JPH07106511B2 - How to assemble the engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an engine assembly including a crankshaft, a piston, a cylinder, and a pair of half-split crankcases divided in the axial direction of the crankshaft. Regarding the method.

(Prior Art) Conventionally, when assembling an engine of this type, a pair of half crankcases are butted against each other with the crankshaft assembled to form a crankcase, and then a small end of a connecting rod is pulled out from the crankcase. After connecting the piston to this, it is common to assemble the cylinder into the crankcase while inserting the piston into the cylinder.In this case, it is difficult for the connecting rod to swing freely and position it automatically. Most of the assembly work is done manually.

(Problems to be Solved by the Invention) By the way, before assembling the crankshaft to the crankcase, the crankshaft, the piston and the cylinder can be easily assembled with the connecting rod positioned using an appropriate jig. It is possible to automate the small assembly work of the engine.

Then, the small assembled assembly is gripped by an appropriate gripping device and assembled to the first half-split crankcase on one side, and then the second half-split crankcase on the other side is assembled to the first half-split crankcase. It is conceivable that the engine assembling work can be automated by attaching it.

However, when the cylinder is seated on the cylinder joint surface of the first half crankcase when the second half crankcase is assembled, there is a clearance between the cylinder joint surface of the second half crankcase and the cylinder. Almost never formed, second
There is a problem that interference with the cylinder is likely to occur when the half shaft crankcase is pushed into the first half crankcase side while inserting the crankshaft into the bearing attached thereto.

It is an object of the present invention to solve the above problems and provide an engine assembling method capable of automating the assembling work.

(Means for Solving the Problems) In order to achieve the above object, the present invention comprises a crankshaft, a piston, a cylinder, and a pair of half-split crankcases divided in the axial direction of the crankshaft. A method of assembling an engine, comprising: a first step of assembling an engine by combining a crankshaft, a piston, and a cylinder in an assembling step; and a first half of one side of the assembly sub-assembled in the first step. It is divided into a second step of assembling to the crankcase and a third step of assembling the second half-split crankcase on the other side to the first half-split crankcase. In the second step, the cylinder is fastened to the first half-split crankcase. Provisionally tighten the through bolt so that the cylinder can move in the cylinder axis direction.
It is characterized in that the cylinder is slid and retracted toward the cylinder head side by using the through bolt as a guide when the second half crankcase is assembled in the process.

(Operation) Since the second half crankcase is assembled to the first half crankcase with the cylinder retracted to the cylinder head side, the cylinder joint surface of the second half crankcase and the cylinder A clearance is formed therebetween, and interference with the cylinder when the second half crankcase is pushed into the first half crankcase side is prevented.

In this case, the cylinder is supported by the through bolts so as to be slidable only in the cylinder axial direction with respect to the first half crankcase, and the cylinder can be installed without assembling the second half crankcase without realigning the cylinder. The through-holes of the through bolts for fastening the cylinders to the second half-crank case match the screw holes of the second half-crank case, and the cylinder can be securely fastened to both the half-crank cases.

(Embodiment) FIG. 7 is an exploded view of a two-cycle engine for a small motorcycle assembled according to the present invention, in which a is a crankshaft, b is a piston, c is a cylinder, and d and e are crankshafts. A pair of first and second half-split crankcases divided in the axial direction, f ₁ is a first through bolt for fastening the cylinder c to the first half-split crankcase d on the right side, and f ₂ is a second half-split crankcase The 2nd through bolt fastened to case e is shown.
The first half crankcase d is formed integrally with the transmission case.

In the engine assembling process, a first process of subassembling the engine by combining a crankshaft a, a piston b, and a cylinder c, and an assembly A assembled in the first process in a first half-split crankcase d. It includes a second step of assembling and a third step of assembling the second half crankcase e with the first half crankcase d.

In the first step, as shown in FIGS. 1 to 3, small assembly work is performed by using the assembly jig (2) mounted on the transfer pallet (1). Jig (2)
Is for positioning and supporting a cylindrical body (3) having a notched front surface and a crankshaft a in front of the cylindrical body (3) so that the crank webs a ₁ , a ₁ face the front surface of the cylindrical body (3). Left and right 1
A pair of supporting bases (4) and (4), and at the large end of the connecting rod a ₂ which is axially mounted between the crank webs a ₁ and a ₁ behind the intermediate parts of the supporting bases (4) and (4). A stopper (5) that abuts from below and a vertically movable guide cylinder (6) with a notched front surface are provided in the cylinder (3). First, the crankshaft a is attached to the support bases (4) and (4). Is placed so that the large end of the connecting rod a ₂ rides on the stopper (5) so that the small end of the connecting rod a ₂ is positioned at a fixed position in the guide tube (6), and then the guide tube ( 6) Insert the piston b from above and set it so that its pin hole is aligned with the small end of the connecting rod a ₂ , and then insert the piston pin into the pin hole from the side of the guide cylinder (6). Part is connected to piston b, and then cylinder c is brought into contact with the upper end of the guide cylinder (6) with its skirt part. Set to push up as.
According to this, the guide tube (6) descends and the piston b
Is inserted into the cylinder c, and then the cylinder head c ₁ is placed on the cylinder c with the first through bolts f ₁ and f ₁ set, and the subassembly work is completed. Note that the upper end of the cylindrical body (3), erected each positioning pin (7) to be fitted to each through-bolt f _1, the insertion hole of the f ₂ of the cylinder c, wherein the first through bolt f _1, The front and rear 1 on the right side in Fig. 1 that fits into the insertion hole of f ₁ .
The length of the pair of positioning pins (7) (7) is shortened so that the first through bolts f ₁ and f ₁ can be dropped into the insertion holes.

Next, as shown in FIG. 4, the gripping device (8) attached to the robot or the like is lowered onto the assembly jig (2), and the assembly A is gripped by the gripping device (8) to assemble the assembly jig (2). ) And carry it to the station for the second process.

The gripping device (8) includes a pair of front and rear first second arms (9 ₁ ) (92) that are closed in synchronization with each other, and a front third arm (9 ₁ ) (9 ₂ ) that is closed later. 9 ₃ ), a gripping member (10) (10) for gripping the cylinder C from the front and the back is attached to the upper part of the first and second arms (9 ₁ ) and (9 ₂ ), and the first arm (9 ₁ ) first view of the left side of the supporting base at the lower end (4) a shaft supporting pieces bent in an L-shape for supporting the shaft portion of the crank shaft a, which issued to the left Zhang from the lower (11), the third arm (9 ₃ ) At the lower end of the left side of the crank web a ₁ and the shaft portion on the left side of the pair of shaft pushing pieces (1
2 ₁ ) (12 ₂ ) and a pair of shaft receiving pieces (12 ′ ₁ ) (12 ′ ₂ ) at the lower end of the second arm (9 ₂ ) facing the respective shaft pushing pieces (12 ₁ ) (12 ₂ ). ), First, as shown in FIG. 4 (a), the first and second arms (9 ₁ ) (9 ₂ ) are closed, the cylinder c is gripped by the gripping members (10) (10), and the shaft is supported. supporting the crankshaft a in semi (11), lifting the assembly a from the assembly jig (2) in this state, then the third arm (9 ₃₎ is closed as shown in the fourth diagram (b) shows, the shaft The pushing pieces (12 ₁ ) (12 ₂ ) roll the crankshaft a on the shaft supporting piece (11) while pushing the crankshaft a to a position directly below the cylinder c, and at the position directly below the crank web a ₁ on the left side.
And the shaft on the left side of the shaft push piece (12 ₁ ) (12 ₂ )
The crankshaft a is positioned by being sandwiched between the front and rear by the shaft receiving pieces (12 ′ ₁ ) and (12 ′ ₂ ).

Incidentally, the intermediate portion of the second arm (9 _2), a cylinder support piece for receiving the crankcase joint surface of the cylinder c and (13), a piston support piece for receiving the piston b protrudes skirt portion of the cylinder c (14 ) And two protrusions are vertically provided, and the first through bolt is further attached to the main body of the gripping device (8).
Tightening shafts (15) and (15) for f ₁ and f ₁ are provided axially, and the first through bolts f ₁ and f ₁ are temporarily tightened in the second step described later.

In the drawing (16) shows a slider which is reciprocating in two stages motion cylinders, each arm to the slider (16) (9 ₁₎
Each cam plate (17 ₁ ) (17 ₂ ) (1 that drives (9 ₂ ) (9 ₃ )
7 ₃ ) is attached, and the first movement of the slider (16)
The second cam plate (17 ₁ ) (17 ₂ ) is used to close the first and second arms (9 ₁ ) and (9 ₂ ), and the second stage movement is performed via the third cam plate (17 ₃ ). and a third arm (9 ₃₎ of the closing operation and so are given.

In the second step, first, as shown in FIG. 5, the right end of the crankshaft a is set on a jig (not shown) while the assembly A is held by the holding device (8) as described above. half and inserted into the bearing d ₁ mounted on the crankcase d, extracting device (18 ₁₎ by pulling out a right axis of the crank shaft a, the bearing d ₁ journal portion a ₃ to the right-side adjacent crank web a ₁ Press into.

The pulling-out device (18) includes a pulling-out shaft (20) having a collet chuck (19) at the tip screwed into a threaded portion a ₄ at the shaft end of the crankshaft a, and a guide bar (20) provided by a cylinder (21). Slide frame (22) that moves back and forth along 22a)
A pin (22b) protruding from the side surface of the pulling shaft (20) is engaged between the flanges (20a) (20a) on the outer periphery of the intermediate portion of the pulling shaft (20), and the slide frame (22) is attached to the pulling shaft (20). A nut runner (23) is attached to the tail end of the rod (21a) through a hollow piston rod (21a) of the cylinder (21) so as to provide an integral forward / backward movement. ), The pull-out shaft (20) is rotatably driven by the nut runner (23), and the outer peripheral operation sleeve (19a) for opening and closing the collet chuck (19) on the slide frame (22).
(24a) that engages between the collars (19b) (19b) at the tail end of the
A lever (24) provided with a protrusion and a cylinder (24b) for swinging the lever (24) are attached, and the cylinder (24b) connects the lever (24) and the operation sleeve (19a) to the collet. The chuck (19) was opened and closed. In the drawing, (25) shows a cylindrical body fixed to the device body accommodating the collet chuck (19), and the tip of the cylindrical body (25) is passed through the shaft through hole on the outer surface of the first half crankcase d to the bearing d ₁ It was made to contact the end face of the.

At the time of extraction, first, with the collet chuck (19) closed, rotate the extraction shaft (20) and move it to the left in the drawing to move the screw part a at the shaft end of the crankshaft a inserted into the bearing d _{1. The} collet chuck (19) is screwed onto the 4 as shown in Fig. 5 (a), and then the withdrawal shaft (20) is retracted to the right to move the right side of the crankshaft a as shown in Fig. 5 (b). The shaft part is pulled out. According to this, the journal part a ₃
While being press-fitted into d ₁ , the cylinder c is drawn to a position directly above the cylinder joint surface d ₂ of the first half crankcase d,
Tightening shafts (15) (15) provided on the gripping device (8) in this state
Is rotated to fasten the first through bolts f ₁ and f ₁ into the screw holes d ₃ and d ₃ of the joint surface d ₂ . In this case, the cylinder c is supported by the gripping device (8) so that a clearance is formed between the lower surface of the cylinder c and the cylinder joint surface d _2, and the head of the first through bolt f ₁ is attached to the cylinder head c. _{Even if} it is tightened until it is seated at ₁ , the cylinder c can move in the axial direction by this clearance.

Next, open the collet chuck (19) and pull out the shaft (20).
Together with disengaging from the crank shaft a, the arm of the gripping device (8) (9 ₁₎ (9 ₂₎ (9 ₃₎ the open assembly A
The gripping device (8) is detached from the assembly, and the assembly of the first half crankcase d and the assembly A is conveyed to the station for the third step.

In the third step, as shown in FIG. 6, the second half split crankcase e is gripped by the assembling device (26), and the shaft portion on the left side of the crankshaft a is attached to the bearing e ₁ attached to the case e. The first half-crank case d is inserted into the first half-crank case d. In the embodiment, the first half-crank case d is set so that the split surface faces upward.
Was assembled from above.

The assembling device (26) is a device having the same structure as the pulling device (18) described above, and is provided with a gripping means (2
7) and a relief means (28) for the cylinder c. The same constituent members as those of the pulling device (18) are designated by the same reference numerals, and the description thereof will be omitted. Here, the gripping means (27) includes a plurality of gripping claws (27b) that engage with protrusions on the outer circumference of the second half-split crankcase e on a support plate (27a) attached to the outer circumference of the tubular body (25). , A plurality of positioning pins (27c) fitted in the insertion holes of the crankcase coupling bolts, and the escape means (28) is mounted on a holder (28b) that is vertically moved by a cylinder (28a). Abutment plate (28c) that contacts the crankcase joint surface of cylinder c
Is supported slidably in the left-right direction in the drawing via a guide bar (28d), and a roller (28e) attached to the tail end of the guide bar (28d) is fixed to the apparatus main body by a cam plate ( 28f) is engaged with the cam groove (28g) formed, and when the holder (28b) is moved upward with respect to the main body of the device, the corresponding plate (28c)
Was guided by the cam groove (28g) and slid to the left.

When mounting the second half crankcase e, the case e is gripped by the gripping means (27), and the escape means (28) is held.
After lowering the holder (28b) of the device, the device body of the assembling device (26) is moved downward, and after the contact plate (28c) is lowered to the position facing the crankcase joint surface of the cylinder c, The holder (28b) is moved upward with respect to the apparatus main body in accordance with the downward movement. According to this, the plate (28c) slides to the left and abuts on the joint surface, and the cylinder c moves to the first through bolt.
It is slid and retracted to the cylinder head c ₁ side using f ₁ and f ₁ as guides, and in this state, the bearing e ₁ of the second half crankcase e is attached to the upper shaft portion of the crankshaft a (the left side of FIG. 4). Shaft)
Is inserted, and when the case e descends to a fixed position,
Rotate the pull-out shaft (20) and lower it, as shown in FIG. 6 (a).
Install the collet chuck (19) on the crankshaft a as shown.
Screw it onto the screw part a ₄ at the upper end of the. Next, withdrawal shaft (20)
Is pulled up by the cylinder (21), but in this case, the device main body is lowered by the pulling reaction force, and the second half-crank case e is pushed down via the tubular body (25). )
As shown, the upper journal portion a ₃ of the crankshaft a is press-fitted into the bearing e ₁ to join the second half crankcase e to the first half crankcase d, in which the cylinder c is in the retracted position as described above. Since there is no interference between the second half crankcase e and the cylinder c, even if a gasket is attached to the crankcase joint surface of the cylinder c,
The gasket is not scratched when the half crankcase e is assembled.

After assembling, open the collet chuck (19) to move the main body of the device upward, and in the next step, fasten both half crankcases d and e with connecting bolts, and attach the second through bolts f ₂ and f ₂ to the cylinder head. Insert the first through bolt f ₁ , f ₁ and the second through bolt f ₂ , f ₃ from the c ₁ side through the cylinder c into the screw holes e ₃ , e ₃ of the cylinder joint surface e ₂ of the second half crankcase e. Tighten ₂ and ₂ , and fasten cylinder c to both half crankcases d and e.

(Effects of the Invention) As described above, according to the present invention, the assembly of the crankshaft and the piston cylinder, which has been assembled in the first step, is assembled in the first half-split crankcase in the second step, and then the third step.
Since the second half-split crankcase is assembled to the first half-split crankcase in the process, compared to the conventional method of assembling the piston and the cylinder after assembling the first and second half-split crankcases and the crankshaft. However, automation of engine assembly work is facilitated. In addition, the second half split crankcase is assembled while the cylinder is retracted using the through bolts temporarily tightened in the second process as a guide. This has the effect that the crankcase can be securely assembled without causing interference with the cylinder, and the subsequent fastening of the cylinder to both half crankcases can also be reliably performed.

[Brief description of drawings]

FIG. 1 is a plan view of an assembly jig used in the first step of the method of the present invention, and FIGS. 2 and 3 are lines II-II and III of FIG. 1, respectively.
-III cross section, FIGS. 4 (a) and 4 (b) are sectional side views for explaining the detaching work of the assembly assembled in the first step from the assembly jig, and FIGS. 5 (a) and 5 (b). ) Is a sectional front view for explaining the work of the second step, FIGS. 6 (a) and 6 (b) are sectional side views for explaining the work of the third step, and FIG. 7 is an exploded perspective view of the engine. a …… Crankshaft b …… Piston c …… Cylinder c ₁ …… Cylinder head d …… First half split crankcase e …… Second half split crankcase f ₁ …… Through bolt

Claims (1)

[Claims] 1. A method of assembling an engine comprising a crankshaft, a piston, a cylinder, and a pair of half-split crankcases divided in the axial direction of the crankshaft. A first step of combining the cylinder and the engine to form a small engine;
A second step of assembling the assembly assembled in one step to the first half-split crankcase on one side and a third step of assembling the second half-split crankcase on the other side to the first half-split crankcase. Separately, temporarily tighten the through bolts that fasten the cylinder to the first half-split crankcase in the second step so that the cylinder can move in the cylinder axis direction, and then install the second half-split crankcase in the third step. A method of assembling an engine, wherein the cylinder is slid and retracted toward the cylinder head side by using the through bolt as a guide.