JPH11159597A - Sprocket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save a space and improve carriage efficiency by a method wherein an overlap width is reduced when a plurality of sprockets are overlapped. SOLUTION: A protrusion 2 for sensing is formed on the surface 3 of a sprocket 1 and a recessed part 11 larger than the profile of the protrusion 2 for sensing is formed in the back 6. Through this constitution, the protrusion 2 for sensing of the adjoining other sprocket 1 is fitted in the recessed part 11 formed in the back 6 of the sprocket 1 and in this way, a plurality of the sprockets are overlapped with each other. Thus, since in the adjoining sprockets 1, an overlap width is decreased by an amount equivalent to width with which the protrusion 2 for sensing is inserted in the recessed part 11, saving of a space is realized and the damage of the protrusion 2 for sensing is reliably prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlocking member of a valve drive system of an internal combustion engine, in particular, a cam timing sprocket,
The present invention relates to a structure of a sprocket such as a sensing sprocket attached to a crankshaft.

[0002]

2. Description of the Related Art As shown in FIGS.
The sprocket 1, which is one of the gears meshed with the timing chain C, has one end face (hereinafter referred to as a surface 3) located outside thereof to detect the phase of the sprocket 1 in order to control the operation of the engine E. ) Is provided with a sensing projection 2. And the surface 3 of the sprocket 1
The sensor head 5 of the sensor 4 is disposed at the position opposing the above, and the sensor 4 detects the phase of the sprocket 1 by obtaining a data waveform representing the time change of the amount of unevenness of the sensing projection 2. .

As shown in FIGS. 9A and 10, a sensing projection 2 provided on a surface 3 of a sprocket 1 is provided.
Are substantially trapezoidal in cross section, and are projectingly provided at predetermined intervals so as to be located on the same radius. FIG.
As shown in (b), the other end surface of the sprocket 1 (hereinafter, referred to as sprocket 1)
The back surface 6) is usually flat. Also, Japanese Patent Application Laid-Open
No. 259965 describes that a signal generating member for detecting a rotational angle position is attached to a side surface of a resin toothed pulley.

[0004]

By the way, when a plurality of sprockets 1 are overlapped for the purpose of delivery and storage to a factory, as shown in FIG. 11, the top surfaces of the sensing projections 2 are adjacent to each other. 1, so that the entire overlapping width H ′ is large (thick). For this reason, a storage space for stacking a large number of sprockets 1 must be ensured, and there is a problem that transportation efficiency is poor. Further, since the top surface of the sensing projection 2 is in contact with the back surface 6 of the adjacent sprocket 1, there is a possibility that the sensing projection 2 may be damaged or worn due to vibration during transportation. In this case, since the clearance between the sensing projection 2 and the sensor 4 (that is, the distance from the head 5 to the top surface of the sensing projection 2... There is a possibility that the projection 2 for use cannot be detected accurately. In the resin toothed pulley disclosed in Japanese Patent Application Laid-Open No. 7-259965, the signal generating member is provided so as to be located inside the end surface of the rim. It is not intended to be transported.

According to the present invention, when a plurality of sprockets are superimposed, the overall overlapping width is reduced to save space and improve transport efficiency, and damage or damage to the sensing projection which may occur due to vibration during transport. An object of the present invention is to provide a sprocket capable of preventing wear.

[0006]

In order to achieve the above object, according to the present invention, there is provided a sprocket having a sensing projection projecting from one end face of the sprocket, wherein the projection is provided on the other end face of the sprocket. Characterized in that a concave portion larger than the outer shape is provided.

According to a second aspect of the present invention, in the first aspect of the present invention, the recess is provided at a position corresponding to the sensing projection.

According to a third aspect of the present invention, in the second aspect of the present invention, the recess is provided concentrically at a position corresponding to the sensing projection.

According to a fourth aspect of the present invention, in the second aspect of the present invention, a part of the recess is formed to have a size capable of accommodating a plurality of adjacent sensing projections collectively.

A fifth aspect of the present invention is characterized in that, in the first to fourth aspects, the sprocket is a sprocket for a timing chain.

In a sixth aspect of the present invention, in the first to fourth aspects, the sprocket is a cam timing sprocket.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention applied to a cam timing sprocket will be described below with reference to the accompanying drawings. In the engine E of the present invention, as shown in FIGS. 7 and 8, a crank timing sprocket 8 is provided at one end of a lower crankshaft 7, and
A cam timing sprocket 1 is provided at an end of the camshaft 9, and a timing chain C is wound between the crank timing sprocket 8 and the cam timing sprocket 1.

Crank timing sprocket 8, cam timing sprocket 1 and timing chain C
Are arranged so as to be stored in a chain case, and the chain case has a chain case cover 10.
(See FIG. 8). The chain case cover 10 is provided with a sensor 4 having a sensor head 5 at a position facing the sensing projection 2 provided on one end surface of the cam timing sprocket 1.

In the cam timing sprocket 1 of the present invention, as shown in FIG. 1, a gear meshing with the timing chain is provided on the outer periphery thereof, and is arranged concentrically with the gear and smaller in diameter than the gear so as to be outward. A plurality of sensing projections 2 are provided on one end face (hereinafter, referred to as a front face 3) located.
The other end surface (hereinafter referred to as the back surface 6) is provided with a concave portion 11 larger than the outer shape of the sensing projection 2. As shown in FIG. 2, the recesses 11 are formed at a plurality of locations corresponding to the positions of the sensing projections 2 provided on the front surface 3.

As shown in FIG. 3, when a plurality of cam timing sprockets 1 are overlapped, the overall overlap width H
Can be made smaller than the overlap width H ′ of the conventional sprocket 1 (see FIG. 11). That is, a plurality of cam timing sprockets 1 are overlapped so that the sensing projection 2 of another adjacent cam timing sprocket 1 is loosely inserted into the concave portion 11 formed on the back surface 6 of the cam timing sprocket 1.
Width h × (n) in which sensing projection 2 is accommodated in recess 11
-1) (Here, h is the height of the sensing projection 2 and n is the number of sprockets) The thickness can be reduced by an amount, so that the overlap width H is reduced.

Here, as shown in FIG. 4, if the depth X of the recess 11 is formed to be larger than the height X ′ of the sensing projection 2 (the same height as h in FIG. 3), the entire sensing projection 2 is formed. Is housed in the recess 11 and the sensing projection 2
Is held in a state in which the top of the cam timing sprocket 1 is separated from the bottom surface of the recess 11, so that the sensing projection 2 can be reliably prevented from being damaged and worn when the cam timing sprocket 1 is stored or transported. it can. In order to simply save the space at the time of storage or the like and to improve the transportation efficiency, the depth X of the recess 11 and the projection 2 for the sensing may be used.
May be equal to each other, or the depth X of the concave portion 11 may be formed smaller than the height X ′ of the sensing projection 2. However, since the tip of the sensing projection 2 may be damaged, It is necessary to consider the material of the cam timing sprocket 1 and the like.

The shape of the concave portion 11 formed on the back surface 6 of the cam timing sprocket 1 may be provided at a position corresponding to the sensing protrusion 2, however, as shown in FIG. And that
When the distance between the adjacent sensing projections 2 is small, a concave portion 11 ′ having a size capable of fitting both of the adjacent sensing projections 2 may be provided. When the sensing projections 2 are located on the same radius of the cam timing sprocket 1, as shown in FIG. 6, the sensing projections 2 are formed as concentric grooves 11 ″ having a width larger than the radial width of the sensing projections 2. Is also good.

Although the cam timing sprocket 1 has been particularly described as the interlocking member of the valve drive system of the internal combustion engine, the present invention is not limited to this, and the cam timing pulley having a projection protruding from one end surface is not limited to this. ,
The same structure can be applied to a crank timing sprocket or a crank timing pulley. In addition, since it has a plurality of camshafts, even when it is necessary to detect each angle, the combination of the sprocket and the detection sensor can be saved in a small space. Absent).

[0019]

As described in detail above, the sprocket according to the first aspect of the present invention has a sprocket having sensing projections protruding from one end of the sprocket.
Since a plurality of recesses larger than the outer shape of the protrusions are provided, when a plurality of sheets are stacked and handled at the time of storage and transportation, the sensing protrusions of another adjacent sprocket are fitted into the recesses formed on the back surface of the sprocket. In addition, a plurality of sprockets can be overlapped. As a result, the sprockets adjacent to each other can be overlapped and reduced in width by the width of the insertion of the sensing projection into the recess, so that space can be saved by stacking a plurality of sprockets. Also, since many sprockets can be overlapped at one time, the transportation efficiency is also improved. Further, since the entirety of the sensing projection is housed in the recess, and the top of the sensing projection is held apart from the bottom surface of the recess, the sensing projection is reliably prevented from being damaged and worn. And parts with stable quality can be provided.

According to the second aspect of the present invention, since the concave portion is provided only at the position corresponding to the sensing projection, when the plurality of sprockets are overlapped, the positioning between the concave portion and the sensing projection is facilitated. The rigidity of the sprocket can be maintained.

According to the third aspect of the present invention, since the concave portion is provided concentrically at the position corresponding to the sensing protrusion, the positioning of the sensing protrusion and the concave portion when the sprockets are overlapped with each other is further simplified. In addition, since the concave portion is uniformly formed on the back surface of the sprocket, the weight can be reduced and the balance can be maintained well.

According to the fourth aspect of the present invention, a part of the recess is formed to have a size capable of accommodating a plurality of adjacent sensing projections at a time. At the time of superposition, the fitting work between the sensing projection and the concave portion becomes easy by visual observation or touch of the hand.

According to the fifth aspect of the present invention, when the present invention is applied to a sprocket for a timing chain, the sensing projections can be reliably protected, so that accuracy in manufacturing can be ensured and an engine control component with a high yield can be provided. . The thin flat plate shape of the timing chain sprocket can be used to save space, and the sensing projection allows the sensor to be provided at a close position regardless of the presence of the timing chain thicker than the sprocket.

According to the sixth aspect of the present invention, when the present invention is applied to a cam timing sprocket, similarly to the fifth aspect of the present invention, the sensing projection can be reliably protected, so that the accuracy at the time of manufacturing can be ensured and the yield can be secured. It is possible to provide engine control parts with high performance.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a sprocket according to an embodiment of the present invention.

FIG. 2 is a plan view of the back surface of the sprocket shown in FIG.

FIG. 3 is a cross-sectional view showing a state in which a plurality of sprockets shown in FIG. 1 are superimposed.

FIG. 4 is an enlarged cross-sectional view taken along a dashed-dotted line A shown in FIG.

FIG. 5 is a plan view showing a sprocket according to another embodiment of the present invention, which is different from FIG.

FIG. 6 is a plan view showing a sprocket according to yet another embodiment of the present invention, which is different from FIG.

FIG. 7 is a front view for explaining a configuration of an interlocking member of a valve drive system of the internal combustion engine.

FIG. 8 is a side view for explaining a main part of the interlocking member shown in FIG. 7;

FIG. 9 is a plan view showing the structure of a conventional sprocket.

FIG. 10 is a sectional view of the conventional sprocket shown in FIG.

11 is a cross-sectional view of a state in which a plurality of the conventional sprockets shown in FIG. 9 are overlaid.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cam timing sprocket 2 sensing projection 3 front surface 6 back surface 11 concave portion

Claims (6)

[Claims] 1. A sprocket having sensing projections protruding from one end surface of a sprocket, wherein a sprocket is provided on the other end surface of the sprocket with a recess larger than the outer shape of the projection. 2. The device according to claim 1, wherein the recess is provided at a position corresponding to the sensing protrusion.
Sprocket described. 3. The sprocket according to claim 2, wherein the recess is provided concentrically at a position corresponding to the sensing projection. 4. The sprocket according to claim 2, wherein a part of said recess is formed to have a size capable of accommodating a plurality of adjacent sensing projections collectively. 5. The sprocket according to claim 1, wherein said sprocket is a sprocket for a timing chain. 6. The sprocket according to claim 1, wherein said sprocket is a cam timing sprocket.