for a DA42NG aircraft according to claim 1, wherein: the prying bar type flywheel separation tool is made of stainless steel or high-carbon steel.