JPH0742832A - Coupling structure for piston with connecting rod - Google Patents

Abstract

PURPOSE:To provide a piston/connecting rod coupling structure, in which a seat cylinder and a slide piece pinching a receptacle member formed at the minor end part of a connecting rod is fitted in a piston upon being installed in a cup-shaped inner sleeve. CONSTITUTION:A semicolumnar sliding piece 9 is butted to the top wall 61a of an inner sleeve 61 in the form of an inverted cup, and a cylindrical recess 16c of a hemispherical receptacle member 16 formed at the minor end of a connecting rod 21 is contacted with the said sliding piece 9. The oversurface 23a in the form of spherical recess of a seat cylinder 23 is put in contact with the undersurface 16b in the form of spherical projection of the receptacle member 16, and a snap ring 65 contacting the undersurface of the seat cylinder 23 is detained with a ring-shaped groove furnished at the inside circumferential wall of the bottom of the inner sleeve 61. The inner sleeve 61 is fitted in the skirt part 2c of the piston, and a retaining cylinder 26 is detained with this skirt part 2c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure for connecting a piston and a connecting rod in an internal combustion engine, and more particularly to a connecting structure for a piston and a connecting rod with improved assemblability.

[0002]

2. Description of the Related Art According to the connecting structure of a piston and a connecting rod disclosed in Japanese Patent Laid-Open No. 4-249671, the swing center of the connecting rod with respect to the piston is the piston crown surface as compared with the connecting structure using a conventional piston pin. If the arm of the crankshaft and the connecting rod are lengthened correspondingly, the displacement will be increased and the output of the engine can be increased without changing the dimensions of the cylinder block.

In the above-described connecting structure of the piston and the connecting rod,
Since the sliding body, the receiving member formed on the small end of the connecting rod, the seat cylinder, and the holding cylinder are sequentially installed inside the piston, it takes a lot of work and may damage the outer surface of the piston during assembly. .

[0004]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to install a sliding member and a seat tube which sandwich a receiving member formed at a small end portion of a connecting rod into a cup-shaped inner sleeve. The purpose of the present invention is to provide a connecting structure for connecting the piston and the connecting rod, which is adapted to be inserted into the inside of the piston.

[0005]

In order to achieve the above object, the structure of the present invention applies a semi-cylindrical slide member to the top wall of an inverted cup-shaped inner sleeve, and the small end portion of the connecting rod is attached to the slide member. The hemispherical receiving member's cylindrical recess formed on the lower sleeve, the lower surface of the receiving member's spherical projection on the lower surface of the seat cylinder's upper surface, and the lower groove of the inner sleeve to the annular groove on the inner wall of the seat cylinder. The retaining ring that contacts the lower surface of the piston is locked, the inner sleeve is fitted into the skirt of the piston, and the holding cylinder that supports the seat cylinder is locked.

[0006]

A semi-cylindrical sliding body, a hemispherical shaped receiving member having a cylindrical recess on the upper surface, and a seat having a spherical recess on the upper surface are formed inside the reverse cup-shaped inner sleeve. The cylinders are assembled in order, and the retaining ring is locked in the annular groove at the lower end of the inner sleeve. This supports the small end of the connecting rod to the inner sleeve. Insert the inner sleeve, the annular adjustment plate, and the holding cylinder into the skirt of the piston in this order, and rotate the holding cylinder to project the ridge protruding radially outward from the holding cylinder. Support on one piece.

The annular adjusting plate is pressed against the lower surface of the catching cylinder by a plurality of vertical bolts screwed to the holding cylinder to adjust the clearance between the inner sleeve and the small end of the connecting rod.

Both ends of the C-shaped detent plate externally fitted to and supported by the bolts are engaged with the circumferential end portions of the projecting pieces of the skirt portion to prevent the holding cylinder from falling off due to rotation.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side sectional view showing a connecting structure of a piston and a connecting rod according to the present invention, in particular, a hatching of a crown portion and a skirt portion of the piston is omitted, and FIG. 2 is a connecting structure of the piston and the connecting rod. It is a front sectional view. However, FIG. 2 shows the adjusting plate 6
1 in that it is provided with 7. The piston 2 according to the present invention is provided with a combustion chamber 4 having an asymmetrical recess on the upper surface of the crown portion 2a, and a plurality of ring grooves 3 on the upper half of the outer peripheral wall. The central portion of the crown 2a is projected downward so as to surround the bottom of the combustion chamber 4, and the lower surface 2b of the crown 2a is flattened. An annular cooling oil chamber 5 is formed so that the lower surface 2b of the crown portion 2a surrounds the combustion chamber 4.

The hemispherical receiving member 16 formed at the small end of the connecting rod 21 is swung by the semi-cylindrical or semi-cylindrical sliding member 9 and the seat tube 23 inside the reverse cup-shaped inner sleeve 61. It is pinched as possible. The lower surface of the top wall 61a of the inner sleeve 61 is provided with an annular groove 62 that partitions the lubricating oil chamber 55, and partially receives the peripheral portion of the receiving member 16 when the connecting rod 21 swings. Crown 2a of piston 2 and top wall 6 of inner sleeve 61
1a and the sliding body 9 are connected by a plurality of connecting pins 36 in the vertical direction. As shown in FIGS. 1 and 3, the slide body 9 is chamfered at both front and rear ends 9d and slidably engaged with a cylindrical recess 16c provided on the upper surface 16a of the receiving member 16. The sliding body 9 supports the top wall 61a of the inner sleeve 61 on the flat upper surface 9a.

A lower surface 16b forming a spherical convex portion of the receiving member 16.
Is slidably supported on the upper surface 23a of the seat tube 23 which forms a spherical recess. The seat tube 23 is a two-piece body for convenience of assembly, and the two-piece body is assembled and fitted into the catch tube 22 and supported on the bottom wall 22b of the catch tube 22. In order to obtain the predetermined position of the seat tube 23 with respect to the catch tube 22, the positioning pin 38 supported by the catch tube 22 is engaged with the axial groove 39 provided on the peripheral wall of the seat tube 23. The catch cylinder 22 is connected to the peripheral wall 61b of the inner sleeve 61 by a pin 30 parallel to the crankshaft so that the seat cylinder 23 and the catch cylinder 22 do not rotate inside the inner sleeve 61. However, the arresting cylinder 22
Is slightly slidable in the crankshaft direction with respect to the inner sleeve 61.

As shown in FIG. 2, the crown portion 2a of the piston 2 is shown.
The cooling oil chamber 5 that surrounds the
It is divided by. Oil injected from an oil jet (not shown) enters the annular cooling oil chamber 5 through the inlet oil passage 33 of the seat cylinder 23 and the oil passage 33a of the inner sleeve 61, cools the crown portion 2a, and cools the inner sleeve 61. Returning to the crank chamber via the oil passage 34a of No. 3 and the outlet oil passage 34 of the seat cylinder 23.

As shown in FIG. 1, the upper surface 23a of the seat cylinder 23 is formed.
In order to lubricate the sliding portion between the lower surface 16 b of the receiving member 16 and the internal member, the internal oil passage 19 of the connecting rod 21 is provided with the oil passage 41 of the sliding body 9.
Through the hole 51 of the top wall 61a. Inner sleeve 6
A plurality of oil passages 44 that extend radially outward from the holes 51 are formed in the top wall 61a of the first unit, and the outer ends of the oil passages 44 are closed by the plugs 45. The oil passage 44 passes through an oil passage 46 extending downward, and then the seat tube 23
Communicating with the oil passage 47 of the seat cylinder 23.
Open to.

As shown in FIGS. 2 and 3, according to the present invention,
In order to prevent rotation of the seat tube 23 with respect to the inner sleeve 61 and to allow a slight relative sliding in the crankshaft direction, the flange 23b (FIG. 1) at the upper end of the seat tube 23 and the catch tube 22 are prevented. A pair of flat surfaces 2 parallel to the crankshaft on each outer peripheral wall
2a is formed, and the pad 20 having a crescent-shaped horizontal section is sandwiched between each flat surface 22a and the peripheral wall 61b of the inner sleeve 61. The pad 20 has a uniform horizontal cross section so as not to impair the strength against lateral load, and is retained by a retaining ring 65 that is locked in an annular groove provided in the inner peripheral wall of the lower end of the inner sleeve 61.

As shown in FIG. 2, an inverted cup-shaped inner sleeve 61 is fitted into the skirt portion 2c, the top wall 61a is brought into contact with the lower surface 2b of the crown portion 2a, and the bottom wall 22b of the captive cylinder 22 is annular. It is supported on the adjusting plate 67. The adjusting plate 67 has an annular protrusion 67a formed on the lower surface thereof engaged with an annular groove formed on the upper surface of the holding cylinder 26. Top wall 61 of inner sleeve 61
The adjustment plate 67 is captured by a plurality of bolts 69 screwed to the holding tube 26 at equal intervals in the circumferential direction so that there is no looseness between the adjustment plate 67, the bottom wall 22b of the catch tube 22, the seat tube 23, and the adjustment plate 67. It is pressed against the bottom wall 22b of the cylinder 22. The bolt 69 is screwed into the screw hole 68 of the holding cylinder 26, and the upper end of the bolt 69 projects into the annular groove of the holding cylinder 26 and abuts on the protrusion 67 a of the adjusting plate 67. As shown in FIG. 4, in order to reduce the weight of the holding cylinder 26, the inner peripheral wall of the holding cylinder 26 is provided with four partially cylindrical notches 26c at equal intervals in the circumferential direction.

As shown in FIG. 4, the holding cylinder 26 is supported on a plurality of projecting pieces 27 formed on the inner peripheral wall of the lower end of the skirt portion 2c. The projecting pieces 27 are arranged on the lower end inner peripheral wall of the skirt portion 2c at equal intervals in the circumferential direction, and project radially inward from the lower end inner peripheral wall. The holding cylinder 26 is provided with an axial groove 26b and a ridge 26a, which are wider in the circumferential direction than the projecting piece 27, on the outer peripheral wall. In order to fit the holding cylinder 26 into the skirt portion 2c, the groove 26b is engaged with the projecting piece 27 and the holding cylinder 26 is pushed into the skirt portion 2c. Next, when the holding cylinder 26 is rotated by a predetermined amount, the holding cylinder 2
The ridge 26 a of No. 6 overlaps the protrusion 27.

As shown in FIG. 4, a C-shaped detent plate 70 that abuts the lower surface of the holding cylinder 26 is externally fitted to the bolt 69,
And it is fastened by nut 71. As shown in FIG.
The rotation stop plate 70 has an intermediate portion supported by the bolt 69, and both ends thereof are engaged so as to sandwich the circumferential end portion of the projecting piece 27 of the skirt portion 2c so as to prevent the holding cylinder 26 from rotating with respect to the piston 2.

From the oil pump (not shown) connected to the end of the crankshaft, pressure oil is sent to the hole 51 through the internal oil passage 19 and the oil passage 41 of the connecting rod 21. The oil in the holes 51 is the oil passages 44, 46 of the top wall 61a of the inner sleeve 61 shown in FIG.
3 through the oil passage 47, the lower surface 16b of the receiving member 16 and the seat tube 2
Lubricate the sliding portion of the upper surface 23a of No. 3 and return to the crank chamber.
The oil in the holes 51 flows into the lubricating oil chamber 55 while lubricating between the top wall 61a and the upper surface 9a of the sliding body 9 shown in FIG. The oil in the lubricating oil chamber 55 lubricates the sliding surface of the cylindrical surface 9b of the sliding body 9 and the cylindrical recess 16c of the receiving member 16. Further, the oil in the lubricating oil chamber 55 lubricates the sliding portions of the ceiling wall 61a and the upper end of the seat cylinder 23 and the sliding portions of the catch cylinder 22 and the pad 20, respectively.

[0019]

According to the present invention, the slide body and the seat cylinder, which sandwich the receiving member formed at the small end of the connecting rod, are assembled into the cup-shaped inner sleeve, and are pressed by the retaining ring, and then the piston Since it is inserted into the inside, it is easy to assemble and damage to the outer peripheral wall of the piston can be prevented.

The seat cylinder is fixed to the peripheral wall of the inner sleeve by a pin parallel to the crankshaft, and the seat cylinder and the catch cylinder are slightly slid in the crankshaft direction with respect to the peripheral wall of the inner sleeve by a pad having a horizontal crescent cross section. Since they are engaged with each other as much as possible, variations in the mutual spacing of the pistons with respect to the crankshaft are absorbed, and the bearing of the crankshaft supporting the connecting rod is not unduly burdened. Since the pad does not need to be processed with pin holes or the like, sufficient strength can be maintained against lateral load (load perpendicular to the crank axis).

Since the C-shaped detent plate externally fitted to the bolt for adjusting the clearance of the sliding portion of the sliding body is engaged so as to sandwich both ends of the projecting piece of the skirt portion in the circumferential direction, it is held. It is possible to prevent the cylinder from falling off due to rotation, and there is no troublesome machining of the pin hole compared to the one in which the retaining cylinder is locked to the skirt by the radial pin as a retaining means for the retaining cylinder, which helps in cost reduction. .

[Brief description of drawings]

FIG. 1 is a side sectional view of a connecting structure of a piston and a connecting rod according to the present invention.

FIG. 2 is a front sectional view of a connecting structure of the piston and the connecting rod.

FIG. 3 is a bottom view of the connecting structure of the piston and the connecting rod.

FIG. 4 is a front cross-sectional view showing an enlarged main part of the connecting structure of the piston and the connecting rod.

[Explanation of symbols]

2: Piston 2c: Skirt 9: Sliding body 16:
Receiving member 16b: Lower surface 16c: Semi-cylindrical recess 19, 41, 44, 50a, 46
-48: Oil passage 21: Connecting rod 22: Captive cylinder 23: Seat cylinder 23a: Upper surface 26: Holding cylinder 30: Pin 61: Inner sleeve 61a: Top wall 65: Retaining ring

Claims (3)

[Claims] 1. A semi-cylindrical sliding body is applied to the top wall of an inverted cup-shaped inner sleeve, and a cylindrical concave portion of a hemispherical receiving member formed at the small end of the connecting rod is applied to the sliding body. Apply the upper surface of the spherical recess of the seat cylinder to the lower surface of the spherical projection, and lock the retaining ring that abuts the lower surface of the seat cylinder to the annular groove provided in the inner peripheral wall of the lower end of the inner sleeve, and then to the skirt of the piston. A connecting structure of a piston and a connecting rod, wherein an inner sleeve is fitted and a holding cylinder supporting a seat cylinder is locked. 2. A semi-cylindrical sliding body is applied to the top wall of an inverted cup-shaped inner sleeve, and a cylindrical concave portion of a hemispherical receiving member formed at the small end portion of the connecting rod is applied to the sliding body. Apply the upper surface of the spherical recess of the seat cylinder to the lower surface of the spherical projection, and lock the retaining ring that abuts the lower surface of the seat cylinder to the annular groove provided in the inner peripheral wall of the lower end of the inner sleeve, and then to the skirt of the piston. The inner sleeve is fitted into the lower end of the skirt of the piston, and the plurality of protrusions are arranged at equal intervals in the circumferential direction and project radially inward. Support the ridges,
The annular adjusting plate is pressed against the lower surface of the catching cylinder by a plurality of vertical bolts screwed to the holding cylinder, and both ends of the C-shaped detent plate externally fitted and supported by the bolt are attached to the circumferential end of the projecting piece of the skirt portion. A connecting structure of a piston and a connecting rod characterized by being engaged with a portion. 3. A captive cylinder is externally fitted to the lower half of a seat cylinder composed of a divided body, and left and right 1 parallel to the crankshaft are attached to the peripheral walls of the seat cylinder and the captive cylinder.
2. A pair of flat surfaces are formed, a pad having a crescent cross section is sandwiched between the inner sleeve and each flat surface, and the inner sleeve and the seat cylinder are connected by a pin in the crankshaft direction so as to be relatively movable. The connecting structure of the piston and the connecting rod described in 2.