JPH04274928A - Power transmission of automobile - Google Patents

Abstract

PURPOSE:To lighten the differential case, and also lessen the total weight of a transaxle, and simplify the constitution without needing the management of the tightening torque of a fixing bolt the slack prevention mechanism of the fixing bolt as ever, and reduce the cost. CONSTITUTION:The differential case 14 of differential gear 6 of power transmission of an automobile is made of soft material, and a plurality of reinforcing ribs are made radially from the center of the rotary shaft of the differential case, and the holes for fixing the ring gears 6 of the differential case are made severally on the extensions of the reinforcing ribs, and when fixing the differential case and the ring gear, the head of the rivet 22 is positioned on the side of the differential case 14, and also the end 22b on the side of plastic deformation of the rivet is positioned on the side of the ring gear.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to a power transmission device for an automobile, and in particular, it inputs driving force from an internal combustion engine to a transaxle, and transmits it from an input shaft to an output shaft to a wheel shaft via a ring gear and a differential gear. Related to automobile power transmission devices.

0002

2. Description of the Related Art Automobiles are equipped with a power transmission device that inputs driving force from an internal combustion engine and transmits it from an output shaft of a transaxle to a wheel shaft via a propulsion shaft as required. The transaxle consists of a clutch part, a speed change gear part, etc.

[0003] As a power transmission device for automobiles, the
There is one disclosed in Japanese Patent No. 2-43884. The power transmission device for a four-wheel drive vehicle disclosed in this publication consists of a transaxle device that integrally includes a transmission and a differential device, and the output of this transaxle device to constantly drive one shaft of the front and rear wheels. The transmission is selectively transmitted to the other axle via a transfer device, enabling two-wheel and four-wheel drive, and the engine and transmission can be arranged in a straight line or in parallel in the left-right direction of the vehicle. As a result, it is possible to shorten the vehicle and increase the cabin space, and it is also possible to share almost all parts when changing between a two-wheel drive vehicle and a four-wheel drive vehicle.

0004

By the way, in a conventional power transmission system for an automobile, as shown in FIG. an input shaft 108 provided with a clutch portion that intermittents force and a plurality of gear trains;
An output shaft 110 provided with a plurality of gear trains and arranged parallel to the input shaft 108, and a drive gear 1 on the outer periphery of the output shaft 110.
A ring gear 116 meshing with 12 and this ring gear 1
16, and a differential case 114 for fixing the.

A differential gear 106 is provided within the differential case 114, and the differential gear 10
6, for example, drives the front wheel axle.

At this time, the differential case 114 and the ring gear 116 are fixed by fixing bolts 130 arranged at equal intervals around the circumference, as shown in FIG. Further, the differential case 114 is generally made of steel material.

[0007] As a result, the weight of the differential case increases,
This method also increases the total weight of the transaxle, making it difficult to carry and install the transaxle, which is disadvantageous in practical terms.

[0008] Furthermore, since it is necessary to control the tightening torque of the fixing bolts during use, inspections become more frequent.
The disadvantage is that it is difficult to use.

Furthermore, since it is necessary to provide a mechanism to prevent loosening of the fixing bolt, the structure is complicated, manufacturing is difficult, and the cost is high, which is disadvantageous economically.

0010

[Means for Solving the Problems] Therefore, in order to eliminate the above-mentioned disadvantages, the present invention transmits driving force input from an internal combustion engine through an input shaft of a transaxle, from an output shaft to a wheel shaft via a differential gear. In a power transmission device for an automobile, the differential case of the differential gear is formed of a soft metal material, a plurality of reinforcing ribs are formed radially from the rotation axis of the differential case, and a ring gear for the differential case is formed on an extension of these reinforcing ribs. The present invention is characterized in that fixing holes are formed in each case, and when the differential case and the ring gear are fixed, the rivet head is located on the differential case side and the plastic deformation side end of the rivet is located on the ring gear side.

[0011]

[Operation] With the invention as described above, when fixing a differential case made of a soft metal material and a ring gear, the rivet head is positioned on the differential case side, and
Position the plastic deformation side end of the rivet on the ring gear side,
In addition to reducing the weight of the differential case, there is no need to manage the tightening torque of the fixing bolts or to prevent loosening of the fixing bolts as in the past, simplifying the configuration and reducing costs.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention. In FIG. 1, 2 is a transaxle connected to an internal combustion engine (not shown) installed horizontally at the front of an automobile.

The transaxle 2 includes a clutch section, a speed change gear section 4, and a differential gear 6 (not shown).

The clutch section connects and connects the driving force from the internal combustion engine to the transmission gear section 4.

The speed change gear unit 4 has an input shaft 8 as a main shaft provided with a plurality of gear trains, and an output shaft 10 provided with a plurality of gear trains and arranged substantially parallel to the input shaft 8. ing.

The differential gear 6 is connected to the output shaft 1
A drive gear 12 fixedly attached to the differential case 14 is connected to the transmission gear section 4 by meshing with a ring gear 16 fixedly attached to the differential case 14. Although not shown, the differential gear 6 is connected to left and right wheel axles that are connected to the left and right front wheels, respectively.

Further, the differential case 14 of the differential gear 6 is formed of a soft metal material, and a plurality of reinforcing ribs 18 are formed radially from the rotation axis of the differential case 14, and the differential case 14 is formed on an extension line of these reinforcing ribs 18.
A fixing hole 20 for the ring gear 16 is formed respectively, and when fixing the differential case 14 and the ring gear 16, the head of the rivet 22 is positioned on the differential case 14 side, and the plastic deformation side end of the rivet 22 is positioned on the ring gear 16 side. The configuration is such that it is located at

In detail, the differential gear 6
The differential case 14 is made of a lightweight and soft metal material such as aluminum, and has a plurality of reinforcing ribs 18-1, for example six reinforcing ribs radially extending from the rotation axis of the differential case 14.
~18-6, and these reinforcing ribs 18-
1 to 18-6, the fixing holes 20-1 to 20-6 for the ring gear 16 of the differential case 14 are reinforced with reinforcing ribs 18-
Only 6 pieces, the same number as 1 to 18-6, are formed.

[0020] Then, the differential case 14 and the ring gear 16
When fixing the head 22a, which is one end of the rivet 22,
is located on the differential case 14 side, and the rivet 2
The plastic deformation side end 22b, which is the other end of 2, is located on the ring gear 16 side.

Reference numerals 24-1 to 24-6 are fixing holes formed in the ring gear 16.

Next, the operation will be explained.

When fixing the ring gear 16 to the differential case 14 of the differential gear 6, the differential case 1
In order to match the fixing holes 20-1 to 20-6 of 4 and the holes 24-1 to 24-6 of the ring gear 16, holes 20-1 to 20-6 and 24-1 to 24-6 are formed. Rivet 2
Insert 2.

At this time, the rivet 22 is attached to the differential case 14.
The head 22a of the rivet 22 is positioned on the differential case 14 side, the plastically deformed end 22b of the rivet 22 is projected toward the ring gear 16, and the plastically deformed end 22b is caulked.

When caulking the plastically deformed side end 22b of the rivet 22, the plastically deformed side end 22b is located on the ring gear 16 side formed of a steel material. It is easy to plastically deform and can perform caulking work efficiently.

[0026] As a result, the differential gear 6
By forming the differential case 14 from a lightweight and flexible aluminum material, the differential case 14 can be made lighter than before, and the total weight of the transaxle 2 can also be reduced, improving workability during transportation and installation. can be improved, which is advantageous in practice.

Furthermore, by using the rivets 22 to fasten the differential case 14 and the ring gear 16, there is no need to manage the tightening torque of the fixing bolts as in the prior art, and usability can be improved.

Furthermore, a differential case 1 made of aluminum material
4 and the ring gear 16 made of steel material, there is no need to provide a mechanism to prevent loosening of fixing bolts as in the past, and the configuration can be simplified, manufacturing is easy, and costs can be reduced. Therefore, it is economically advantageous. In other words, the differential case 14 is made of metal materials with different hardness.
By fastening the ring gear 16 to the ring gear 16, the soft differential case 14 functions as a cushion at the time of fastening, and no loosening occurs after fastening.

Furthermore, the head 22a of the rivet 22
By increasing the area by increasing the diameter of the differential case 14, even if the differential case 14 is made of aluminum, it is possible to increase the surface pressure and make it possible to securely fix the case. In comparison, the thickness in the axial direction can be made smaller.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be modified in various ways.

For example, in the embodiment of the present invention, the differential case is made of an aluminum material, which is a soft metal material. It is also possible to do so.

[0032]

As described in detail above, according to the present invention, the differential case of the differential gear of the power transmission device is formed of a soft metal material, and a plurality of reinforcing ribs are formed radially from the rotation axis of the differential case. , the fixing holes for the ring gear of the differential case are formed on the extension line of the reinforcing ribs, and when fixing the differential case and the ring gear, the rivet head is positioned on the differential case side, and the plastic deformation side end of the rivet is positioned on the ring gear side. Because of this configuration, the weight of the differential case can be reduced compared to the conventional one, and the total weight of the transaxle can also be reduced, and workability during transportation and installation can be improved. Further, by using rivets to fasten the differential case and the ring gear, there is no need to manage the tightening torque of the fixing bolts as in the past, and usability can be improved. Furthermore, by fastening the differential case made of a soft metal material to the ring gear, the soft differential case functions as a cushion during fastening, preventing loosening after fastening, and it is necessary to provide a mechanism to prevent loosening of fixing bolts as in the past. Therefore, the structure can be simplified, manufacturing is easy, and the cost can be reduced, which is economically advantageous. Furthermore, if the diameter of the rivet head is increased to increase the area, even if the differential case is made of a soft metal material, the surface pressure can be increased and strong fixation can be achieved, thereby eliminating any inconvenience. In addition, the axial thickness can be made smaller than that of a fixing bolt.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a transaxle of a power transmission device for an automobile showing an embodiment of the present invention.

FIG. 2 is a front view of a differential case and a ring gear of the transaxle.

FIG. 3 is a front view of a differential case and a ring gear of a transaxle showing a conventional technique of the present invention.

FIG. 4 is a schematic cross-sectional view of the transaxle.

[Explanation of symbols]

2 Transaxle 4 Speed gear part 6 Differential gear 8 Input shaft 10 Output shaft 12 Drive gear 14 Differential case 16 Ring gear 18-1 to 18-6 Reinforcement rib 22 Rivet 22a Head 22b Plastic deformation side end

Claims (1)

[Claims] 1. A power transmission device for an automobile that transmits driving force input from an internal combustion engine through an input shaft of a transaxle, from an output shaft to a wheel shaft via a differential gear, in which a differential case of the differential gear is made of a soft metal material. A plurality of reinforcing ribs are formed radially from the rotation axis of the differential case, and fixing holes for the ring gear of the differential case are formed on the extension lines of these reinforcing ribs, and rivets are formed when fixing the differential case and the ring gear. A power transmission device for an automobile, characterized in that the head is located on the differential case side, and the plastic deformation side end of the rivet is located on the ring gear side.