JPH04133061U - Connection structure of piston and connecting rod - Google Patents

Abstract

(57) [Summary] [Purpose] To enable the presser foot that supports the bowl-shaped receiving plate at the tip of the connecting rod to be assembled into a piston as an annular body without making it into a separate body. [Structure] A spherical protrusion provided on the lower surface 5a of the piston crown 5 and an annular presser foot 1 supported on the skirt portion 23 of the piston 2.
9, a bowl-shaped receiving plate 3 formed at the tip of the connecting rod 34.
1 in a swingable manner. A semi-cylindrical portion 44 that engages with the crank pin is provided at the base end of the connecting rod 34, and the end surface 45 of the semi-cylindrical portion 44, which is overlapped and coupled with the bearing cap 48, is connected to the connecting rod 3.
4, and the annular presser foot 19 is inserted from the proximal end of the connecting rod 34 and assembled to the skirt portion 23.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention focuses on the connection structure between the piston and connecting rod in internal combustion engines, especially at the tip of the piston. The bowl-shaped receiving plate provided at the (small end) is swingably attached to the spherical protrusion provided on the piston crown. An annular presser foot that maintains this contact state can be easily incorporated into the skirt part. This relates to a possible connection structure between a piston and a connecting rod.

0002

[Conventional technology]

According to the connection structure of the piston and connecting rod of Japanese Patent Application No. 2-417472 filed by the present applicant. For example, compared to the conventional piston pin connection structure, the center of swing of the connecting rod is closer to the piston crown. is offset near the upper surface (top surface) of the part, and is connected to the crankshaft arm by the amount of deviation of the center of rotation. By making the rod longer, the piston can be adjusted without changing the length of the cylinder body or the maximum angle of inclination of the connecting rod. The stroke of the ston increases, making it possible to increase the output of the engine due to the increase in displacement. . In the piston and connecting rod connection structure described above, the spherical protrusion on the lower surface of the piston crown is is supported by a bowl-shaped receiving plate provided at the tip of the connecting rod, and the receiving plate is supported by the spherical concave part of the annular presser foot. The annular presser foot is supported on a stepped portion of a holding cylinder screwed onto the skirt portion. Receiving The inner diameter of the presser foot that supports the plate is smaller than the outer diameter of the receiving plate, so for convenience of assembly, the presser foot should be used twice. It is a split body that abuts the lower surface of the receiving plate and is connected in an annular shape with bolts.

0003 However, as mentioned above, with the two-part structure of the presser foot, the efficiency of the presser foot assembly work is poor. Also, the joint of the presser foot easily loosens. Then, when the presser foot is expanded by an external force, the presser foot The gap between the supporting part or the abutting part of the receiving plate becomes larger, and the piston is removed during the exhaust stroke of the engine. When the piston moves upward away from the connecting rod due to inertia, the top surface of the piston collides with the intake and exhaust valves. There is a risk that

0004

[Problem that the invention attempts to solve]

In view of the above-mentioned problems, the purpose of this invention is to make the presser foot that supports the receiving plate of the connecting rod into a divided body. To provide a connecting structure of a piston and a connecting rod that can be assembled as an annular body without having to There is a particular thing.

[0005]

[Means to solve the problem]

In order to achieve the above purpose, the structure of the present invention is to provide a spherical surface on the lower surface of the piston crown. A shape is attached to the tip of the connecting rod between the protrusion and an annular retainer supported on the skirt of the piston. The bowl-shaped receiving plate is swingably sandwiched between the two halves that engage with the crank pin at the base end of the connecting rod. A cylindrical part is provided, and the end face of the semi-cylindrical part which is overlapped and connected to the bearing cap is connected to the connecting rod. Tilt with respect to the longitudinal axis and insert the annular presser foot from the proximal end of the connecting rod to the skirt section. This allows for assembly.

[0006]

[Effect]

According to the present invention, the same semi-cylindrical part is used for the semi-cylindrical part at the base end (big end) of the connecting rod. The overlapping surface with the bearing cap provided is inclined with respect to the longitudinal axis of the connecting rod. This allows the annular presser foot to be inserted from the proximal end of the connecting rod and come into contact with the bottom surface of the receiving plate. Similarly, the presser foot was inserted from the base end of the connecting rod and screwed onto the skirt of the piston. Supported by the stepped part of the holding cylinder.

[0007]

[Example of idea]

FIG. 1 is a front sectional view showing a connection structure between a piston and a connecting rod according to the present invention. machine The cylinder body 42 is connected to a cylinder (not shown) through a gasket 41 at the upper end. Tsudo is combined. The piston 2 fitted into the cylinder head and the cylinder body 42, Fuel is combusted between the pistons 2 and 2, and the piston 2 is reciprocated up and down. The reciprocating motion of piston 2 is The connecting rod 34 transmits the rotation to a known crank arm, which imparts rotation to the crankshaft. de A piston 2 for an easel engine is provided with a recess on the upper surface of the piston crown 5 to form a combustion chamber 4. The circumferential wall is provided with a plurality of annular grooves for mounting the piston rings. Piss The lower half of the tongue 2 forms a cylindrical skirt portion 23. The piston crown 5 is a combustion chamber A flat lower surface 5a defined by an annular cavity 6 for cooling the peripheral wall of the It is slidably abutted against the body 12.

[0008] The annular cavity 6 is partitioned into a cooling chamber by a partition plate 8 fitted onto the piston crown 5 . The partition plate 8 is provided with an inlet and an outlet (not shown) on opposite sides in the circumferential direction. of the annular cavity 6 The cross section is not uniform in the circumferential direction, being narrower at the inlet and wider at the outlet. sliding The body 12 is provided with a through passage 14 in the center, the lower end of which widens in a conical shape, and on the lower surface. A spherical protrusion is formed.

[0009] The connecting rod 34 is integrally formed with a bowl-shaped receiving plate 31 at its tip, and the upper surface of the receiving plate 31 has a spherical surface. The recess 31a supports the spherical protrusion of the sliding body 12. The lower surface of the receiving plate 31 has a spherical protrusion 31 form b. The spherical protrusion 31b is supported in a spherical recess 19a formed in the annular presser foot 19. held. Preferably, the presser foot 19 has a reinforcing sleeve 18 fitted in its upper half. It will be done.

0010 The lower end surface of the presser foot 19 is supported by a stepped portion 22a provided on the inner surface of the holding cylinder 22. Retention The tube 22 is screwed into a screw hole provided on the inner peripheral surface of the skirt portion 23. Loosening of the holding cylinder 22 The strain is suppressed by a retaining ring 24 that is engaged with an annular groove in the skirt portion 23. The above structure As is clear from the structure, the receiving plate 31 of the connecting rod 34 is provided on the lower surface of the piston crown 5. It is sandwiched between the sliding body 12 and the presser foot 19 supported on the skirt portion 23, and prevents engine operation. As it rotates, it swings from side to side in the figure.

[0011] In order to allow oil to flow through the annular cavity 6 for cooling, a presser foot 19 and a sleeve 18 are provided. An inlet passageway and an outlet passageway (not shown) are provided. Disposed at the lower end of the cylinder body 42. The oil spouted from the well-known oil jet installed in the presser foot 19 and the partition plate 8 is It enters the annular cavity 6 through the inlet, cools the peripheral wall of the combustion chamber 4, and enters the annular cavity from the exit of the partition plate 8. It accumulates in the shaped cavity 16. The oil in the annular cavity 16 flows through the spherical recess 19a of the presser foot 19 and the receiving plate 31. It lubricates the space between it and the spherical protrusion 31b and flows down to the skirt portion 23. At the same time, the annular cavity The oil 16 lubricates between the spherical recess 31a of the receiving plate 31 and the spherical protrusion of the sliding body 12. It collects in the center of the receiving plate 31 and flows from the outlet 25 to the skirt portion 2 through the internal passage of the connecting rod 34. Flows into 3. Further, the oil in the annular cavity 16 is distributed between the upper surface of the sliding body 12 and the piston crown 5. It lubricates between the lower surface 5a and flows through the through passage 14 to the center of the receiving plate 31. annular cavity The remaining oil from step 16 flows from the outlet passage of presser foot 19 to the engine crank via skirt portion 23. Flows down into the room.

0012 Naturally, the inner diameter D of the presser foot 19 that supports the receiving plate 31 is larger than the outer diameter of the receiving plate 31. Since the pressure is also small, the annular presser foot 19 is placed in contact with the lower surface of the receiving plate 31 from the tip side of the connecting rod 34. It is impossible to touch. Therefore, in the present invention, the shape of the connecting rod 34 is In the conventional connecting rod, the end surface of the proximal semi-cylindrical part is perpendicular to the longitudinal axis of the connecting rod. The annular presser foot 19 is inserted from the proximal end of the connecting rod 34. , which enables contact with the lower surface of the receiving plate 31. That is, at the proximal end of the connecting rod 34 A semi-cylindrical portion 44 having a center O is formed on the central axis 52 of the connecting rod 34, and the semi-cylindrical portion 44 has a center O. The end face 45 of the section 44 is inclined with respect to the longitudinal axis 52 of the connecting rod 34 by an inclination angle α.

[0013] The middle portion of the connecting rod 34 has an I-shaped cross section like a typical connecting rod. connecting rod The side edge 49 of the middle part of 34 is a gently arcuate surface or slope that connects to the peripheral wall 43 of the semi-cylindrical part 44. Connecting. Regarding the shape of the side edge 49a extending from the middle part of the connecting rod 34 to the end surface 45, Not particularly limited. The bearing cap 48 is equipped with a semi-cylindrical portion 47 as in the conventional one. The end face 46 is superimposed on the end face 45 of the connecting rod 34.

[0014] According to the present invention, the end surface 45 of the semi-cylindrical portion 44 at the proximal end of the connecting rod 34 is By tilting the end face 45 and the connecting rod 34 by an inclination angle α with respect to the longitudinal axis 52 of the The distance W between the intersection 50 with the side edge 49a of the connecting rod 34 and the side edge 49 of the connecting rod 34 is determined by the presser foot 19. It can be made smaller than the inner diameter D of. Therefore, the annular presser foot 19 is connected to the connecting rod. It can be inserted from the base end side of 34 and abutted against the lower surface of the receiving plate 31. Similarly, Insert the retainer 22 from the proximal end of the connecting rod 34 and screw it into the screw hole of the skirt portion 23. , connect the piston 2 to the connecting rod 34 as shown. Next, the semicircle of the connecting rod 34 The cylindrical portion 44 and the semi-cylindrical portion 47 of the bearing cap 48 are aligned with each other so as to sandwich the crank pin. After overlapping the end faces 45 and 46, fasten them with bolts and nuts (not shown). Ru.

[0015]

[Effect of the idea]

As mentioned above, the present invention combines the spherical protrusion provided on the lower surface of the piston crown and the piston slide. A bowl-shaped receiving plate formed at the tip of the connecting rod is placed between the annular presser foot supported on the cart part. A semi-cylindrical part is provided at the base end of the connecting rod to engage with the crank pin, and the bearing The end face of the semi-cylindrical part that is overlapped with the cap is aligned with respect to the longitudinal axis of the connecting rod. Since it is tilted, the annular presser foot is not divided into parts, and the presser foot is attached to the base end of the connecting rod. It can be attached to the skirt part by extrapolating from the side, increasing the rigidity and strength of the presser foot. This suppresses the expansion deformation of the presser foot, and the deformation of the presser foot prevents the piston from separating from the connecting rod. There is no risk that the upper surface of the piston will collide with the intake and exhaust valves. Also, follow Compared to the conventional model, the number of man-hours required for machining the presser foot is reduced and machining accuracy is improved.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing a connection structure between a piston and a connecting rod according to the present invention.

[Explanation of symbols]

5: Piston crown 5a: Lower surface 19: Presser 23: Skirt 31: Receiving plate 34: Connecting rod 44, 47: Semi-cylindrical portion 45, 46: End surface 48: Bearing cap 52: Center axis line

Claims (1)

[Scope of utility model registration request] Claim 1: A bowl-shaped receiving plate formed at the tip of a connecting rod is swingably sandwiched between a spherical protrusion provided on the lower surface of the piston crown and an annular presser supported on the skirt of the piston. , a semi-cylindrical part that engages with the crank pin is provided at the base end of the connecting rod,
The end face of the semi-cylindrical part which is overlapped and joined to the bearing cap is inclined with respect to the longitudinal axis of the connecting rod, so that the annular presser can be inserted from the base end of the connecting rod and assembled to the skirt part. The connecting structure of the piston and connecting rod.