JP2001173739A - Pulley for belt tensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve an air pocket problem generated by air taken in a double wall structure when dipping into a treating liquid in a plating process, in a pulley of the double wall structure as one in major constituting elements of a belt tensioner for guaranteeing sure transmission of driving force by removing the looseness of a belt of a belt driving mechanism. SOLUTION: The pulley of a double wall structure is composed of an annular end surface wall part 10, an outer peripheral wall part 12 extending from an outer peripheral edge nearly perpendicular to the annular end surface wall part, and an inner circumferential wall part 14 extending to the same side as the outer peripheral wall part from the inner circumferential edge nearly perpendicular to the annular end surface wall part. At least one small holes 16 or 16' is formed on a suitable position of the pulley for venting air in a space enclosed by the annular end surface wall part, the outer peripheral wall part and the inner circumferential wall part when the pulley is dipped into various kinds of treating liquids in a plating process for the pulley.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt tensioner for ensuring reliable transmission of a driving force of a belt driving mechanism by eliminating slack of a belt, and more particularly, one of the main components of the belt tensioner. The present invention relates to a pulley, that is, a pulley resiliently engaged with a belt of a belt drive mechanism to remove slack of the belt.

[0002]

2. Description of the Related Art A belt tensioner is used, for example, in a belt drive mechanism incorporated in an engine of an automobile. Such a belt drive mechanism is used to transmit the rotational driving force of an engine to various systems mounted on an automobile, such as a power generation system, a power steering system, and an air conditioning system. The belt tensioner includes a fixed portion fixed to a block of the engine, a swing arm pivotally mounted on the fixed portion, and an elastic attachment provided in the fixed portion to elastically apply a biasing force to the swing arm. Biasing means, and a pulley rotatably mounted on the tip of the swing arm. The pulley engages the belt of the belt drive mechanism in such a manner that the pulley resists the elastic urging force of the elastic urging means. This ensures that the belt is not slackened during the operation of the belt drive, thus ensuring a reliable transmission of the rotational drive to the various systems described above.

Since the pulley of the belt tensioner as described above receives a large force from the belt while the belt driving mechanism is being driven, its structure must be provided with a desired strength and rigidity. Lightening is desired. To satisfy these conflicting requirements, the pulley is generally configured as a double-walled annular body. That is, the pulley includes an annular end wall, an outer peripheral wall extending from the outer peripheral edge substantially perpendicular to the annular end wall, and an inner peripheral edge extending substantially perpendicular to the annular end wall from its inner peripheral edge. And an inner peripheral wall portion extending on the same side as The pulley having such a structure is obtained by pressing an annular steel sheet material having a predetermined thickness, and then the pulley is finished as a final component by plating.

During the plating process, the pulleys are immersed in various processing liquids, for example, a pre-cleaning liquid, a plating liquid and a post-cleaning liquid. With pulleys, the problem is how to pull the pulley into the processing liquid. I mean,
This is because air entrapment into the double-walled structure of the pulley during immersion must be eliminated, and air may be taken into the double-walled structure depending on the attitude of the pulley during immersion.

In general, a method is employed in which a pulley is hung on an upward hook-shaped element, a so-called hanger, on the inner wall surface of its outer peripheral wall, the hanger itself is lowered into the processing liquid, and the pulley is immersed in the processing liquid. ing. When the pulley is immersed in such a manner, the pulley is immersed in the processing liquid with the opening side of the double-walled structure slightly inclined to the processing liquid surface, but the pulley immersion speed is extremely slow. By doing so, the ingestion of air into the double wall structure of the pulley can be substantially eliminated.

[0006]

As described above, as described above,
Conventional pulleys have a problem that the efficiency of the plating process is extremely low because the immersion speed when immersing in various processing solutions during the plating process becomes very slow due to the double-wall structure. Becomes For example, when compared to the daily throughput of a part whose shape is not a problem for air intake,
The throughput of double-walled pulleys is reduced to about 1/3 to about 1/4. On the other hand, there has been proposed a plating apparatus configured to appropriately apply fine vibration to the hanger during immersion of the double-walled pulley and to actively release air taken into the double-walled structure of the pulley. In this case, the throughput can be increased by increasing the immersion speed of the pulley, but by incorporating a vibration generator into the plating equipment,
This raises a problem that the cost of the plating equipment itself increases.

Accordingly, an object of the present invention is a pulley having a double wall structure as described above, which is configured to eliminate the problem of air intake when immersed in a processing solution during a plating process. Is to provide pulleys.

[0008]

SUMMARY OF THE INVENTION A pulley according to the present invention is used for a belt tensioner and has a double wall structure. That is, the pulley according to the present invention has an annular end wall, an outer peripheral wall extending from the outer peripheral edge substantially perpendicular to the annular end wall, and an inner peripheral edge substantially perpendicular to the annular end wall. An outer peripheral wall and an inner peripheral wall extending to the same side. According to the present invention, in such a pulley, when the pulley is immersed in various processing liquids during a plating process of the pulley, an annular end wall portion, an outer peripheral wall portion,
At least one small hole is formed at an appropriate location on the pulley to allow air in the space surrounded by the inner peripheral wall to escape.

In the present invention, the pulley is hung on a suitable hanger in such a manner that the opening side of the double-walled structure is slightly inclined toward the processing liquid surface, and is immersed in the processing liquid together with the hanger. If so, the small holes are located at or adjacent to the boundary between the annular end wall and the outer peripheral wall of the pulley. Of course, when the pulley is hung on the hanger, the small holes are made to be at the highest level, so that the air taken into the double wall structure during the immersion of the pulley is released through the small holes. Therefore, it is possible to greatly increase the immersion speed of the pulley.

A plurality of small holes may be formed in the pulley. In this case, the number of places where the pulley should be hung on the hanger is increased by the number of the small holes, so that the operation of hanging the pulley on the hanger becomes easy. , Its work efficiency is improved. Also,
When a plurality of small holes are formed, the small holes are preferably arranged at equal intervals along the circumferential direction of the pulley, so that the rotation balance of the pulley can be reliably maintained.

In the present invention, the pulley itself having the double wall structure according to the present invention is obtained by pressing an annular steel plate material having a predetermined thickness in the same manner as in the conventional case, and forming small holes in such a pulley. Is preferably performed by introducing piercing during the pressing. In this case, the diameter of the small hole cannot be made extremely small in consideration of the mass productivity of the pulley and the life of the piercing tool. This is because the smaller the diameter of the small hole, the smaller the diameter of the piercing tool, and the more easily the piercing tool is damaged.
On the other hand, it is preferable to increase the diameter of the small holes from the viewpoint of mass productivity of the pulley and the life of the piercing tool, but increasing the diameter of the small holes more than necessary is necessary in terms of the structural strength of the pulley. Is not preferred. In consideration of such a situation, it is preferable that the diameter of the small hole be at most twice the thickness of the pulley.

Preferably, when the diameter of the small hole is set to be twice or less the thickness of the pulley itself, the thickness of the portion of the pulley where the small hole is to be formed is locally thinned in advance by so-called embossing. The small holes are formed therein. The diameter of such small holes is at most twice the thickness of the previously locally reduced thickness of the pulley, so that the diameter of the small holes is less than twice the thickness of the pulley itself. obtain.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a pulley according to the present invention will be described below with reference to the accompanying drawings.

Referring to FIGS. 1, 2 and 3, a pulley according to the invention is shown in its entirety, and as can be seen, the pulley is configured as a double-walled annular body. That is, the pulley includes an annular end wall portion 10, an outer peripheral wall portion 12 extending from the outer peripheral edge substantially perpendicular to the annular end wall portion 10, and an inner peripheral edge substantially perpendicular to the annular end surface wall portion 10. And an inner peripheral wall portion 14 extending to the same side as the outer peripheral wall portion. Such a pulley is integrally formed by pressing a circular steel plate material having a predetermined thickness.

More specifically, in the present embodiment, the inner area of the annular end wall 10 is recessed into an annular recessed area 10a, the outer area thereof is an annular raised area 10b, and the transition area therebetween is an annular shoulder. The region 10c is set. Outer wall 1
Numeral 2 extends in a skirt shape along the outer peripheral edge of the annular raised region 10b, while the inner peripheral wall portion 14 extends in a skirt shape along the inner peripheral edge of the annular recessed region 10a. As best shown in FIG. 2, the area between the annular recessed area 10a and the inner peripheral wall 14 is a curved area, and the lower end of the inner peripheral wall 14 is curved inward.

When the pulley having such a configuration is rotatably attached to the tip of the swing arm of the belt tensioner, a ball bearing is pressed into the inner peripheral wall portion 14 of the pulley, and the outer race and the inner peripheral wall of the ball bearing are inserted. The inner race of the ball bearing is secured to the tip of the swing arm of the belt tensioner by a bolt inserted through the center of the inner race of the ball bearing.
Thus, the pulley itself can freely rotate with the outer race of the ball bearing, and the outer peripheral wall 12 of the pulley is engaged with the belt of the belt drive mechanism to eliminate slack in the belt.

In the present embodiment, four small holes 16 are formed along the annular raised area 10b of the annular end wall 10, and these small holes 16 are arranged at equal intervals along the circumferential direction of the pulley. The formation of the small holes 16 is preferably performed by introducing piercing when pressing the pulley itself. However, if necessary, the small holes 16 may be separately formed after the pressing.

More specifically, as described above, the pulley having the double wall structure according to the present invention is obtained by pressing a steel plate material having a predetermined thickness, and the small holes are formed in the pulley. The formation is performed by mounting a piercing tool on a press die used during the press working and piercing the annular raised area 10b of the annular end face wall 10 with the piercing tool. In this case, considering the mass productivity of the pulley and the life of the piercing tool, etc., the small hole 1
The diameter of 6 cannot be made extremely small. That is, the smaller the diameter of the small hole 16,
This is because the diameter of the piercing tool is reduced, and the piercing tool can be easily broken. On the other hand, it is preferable to increase the diameter of the small hole 16 from the viewpoint of mass productivity of the pulley and the life of the piercing tool.
It is not preferable to make the diameter of the pulley larger than necessary from the viewpoint of the structural strength of the pulley. In consideration of such a situation, it is preferable that the diameter of the small hole 16 be at most about twice the thickness of the pulley.

Referring to FIG. 4, the pulley is shown immersed in the plating solution L. Specifically, pulley 1
8 is hung by a hanger 18 as shown in the figure, the hanger 18 is supported by a lifting frame 20, and the pulley is immersed in the plating solution L by processing the lifting frame 20. In the example shown in FIG.
Molded, for example formed from copper wire having a diameter of about 3 mm, one end thereof is caused to fixed appropriately to the lifting frame 20, so that the other end may multiply hanging pulley at three points P _1, P ₂ and P ₃ Is done. In addition, as is apparent from FIG.
To hang a pulley on one of the four small holes 16
One is positioned at the top.

Here, the plating step will be briefly described. Although not shown in FIG. 4, the lifting frame 20 is attached to an endless chain via a suitable lifting mechanism, and various kinds of processing liquids, For example, it can be sequentially moved on a tank holding a pre-cleaning treatment liquid, a plating treatment liquid, a post-cleaning treatment liquid, and the like. The elevating frame 20 is temporarily stopped above each tank and then lowered by the elevating mechanism, whereby the pulleys are immersed in the processing liquid in each tank, and when predetermined processing is completed, the elevating frame 20 is raised and lowered. Raised by the mechanism,
Moved to the next tank. A plurality of, for example, 20 hangers 18 are attached to the lifting frame 20, and pulleys are hung on each hanger 18 as shown in FIG.

As apparent from FIG. 4, the pulley is hung on the hanger 18 in such a manner as to be slightly inclined with respect to the vertical line. The posture is slightly inclined toward the liquid surface. When immersed in the processing liquid L in such a posture, air is easily taken into the double wall structure of the pulley. However, according to the present invention, air in the double wall structure of the pulley escapes from the small hole 16. As a result, the inner wall surface on the top side of the double wall structure of the pulley is also completely brought into contact with the processing liquid, whereby the inner wall surface can be completely plated.

On the other hand, referring to FIG. 5, a conventional pulley,
That is, the pulley having no small hole (16) is
4 in the same manner as in the case of FIG.
The state where it was immersed in is shown. As is clear from the figure, the pulley has a double-walled structure in which the opening side is slightly inclined toward the liquid surface of the plating solution L, so that air is trapped on the top side of the double-walled structure of the pulley. That is, the air pocket AR is easily formed. Conventionally, air pocket AR
To minimize formation of air pockets or air pockets A
In order to make R as small as possible, the speed of immersing the pulley in the processing solution is made very slow, and therefore the efficiency of the plating process becomes extremely poor. That is, as described above, the processing amount of the conventional pulley is about 1/3 to about 1 /
It will drop to 4.

In the pulley according to the present invention, the processing liquid L
If air is trapped in the double-walled structure of the pulley during immersion into the
The immersion speed of the pulley in the processing liquid L can be greatly increased as compared with the conventional pulley.

When a pulley is hung on a hanger 18 as shown in FIG. 4, the small holes 16 do not necessarily have to be formed in the annular raised area 10b of the annular end face wall 10. For example, if necessary, the small holes 16 may be formed in the outer peripheral wall 12 at or near the boundary between the annular end wall 10 and the outer peripheral wall 12. Further, according to the present invention, when the pulley is immersed in the treatment liquid, the posture thereof can be freely selected, and the small holes 16 are formed so that the intake air can be removed according to the immersion posture. The location can be determined.

In the example shown in FIG. 4, the hanger 18 is formed from a copper wire formed as shown in FIG. 4, but the hanger is formed by the upward hook-shaped element, that is, the lifting frame 20 described above. An upward hook-like element supported in the form of a cantilever may be used, wherein the pulley can be hung on the inner wall surface of the outer peripheral wall 12 thereof.

Referring to FIGS. 6 and 7, there is illustrated a method of forming a small hole having a smaller diameter than the small hole 16 described above in the annular raised area 10b of the annular end wall 10. As shown in FIG. First, a hemispherical recess 22 as shown in FIG. 6 is formed by embossing at a predetermined position on the inner wall surface of the annular raised area 10b, that is, a position where a small hole is to be formed during the pulley pressing step. The area of the depression 22 is made thinner, and then a small hole 16 'as shown in FIG. 7 is formed in the thinner area using a piercing tool. In this case, the hemispherical recess 2
Since the thickness of the thin region 2 is smaller than the thickness of the pulley itself, it is possible to use a piercing tool having a diameter smaller than the diameter of the piercing tool used to form the small holes 16. For example, as shown in FIG.
Is at most twice the thickness t of the thin region of the hemispherical recess 22. In short, the diameter of the piercing tool when drilling the small hole 16 ′ is smaller than the diameter of the piercing tool when forming the small hole 16, but the thickness of the thin region of the hemispherical recess 22 is small. Since the thickness of the piercing tool for drilling the small hole 16 'is not extremely shortened, the mass productivity of the appropriate pulleys can be maintained without extremely shortening the life of the piercing tool.

In the example shown in FIGS. 6 and 7, the hemispherical recess 22 is formed on the inner wall surface side of the annular raised area 10b, but the hemispherical recess 22 is shown in FIGS. 8 and 9. As described above, it may be formed on the outer wall surface side of the annular raised region 10b, and the small hole 16 'may be formed in the thin region. Of course, also in this case, the diameter d of the small hole 16 'is preferably at most 2 in the thickness t of the thin region of the hemispherical recess 22.
Doubled.

In the above-described embodiment, the small holes (16, 16 ') are formed in the flat pulley, that is, the pulley whose outer peripheral wall of the outer peripheral wall portion 10 is a smooth surface. Small holes (16, 16 ') can also be formed according to the present invention on a pulley having a V-groove formed on the outer peripheral wall surface of the wall portion. Of course, such a grooved pulley is used for a V-rib belt.

[0029]

As apparent from the above description, in the pulley according to the present invention, the immersion speed in the processing solution during the plating process can be greatly increased as compared with the conventional pulley. The efficiency of the plating process can be improved, which can contribute to a reduction in the manufacturing cost of the pulley.

[Brief description of the drawings]

FIG. 1 is a front view of a pulley for a belt tensioner according to the present invention.

FIG. 2 is a longitudinal sectional view taken along the line II-II of FIG.

FIG. 3 is a rear view of the belt tensioner pulley of FIG. 1;

FIG. 4 is a view showing a state in which a pulley for a belt tensioner according to the present invention is immersed in a processing liquid during a plating process, and is an explanatory view for explaining the function of a small hole formed in the pulley.

FIG. 5 is a view showing a state in which a conventional belt tensioner pulley is immersed in a processing liquid during a plating process, and is an explanatory view for comparison with a tensioner pulley according to the present invention.

6 is a partially enlarged cross-sectional view of the pulley according to the present invention, and is a process diagram showing one step of a drilling method for forming a small hole in the pulley having a smaller diameter than the small hole of the pulley shown in FIG. 2; is there.

7 is a partially enlarged cross-sectional view similar to FIG. 6, showing a step that follows the step shown in FIG. 6;

8 is a partial enlarged cross-sectional view of the pulley according to the present invention, showing a step of another drilling method for forming a small hole in the pulley having a diameter smaller than the small hole of the pulley shown in FIG. 2; FIG.

FIG. 9 is a partially enlarged cross-sectional view similar to FIG. 8, showing a step that follows the step shown in FIG. 8;

[Explanation of symbols]

 Reference Signs List 10 annular end wall 12 outer peripheral wall 14 inner peripheral wall 16.16 'small hole 18 hanger 20 lifting frame 22 hemispherical recess L treatment liquid

Continued on the front page F term (reference) 3J031 AC07 BC03 BC08 BC10 CA01 CA02 3J049 AA01 BF10 CA01 CA04

Claims (7)

[Claims] 1. A pulley for use in a belt tensioner, comprising: an annular end wall, an outer peripheral wall extending from an outer peripheral edge thereof substantially at right angles to the annular end wall, and A pulley consisting of an inner peripheral wall extending from the inner peripheral edge to the same side as the outer peripheral wall at a substantially right angle. When the pulley is immersed in various processing liquids during a plating process of the pulley, the annular end face wall is formed. A pulley, wherein at least one small hole is formed at an appropriate position of the pulley to allow air in a space surrounded by the portion, the outer peripheral wall, and the inner peripheral wall to escape. 2. The pulley according to claim 1, wherein the small holes are arranged adjacent to a peripheral edge of a boundary between the annular end face wall and the outer peripheral wall. 3. The pulley according to claim 1, wherein the small holes are arranged at a peripheral edge of a boundary between the annular end wall and the outer peripheral wall. 4. The pulley according to claim 1, wherein a plurality of the small holes are formed.
A pulley wherein the small holes are arranged at equal intervals along the circumferential direction of the pulley. 5. The pulley according to claim 1, wherein the diameter of the small hole is at most twice the thickness of the pulley. 6. The pulley according to claim 1, wherein a thickness of a portion of the pulley where the small hole is to be formed is locally reduced in advance, and then the small hole is formed therein. A pulley characterized by being formed. 7. The pulley according to claim 6, wherein the diameter of the small hole is at most twice the thickness of the portion of the pulley that has been locally thinned beforehand.