JPS60241568A - Drive plate of internal-combustion engine - Google Patents

Abstract

PURPOSE:To reduce noise due to vibration by forming an odd number of notch holes on a drive plate body of an internal-combustion engine. CONSTITUTION:A plate body 2 is provided with an odd number of notch holes 5 for reducing vibration which are formed by equal pitches on the same pitch circle 6 between crankshaft fitting holes 3 and torque converter fitting holes 4 and set in such a manner that the notch rate (total extent of notched portion/the peripheral length of pitch circle) by the notch holes 5 on the same pitch circle is more than 50%. Thus, every diameter line passing through the center 7 always intersects or contacts the notch holes 5a-5e, so that stable vibration mod is hard to form to reduce the generation of noise.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an improvement in a drive plate that connects a crankshaft and a torque converter of an internal combustion engine.

(Technical side 1) Internal combustion engines with automatic transmissions are generally equipped with a fluid clutch, or torque converter, instead of a mechanical latch in the power transmission system, and the rotation of the crankshaft is input to the torque converter. Conventionally, a drive plate 1 as shown in FIGS. Published by Nissan Motor Co., Ltd., September 2013).

The disc-shaped plate main body 2 has a ring gear 8 on its outer periphery.
are welded together and engage with the starter motor's pinion (not shown) during startup to perform cranking.

The plate body 2 has a plurality of crankshaft mounting holes 3 concentrically formed in order to be concentrically connected to the crankshaft, and a converter mounting hole 4 for connecting to the input side of the torque converter is formed on the outside thereof. Multiple concentric circles are formed in the same way.

Incidentally, the plate main body 2 is formed by press molding a thin steel plate, etc., but due to the transmission of power from the crankshaft, the rotational speed is relatively low in the primary, secondary, tertiary, etc. A phenomenon was observed in which low-order vibration modes were easily excited, and vibration-based noise was radiated.

The vibration of a disc such as the plate body 2 forms an abdominal region with maximum amplitude at the free end (outer peripheral end), with nodes of vibration on the diameter line passing through the center of the disc, and these are located at the center of the disc surface. It has a vibration mode based on each dividing line, which is divided into 2, 4, 6, 8, etc.

If a simple disk is formed in the central part where the power rotation is transmitted, as in the case of the plate body 2, vibration modes at low rotational speeds are likely to be formed stably, and this is because the thin plate Since the circular disk is excited with a large amplitude and a large amount of sound energy, this causes an increase in vibration noise from the drive plate 1 mainly in the low rotational speed range of the engine.

(Object of the invention) The present invention suppresses plate vibration excited in the plate body,
An object of the present invention is to provide a drive plate for an internal combustion engine that reduces vibration noise.

(Disclosure of the Invention) In a drive plate of an internal combustion engine that connects a crankshaft and a torque converter, it is located between a crankshaft mounting hole formed in the center of the plate body and a torque converter mounting hole arranged outside the crankshaft mounting hole. Then, an odd number of cut holes are formed at approximately equal pitches in the circumferential direction.

The notch holes are preferably arranged on the same circumference, and the notch ratio of the plate body on this same circle (pitch circle) is approximately 5.
Set it so that it is 0% or more.

When the notch holes are provided in the plate body in this way, the vibration mode generated in the disc-shaped plate body whose node is the diameter line is divided into nodes by the notch hole and becomes higher-order. Suppresses plate vibration near the center to reduce sound production.

(Example) Embodiments of the present invention will be described below based on the drawings.

As shown in FIGS. 1 to 3, the plate body 2 has a notch hole 5 for vibration reduction located on the same pitch circle 6 between the crankshaft mounting hole 3 and the torque converter mounting hole 4. ,
An odd number of them are formed at equal pitches.

Then, the notch ratio (total length of the notch portion/pitch circumference length) of the notch holes 5 on the same pitch circle is set to be 50% or more.

As described above, the flat plate vibration of the drive plate 1 has vibration modes such as 2-division, 4-division, 5-division, 6-division, etc. through the center of the disk.

This vibration mode consists of an abdomen with a large amplitude and a nodal part that hardly shakes.
) coincides with the diameter line passing through the center 7.

However, if the notch hole 5 is provided in the plate body 2, the rigidity will decrease in the vicinity of the notch hole 5, making it easier to shake.
The vicinity of the notch holes 5 becomes the abdomen of vibration, and conversely, since the rigidity between the notch holes 5 becomes relatively high, this part becomes the node of vibration.

By the way, as is clear from FIG. Also, the notch holes 5a to 5e are always crossed or in contact with each other. is cut in the middle, making it difficult to form a stable vibration mode on the disc like in the past.

Therefore, the generation of noise due to plate vibration, especially the low frequency sound level in the low engine rotation range, is reduced.

Figure 4 shows drive plate 1 during cranking.
This figure shows a comparison of the noise emitted from the conventional method and the present invention, and it can be seen that the noise is relatively reduced.

In the above embodiment, five notch holes 5 are arranged in stages, but any odd number such as 3, 7, etc. may be used, and the notch ratio may be set to 5.
As long as it is 0% or more, they do not need to be on the same pitch circle, for example.

(Effects of the Invention) As described above, according to the present invention, an odd number of notched holes are formed in the intermediate portion of the plate body at approximately equal pitches in the circumferential direction, so that the notched holes prevent the generation of plate vibration. , the vibration amplitude becomes relatively small, the noise energy radiated from the drive plate can be reduced, and the sound level can be lowered.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is its I
- I line sectional view, Figure 3 is an explanatory diagram of the structure, Figure 4 is an explanatory diagram showing the generated noise level in comparison with the conventional example, Figure 5 is a plan view of the conventional example, and Figure 6 is the same as the ■-■ line. FIG. 1... Drive plate, 2... Plate body, 3
...Crankshaft mounting hole, 4...Converter mounting hole,
5... Notch hole, 8... Ring gear. Patent applicant Nissan Motor Co., Ltd. Figure 1

Claims (1)

[Claims] 1. In a drive plate of an internal combustion engine that connects a crankshaft and a torque converter, the drive plate is located between the crankshaft mounting hole and the torque converter mounting hole formed in the plate body, and extends in the circumferential direction. A drive plate for an internal combustion engine Ia, characterized in that an odd number of vibration reduction notches are formed at approximately equal pitches. 2. The internal combustion engine according to claim 1, wherein the notched holes are formed at equal pitches on the same pitch circle f, and the notch ratio on the pitch circle is set to be approximately 50% or more. drive plate.