JPH02223656A - Reinforcing member for engine - Google Patents

Abstract

PURPOSE:To reduce the weight of a member, to improve rigidity, and to reduce production vibration by a method wherein the beam part of a bearing cap is coupled to a plurality of bolt boss parts with a lower block. CONSTITUTION:Adjoining caps 7 are integrally formed by means of a pair of beam parts 8a and 8b mounted on both sides of a lower end and extended in the axial direction of the crank of an engine 1 to form a bearing cap 4. To the lower end of a skirt part 6 of a cylinder block 2, four side wall parts 10 intercoupled by means of a plurality of bolts 9, a plurality of bolt boss parts 13 formed in positioned facing beam parts 8a and 8b of a cap 4, and a lower block 12 having a plurality of ribs 15 by means of which the bolt boss part and the side wall part 10 are intercoupled are provided. The beam parts 8a and 8b of the cap 4 are coupled to the lower block 12 by means of a plurality of bolt boss parts 13. Separation of the cap 4 away from the lower block 12 suppresses lowering of natural frequency, and formation of a number of boss parts 13 positioned facing the beam parts 8a and 8b causes improvement of joining rigidity, and mounting of the ribs 15 results in reduction of weight.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine reinforcing member that increases the rigidity of a bearing cap and reduces generation of vibration.

(Prior Art) Generally, a main bearing section that supports the crankshaft of an engine is composed of a half-shaped bulkhead formed in a cylinder block and a bearing cap that is tightly coupled to the bulkhead. However, if the bearing cap is individually tightened and connected to each main bearing part in this way, it is difficult to ensure rigidity against explosive loads that act through the crankshaft. It is not possible to sufficiently reduce the vibrations of the bearing cap in the longitudinal and torsional directions. Furthermore, if each bearing cap is made thick in order to increase rigidity, an increase in weight is unavoidable. Therefore, various attempts have been made in the past to reduce the deformation vibrations described above by integrally connecting each bearing cap. For example, Utsukai Showa 57-12
Japanese Patent No. 7832 describes a bearing cap in which bearing caps are connected to each other by, for example, beam members in the crankshaft direction provided on both sides of the lower end. Further, in the device disclosed in Japanese Utility Model Application Publication No. 59-110359, the skirt portions on both sides of the main bearing are connected by a frame, and the frame and each bearing cap are connected by bolts. Also, Utsukai Showa 56
Publication No. 25041 discloses that each bearing cap is connected by a beam provided at both ends to form an integrated lower block that is tightly coupled to the main bearing portion and both skirt portions of the cylinder block, and that the bearing caps and A model in which a transmission case is connected to one end of an integrated lower block is described in g.

By the way, if the bearing caps are simply connected by a beam member extending in the crankshaft direction as described in the above-mentioned Japanese Utility Model Application Publication No. 57-127832, in reality, unless the beam members are made very thick, the longitudinal direction of the bearing caps will be reduced. It is not possible to sufficiently suppress vibrations in the runout and torsion directions. However, if the thickness of the beam member is increased, the weight will naturally increase. In addition, the above-mentioned Utility Model No. 56-,
If the bearing cap is integrated with the lower block and connected to the cylinder block as described in Publication No. 25041, the rigidity of the connection between the cylinder block and the bearing cap increases, and by connecting the transmission case to the lower block, so-called power plant It is also possible to suppress bending, but in this case, the natural frequency of the cylinder block skirt and bearing cap decreases, resulting in a muffled sound generation frequency range of about 200 to 50011z, which increases the noise. .

It is believed that the reduction in the natural frequency can be suppressed if the frame connecting the skirts of the cylinder block, that is, the lower block, and the bearing cap are separated, as described in the above-mentioned Japanese Utility Model Application Publication No. 59-110359. However, in this case, if each bearing cap is individually connected to the lower block with bolts as described in the same publication, it is difficult to ensure sufficient joint rigidity between the bearing cap and the lower block, and as a result, deformation vibration cannot be adequately prevented. Furthermore, if the thickness of the joints, etc. is increased in an attempt to increase the joint rigidity, an increase in weight is unavoidable.

Although it is possible to increase rigidity and reduce vibration by connecting the bearing caps together, it is difficult to simultaneously achieve the goals of being lightweight, having high rigidity, and suppressing the drop in natural frequency. is the current situation.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and is lightweight and has high rigidity, and can also reduce vibration by suppressing a decrease in the natural frequency of the bearing cap. The purpose is to obtain reinforcement members for engines.

(Structure of the Invention) The present invention suppresses a drop in the natural frequency by separating the bearing cap, which is integrally connected by a beam portion, and the lower block, which is tightly connected to the lower end of the skirt of the cylinder block, and By forming a large number of bolt boss parts on the reinforcing member corresponding to the beam parts of the bearing cap, the joint rigidity is increased, and by providing ribs between these bolt boss parts and the side wall parts, it is lightweight and has a strong reinforcing effect. It consists of a high crankshaft support device.

That is, the engine reinforcing member according to the present invention forms a bearing cap by integrating adjacent cap parts by a pair of beam parts extending in the direction of the crankshaft of the engine, which are provided on both sides of the lower end, and also forms a bearing cap for the cylinder block. a side wall portion that is fastened to the lower end of the skirt;
A lower block having a plurality of bolt boss parts formed at positions corresponding to the beam parts of the bearing cap and a plurality of ribs connecting the bolt boss parts and the side wall part is provided, It is characterized in that it is connected to the lower block at a plurality of bolt boss portions.

(Function) Each cap portion of the bearing cap is connected and integrated by a pair of beam portions extending in the crankshaft direction on both sides of the lower end, and therefore has high rigidity against falling or torsional deformation in the front-rear direction. In addition, the lower block, which is fastened to the lower end of the cylinder block skirt in the side wall, is connected to the beam part of the bearing cap by multiple bolt bosses, so the joint rigidity of the integral bearing cap and lower block is high. , Therefore, the resistance to deformation vibration of the bearing cap is large. Further, since the bearing cap and the lower block are originally configured as separate bodies, a decrease in the natural frequency of the bearing cap and the cylinder block skirt portion is suppressed.

As mentioned above, the bearing cap has a lightweight structure integrated by a pair of beam parts, and the lower block has a lightweight and highly rigid structure in which the side wall part and bolt boss part are connected by a plurality of ribs. The crankshaft support device constituted by these is lightweight as a whole, has sufficient rigidity as described above, and can have a high natural frequency to reliably reduce vibrations.

(Example) Examples will be described below based on the drawings.

FIG. 1 is an overall front view of an embodiment of the present invention.

The engine 1 of this embodiment is a V-type six-cylinder engine, and four half-shaped bulkheads 3 are provided at the center of the lower end of the cylinder block 2 in a row in the crankshaft direction. The bearing cap 4 is tightened and connected by each pair of bolts 5, 5, and by these,
A bearing portion rotatably supports the journal portion of the crankshaft.

The bearing cap 4 has a cap part 7 provided at a position corresponding to each bulkhead 3, and each cap part 7 is connected by a pair of beam parts 8a and 8b extending in the crankshaft direction at both sides of the lower end. and are integrated. These beam portions 8a, 8b are located outside the bolt 5 for tightening the cap.

Further, at the lower end of the skirt portion 6 of the cylinder block 2, a plate portion 11 extending between four side wall portions 10 connected to the lower end of the skirt portion 6 with a plurality of bolts 9 and the side wall portion 100 is provided.
A lower block 12 is provided. The lower block 12 reinforces the skirt portion 6 of the cylinder block 2 and the bearing cap 4 at the same time, and the plate portion 11 is provided at positions corresponding to the beam portions 8a and 8b on both sides of the lower end of the bearing cap 4. 6 each
Bolt boss portions 13 are formed.

The beam portions 8a and 8b of the bell ring cap 4 are coupled to the lower block 12 by bolts 14 passing through these bolt boss portions [3]. Further, on both sides of the lower block 12, a plurality of ribs 15 are formed in a triangular shape between the side wall portion 10 and each bolt boss portion 13, and an oil pan 16 is connected to the lower end of the side wall portion 10. .

2 and 3 show the upper and lower surfaces of the bearing cap 4. FIG. As is clear from these figures, the bearing cap 4 has a structure in which four cap portions 7 are provided in line in the crankshaft direction, and these are connected by beam portions 8a and 8b on both sides of the lower end.

4 and 5 are a plan view and a right side view of the lower block 12, and FIG. 6 is a sectional view taken along line AA in FIG. 4. Bolt boss portions 13 for fixing the bearing cap 4 of the lower block I2 are provided on both sides of the plate portion 11.
They are set for each individual. And lower block 1
On the side of the plate part 11 located inside the oil pan rail 17 from the center part of 2 to the front side (left side in FIG. 4), there is oil between each rib 15 connecting the side wall part 10 and the bolt boss part 13. A hole 18 for return is formed. Further, a hole 20 for collecting oil on the bottom plate 19 on the rear side of the lower block 12 is provided at the innermost rearmost portion of the oil pan rail 17 over substantially the entire width between the left and right bolt boss portions 13. A hole 23 is provided at the front end of the plate portion 11, through which an oil vibe 22 for guiding oil from an oil strainer 21 disposed in the oil pan 16 to an oil pump (not shown) passes through. , a strainer 21 is installed in the plate section II.
Holes 24 are formed for attachment and repair. Further, on the rear side bottom plate 19 of the lower block 12, a large number of ribs 25 are formed facing the rear side holes 20, which serve both for rectifying oil flow and for reinforcing the oil return.

As shown in FIG. 1, the plate portion 11 of the lower block 12 is formed into a medium-height shape that is slightly curved upward. Therefore, the oil on the plate portion 11 easily flows into the oil return hole 18 on the side of the plate portion Il, and is easily collected into the oil pan 16. In addition, since the plate portion 11 is curved, stress caused by deformation due to an explosive load or the like is alleviated and vibrations are absorbed, thereby preventing damage to the lower block 12.

A tightening portion 27 that constitutes a mating surface 26 with a transmission case (not shown) is integrally formed at the rear end of the lower block. By tightening the transmission case to this tightening portion, the crankshaft support portion and the mission case are integrally connected via the beam portions 8a and 8b, increasing their mutual rigidity. Power plant bending is reduced.

Incidentally, a mating surface 28 on the cylinder block 2 side is provided in an annular shape at the upper end of the side wall portion 10 of the lower block 12, but this mating surface 28 on the cylinder block 2 side is formed on the rear side as shown in FIG. In other words, the seal width on the transmission side is formed to be larger than the seal width on the front side.

In order to suppress the vertical mode bending vibration of the mission, it is necessary to increase the rigidity near the mating surface 26 with the mission case, and for this purpose, it is effective to increase the seal width on the mission side in this way. . and again,
On the front side, the seal width is kept to a certain level to ensure sealing performance, so overall weight increase can be suppressed, and by reducing the weight of the front part of the engine, the above-mentioned bending vibration reduction effect can be further enhanced. Can be done. 2 in the diagram
Reference numeral 9 denotes a bolt boss portion formed on the side wall portion 10 for connection with the cylinder block 2. This bolt boss part 29
The overlapping portion of the oil pan rail 17 is also used as a boss portion for attaching the oil pan 16. Further, in a portion of the oil pan rail 17 where the bolt boss portion 29 of the side wall portion 10 cannot be shared, a bolt boss portion 30 for mounting the oil pan rail 17 is separately provided.

Further, the bearing cap 4 has a pair of beam parts 8a, 8.
It has a bifurcated shape with b facing down, and its beam portion 8a
8b is bolted to the bolt boss lff1 I3 of the roller block 12 as described in [2], so it is lightweight and rigid. The bearing cap 4 has a high height and has a large resistance against tilting in the rear direction and torsional vibration.In addition, the bearing cap 4 with such a structure has a moderate flexibility.
1. Since the crankshaft can be deformed according to the deflection of the crankshaft, it is possible to prevent uneven contact of the crankshaft at the bearing portion and suppress an increase in drive resistance.

The lower block 12 is composed of a side wall portion 10, a brace portion 11, a bolt boss portion 13, a rear bottom plate portion 19, and the like.
The rear side is reinforced with ribs 25 that also serve to rectify return oil, making it lightweight and highly rigid.

Next, another embodiment will be described.

FIG. 7 is a plan view of a lower block according to another embodiment of the invention. In this embodiment, the cylinder block and bearing cap of the engine are of the same construction as those of the previous embodiment shown in FIGS. 1 to 3, and only the lower block is different in construction. In the following explanation, the parts that are roughly the same as those in the previous embodiment will be described as follows.
The same reference numerals are used, including those not shown. That is, in this embodiment, the lower block +12 is provided with four side wall parts 110 that are bolted to the lower end of the skirt part 6 of the cylinder block 2, and the upper end of the side wall part IIO is provided with a joint 7 on the cylinder block 2 side. A top surface 128 is provided. Further, on the lower surface of the lower block 112, the rear side (
The end (on the right side in FIG. 7) extends in the width direction at a position slightly forward of the rear end wall portion of the side wall portion 110, and on the front side thereof, is mostly shaped like the mating surface 128 on the cylinder block 2 side. An extending oil pan rail 117 is provided. The oil pan rail 117 has a structure in which a portion of the front side is offset outward from a mating surface 128 on the cylinder block 2 side, as will be described later. The lower surface of the lower block 112 on the rear side of the oil pan rail 117 is covered by a bottom plate 119. The lower block 112 also has beam portions 8a and 8b of the bearing cap 4 at positions corresponding to the beam portions 8a and 8b on both sides of the lower end of the bearing cap 4.
Five bolt boss portions 113 are formed for bolting bolts a and 8b to the lower block 112. A plurality of ribs 115 are formed on both sides of the lower block 112 in a triangular shape between the side wall 110 and each bolt boss 113, and between each of these ribs 115 there is a hole for oil return. 118 is formed.

Bolt boss portions 129 for connection to the cylinder block 2 are provided at predetermined intervals on the side wall portion 110 of the lower block 112. These bolt boss portions 129 are mating surfaces on the cylinder block 2 side! The oil pan rail 117 at a position overlapping with the oil pan rail 117 is also used as a boss portion for attaching the oil pan 16. The rib 115 provided between the bolt boss 1113 for mounting the bearing cap and the side wall portion 110 is connected to the bolt boss 113 for mounting the bearing cap and the cylinder block 2
The bolt boss part +29 is connected to the bolt boss part +29. Furthermore, two dedicated bolt boss portions 130 for mounting the oil pan are provided at the rear portion of the oil pan rail 117 that does not overlap with the mating surface 128 on the cylinder block 2 side.

Annular cylinder block side mating surface 128
As in the previous embodiment, the seal width on the rear side, that is, on the transmission side, is made larger than the seal width on the front side, so as to suppress vertical bending vibration of the transmission.

In the lower block 112 of this embodiment, the hole 120 for oil return to the oil pan 16 spans the entire width between the left and right bearing cap mounting bolt boss portions 113 in the width direction, and extends in the front and back direction. has a large opening extending from the front end wall portion of the side wall portion 110 to the rear end portion of the oil pan rail 117. In addition, the bearing cap is attached to the bolt boss part 113 and the side wall part 11.
The reinforcing rib 115 between the lower block 1
12, the front row bearing cap attachment is formed from the bolt boss part 113 of the lower block 112 to the bolt boss part 129 in the center of the front end wall part of the lower block 112, and this rib 115 A hole 118 for oil return is also provided on the side wall portion 110 side of the tank. Also, lower block 1
On the upper surface of the bottom plate 119 in the rear part of the bearing cap 12, a rib 115 is provided extending in the front-rear direction between the left and right bolt boss parts 113 for mounting the bearing cap located in the last row and the rear end wall part of the side wall part 110. , a bolt boss portion 12 for cylinder block coupling located at the center of the rear end wall portion of the side wall portion 110.
A pair of ribs 131 are provided from 9 toward the front. A tightening portion 127 is integrally formed at the rear end of the lower block +12 and forms a fitting part 26 with a transmission case (not shown).

By the way, in this embodiment, the oil pan rail 117 of the lower block II2 is provided at a position where most of it, except for the rear side, overlaps the mating surface 128 on the cylinder block 2 side, as described above, and the connection with the cylinder block 2 is prevented. The bolt boss portion 129 for oil pan mounting is also used for mounting the oil pan, but in a position where the mating surface 128 on the cylinder block 2 side cannot be widened because an auxiliary device such as a starter is installed. Oil pan rail 1 at the position relative to the cylinder block side mating surface 128a
17a is offset outward. This increases the capacity of the oil pan 16, and at the same time, the lower block through hole 12 widens by the amount of this offset, increasing the rigidity to suppress twisting and the opening/closing mode of the skirt portion 6.

Note that although the above embodiment is an example in which the present invention is applied to a V-type engine, it is of course possible to apply the present invention to other engines. Further, the specific structure of the bearing cap and the lower block can be modified in various ways other than those of the above embodiments.

(Effects of the Invention) Since the present invention is configured as described above, it is possible to obtain a bearing cap that is lightweight, has high rigidity, and has a high natural frequency, thereby sufficiently reducing the vibration of the bearing cap. can.

Furthermore, since the bearing cap is separate from the lower block, it is easy to assemble, and the main bearing surface can be machined with only the bearing cap assembled, resulting in excellent workability.

[Brief explanation of the drawing]

Fig. 1 is an overall front view of an embodiment of the present invention, Fig. 2 is a bottom view of a bearing cap in the same embodiment, Fig. 3 is a plan view of the same, and Figs. 4 and 5 are a lower view of the same embodiment. A plan view and a side view of the block, FIG. 6 is a sectional view taken along the line AA in FIG. 4, and FIG. 7 is a plan view of a lower block according to another embodiment of the present invention. l: Engine, 2 Niji cylinder block, 3: Main bearing part, 4: Bearing cap, 6: Skirt part,
8a, 8b: beam section, 10. [10: Side wall part, 12,
112: Lower block, [3,113: Bolt boss part,
15,115: Ribs.

Claims (1)

[Claims] (1) A pair of beam parts extending in the direction of the engine crankshaft provided on both sides of the lower end integrate the adjacent cap parts to form a bearing cap, and are fastened to the lower end of the skirt of the cylinder block. a lower block having a side wall portion, a plurality of bolt boss portions formed at positions corresponding to the beam portions of the bearing cap, and a plurality of ribs connecting the bolt boss portions and the side wall portion; A reinforcing member for an engine, wherein a beam portion of the engine is connected to the lower block at the plurality of bolt boss portions.