JPH11125323A - Rotary driving force transmission wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight to decrease inertia moment by constructing the transmission wheel by a steel-made outer peripheral part, a light alloy cast inner peripheral part, and a torque transmitting part provided in a boundary between both parts to integrally join both members to each other. SOLUTION: An outer peripheral part 20 is so constructed that a chain belt is wrapped round a tooth part 23 of the outer peripheral surface 22, a saw-toothed inner peripheral surface 21 is taken as one structural element of a torque transmitting part 40, and formed of a carbon steel or the like to have high strength and be excellent in wear resistance. The inner peripheral part 30 is so constructed that the outer peripheral surface 31 is saw-toothed to be meshed with the inner peripheral surface 21 and taken as the other structural element of the torque transmitting part 40, the central part is provided with a boss part 32 where a cam shaft is passed through, the fiver piercing parts 34 piercing the inner peripheral part 30 in the direction of thickness are provided at equal spaces in the circumferential direction, and formed of a light- alloy cast such as an aluminium alloy or the like. The inner peripheral part 30 is insert-cast on the inner peripheral side of the outer peripheral part 20. Thus, the compressive force is worked on the torque transmitting part 40 to transmit torque, and the weight of the whole is reduced to decrease the inertia moment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary driving force transmission vehicle used as, for example, a cam sprocket of a vehicle engine, and more particularly to a vehicle for reducing the moment of inertia by reducing the weight.

[0002]

2. Description of the Related Art Conventionally, this kind of rotary driving force transmission vehicle is used, for example, as a cam sprocket of a vehicle engine.

[0003] The cam sprocket is a member for transmitting the rotational driving force of the crankshaft to the camshaft, and a chain belt is stretched between a crankshaft timing gear provided on the crankshaft and the cam sprocket. Thus, the rotational driving force of the crankshaft is transmitted to the camshaft. As described above, since a large rotational driving force is applied to the cam sprocket, the cam sprocket needs to be formed of a material having high strength and excellent wear resistance. Therefore, the conventional cam sprocket is made of a casting or a sintered alloy, and is integrally formed as a whole. Specifically, the cam sprocket is formed of, for example, an Fe-based sintered alloy and weighs, for example, about 630 g.
Had become.

[0004]

However, the above-described cam sprocket as a conventional rotary driving force transmission wheel is made of a castable or sintered alloy integrally formed.
The weight was roughly determined by the specific gravity of the material, and the weight could not be reduced. For this reason, there is a problem that the moment of inertia is large and it is difficult to quickly respond to a command to increase or decrease the number of revolutions during operation.

[0005] By the way, the lighter the cam sprocket used as a component of the engine, the quicker it can follow the rotational speed increase / decrease command during operation. However, as described above, it is difficult to reduce the weight of the conventional cam sprocket from the viewpoints of strength, wear resistance, and the like, which has been one of the factors that hinders high performance of the engine.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned problems of the prior art, and has as its object to provide a rotary driving force transmission vehicle capable of reducing the moment of inertia by reducing the weight. And

[0007]

The present invention has the following features in order to achieve the above object.

The invention according to claim 1 is provided at an outer peripheral portion formed of steel, an inner peripheral portion formed of a light alloy casting, and at a boundary between the outer peripheral portion and the inner peripheral portion, wherein the outer peripheral portion is provided. And a torque transmitting portion that transmits torque by integrally joining the inner peripheral portion and the inner peripheral portion, to form a rotational driving force transmission vehicle that transmits rotational driving force.

According to the present invention, the outer peripheral portion and the inner peripheral portion are integrally joined by a torque transmitting portion provided at a boundary between the two. Further, since the outer peripheral portion is formed of steel having high strength and excellent wear resistance, it can exhibit sufficient strength and wear resistance when transmitting rotational driving force. On the other hand, since the inner peripheral portion is made of a light-weight light alloy casting, the moment of inertia can be reduced by reducing the weight of the entire rotary driving force transmission vehicle.

The second aspect of the present invention is the first aspect of the present invention.
In addition to the features of the invention described above, the torque transmitting portion forms a boundary surface between the outer peripheral portion and the inner peripheral portion as a saw-tooth shape that meshes with each other.

According to the present invention, since the boundary between the outer peripheral portion and the inner peripheral portion is a serrated torque transmitting portion that meshes with each other, the entire peripheral surface of the boundary between the outer peripheral portion and the inner peripheral portion is formed. , The torque is reliably transmitted.

[0012] The third aspect of the present invention is the second aspect of the present invention.
In addition to the features of the invention described above, the front surface in the rotational direction of the rotational driving force transmission wheel substantially coincides with the diametrical direction of the serrated boundary surface forming the torque transmitting portion.

According to the present invention, since the front boundary surface in the rotation direction of the rotary driving force transmission wheel substantially coincides with the diameter direction, torque can be transmitted more efficiently.

The invention according to claim 4 is the above-described claim 1.
In addition to the features of the invention described in the above, the torque transmitting portion is provided with a plurality of holes penetrating the outer peripheral portion in the thickness direction in the outer peripheral portion, and a light alloy casting forming the inner peripheral portion in the hole. Is formed by filling.

According to the present invention, the torque transmitting portion is formed by filling the plurality of holes penetrating the outer peripheral portion in the thickness direction with the light alloy casting constituting the inner peripheral portion. A gap is less likely to be formed in the joint surface between the shaft and the inner peripheral portion, and rattling of rotation is reliably prevented.

The invention according to claim 5 is the above-described claim 1.
In addition to the features of the invention according to any one of claims 4 to 4, a metal layer for preventing electrolytic corrosion is provided on a boundary surface between the outer peripheral portion and the inner peripheral portion.

According to the present invention, since the metal layer for preventing electric field corrosion provided at the boundary between the inner peripheral part and the outer peripheral part is formed, electric field corrosion does not occur between dissimilar metals.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows a rotary driving force transmission wheel 10A according to Embodiment 1 of the present invention.
(A) is a partially cut-away half cross-sectional view, and (B) is a partially cut-away bottom view when (A) is viewed from below.

[0020] Rotary driving force transmission vehicle 10A according to Embodiment 1
Is used, for example, as a cam sprocket of a vehicle engine, and has an annular outer peripheral portion 20, an inner peripheral portion 30 integrally joined to the outer peripheral portion 20 on the inner peripheral side of the outer peripheral portion 20,
A torque transmitting portion 40 is provided at a boundary between the inner peripheral portion 20 and the inner peripheral portion 30 and transmits the torque by integrally joining the outer peripheral portion 20 and the inner peripheral portion 30 together. The torque transmitting unit 40 is capable of transmitting torque by applying a vertical (compression) force instead of a shear force to a boundary between the outer peripheral portion 20 and the inner peripheral portion 30.

The outer peripheral portion 20 has a tooth portion on its outer peripheral surface 22.
23 is provided, and a chain belt is stretched over the teeth portion 23 to transmit the rotational driving force of the crankshaft to the camshaft engaged with the inner peripheral portion 30 (neither is shown). ).

On the other hand, the inner peripheral surface 21 of the outer peripheral portion 20 is formed in a sawtooth shape. This serrated inner peripheral surface 21 is
Functions as a component of. In the embodiment shown in FIG. 1, the teeth 23 provided on the outer peripheral surface 22 of the outer peripheral part 20 are indicated by pitch circles.

The outer peripheral portion 20 is formed of carbon steel, cast iron, a sintered alloy or the like, and has high strength and excellent wear resistance. Specifically, for example, S35C is used.

The inner peripheral portion 30 has an outer peripheral surface 31.
Is formed into a saw-tooth shape that meshes with the inner peripheral surface 21 of the outer peripheral portion 20 by casting as described later. This serrated outer peripheral surface
31 will function as another component of the torque transmitting unit 40. A boss 32 is provided at the center of the inner peripheral portion 30 so as to penetrate a camshaft (not shown).
32 has an engaging recess 33 for engaging with the camshaft.

Further, the inner peripheral portion 30 has an inner peripheral portion in the thickness direction.
There are provided five penetrating portions 34 penetrating through 30 at equal intervals in the circumferential direction. With this through portion 34, the weight of the rotary driving force transmission wheel 10 can be further reduced.

The inner peripheral portion 30 is made of a light alloy casting such as an aluminum alloy or a magnesium alloy. Specifically, for example, an aluminum alloy AC4C is used, and T6 treatment is performed.

As described above, by using S35C for the outer peripheral portion 20 and using AC4C-T6 for the inner peripheral portion 30,
The total weight of the rotary driving force transmission wheel 10A can be, for example, about 350 g, and the weight can be reduced by about 280 g as compared with the above-described about 630 g when a conventional Fe-based sintered alloy is used.

The rotary driving force transmission wheel 10A is formed by casting the inner peripheral portion 30 on the inner peripheral side of the outer peripheral portion 20. In this insert casting, it is preferable to cast by squeeze casting. This squeeze casting has the following advantages over gravity casting or die casting. That is, since the molten metal is poured at a higher pressure than in the heavy casting, a dense structure can be obtained by laminar flow pouring and high-pressure solidification. Also, compared to casting by die casting, since the casting is performed at a low speed, there is no entrapment of air bubbles, and heat treatment can be performed. It should be noted that the tempered product is used as S35C used for the outer peripheral portion 20, and after the inner peripheral portion 30 is cast-molded, the teeth 23 can be subjected to induction hardening to increase the strength of the teeth 23.

Prior to casting, it is preferable to provide a metal layer (not shown) for preventing electric field corrosion on the boundary surfaces 21 and 31 between the outer peripheral portion 20 and the inner peripheral portion 30 which are the torque transmitting portions 40. The metal layer for preventing electric field corrosion is formed by surface treatment such as plating. By providing such a metal layer for preventing electric field corrosion, electric field corrosion occurring between different metals can be prevented, and the life of the rotary driving force transmission wheel 10A can be extended.

(Embodiment 2) FIG. 2 shows a rotary driving force transmission wheel 10B according to Embodiment 2 of the present invention.
(A) is a partially cut-away half cross-sectional view, and (B) is a partially cut-away bottom view when (A) is viewed from below.

[0031] The rotary driving force transmission wheel 10B according to the second embodiment.
Is a rotary driving force transmission vehicle 10A according to the first embodiment.
The shapes of the boundary surfaces 21 and 31 between the outer peripheral portion 20 and the inner peripheral portion 30 forming the torque transmitting portion 40 are different from those of the first embodiment, and other configurations are the same as those of the rotary driving force transmission wheel 10A according to the first embodiment. The same is true. Therefore, members having the same functions are denoted by the same reference numerals, and detailed description is omitted.

[0032] The rotational driving force transmission vehicle according to the second embodiment.
As shown in FIG. 2, among the sawtooth-shaped boundary surfaces 21 and 31 forming the torque transmitting portion 40, the front side surfaces 21A and 31A in the rotational direction of the rotary driving force transmission wheel 10B are substantially one in the diameter direction, as shown in FIG. I do.

Therefore, when the rotary driving power transmission wheel 10B rotates, the rotary driving force is applied to the boundary surfaces 21A, 31A substantially coincident with each other in the diametrical direction, and the torque can be transmitted more efficiently.

[0034] The rotary driving force transmission vehicle according to the second embodiment.
The method of forming 10B is the same as in the first embodiment.

(Embodiment 3) FIG. 3 shows a rotary driving force transmission wheel 10C according to Embodiment 3 of the present invention.
(A) is a partially cut-away half cross-sectional view, and (B) is a partially cut-away bottom view when (A) is viewed from below.

[0036] Rotary driving force transmission vehicle 10C according to Embodiment 3
Is a rotary driving force transmission vehicle 10A according to the first embodiment.
As compared with the point that the boundary surface between the outer peripheral portion 20 and the inner peripheral portion 30 is not serrated, and that a plurality of cutouts 35 and holes 36 are provided in the outer peripheral portion 20 are different, This is the same as the rotary driving force transmission wheel 10A according to the first embodiment. Therefore, members having the same functions are denoted by the same reference numerals, and detailed description is omitted.

The rotational driving force transmission vehicle according to the third embodiment
As shown in FIG. 3, the outer peripheral portion 20 of 10C has a notch 35 at a position facing the penetrating portion 34 of the inner peripheral portion 30, and the outer peripheral portion 20 has a thickness between adjacent notches 35. A hole 36 penetrating in the direction is provided.

The rotational driving force transmission vehicle according to the third embodiment
At 10C, the hole 36 is filled with a light alloy forming the inner peripheral portion 30 when the inner peripheral portion 30 is cast-injected with respect to the outer peripheral portion 20. Therefore, the outer peripheral portion 20 and the inner peripheral portion 30 can be firmly integrated. Further, since the light alloy filled in the hole 36 contracts toward the center of the hole 36, the outer peripheral portion 20 and the inner peripheral portion 30 are contracted.
A gap is less likely to be formed on the joint surface with the shaft, and it is possible to reliably prevent the occurrence of rattling of rotation. Further, the weight of the outer peripheral portion 20 can be reduced by the notch 35 described above.

(Embodiment 4) FIG. 4 shows a rotary driving force transmission wheel 10D according to Embodiment 4 of the present invention.
(A) is a partially cut-away half cross-sectional view, and (B) is a partially cut-away bottom view when (A) is viewed from below.

[0040] Rotary driving force transmission vehicle 10D according to Embodiment 4
Is a rotary driving force transmission vehicle 10C according to the third embodiment.
The difference is that the notch 35 of the outer peripheral portion 20 and the hole 36 are formed continuously, and the other configuration is the same as that of the rotary driving force transmission wheel 10C according to the third embodiment. Therefore, members having the same functions are given the same reference numerals,
Detailed description is omitted.

Embodiment 4 A rotary driving force transmission vehicle according to the fourth embodiment
As shown in FIG. 4, the outer peripheral portion 20 of the 10D has a notch 35 at a position facing the through portion 34 of the inner peripheral portion 30, and the outer peripheral portion 20 has a thickness that is continuous with the adjacent notch 35. A hole 36 penetrating in the vertical direction is provided. Therefore, the hole 36 eventually has a notch shape in which a part of the hole is opened.

A rotational driving force transmission wheel 10D according to the fourth embodiment.
Is the same as in the above-described third embodiment.

Fourth Embodiment A rotary drive power transmission vehicle according to the fourth embodiment.
In 10D, the notch 35 and the hole 36 are continuous, so that the weight of the outer peripheral portion 20 can be further reduced, and the manufacturing cost can be reduced.

(Fifth Embodiment) FIG. 5 shows a rotary driving force transmission wheel 10E according to a fifth embodiment of the present invention.
(A) is a partially cut-away half cross-sectional view, and (B) is a partially cut-away bottom view when (A) is viewed from below.

Rotational driving force transmission wheel 10E according to Embodiment 5
Is a rotary driving force transmission vehicle 10C according to the third embodiment.
The difference is that the inner peripheral portion 30 is not provided with the penetrating portion 34 and the outer peripheral portion 20 is not provided with the cutout portion 35. Same as 10C. Therefore, members having the same functions are denoted by the same reference numerals, and detailed description is omitted.

The rotational driving force transmission vehicle according to the fifth embodiment.
10E has an annular outer peripheral portion 20 and an outer peripheral portion as shown in FIG.
On the inner peripheral side of 20, an outer peripheral portion 20 and an inner peripheral portion 30 integrally joined are provided.

The outer peripheral portion 20 is provided with five holes 36 penetrating the outer peripheral portion 20 in the thickness direction at equal intervals in the circumferential direction.

A rotary driving force transmission wheel 10E according to the fifth embodiment.
Is the same as in the above-described third embodiment.

Embodiment 5 A rotary driving force transmission vehicle according to the fifth embodiment
In 10E, since the penetrating part 34 and the notch part 35 are omitted,
The structure of the rotary driving force transmission wheel 10E can be simplified.

(Embodiment 6) FIG. 6 shows a rotary driving force transmission wheel 10F according to Embodiment 6 of the present invention.
(A) is a partially cut-away half cross-sectional view, and (B) is a partially cut-away bottom view when (A) is viewed from below.

Rotational driving force transmission wheel 10F according to Embodiment 6
Is a rotary driving force transmission vehicle 10C according to the third embodiment.
The difference is that the outer peripheral portion 20 is not provided with the hole 36, and the other configuration is the same as that of the rotary driving force transmission wheel 10C according to the third embodiment. Therefore, members having the same functions are denoted by the same reference numerals, and detailed description is omitted.

Embodiment 6 A rotary driving force transmission vehicle according to the sixth embodiment
As shown in FIG. 6, the outer peripheral portion 20 of the 10F is provided with a cutout portion 35 at a position facing the through portion 34 of the inner peripheral portion 30.

A rotational driving force transmission wheel 10F according to the sixth embodiment.
Is the same as in the first embodiment.

The rotational driving force transmission vehicle according to the sixth embodiment.
In 10F, the joint surface between the notch 35 of the outer peripheral portion 20 and the inner peripheral portion 30 functions as a torque transmitting portion 40.

The embodiments described above are not described to limit the present invention, and various modifications can be made. For example, in the above-described embodiment, the case where the tooth portion 23 is formed on the outer peripheral portion 20 of the rotary driving force transmission wheel is described. However, the present invention is not limited to this. For example, a pulley groove on which a V-belt is mounted It is needless to say that the present invention can also be applied to those in which.

[0056]

According to the present invention having the above-described structure,
The following effects are obtained.

According to the first aspect of the present invention, the outer peripheral portion is
It is made of high-strength, wear-resistant steel, and its inner periphery is made of a light-weight light-alloy casting. Is transmitted.

Therefore, the weight of the entire rotary driving force transmission vehicle can be reduced, and the moment of inertia can be reduced.
For this reason, for example, when used as a cam sprocket, which is a component of the engine, the acceleration or deceleration is smooth because the moment of inertia is small, and the driving performance can be improved.

Further, when the moment of inertia is small, the required power is small, the fuel efficiency is improved, and the pollution can be greatly reduced.

Further, when the moment of inertia is small, the load on the chain belt and the like is reduced, the life of the chain belt is extended, and noise can be reduced.

According to the second aspect of the present invention, the boundary surface between the outer peripheral portion and the inner peripheral portion is a serrated torque transmitting portion that meshes with each other. Therefore, torque can be reliably transmitted over the entire periphery of the boundary surface between the outer peripheral portion and the inner peripheral portion.

According to the third aspect of the present invention, the front boundary surface in the rotation direction of the rotary driving force transmission wheel substantially coincides with the diameter direction. Therefore, torque can be transmitted more efficiently.

According to a fourth aspect of the present invention, the torque transmitting portion is formed by filling a plurality of holes penetrating the outer peripheral portion in the thickness direction with a light alloy casting forming the inner peripheral portion. Therefore,
A gap is less likely to be formed in the joint surface between the outer peripheral portion and the inner peripheral portion, and it is possible to reliably prevent the rattling of the rotation.

According to a fifth aspect of the present invention, a metal layer for preventing electric field corrosion is provided on a boundary surface between an inner peripheral portion and an outer peripheral portion. Therefore, no electrolytic corrosion occurs at the boundary between the outer peripheral portion and the inner peripheral portion. For this reason, the life of the rotary driving force transmission vehicle can be further extended.

[Brief description of the drawings]

1A and 1B show a rotary driving force transmission vehicle according to a first embodiment, in which FIG. 1A is a partially cut-away half-sectional view, and FIG.
FIG. 3A is a partially cutaway bottom view when viewed from below.

2A and 2B show a rotary driving force transmission vehicle according to a second embodiment, in which FIG. 2A is a partially cut-away half-sectional view, and FIG.
FIG. 3A is a partially cutaway bottom view when viewed from below.

3A and 3B show a rotary driving force transmission vehicle according to a third embodiment, in which FIG. 3A is a partially cut-away half cross-sectional view, and FIG.
FIG. 3A is a partially cutaway bottom view when viewed from below.

4A and 4B show a rotary driving force transmission vehicle according to a fourth embodiment, in which FIG. 4A is a partially cut-away half-sectional view, and FIG.
FIG. 3A is a partially cutaway bottom view when viewed from below.

5A and 5B show a rotary driving force transmission vehicle according to a fifth embodiment, in which FIG. 5A is a partially cutaway half-sectional view, and FIG.
FIG. 3A is a partially cutaway bottom view when viewed from below.

6A and 6B show a rotary driving force transmission vehicle according to a sixth embodiment, in which FIG. 6A is a partially cut-away half-sectional view, and FIG.
FIG. 3A is a partially cutaway bottom view when viewed from below.

[Explanation of symbols]

 10A to 10F: rotary driving force transmission wheel, 20: outer peripheral portion, 21: inner peripheral surface, 22: outer peripheral surface, 23: tooth portion, 30: inner peripheral portion, 31: outer peripheral surface, 32: boss portion, 33: engagement Joint recess, 34 ... penetrating part, 35 ... notch, 36 ... hole, 40 ... torque transmitting part.

Claims (5)

[Claims] 1. A rotational driving force transmission vehicle for transmitting rotational driving force, comprising: an outer peripheral portion formed of steel; an inner peripheral portion formed of a light alloy casting; the outer peripheral portion and the inner peripheral portion; And a torque transmission unit that is provided at a boundary of and transmits the torque by integrally joining the outer peripheral portion and the inner peripheral portion. 2. The rotary driving force transmission vehicle according to claim 1, wherein the torque transmission unit forms a boundary surface between the outer peripheral portion and the inner peripheral portion in a saw-tooth shape that meshes with each other. 3. The rotary drive according to claim 2, wherein the saw-toothed boundary surface forming the torque transmitting portion has a front surface in the rotational direction of the rotary drive power transmission wheel substantially coincident with a diameter direction. Power transmission vehicle. 4. The torque transmitting portion is formed by providing a plurality of holes in the outer peripheral portion penetrating the outer peripheral portion in a thickness direction, and filling the holes with a light alloy casting forming the inner peripheral portion. The rotary drive power transmission vehicle according to claim 1, wherein 5. An interface between the outer peripheral portion and the inner peripheral portion,
The rotary driving force transmission vehicle according to any one of claims 1 to 4, wherein a metal layer for preventing electric field corrosion is provided.