JPS5916515Y2 - low noise engine - Google Patents

Description

[Detailed description of the invention] This invention is a low-noise automobile in which the crankcase and oil pan are composed of a highly rigid crank frame that supports the crankshaft and a soundproof cover that also serves as the oil pan and covers the so-called crank chamber. related to engines.

In this type of engine, in order to fully utilize the noise reduction function of the soundproof cover, it is necessary to seal the soundproof cover and the cylinder block with oil and at the same time to make an elastic connection between the soundproof cover and the cylinder block.

In addition, in automobile engines, the front end of the transmission is connected to the rear end of the engine, but since the shapes of the two are significantly different, it is necessary to satisfy both oil sealing and elastic connection between the soundproof cover and the cylinder block. This was extremely difficult.

In order to overcome these drawbacks, it has been proposed in the past to separate the engine and transmission and connect them via a universal joint. It is necessary to use constant velocity universal joints to ensure power transmission when moving relative to each other, which complicates the structure and increases the number of parts. Moreover, since the soundproof cover and the transmission are coupled, there is a risk that vibrations from the transmission part will propagate to the soundproof cover and generate noise.

The present invention was developed in view of the above circumstances, and includes a rear plate fixed to the rear surface of the cylinder block, and a seal provided at the rear edge of the soundproof cover on the seal support surface protruding from the front surface of the rear plate. By tightening and fixing with a band, it ensures oil sealing performance and elastic support performance between the soundproof cover and the cylinder block, and also enables rigid connection between the transmission and engine, reducing vibrations between both and reducing noise. An object of the present invention is to provide an automobile engine capable of reducing the occurrence of.

The present invention will be described in detail below based on embodiments shown in the accompanying drawings.

In FIGS. 1 to 7 showing one embodiment, an engine main body 1 has a cylinder block 2 and a crank arm 3 that supports a crankshaft (not shown) on the cylinder block 2. Seal mounting surfaces 4 are formed on both side surfaces and the front surface, respectively.

On the rear surface of the cylinder block 2, a rear plate 5 made of a thick plate is closely tightened and fixed with bolts (not shown).Furthermore, on the rear surface of the rear plate 5, a transmission 6 is fixed with bolts to the cylinder block 2 and the crank. By directly tightening and fixing to the frame 3, the cylinder block 2, crank frame 3, and transmission 6 are rigidly connected via the rear plate 5.

7 is a fastening hole between the cylinder block 2 and the crank frame 3 and the rear plate 5; 8 is a fastening hole between the rear plate 5 and the transmission 6; 9 is a fastening hole that serves both;
10 is a starter mounting hole, and 11 is a crankshaft insertion hole.

A band plate 12 curved in a substantially U-shape from the front is welded and fixed to the front surface of the rear plate 5, and both ends of a seal support surface 13 formed by the circumference of this band plate 12 are as shown in FIGS. 1 and 3. As shown in the figure, it is configured to be continuous on the same plane as the rear ends of seal mounting surfaces 4 formed on both side surfaces of the cylinder block 2.

Further, seals 15 each having a substantially U-shaped cross section and made of an elastic material are provided at the upper and rear opening edges of the soundproof cover 14 that covers the so-called crank chamber.
It is tightened and fixed at 7.

The seal 15 attached to the upper edge of the soundproof cover 14 is tightened and fixed onto the seal mounting surface 4 formed on the cylinder block 2 with a presser plate 18 and bolts 19, thereby connecting the cylinder block 2 and the upper edge of the soundproof cover 14. It is sealed with oil and then elastically bonded.

On the other hand, the seal 15 located at the rear edge of the soundproof cover 14 is
Seal support surface 13 protruding from the front surface of rear plate 15
They are placed on top of each other and are held in place by a tightening band 20.

One end of this tightening band 20 is tightened and fixed near one end of the seal support surface 13 by two bolts 21 as fixing devices.

The other end of the tightening band 20 is formed into a loop shape and is removably locked to a hook 23 at the tip of the tension device 22.

As shown in FIGS. 4 and 6, the tension device 22 includes a support 24 installed on the opposite side of the bolt 21 serving as the fixing device, and a support 24 that extends and retracts toward the support surface 13. The screwed bolt 25 and this bolt 25
A rotating head 2 rotatably connects a hook 23 to the tip of the
6 and a locking nut 27 for the bolt 25,
The tension of the tightening band 20 is adjusted by moving the bolt 25 back and forth.

Further, in the vicinity of this tension device 22, there is a support column 28 installed on the front surface of the rear plate 5 and the support surface 13.
A tightening device 31 is provided, which is formed by a bolt 29 screwed into the support column 28 so as to move toward and away from the bolt 29, and a head 30 having a semicircular cross section rotatably attached to the tip of the bolt 29.

Therefore, in such a configuration, the engine body 1 and the transmission 6 are rigidly coupled via the rear plate 5, so vibrations of the engine body 1 and the transmission 6 are significantly reduced, and relative movement between the two is reduced. Since this is prevented, there is no need to interpose a universal joint between the crankshaft and the input shaft on the transmission side.

On the other hand, the seal 15 provided on the upper edge of the soundproof cover 14 is fixed with a presser plate 18 on the seal mounting surface 4 formed on the cylinder block 2, and the seal 15 on the rear edge of the soundproof cover 14 is fixed on the seal mounting surface 4 formed on the cylinder block 2. The retainer is fixed onto the seal support surface 13 with a retainer band 20.

At this time, although the seal support surface 13 is formed into a substantially U-shape from the front, the seal 15 is held down and fixed with the tightening band 20 instead of being tightened and fixed using bolts or the like. , the tension force is made uniform, the oil sealing function is improved, and at the same time, the ease of attachment and detachment of the seal 15, that is, the maintainability is improved.

Also, since both ends of this support surface 13 are connected on the same plane as the rear end of the mounting surface 4 provided on the cylinder block 2,
A continuous sealing surface is ensured from the Ginonda block to the rear plate to the cylinder block.

Therefore, the oil sealing performance of the soundproof cover 14 is significantly improved, and elastic support performance is ensured.

In addition, when the seal support surface 13 is provided with a convex line or groove along the curved direction of the support surface 13 as shown in FIGS. 8A, B, and C, the oil seal between the seal 15 and the seal support surface 13 is It goes without saying that the performance is improved and at the same time the displacement of the tightening band 20 can be prevented.

On the other hand, the tightening band 20 does not necessarily have to be a band-like body, and may be composed of a string-like body such as a wire as shown in FIG. 8C.

Further, as a support device for the tightening band 20, the tension device 22 and the tightening device 31 are not necessarily required, but in the case of the embodiment, the tightening band 20
The tension or hold on the seal 15 is advantageous because the force can be easily and quickly adjusted.

As described above, according to the present invention, the rear plate is fixed to the rear end of the cylinder block, and the seal at the rear edge of the soundproof cover is mounted on the approximately U-shaped seal support surface protruding from the front surface of the plate. Since it is tightly fixed with a tightening band and the end of the support surface is continuous on the same plane as the rear end of the seal mounting surface provided on the cylinder block, there is no gap between the soundproof cover and the engine body. It is possible to improve the oil sealing performance between the two without impairing the elastic coupling performance, and at the same time, improve maintainability.

In addition, since the engine body and transmission can be rigidly connected via the rear plate, vibrations between the two can be reduced and noise can be prevented, and there is no need to incorporate a universal joint into the power transmission line between the two. Its structure can be simplified and its durability can be improved.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts showing an embodiment of the present invention, Fig. 2 is a perspective view of the improved rear plate, Fig. 3 is an exploded perspective view of the main parts showing the installed state, and Fig. 4 is the same as above. Figure 5 is a front view of the assembled state with parts broken away, Figure 5 is a sectional view taken along line v-■ in Figure 4, Figure 6
is a perspective view of a part of the tension device, FIG. 7A is a perspective view of a part of the tightening device, FIG. C is a sectional view showing a modified example of the seat support surface. 2... Cylinder block, 3... Crank frame, 4... Seal mounting surface, 5... Rear play 1, 6
... I. Lance transmission, 13... Seal support surface, 14... Soundproof cover, 15... Seal, 20...
- Tightening band, 21... Fixture, 22... Tension device, 31... Tightening device.

Claims (4)

[Scope of utility model registration request] (1) In a low-noise engine in which at least the crankcase and oil pan are constructed of a highly rigid crank frame and a soundproof cover elastically supported on the engine body, the supporting surface of the seal provided at the rear edge of the soundproof cover is attached to the cylinder block. 1. A low-noise engine, characterized in that a support plate is provided on a rear surface and is formed in a substantially U-shape from the front, and a seal at the rear edge of the soundproof cover is removably pressed and fixed to the support surface by a tightening band. (2) The low-cost vehicle according to claim 1 of the utility model registration claim, characterized in that the seal support surface protruding from the front surface of the rear plate is provided with a protrusion or a groove along the curved direction of the seal support surface. noise engine. (3) The tightening band support device is characterized by comprising a fixture that fixes one end of the band, a tension device that applies tension to the band, and a tightening device that presses the band against the support surface. A low-noise engine according to claim 1 or 2 of the utility model registration claim. (4) The low-noise engine according to any one of claims 1 to 3, wherein a transmission is rigidly connected to the rear end of the cylinder block via a lever plate.