JPH0550051U - Engine with ladder frame - Google Patents

Abstract

(57) [Summary] [Purpose] In an engine with a ladder frame, when installing the ladder frame at the lower end of the crankcase via a liquid gasket, the liquid gasket protruding from the mating surface falls into the engine and mixes with the oil. (EN) Provided is a simple and inexpensive structure capable of preventing a failure of each part of an engine. [Structure] A liquid gasket is applied between the lower end surface of the skirt portion of the crankcase and the upper end surface of the side wall of the ladder frame that faces the lower end surface of the skirt portion so that the lower end surface of the skirt portion and the upper end surface of the side wall of the ladder frame are connected. In the case where the ladder frame is pressed by a tightening means such as a bolt, a step portion is formed along the inner peripheral edge of the upper end surface of the side wall of the ladder frame for accommodating the excess liquid gasket protruding by the press contact when the ladder frame is cast. ..

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an engine with a ladder frame, in which a so-called ladder frame or an underframe having a substantially ladder-like planar shape is attached to a lower end of a skirt portion of a crankcase.

[0002]

[Prior Art]

 An example of a conventional engine with a ladder frame will be described with reference to the schematic side view of FIG. 1 and the plan view of the ladder frame of FIG. 2 showing an embodiment of the present invention for convenience, and with reference to FIG. In the figure, reference numeral 10 generally indicates an engine for a vehicle such as a truck, and the engine 10 includes a ladder frame 14 attached to a lower end of a skirt portion of a crankcase 12. The ladder frame 14 includes left and right side walls 16 extending in the crank axis direction, and a plurality of lateral members 18 extending in the direction perpendicular to the crank axis and having both ends connected to the side wall 16. A bearing portion 20 for supporting a journal portion of a crankshaft (not shown) is formed in the central portion of the lateral member 18, respectively.

The ladder frame 14 has main tightening bolts that are respectively inserted into bolt holes 22 formed on the lateral member 18 on both sides of the bearing portion 20, and both end portions of the lateral member 18. It is attached to the lower end of the skirt portion of the crankcase 12 by means of auxiliary bolts inserted into a large number of bolt holes 24 bored in the adjacent side walls 16. By tightening the main tightening bolt and the auxiliary bolt, the upper end surface 26 of the flange portion formed on the upper end of the side wall 16 and the lower end surface 28 of the skirt portion of the crankcase 12 are pressed against each other.

The upper end surface 26 of the side wall of the ladder frame and the lower end surface 28 of the crankcase skirt portion need to be pressed in an oil-tight manner in order to prevent oil and blow-by gas inside the engine from leaking to the outside. .. Therefore, a liquid gasket is often interposed between the upper end surface 26 of the side wall of the ladder frame and the lower end surface 28 of the skirt portion. (Note that the stepped portion denoted by reference numeral 36 and the recessed groove denoted by reference numeral 38 in FIG. 2 are characteristic configurations of the present invention, as will be described later, and are not provided in the conventional ladder frame 14.)

The liquid gasket applied between the upper end surface 26 of the side wall of the ladder frame and the lower end surface 28 of the skirt portion has a surplus part on both sides 26 and 28 due to the tightening of the main tightening bolt and the auxiliary bolt. It will protrude from the abutting part to the inside and outside of the engine. There is no particular problem with the liquid gasket protruding outside the engine from the abutting portions of both surfaces 26 and 28, but the liquid gasket protruding inside the engine does not contact the inner wall of the crankcase 12 and the inner wall of the ladder frame 14. Along with the oil flowing down along it, it flows down into the oil pan 30 attached to the lower side of the ladder frame 14 and solidifies, or after solidifying, it falls into the oil pan 30 by the oil flow and mixes with the oil. Carried to each part of the engine. As a result, the oil filter and the oil strainer may be clogged, or the oil filter and the oil strainer may enter the inside of the oil pump and cause a failure.

Conventionally, therefore, as shown in FIG. 5, a shallow gutter-shaped groove 32 is machined in the upper end surface 26 of the side wall of the ladder frame to machine the excess liquid gasket inside the engine. Measures are taken to prevent protrusion to the outside. However, since a large number of grooves 32 are formed in the upper end surface 26 of the side wall of the ladder frame, a large amount of machining cost is required, which causes a disadvantage of increasing the manufacturing cost of the ladder frame 14 and eventually the manufacturing cost of the engine.

[0007]

[Problems to be solved by the device]

 The present invention was devised in view of the above circumstances, and in an engine in which a ladder frame is attached to the lower end of the crankcase skirt of the engine through a liquid gasket, the liquid gasket flows down along the inner peripheral wall of the ladder frame. It is an object of the present invention to provide a simple and inexpensive structure that can effectively prevent the oil from solidifying or solidifying and then falling and mixing into oil.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention applies a liquid gasket between the lower end surface of the skirt of the crankcase and the upper end surface of the side wall of the ladder frame that faces the lower end surface of the skirt, and In the case where the end face and the upper end face of the side wall of the ladder frame are brought into pressure contact with each other by tightening means such as bolts, the excess liquid gasket that overflows due to the above pressure contact is accommodated along the inner peripheral edge of the upper end face of the side wall of the ladder frame. The present invention proposes an engine with a ladder frame, in which the stepped portion is formed during casting of the ladder frame.

[0009]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. (Note that members and portions substantially the same as or corresponding to those of the conventional configuration described above with reference to FIGS. 1, 2 and 5 are denoted by the same reference numerals, and duplicate description will be omitted.) According to this, the ladder frame 14 attached to the lower end of the skirt portion of the crankcase 12 is cast from cast iron (including malleable cast iron, spheroidal graphite cast iron, etc.). The ladder frame 14 includes left and right side walls 16 extending in the crank axis direction and a plurality of lateral members 18 extending in a direction orthogonal to the crank axis, and includes a flange portion 34 formed at an upper end of the side wall 16. A step portion 36, which is recessed downward from the upper end surface 26 of the inner peripheral edge, is formed at the intermediate portion between the horizontal members 18 at the time of casting, and a joint portion with the horizontal member 18 is also formed from the upper end surface 26 from the upper end surface 26. A pair of short recessed grooves 38 which are recessed downward and extend in the crankshaft axis direction are formed by casting.

When the ladder frame 14 is attached to the lower end of the skirt portion of the crankcase 12, the liquid gasket g is usually applied to the upper end surface 26 of the upper end flange portion 34 of the side edge 16 of the ladder frame, and then the lower end of the skirt portion is The lower end surface 28 of the flange portion 40 is brought into contact with the upper end surface 26, the main tightening bolt is inserted into the bolt hole 22 of the ladder frame 14, and screwed into the corresponding screw hole on the crankcase side to tighten the bolt. Insert an auxiliary bolt into hole 24 and screw it into the corresponding screw hole on the crankcase side to tighten.

By tightening the main tightening bolt and the auxiliary bolt, a surplus liquid gasket is provided between the lower end surface 28 of the lower end flange portion 40 of the crankcase skirt portion and the upper end surface 26 of the upper end flange portion 34 of the side edge of the ladder frame. As shown by reference characters A and B in FIG. 4, g protrudes outside and inside the engine, respectively.

The excess liquid gasket A protruding outward from between the lower end surface 28 of the crankcase 12 and the upper end surface 26 of the ladder frame 14 can be easily wiped off after mounting the ladder frame 14, and Even if it is left as it is and solidified, it does not cause any particular malfunction in the operation of the engine. On the other hand, the surplus liquid gasket B protruding from the both surfaces 26 and 28 to the inside of the engine is housed in the step portion 36 and the concave groove 38 and solidified, and thus is retained in the step portion 36 and the concave groove 38. . Therefore, as shown by the arrow C in FIG. 4, the oil that flows down along the inner peripheral walls of the crankcase 12 and the ladder frame 14 will not be pushed into the oil pan 30. As a result, there is no problem that a small piece of the solidified excess liquid gasket is mixed into the oil to accelerate the clogging of the oil strainer or the oil filter, or enters the oil pump to cause seizure or the like. Further, since the step portion 36 and the concave groove 38 for accommodating and holding the excess liquid gasket are formed by casting instead of machining, the manufacturing cost of the ladder frame 14 can be reduced as compared with the conventional structure shown in FIG. As a result, there is an advantage that the manufacturing cost of the engine can be correspondingly reduced.

[0013]

[Effect of the device]

 As described above, in the engine with a ladder frame according to the present invention, a liquid gasket is applied between the lower end surface of the skirt portion of the crankcase and the upper end surface of the side wall of the ladder frame that faces the lower end surface of the skirt portion. In such a structure in which the lower end surface of the section and the upper end surface of the side wall of the ladder frame are pressed against each other by tightening means such as bolts, the excess liquid gasket protruding along the inner peripheral edge of the upper end surface of the side wall of the ladder frame and protruding from the above A step portion for accommodating the oil is formed at the time of casting the ladder frame, and it is possible to effectively prevent the excess liquid gasket protruding from the contact surface between the crankcase skirt portion and the ladder frame from entering the oil. And small pieces of the solidified liquid gasket can clog the oil strainer and oil filter. Ri, since it either possible to provide a Oiruponbu is baked Ku such failure that structure easy single and no inexpensive cause configuration, is practically useful.

[Brief description of drawings]

FIG. 1 is a side view of an entire engine showing an embodiment of the present invention.

FIG. 2 is a plan view showing a ladder frame of the engine shown in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is a partially enlarged plan view of a conventional ladder frame.

[Explanation of symbols]

 10 engine 12 crankcase 14 ladder frame 36 steps

Claims (1)

[Scope of utility model registration request] 1. A lower end surface of a skirt portion of a crankcase,
A liquid gasket is applied between the lower end surface of the skirt portion and the upper end surface of the side wall of the ladder frame, and the lower end surface of the skirt portion and the upper end surface of the side wall of the ladder frame are brought into pressure contact with each other by tightening means such as bolts. In things,
An engine with a ladder frame, wherein a step portion for accommodating an excess liquid gasket protruding due to the pressure contact is formed along the inner peripheral edge of the upper end surface of the side wall of the ladder frame when the ladder frame is cast.