JPH0530447U - Engine crank frame - Google Patents

Abstract

(57) [Summary] [Purpose] Achieves both rigidity and weight reduction of the engine crank frame. [Structure] A bearing cap portion 2 for rotatably supporting a crankshaft, left and right side frame portions 4 extending in a direction parallel to the crankshaft, and each bearing cap portion 2 connected to the left and right side frame portions 4 in a ladder shape. In a crank frame of an engine having a bulk portion 3, a recess 11 having a substantially rectangular parallelepiped shape is opened in the side frame portion 4 as a lightening portion of the bulk portion 3. In addition, as the lightening portion of the bulk portion 3, the concave portion 2 having a substantially rectangular parallelepiped shape is used.
1 is opened in the upper and lower surfaces 25 and 26 of the bulk portion 3, and the light weight material 22 is interposed in the recess 21. In addition, the bulk portion 3
The hollow honeycomb material 3 is provided inside the bulk part 3 as a thinned part of
Cast 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a crank frame that supports a crank shaft of an engine.

[0002]

[Prior Art]

 In automobile engines and the like, a crank frame in which each bearing cap is connected to each other through a beam member is used in order to increase the support rigidity of the crankshaft.

Conventionally, for example, as shown in FIG. 9, in a crank frame 41, a bearing cap portion 42 coupled to each bearing holding portion 45 of a cylinder block 44 is integrally formed on a bearing beam portion 43 as a beam member. Therefore, the bending pressure generated in the crankshaft via the connecting rod due to the combustion pressure applied to the piston is suppressed (see Japanese Utility Model Laid-Open No. 57-71741).

[0004]

[Problems to be solved by the device]

 However, in such a conventional device, in order to sufficiently secure the support rigidity of the crankshaft, the crankframe 1 itself is expanded by enlarging the cross-sectional area of each part of the crankframe 1 or casting a reinforcing material. The rigidity of the vehicle should be increased, but as the rigidity increases, the weight increases, and for an automobile engine that is strongly required to be lightened, it goes against the original purpose.

The present invention focuses on the above points and aims at achieving both rigidity and weight reduction of the crank frame.

[0006]

[Means for Solving the Problems]

 The present invention has a bearing cap portion that rotatably supports a crankshaft, left and right side frame portions that extend in a direction parallel to the crankshaft, and a bulk portion that connects each bearing cap portion to the left and right side frame portions in a ladder shape. In a crank frame of an engine having: a substantially rectangular parallelepiped concave portion as a lightening portion of the bulk portion, which is opened in the side frame portion, and the bulk portion extends in the lateral direction orthogonal to the cylinder center line; It has front and rear vertical beam portions extending in a vertical direction orthogonal to the shaft rotation axis.

Further, a recess of a substantially rectangular parallelepiped is opened in the upper and lower surfaces of the bulk part as a lightening part of the bulk part, and a lightweight material is interposed in this recess.

Further, a hollow honeycomb material is cast inside the bulk portion as a thinned portion of the bulk portion.

[0009]

[Action]

 When the engine is operating, the combustion pressure received by the piston acts on the crankshaft via the compressor, and from this crankshaft to the bearing caps, the load parallel to the rotation axis of the crankshaft and the direction orthogonal to the rotation axis. The combined force with the above load acts, and due to these loads, bending stress acts in the vertical and longitudinal directions between each bearing cap and each bulk.

By opening a recess of a substantially rectangular parallelepiped into the side frame portion as a thinned portion of the bulk portion, the bulk portion has upper and lower horizontal beam portions extending in the lateral direction orthogonal to the cylinder center line, a crankshaft rotating shaft, and Since it has a box shape consisting of front and rear vertical beams extending in the orthogonal vertical direction, it ensures high rigidity against the bending stress of the bulk part and reduces the cross-sectional area of the bulk part for weight reduction. You can measure.

Further, as a hollow portion of the bulk portion, a substantially rectangular parallelepiped concave portion is opened on the upper and lower surfaces of the bulk portion, and a lightweight material is interposed in the concave portion, so that the bulk portion has a vertical direction orthogonal to the crankshaft rotation axis. The front and rear vertical beams extend in the same direction, and the lightweight material intervenes between the front and rear vertical beams.The bending stress of the bulk part is calculated as the compressive stress of the lightweight material sandwiched between the front and rear vertical beams. Since it is widely dispersed, the bending rigidity of the bulk part is secured and the weight is reduced by using a lightweight material.

Further, by casting a hollow honeycomb material inside the bulk portion as a thinned portion of the bulk portion, the bulk portion has upper and lower horizontal beam portions whose cross section extends in the lateral direction orthogonal to the cylinder center line, It has a box shape consisting of front and rear vertical beams that extend in the vertical direction orthogonal to the crankshaft rotation axis, and the bending stress of the bulk part is the compressive stress of the honeycomb material sandwiched between these beams. Since it is widely dispersed, the bending rigidity of the bulk part is secured and the weight is reduced by using the honeycomb material.

[0013]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the crank frame 1 includes six bearing cap portions 2 coupled to a bearing holding portion of a cylinder block (not shown), and two bearing cap portions 2 extending on both sides of each bearing cap portion 2. It has a side frame part 4 and a bulk part 3 connecting each bearing cap part 2 to each side frame part 4 in a ladder shape, and these are integrally formed by casting using an aluminum alloy or the like as a material.

As shown in FIG. 2, each bearing cap portion 2 has a bearing surface 5 formed in a curved arc shape, and a journal portion of a crankshaft is interposed with a bearing metal (not shown) joined to the bearing surface 5. Rotatably supported. Boss portions 6 are formed at both ends of each bearing surface 5, and a bolt screwed into the cylinder block penetrates through a bolt hole 7 opened in the boss portion 6 so that each bearing cap portion 2 is fastened to the cylinder block. Is becoming

As shown in FIG. 3, the side frame portion 4 is formed in a U-shaped cross section, and includes an upper beam portion 8, a side beam portion 9 and a lower beam portion 10.

As a thinned portion of each bulk portion 3, a rectangular parallelepiped concave portion 11 is formed therein. One end of the recess 11 opens into the side beam portion 9 of the side frame portion 4 and is integrally molded when the crank frame 1 is cast, and the mold is extracted from this opening.

As shown in FIG. 4, the concave portion 11 defines a rectangular parallelepiped space inside the bulk portion 3, and the bulk portion 3 includes the upper horizontal beam portion 12, the lower horizontal beam portion 13, and the upper and lower horizontal beam portions 12, 13. It is formed in a box shape consisting of front and rear vertical beam portions 14 and 15 connecting both ends. The upper and lower horizontal beam portions 12 and 13 and the front and rear vertical beam portions 14 and 15 are connected orthogonally to each other.

Next, the operation will be described.

When the engine is operating, the combustion pressure received by the piston acts on the crankshaft via the compressor, and from this crankshaft to each bearing cap portion 2, as shown by the arrow in FIG. The combined force of the load Fs in the direction parallel to and the load Fr in the direction orthogonal to the rotation axis O acts.

The load Fs acting on the bearing cap portion 2 in the direction parallel to the rotation axis O of the crankshaft is mainly supported by the upper and lower horizontal beam portions 12 and 13 of the bulk portion 3. Bending stress in the engine longitudinal direction acts between the bearing cap portion 2 and the bulk portion 3 due to this load Fs, but the cross sections of the upper and lower horizontal beam portions 12 and 13 extend in the lateral direction orthogonal to the cylinder center line. Therefore, it has a high section modulus against this bending stress, and sufficiently secures the bending rigidity of the bulk portion 3.

A load Fr acting on the bearing cap portion 2 in a direction orthogonal to the rotation axis O of the crankshaft is mainly supported by the front and rear vertical beam portions 14 and 15 of the bulk portion 3. The load Fr causes bending stress in the engine vertical direction between the bearing cap portion 2 and the bulk portion 3, but the longitudinal cross-sections of the front and rear vertical beam portions 14 and 15 are perpendicular to the crankshaft rotation axis O. Has a high section modulus against this bending stress, so that the bending rigidity of the bulk part 3 is sufficiently secured, and the cross-sectional area of the bulk part 3 can be reduced to reduce the weight. it can.

Next, in another embodiment shown in FIG. 5, a rectangular parallelepiped concave portion 21 opening to the upper and lower surfaces 25 and 26 of the bulk portion 3 is formed as a lightening portion of the bulk portion 3, and the concave portion 21 is lightweight. The material 22 is interposed.

As shown in FIG. 6 as well, the bulk portion 3 is composed of front and rear vertical beam portions 23 and 24 that vertically extend with the lightweight material 22 interposed therebetween, and the front and rear vertical beam portions 23 and 24 have a rectangular cross section that extends vertically. I have

The light-weight material 22 is made of another resin, such as plastic, which is lighter than an aluminum material, and is filled in the recess 21.

In this case, the load Fr acting on the bearing cap portion 2 shown in FIG. 1 in the direction orthogonal to the rotation axis O of the crankshaft is mainly supported by the front and rear vertical beam portions 23, 24 of the bulk portion 3. On the other hand, the load Fs acting in the direction parallel to the rotation axis O of the crankshaft is widely dispersed as a compressive stress in the lightweight material 22 sandwiched between the front and rear beam portions 14 and 15, so that the bulk portion 3 has sufficient bending rigidity. In addition to the above, the weight can be reduced through the lightweight material 22.

Next, in another embodiment shown in FIG. 7, the hollow honeycomb material 31 is cast inside each bulk portion 3 as a thinned portion of each bulk portion 3.

As shown in FIG. 8, the honeycomb material 31 is formed by laminating metal foils in a hexagonal honeycomb shape, and is cast into the bulk portion 3. The bulk part 3 has upper and lower horizontal beam members 32 and 33 and front and rear vertical beam parts 34 and 35 along the outer surface of the honeycomb material 31.

In this case, the load Fs acting on the bearing cap portion 2 shown in FIG. 1 in the direction parallel to the rotation axis O of the crankshaft is mainly supported by the upper and lower horizontal beam members 32 and 33 and the honeycomb member 31, The load Fr applied in the direction orthogonal to the rotation axis O of the crankshaft is widely supported as the compressive stress of the honeycomb material 31 supported between the front and rear vertical beam portions 34 and 35 and sandwiched between the front and rear vertical beam portions 32 and 33. Since the particles are dispersed, the bending rigidity of the bulk portion 3 is sufficiently secured, and the weight is reduced through the honeycomb material 31.

[0030]

[Effect of the device]

 As described above, according to the present invention, the bearing cap portion that rotatably supports the crankshaft, the left and right side frame portions that extend in the direction parallel to the crankshaft, and the bearing cap portions for the left and right side frame portions are ladder type. In a crank frame of an engine having a bulk part that is connected to a bulk part, a substantially rectangular parallelepiped recess is opened in the side frame part as a thinned part of the bulk part, and the bulk part extends in a lateral direction orthogonal to the cylinder center line. The upper and lower horizontal beams and the front and rear vertical beams that extend in the vertical direction orthogonal to the crankshaft rotation axis ensure high rigidity against bending stress in the bulk and reduce the cross-sectional area of the bulk. The weight can be reduced.

Further, as a hollow portion of the bulk portion, a substantially rectangular parallelepiped concave portion is opened on the upper and lower surfaces of the bulk portion, and a lightweight material is interposed in the concave portion. Therefore, the bending stress of the bulk portion is increased between the front and rear vertical beam portions. It is widely dispersed as the compressive stress of the sandwiched lightweight material to secure the bending rigidity of the bulk part, and the lightweight material is used to reduce the weight.

Further, since the hollow honeycomb material is cast inside the bulk portion as a thinned portion of the bulk portion, the bending stress of the bulk portion is widely dispersed as the compressive stress of the honeycomb material. In addition to being secured, the weight can be reduced by using a honeycomb material.

[Brief description of drawings]

FIG. 1 is a perspective view of a crank frame showing an embodiment of the present invention.

FIG. 2 is a perspective view of the same main portion.

FIG. 3 is a cross-sectional view of the same main part.

FIG. 4 is a vertical sectional view taken along line AA of FIG.

FIG. 5 is a sectional view of a main part of a crank frame showing another embodiment.

FIG. 6 is likewise a vertical cross-sectional view of a main part.

FIG. 7 is a sectional view of a main part of a crank frame showing still another embodiment.

FIG. 8 is likewise a vertical cross-sectional view of a main part.

FIG. 9 is a perspective view showing a conventional example.

[Explanation of symbols]

 1 Crank frame 2 Bearing cap part 3 Bulk part 4 Side frame part 11 Recessed part 12 Upper horizontal beam part 13 Lower horizontal beam part 14 Front vertical beam part 15 Rear vertical beam part 22 Light material 23 Front vertical beam part 24 Rear vertical beam part 31 Honeycomb material

Claims (3)

[Scope of utility model registration request] 1. A bearing cap part for rotatably supporting a crankshaft, left and right side frame parts extending in a direction parallel to the crankshaft, and a bulk part for connecting the bearing cap parts to the left and right side frame parts in a ladder shape. In a crank frame of an engine having: a hollow portion of the bulk portion, a substantially rectangular parallelepiped recess is opened in the side frame portion, and the bulk portion extends in a direction orthogonal to the cylinder center line; A crank frame of an engine having front and rear vertical beam portions extending in a direction orthogonal to a rotation axis. 2. A bearing cap portion that rotatably supports the crankshaft, left and right side frame portions that extend in a direction parallel to the crankshaft, and a bulk portion that connects the bearing cap portions to the left and right side frame portions in a ladder shape. A crank frame of an engine having: a crank portion of the engine, wherein a recess of a substantially rectangular parallelepiped is opened on the upper and lower surfaces of the bulk portion as a lightening portion of the bulk portion, and a lightweight material is interposed in the recess. 3. A bearing cap portion that rotatably supports the crankshaft, left and right side frame portions that extend in a direction parallel to the crankshaft, and a bulk portion that connects the bearing cap portions to the left and right side frame portions in a ladder shape. A crank frame for an engine, comprising: a hollow honeycomb material cast into the bulk portion as a thinned portion of the bulk portion.