JPH1163125A - Propelling force providing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To limit the inclination of a pressing body to a minimum so as to prevent contact between the pressing body and a rotary body irrespective of the application of a load on the pressing body having an angle to the center axis of the rotary body by extending the guide hole of a bearing by providing the projection part of a pressing body advancing direction and extending the guide length of the pressing body. SOLUTION: The contact part of a guide hole with a pressing body 3 is extended to a cylinder 11g in a direction opposite the advancing direction of the pressing body 3. Thus, the guide length of the pressing body 3 is lengthened, and the part extended to the cylinder 11g is used as a spring guide for guiding the end part of a spring 4. Since the contact part of a bearing 11 with the pressing body 3 is increased in an axial direction, the length of the pressing body 3 guided by the bearing 11 is extended and, even if a pressing force is applied to the pressing force 3 from a direction inclined against the center axis of a rotary body 2a, the inclination of the pressing body 3 against the center axis of the rotary body 2a is limited to a minimum, and the tip outer peripheral part of the rotary body 2a is prevented from being contacted with the inner surface of the pressing body 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force applying device for applying a constant tension to a chain or a timing belt for driving a camshaft of an engine.

[0002]

2. Description of the Related Art Propulsion devices such as a chain tensioner and a belt tensioner press a chain or a belt in a certain direction when the chain or a belt is loosened due to extension or wear during use. Used to maintain a constant tension. FIG. 13 shows a longitudinal sectional view of a conventional example of this propulsion force applying device. The propulsion force applying device includes a casing 1 having an axial cavity 1a formed therein, a rotating body 2 rotatably inserted into the casing 1, and a pressing body 3 screwed to a tip end of the rotating body 2. A spring 4 that is externally inserted into the rotating body 2 and the pressing body 3 in a screwed state, and applies a rotational force to the rotating body 2, a seal bolt 6 that is screwed into the base end of the casing 1, and a pressing body. A main part is constituted by a bearing 7 that guides the bearing 3 slidably in the axial direction, a bearing guide 8 that guides the bearing 7 and prevents wear of the casing 1 due to the bearing 7, a cap 9, and the like. Then, a bellows covering these can be extended between the distal end portion of the pressing body 3 and the casing 1.

FIG. 14 is a structural view showing the structure of the bearing 7. Reference numeral 7a denotes a guide hole for restricting the rotation of the pressing body 3, and through which the pressing body 3 is slidably inserted in the axial direction. FIG. 15 is a configuration diagram showing the structure of the bearing guide 8, and reference numeral 8 a denotes a bearing guide portion for fixing the bearing 7 in the casing 1.

[0004]

Since the conventional propulsion device is constructed as described above, the bearing 7 can slide on the pressing body 3 but restricts the rotation. Therefore, the thickness of the bearing 7 is thin, and a predetermined clearance is required between the guide hole 7a of the bearing 7 and the external dimensions of the pressing body 3 inserted into the guide hole 7a. The pressing body 3 has an angle with respect to the center axis of the rotating body 2.
, The center axis of the pressing body 3 is tilted with respect to the center axis of the rotating body 2 as shown in FIG. As described above, when the center axis of the pressing body 3 is inclined with respect to the center axis of the rotating body 2 and the outer peripheral portion of the rotating body comes into contact with the inner surface of the pressing body 3, the screw cannot be normally screwed and the screw is crushed. Press body 3
There is a problem that the behavior of becomes unstable.

In particular, it is difficult to set a large clearance between the inner diameter of the pressing body and the effective diameter of the female screw due to the demand for miniaturization and weight reduction, and the contact clearance with the outer peripheral part of the rotating body male screw becomes small. The effect on the inclination becomes more remarkable.

Further, since the bearing guide 8 is provided in addition to the bearing 7, there is also a problem that the number of parts is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and even if a load is applied to the pressing body at an angle with respect to the center axis of the rotating body, the inclination of the pressing body can be reduced. It is an object of the present invention to provide a thrust applying device capable of preventing the outer peripheral portion of the rotating body from coming into contact with the inner surface of the pressing body and stabilizing the behavior of the pressing body.

It is another object of the present invention to provide a driving force applying apparatus capable of suppressing assembly costs and component costs.

[0009]

In order to achieve the above object, a driving force applying apparatus according to the present invention comprises a rotating body urged to rotate by a spring and a guide hole of a bearing. A thrust that is inserted into the casing in a threaded state with a pressing body that has passed through the guide hole, and that converts the rotational force of the rotating body that is rotationally biased by the spring into an axial thrust of the pressing body. In the application device, the guide hole of the bearing is extended by providing a projection in a forward direction, a reverse direction, or both forward and backward directions of a pressing body advance direction, and a guide length of the pressing body is extended.

[0010] In the thrust applying apparatus according to the present invention, the bearing and a bearing guide for fixing the bearing in the casing are integrally formed.

Further, in the thrust applying apparatus according to the present invention, the bearing is provided with a spring guide portion for guiding the spring.

[0012] The thrust applying apparatus according to the present invention is characterized in that the bearing is formed of a polymer material.

[0013] The thrust applying apparatus according to the present invention is characterized in that the bearing has a guide hole formed in a polygonal shape.

Further, the thrust applying apparatus according to the present invention is characterized in that the bearing has a guide hole formed in an oval shape.

Further, the propulsion force applying device according to the present invention is characterized in that a frictional resistance reducing means for reducing the frictional resistance with the pressing body is provided on the inner surface of the guide hole.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional structural view showing a configuration of a propulsion force applying device according to the present embodiment. In the drawing, 1 is a casing, 1a is a space formed inside the casing 1, 2a is a rotating body, 2b is a male screw portion of the rotating body 2, 2c is a base of the rotating body 2, 3 is a pressing body, 3a is a pressing body. 3 is a female screw portion formed on the inner surface. Reference numeral 4 denotes a spring for urging the rotating body 2a with a rotating force.
c, and the other end is fixed to the casing 1. 6 is a seal bolt attached to the rear end of the casing 1, and 9 is a cap attached to the tip of the pressing body 3.

Reference numeral 11 denotes a bearing mounted on the front end of the casing 1, which guides the pressing body 3 slidably while restricting rotation. FIG. 2 is a structural view showing a configuration of the bearing 11, wherein 11a is the bearing guide portion, and 11b is the pressing body 3.
Are guide holes to be inserted. The bearing guide 11a is
For fixing the bearing 11 to the casing 1,
It is configured integrally with the bearing 11. Also, the guide hole 11
b restricts the rotation of the pressing body 3 and guides it slidably.

The guide hole 11b of the bearing 11 increases the contact portion with the pressing body 3 in the axial direction. In this example, the contact portion of the guide hole 11b with the pressing body 3 is extended in a cylindrical shape 11g in a direction opposite to the advance direction of the pressing body 3. According to this embodiment, the guide length of the pressing body 3 can be increased, and the portion extending to the cylindrical shape 11g can be used as a spring guide for guiding the end of the spring 4. When this spring guide is used, it is preferable that a cross-section R be provided at a tip corner of a portion extending to the cylindrical shape 11g.

The bearing 11 can be made of a polymer material such as resin and mass-produced at low cost. When constituted by such a polymer material, abnormal sounds such as an impact sound and a sliding sound which may be generated between the pressing body 3 and the pressing body 3 are suppressed. It is also possible to use an oil-impregnable sintered material or the like. Further, the surface of the guide hole 11b of the bearing 11 is subjected to surface improvement such as tuftride, chrome plating, and Kanigen plating, and surface treatment, so that the friction characteristics with the pressing body 3 can be improved.

In the propulsion force applying apparatus of this embodiment, since the contact portion of the bearing 11 with the pressing body 3 is increased in the axial direction, the length by which the pressing body 3 is guided by the bearing 11 is extended, Even if the pressing force acts on the pressing body 3 from the direction inclined with respect to the central axis of the rotating body 2a, the inclination of the pressing body 3 with respect to the central axis of the rotating body 2a is minimized as shown in FIG. In addition, the outer peripheral portion of the tip of the rotating body 2 a does not contact the inner surface of the pressing body 3. In addition, since the bearing 11 and the bearing guide portion 11a are integrally formed and are not configured as independent components as in the related art, assembly is facilitated, and assembly costs and component costs can be reduced. Become.

FIG. 4 is a sectional structural view showing a configuration of a propulsion force applying apparatus according to another embodiment. 4, the same or corresponding parts as in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this example, the contact portion of the bearing 21 with the pressing body 3 is extended in the vertical direction (in both forward and reverse directions with respect to the advance direction of the pressing body 3) in a cylindrical shape, and the pressing body 3 is guided by the guide hole 21b. It is a longer one. Also in the bearing 21 of this example, a bearing guide portion 21 a for fixing the bearing 21 to the casing 1 is integrally formed, and a downwardly extending cylindrical portion guides the end of the spring 4. Guide part 2
1 g.

FIG. 5 is a structural view showing the structure of the bearing 21, wherein 21a is the bearing guide portion, 21b is the guide hole through which the pressing body 3 is inserted, and the guide hole 21b is only in the direction of the seal bolt 6. Not the direction of the cap 9 (pressing body 3
(In the forward and reverse directions with respect to the direction of advance).

The bearing 2 of the propulsion device according to this embodiment
1 can also be mass-produced at low cost by molding with a polymer material such as resin. It is also possible to use an oil-impregnated sintered material or the like. Further, the surface of the guide hole 21b of the bearing 21 is subjected to surface improvement and surface treatment such as tuftlite, chrome plating, and Kanigen plating, The friction characteristics with the pressing body 3 can be improved, and the same effects as in the above embodiment can be obtained.

FIGS. 6 to 10 are plan views showing the structure of a bearing in a thrust applying apparatus according to another embodiment. In the structure of the bearing shown in FIG.
A band-shaped convex portion 31c for reducing the frictional resistance with the pressing body 3 is formed on the inner surface of b in parallel with the central axis of the pressing body 3. Further, in the bearing structure shown in FIG. 7, a band-shaped concave portion 41 c for reducing frictional resistance with the pressing body 3 is formed in the inner surface of the guide hole 41 b of the bearing 41 in parallel with the central axis of the pressing body 3. In the structure of the bearing 51 shown in FIG.
The guide hole 51b has a hexagonal shape. Further, in the structure of the bearing 61 shown in FIG. 9, the shape of the guide hole 61b is a square shape in which four corners are rounded.
In the structure of the bearing 71 shown in FIG.
The shape of b is a D-cut shape.

With such a configuration, it is possible to manufacture a large amount at low cost by molding using a polymer material such as a resin, and it is possible to reduce assembly costs and parts costs. Will be possible.

FIGS. 11 and 12 are cross-sectional views showing still another embodiment, and the same reference numerals as those of the above-mentioned embodiment indicate the same parts. In this example, the propulsion force applying device has a serial structure, and reference numerals 81 and 91 indicate bearings.

A bearing 81 shown in FIG. 11 is a case where a contact portion (guide hole) with the pressing body 3 is extended upward in a cylindrical shape.
The bearing 91 of FIG. 12 is a case where the contact portion (guide hole) with the pressing body 3 is extended downward in a cylindrical shape.

[0028]

As described above, according to the present invention, the bearing guide portion for fixing the bearing in the casing is formed integrally with the bearing, and the guide length of the pressing body by the bearing is extended. Therefore, even if a load is applied to the pressing body at an angle to the center axis of the rotating body, the inclination of the pressing body can be minimized, and the inner surface of the pressing body It is possible to prevent the outer peripheral portion of the rotating body from coming into contact, and it is not necessary to separately incorporate the bearing and the bearing guide portion, so that there is an effect that assembly costs and component costs can be reduced.

Also, since the bearing is formed of a polymer material, generation of abnormal noise such as hitting noise and sliding noise is prevented, and a guide hole having a free shape as a molded product is provided. It is easy to manufacture the bearing inexpensively, and there is an effect that the cost of parts can be reduced.

Further, since the frictional resistance reducing means for reducing the frictional resistance with the pressing body is provided on the inner surface of the guide hole of the bearing, the axial movement of the pressing body is smooth and the propulsion is performed. There is an effect that the functionality as a force applying device is improved.

[Brief description of the drawings]

FIG. 1 is a sectional structural view of a propulsion device according to an embodiment of the present invention.

FIG. 2 is a structural diagram showing a configuration of a bearing of the propulsion force applying device according to one embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating an effect of the propulsion force applying device according to the embodiment of the present invention.

FIG. 4 is a sectional structural view of a propulsion force applying device according to another embodiment of the present invention.

FIG. 5 is a structural diagram showing a configuration of a bearing of a propulsion force applying device according to another embodiment of the present invention.

FIG. 6 is a plan view showing a structure of a bearing in a propulsion force applying apparatus according to another embodiment of the present invention.

FIG. 7 is a plan view showing a structure of a bearing in a propulsion force applying device according to another embodiment of the present invention.

FIG. 8 is a plan view showing a structure of a bearing in a propulsion force applying device according to another embodiment of the present invention.

FIG. 9 is a plan view showing a structure of a bearing in a propulsion device according to another embodiment of the present invention.

FIG. 10 is a plan view showing the structure of a bearing in a propulsion device according to another embodiment of the present invention.

FIG. 11 is a cross-sectional view of a propulsion force applying apparatus showing another embodiment of the present invention.

FIG. 12 is a cross-sectional view of a propulsion force applying apparatus showing still another embodiment of the present invention.

FIG. 13 is a sectional structural view of a conventional propulsion force applying device.

FIG. 14 is a configuration diagram showing the structure of a bearing of a conventional propulsion device.

FIG. 15 is a configuration diagram illustrating a structure of a bearing guide of a conventional propulsion force applying device.

FIG. 16 is an explanatory diagram showing a problem of a conventional propulsion force applying device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2a Rotating body 3 Pressing body 4 Spring 11 21, 21, 81, 91 Bearing 11a, 21a Bearing guide part 11b, 21b Guide hole 11g, 21g Spring guide part 31c Belt-shaped convex part (friction resistance reduction means) 41c Belt-shaped concave part (Means for reducing frictional resistance)

Claims (7)

[Claims] 1. A rotating body urged by a spring and a pressing body whose rotation is restricted by a guide hole of a bearing and slidably inserted through the guide hole are inserted into the casing in a screwed state, In a thrust applying device for converting a rotational force of the rotating body rotationally urged by the spring into an axial thrust of the pressing body, a guide hole of the bearing is provided in a forward direction or a reverse direction of a pressing body advance direction or A propulsion force applying device, wherein a protruding portion in both forward and reverse directions is provided and extended, and a guide length of a pressing body is extended. 2. The thrust applying device according to claim 1, wherein a bearing and a bearing guide for fixing the bearing in the casing are formed integrally. 3. The bearing according to claim 1, wherein the bearing includes a spring guide for guiding the spring.
Or the propulsion applying device according to 2. 4. The thrust applying device according to claim 1, wherein said bearing is formed of a polymer material. 5. The propulsion applying device according to claim 1, wherein the bearing has a guide hole formed in a polygonal shape. 6. The thrust applying device according to claim 1, wherein the bearing has a guide hole formed in an oval shape. 7. The propulsion force applying device according to claim 1, wherein a frictional resistance reducing means for reducing frictional resistance with the pressing body is provided on an inner surface of the guide hole. .