WO2015115381A1

WO2015115381A1 - Chain tensioner and mounting structure for torsion coil spring for chain tensioner

Info

Publication number: WO2015115381A1
Application number: PCT/JP2015/052068
Authority: WO
Inventors: 卓彦中島
Original assignee: 株式会社ニフコ
Priority date: 2014-01-31
Filing date: 2015-01-26
Publication date: 2015-08-06
Also published as: JP2015143542A; JP6294089B2

Abstract

A chain tensioner (CT) has a body member (10) and a torsion coil spring (20). The torsion coil spring (20) has a helical section (21), a first extension section (22), and a second extension section (23), the first and second extension sections (22, 23) extending from the helical section (21). The body member (10) has a base body (11), a cylindrical section (12) which protrudes from the base body (11), and a shoe wall surface (13). The helical section (21) is fitted to and held by the cylindrical section (12). The first extension section (22) is held at longitudinal locations by the base body (11) by means of a first holding section (14) and a second holding section (15), which are formed on the base body (11). The second holding section (15) can be constituted by two protrusion bodies (16, 17) for holding the first extension section (22) from the left and right.

Description

Chain tensioner and torsion coil spring mounting structure of chain tensioner

The present invention relates to a chain tensioner and a structure for mounting a torsion coil spring of the chain tensioner.

Chains are used in various fields for power transmission. For example, in an engine, auxiliary devices such as a camshaft and an oil pump are driven via a chain by a crankshaft. In order to prevent the chain from sagging, a chain tensioner is generally provided.

In Patent Document 1, as a chain tensioner, there is a main body member that has a shoe wall surface (shoe surface) that is slid with respect to a chain and is held so as to be swingable with respect to the attached member, and the main body member and the attached member. There is disclosed one provided with a torsion coil spring that is interposed between members and swings and biases the main body member in a direction in which the shoe wall surface is pressed against the chain.

The torsion coil spring includes a spiral part that is formed on the main body member and is fitted to the outer periphery of the cylindrical part that is the center of swinging, a first extension part that extends from one end side of the spiral part, and the spiral part. A second extension extending from the end side. And the front-end | tip part of one extension part is hold | maintained by the holding | maintenance part formed in the main body member, On the other hand, the other extension part is latched by the to-be-attached member. The holding portion described in Patent Document 1 has a substantially L-shaped cross section, and the one extension portion is inserted and held through an opening on the side thereof. In the holding state, the spiral portion is separated from the cylindrical portion. It is designed to restrict movement in the direction of exit.

JP 2012-36996 A

In the thing of the said patent document 1, since the said one extension part of a torsion coil spring is hold | maintained only by one holding part made into cross-sectional substantially L shape, the side opening side of this holding part The holding action is easy to be released through. In other words, in a state where the torsion coil spring is assembled to the main body member, the torsion coil spring is inadvertently dropped from the main body member, for example, when the main body member is in an upside down posture in which the torsion coil spring is directed downward. It was easy to produce. In particular, when the main body member holding the torsion coil spring is brought close to the attached member or attached to the attached member in a swingable manner, the main body member must be in a posture state in which the torsion coil spring is likely to fall off. However, how to prevent the torsion coil springs from being accidentally dropped becomes a problem.

The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a chain tensioner and a torsion coil for the chain tensioner that can reliably maintain a state in which a torsion coil spring is attached to a main body member. It is to provide a spring mounting structure.

In order to achieve the above object, in the chain tensioner according to the present invention,
A body member that has a shoe surface that is slid relative to the chain and is swingably attached to the attached member;
A torsion coil spring interposed between the body member and the mounted member and swinging and biasing the body member in a direction in which the shoe surface is pressed against the chain;
In the chain tensioner with
The main body member has a base on which a shoe wall surface constituting the shoe surface is erected at an outer peripheral edge portion, and a spiral portion of the torsion coil spring that is erected from the base and is fitted to the attached member. A cylindrical portion that becomes a swingable mounting portion of
Have
A plurality of holding parts for holding one extension part of the torsion coil spring fitted to the cylindrical part are formed on the base body at intervals in the longitudinal direction of the one extension part. It is.

According to the chain tensioner according to the present invention, the torsion coil spring is held by the plurality of holding portions provided on the base body at intervals in the longitudinal direction of one of the extension portions. The holding action of the torsion coil spring can be drastically increased, and the situation where the torsion coil spring is inadvertently dropped from the main body member can be prevented.

Preferred embodiments of the chain tensioner according to the present invention are as follows.
1) As the holding portion, a first holding portion that holds a tip portion of the one extension portion, and a second holding that holds the one extension portion in a portion closer to the cylindrical portion than the first holding portion. And
The first holding portion includes a wall portion that is formed to form a gap with the base body, and the one extension portion regulates displacement in a direction away from the base body. is there. In this preferred embodiment, it is preferable to stably and surely hold one extension portion while minimizing the number of holding portions. In particular, since the first holding part has a wall part that restricts the movement of the one extension part in the direction away from the base body, the first holding part more reliably prevents the torsion coil spring from falling off the main body member. Is preferable.

2) The first holding portion is erected from the base, and is formed in an approximately L shape in which one side is open or an arch shape in which both sides are closed,
The one extension part has a tip bending part extending in the same direction as the cylindrical part while being held by the first holding part,
The gap between the wall portion and the base body is made smaller than the length of the bent end portion. In this preferred embodiment, one of the extension portions is held by the base body with the bent end portion passing through the first holding portion. In this holding state, the wall portion and the base body between the first holding portion and the base portion are held. Since the tip bent portion formed in one of the extension portions is longer than the gap, the situation where the tip bent portion is inadvertently pulled out from the first holding portion is prevented, and the torsion coil spring is removed by the body member. It can be held securely.

3) The second holding portion is erected from the base, and an inclined surface on which the one extension portion can get over when the torsion coil spring is attached to the main body member; The protrusion is formed as a protrusion having a restricting wall portion that restricts reversal after the inclined surface is overcome. In this preferable aspect, when one extension portion is held by the second holding portion, the inclined surface is used to move the one extension portion in the direction of approaching the base without fail while exceeding the inclined surface. After that, it is possible to prevent the extension portion from being separated from the base body by the restriction wall portion, and to further prevent the torsion coil spring from falling off from the main body member.

4) The second holding portion has a pair of left and right projections, and the one extension portion is sandwiched from the left and right by the pair of projections. In this preferred embodiment, by providing a pair of left and right projections having inclined surfaces and restricting wall portions, the torsion coil spring can be more reliably prevented from falling off from the main body member. In particular, the left and right regulating wall portions prevent the one extension portion from being separated from the base body, so that the function of preventing the torsion coil spring from falling off the base body can be made extremely high.

5) The second holding portion has another protrusion in addition to the one protrusion, and the one extension is sandwiched from the left and right by the one protrusion and the other protrusion. It has been done. In this preferred embodiment, in addition to the protrusion having the inclined surface and the regulating wall portion, another holding member is also used to sandwich one extension portion from the left and right, thereby enhancing the holding action at the second holding portion. Thus, the function of preventing the torsion coil spring from falling off from the base body can be made extremely high.

In order to achieve the above object, in the mounting structure of the torsion coil spring of the chain tensioner in the present invention,
The main body member in a direction in which the shoe surface is pressed against the chain with respect to the main body member that has a shoe surface that is slid with respect to the chain and is swingably attached to the attached member. A torsion coil spring mounting structure for a chain tensioner that holds a torsion coil spring that oscillates and biases
The main body member has a base on which a shoe wall surface constituting the shoe surface is erected at an outer peripheral edge portion, and a spiral portion of the torsion coil spring that is erected from the base and is fitted to the attached member. A cylindrical portion that becomes a swingable mounting portion,
A plurality of holding portions for holding one extension portion of the torsion coil spring fitted to the cylindrical portion are formed on the base body at intervals in the longitudinal direction of the one extension portion,
As the holding part, a first holding part that holds a tip part of the one extension part, and a second holding part that holds the one extension part in a portion closer to the cylindrical part than the first holding part, Have
The first holding part includes a wall part that forms a gap with the base body and restricts displacement of the one extension part in a direction away from the base body.
The first holding portion is erected from the base body, and is formed in an approximately L shape in which one side is open or an arch shape in which both sides are closed,
The one extension portion has a tip bending portion extending in the same direction as the cylindrical portion while being held by the first holding portion,
The gap between the wall portion and the base is made smaller than the length of the tip bending portion,
The second holding portion is erected from the base body, and an inclined surface on which the one extension portion can get over when the torsion coil spring is attached to the main body member, and the one extension portion is the inclined surface. Is formed as a projecting body having a regulating wall portion that regulates the reversal after overcoming,
When the torsion coil spring is attached to the main body member, after the front end bent portion of the one extension portion passes below the wall portion in the first holding portion, the inclined surface in the second holding portion is moved. This is done by fitting the spiral part to the cylindrical part while getting over. According to the mounting structure of the torsion coil spring of the chain tensioner according to the present invention, the same effect as described with respect to the chain tensioner according to the present invention can be obtained, and one extension portion of the torsion coil spring can be attached to the main body member. The attachment work to be held by the can also be facilitated.

According to the present invention, it is possible to reliably maintain the attachment state of the torsion coil spring to the main body member, which is preferable for preventing the torsion coil spring from being inadvertently dropped.

It is a front view showing an example at the time of applying a chain tensioner by one embodiment of the present invention to a water pump drive chain of an engine. It is the top view which looked at the said chain tensioner from the surface by the side of the attachment of a torsion coil spring. FIG. 3 is a right side view of the chain tensioner shown in FIG. 2. FIG. 3 is a top view of the chain tensioner shown in FIG. 2. FIG. 3 is an end view corresponding to line X5-X5 in FIG. 2; It is a top view which shows the main-body part of the said chain tensioner. It is a bottom view of the main-body part shown in FIG. It is a bottom view of the main-body part shown in FIG. It is a right view of the main-body part shown in FIG. FIG. 8 is an end view corresponding to line X10-X10 in FIG. 7; FIG. 7 is an end view corresponding to line X11-X11 in FIG. 6; FIG. 7 is an end view corresponding to line X12-X12 in FIG. 6; FIG. 7 is an end view corresponding to line X13-X13 in FIG. 6; FIG. 8 is an end view corresponding to line X14-X14 in FIG. 7; FIG. 7 is an end view corresponding to line X15-X15 in FIG. 6; FIG. 10 is a perspective view showing a main part of a process of attaching a torsion coil spring to a main body member and showing a state immediately after a distal end bending portion of a first extension portion is inserted into a first holding portion. It is a principal part perspective view which shows the attachment completion state to the main body member of a torsion coil spring.

Hereinafter, embodiments of the present invention will be described in detail.
In FIG. 1, reference numeral 1 is an automobile engine body, and its crankshaft is indicated by reference numeral 2. A water pump 3 as an auxiliary device is fixed to the engine body 1. A chain 6 is wound between a sprocket 4 fixed to the crankshaft 2 and a sprocket 5 fixed to a water pump 3 (drive shaft thereof). Thereby, the water pump 3 is rotationally driven by rotating the crankshaft 2.

The chain engine body 1 is further provided with a chain tensioner CT. The chain tensioner CT includes a main body member 10 and a torsion coil spring 20. The main body member 10 is attached to the engine main body 1 so as to be swingable about an attachment shaft 7 provided in the engine main body 1. The main body member 10 has a shoe surface 10 a that is slidably pressed against the chain 6.

The torsion coil spring 20 will be described in detail later together with the main body member 10, but as shown in FIG. 16, the spiral portion 21 fitted and held in the main body member 10 and a linear extension from one end portion of the spiral portion 21. The first extension portion 22 that becomes one of the extended portions (cantilever portion) and the second extension portion 23 that extends linearly from the other end portion of the spiral portion 21. The first extension 22 is held by the main body member 10 as described later. The second extension 23 is locked to a locking pin 8 that protrudes from the engine body 1.

In the state where the chain tensioner CT is attached to the engine body 1 in FIG. 1, the torsional force is stored in the torsion coil spring 12, and the reaction force of the torsional force causes the body member 10 to center on the attachment shaft 7. 1 is urged to swing in the clockwise direction in FIG. 1 (the direction in which the shoe surface 10a is pressed against the chain 6). Thereby, the slack of the chain 6 is prevented.

Next, with reference to FIG. 2 and subsequent drawings, the details will be described by focusing on the holding portion for holding the torsion coil spring 20 with respect to the main body member 10. First, as shown in FIGS. 2, 5, 6, etc., the main body member 10 has a plate-like base 11. And the cylindrical part 12 made into the cylindrical shape is protrudingly provided by the board surface of the base | substrate 11 at the one end part side. The spiral portion 21 of the torsion coil spring 20 is fitted and held on the outer periphery of the cylindrical portion 12 (see FIGS. 2 and 5).

From the heel base 11, a shoe wall 13 that is gently curved is erected on the outer peripheral edge thereof. The outer surface of the shoe wall surface 13 is a shoe surface 10a that is pressed against the chain 6 described above.

The first extension portion 22 of the torsion coil spring 20 is formed with a distal end bent portion 22a bent (bent) at approximately 90 degrees (see FIGS. 2, 16, and 17). Similarly, the second extension portion 23 is formed with a tip bent portion 23a bent (bent) at approximately 90 degrees (see FIGS. 2, 3, 4, and 16).

The torsion coil spring 20 is held by the first holding part 14 and the second holding part 15 formed on the base 1 so as not to be separated from the base 11 (that is, the main body member 10). The first holding part 14 holds the vicinity of the tip part of the first extension part 22. The second holding portion 15 holds the vicinity of the base end portion of the first extension portion 22 (portion close to the cylindrical portion 12).

In the embodiment, as shown in FIG. 16, the first holding unit 14 includes a wall portion 14 a that is separated from the base body 11 and extends substantially parallel to the base body 11, and left and right ends that connect the left and right ends of the wall portion 14 a to the base body 11. Connecting portion 14b. In other words, the first holding portion 14 constitutes a closed insertion hole 14 c that is substantially parallel to the plate surface of the base 11. The distal end bent portion 22a of the first extension portion 22 can be inserted through the insertion hole 14c. And the length of the front bending part 22a is set so that it may become larger than the height of the insertion hole 14c (height from the base | substrate 11 of the wall part 14a).

The second holding part 15 is composed of two protrusions, a first protrusion 16 and a second protrusion 17 (see FIG. 16). Each of the

protrusions

16 and 17 protrudes in the same direction as the cylindrical portion 12.

As shown in FIGS. 13 and 16, the first protrusion 16 has an inclined surface 16a and a regulating wall portion 16b formed below the inclined surface 16a. The inclined surface 16a is inclined so as to gradually approach the first extension portion 22 in the attachment completion state of the torsion coil spring 20 shown in FIG. The restricting wall portion 16b is formed in the form of a locking step portion so as to constitute an upper surface of the locking recess portion 16c into which at least a part of the first extension portion 22 in the attachment completed state can be inserted below the inclined surface 16a. It is configured.

The second protrusion 17 is set at a position where the first extension 22 is sandwiched from the left and right in cooperation with the first protrusion 16 when the torsion coil spring 20 is completely attached. And the 1st projection body 16 and the 2nd projection body 17 are positioned so that it may have a space in the longitudinal direction of the 1st extension part 22 in the attachment completion state, and in the embodiment, the 2nd projection body 17 is The position is set so as to be closer to the first holding portion 14 than the first protrusion 16 (see FIG. 17). As shown in FIG. 12, the second protrusion 17 is formed with an inclined surface 17 a that gradually approaches the first extension portion 22 that is in the attached state as it goes downward. The minimum distance between the

protrusions

16 and 17 is set to be slightly smaller than the outer diameter of the first extension 22, but is the same as or slightly larger than the outer diameter of the first extension 22. It may be set.

The second extension 23 protrudes outward from the main body member 10 when the torsion coil spring 20 is attached to the main body member 10 (see FIG. 1). Note that the length of the tip bent portion 23a is longer than the length of the tip bent portion 22a (see FIG. 16).

本体 Here, the main body member 10 is integrally formed of synthetic resin as a whole.

Small holes

30 and 31 are formed in the base 1 at positions corresponding to the holding portions 14 and 15 (see FIGS. 6, 16, and 17). The formation of the

small holes

30 and 31 facilitates the release of the split mold after the body member 10 is molded and prevents sink marks after the molding.

In the configuration as described above, the torsion coil spring 20 is attached to the main body member 10 as follows. That is, first, as shown in FIG. 16, the spiral portion 21 of the torsion coil spring 20 is inclined with respect to its axis at a position above the tubular portion 12, and the first extension portion 22 is each holding portion. The posture state is a direction connecting 14 and 15. From this posture state, the distal end bending portion 22a of the first extension portion 22 is inserted into the first holding portion 14 (the insertion hole 14c), and the state immediately after the insertion is shown in FIG.

16 From the state of FIG. 16, the first extension portion 22 is pressed downward (in the direction of approaching the base body 11) while fitting the spiral portion 21 to the cylindrical portion 12. At this time, the first extension portion 22 is guided (moved) downward along the inclined surface 16a of the first protrusion 16, and eventually gets over the inclined surface 16a. After the first extension 22 has climbed over the inclined surface 16a, at least a part of the first extension 22 is positioned in the locking recess 16c below the inclined surface 16a, and is separated from the base 11 by the restriction wall 16b. The separation is restricted. Further, when the first extension 22 is moved toward the base 11, the movement of the first extension 22 toward the base 11 is also smoothly guided by the inclined surface 17 a of the second protrusion 17.

As described above, the torsion coil spring 20 is attached to the main body member 10 by inserting the distal end bent portion 22a of the first extension portion 22 into the first holding portion 14 and directing the torsion coil spring 20 to the base body 11 from this state. It can be done very easily by simply pressing it.

In the embodiment, the minimum distance between the two

protrusions

16 and 17 is set smaller than the outer diameter of the first extension 22, but the first extension 22 is moved downward from the state of FIG. 16 ( When pressed, the two

protrusions

16 and 17 are elastically deformed, and the minimum distance between them is increased.

In the state where the scissors are attached, the first extension portion 22 is prevented from being separated from the base body 11 by the first holding portion. Further, the locking action of the first protrusion 16 restricts the first extension portion 22 from being separated from the base body 11. Since the first protrusion 16 and the second protrusion 17 sandwich the first extension 22 from the left and right, the first extension 22 is disengaged from the first protrusion 16 (the locking recess 16c). Things are prevented.

As described above, in the process of assembling the main body member 10 to the engine main body 1 in a state in which the torsion coil spring 20 is stably attached to the main body member 10 and the torsion coil spring 20 is assembled. This prevents the torsion coil spring 20 from being inadvertently dropped. In particular, even if the main body member 10 holding the torsion coil spring 20 is changed to various posture states, the torsion coil spring 20 is prevented from falling off.

The main body member 10 to which the torsion coil spring 20 is assembled (held) as described above is rotatably attached to the mounting shaft 7 of the engine main body 1 at the cylindrical portion 12 thereof. And the 2nd extension part 23 is latched by the locking pin 8 mentioned above so that the torsion coil spring 20 may hold | grip the front-end | tip bending part 23a, and a torsional force may be stored in the spiral part 21. (The second extension portion 23 is swung in the counterclockwise direction in FIG. 2 around the cylindrical portion 12 and accumulated).

Although the embodiments have been described above, the present invention is not limited to the embodiments, and appropriate modifications can be made within the scope of the claims. You may provide 3 or more holding parts of the 1st extension part 22 in the longitudinal direction of the 1st extension part 22 at intervals. Similarly to the first protrusion 16, the second protrusion 17 may have a structure having an inclined surface, a regulating wall portion, and a locking recess (the inclined surfaces of both protrusions are in a positional relationship facing each other). Further, the first protrusion 16 and the second protrusion 17 may be set at the same position in the longitudinal direction of the first extension 22. The second holding portion 15 may not have the second protrusion 17. The chain on which the chain tensioner CT according to the present invention is slid is not limited to the water pump 3 drive, but can be a chain for an appropriate use such as a camshaft drive or an oil pump drive. The chain used may be used. The attached member to which the chain tensioner CT is attached is not limited to the engine main body 1, and an appropriate fixing member (non-moving member) near the engine main body 1 can be selected. Of course, the object of the present invention is not limited to what is explicitly stated, but also implicitly includes providing what is substantially preferred or expressed as an advantage. For example, to a body member of a torsion coil spring. It is also possible to grasp this as an assembly method.

The present invention can be applied, for example, to prevent sagging of an engine accessory driving chain.
It should be noted that the entire content of the specification, claims, drawings and abstract of Japanese Patent Application No. 2014-016912 filed on January 31, 2014 is cited herein as the disclosure of the specification of the present invention. Incorporate.

Claims

A body member that has a shoe surface that is slid relative to the chain and is swingably attached to the attached member;
A torsion coil spring interposed between the body member and the mounted member and swinging and biasing the body member in a direction in which the shoe surface is pressed against the chain;
In the chain tensioner with
The main body member has a base on which a shoe wall surface constituting the shoe surface is erected at an outer peripheral edge portion, and a spiral portion of the torsion coil spring that is erected from the base and is fitted to the attached member. A cylindrical portion that becomes a swingable mounting portion of
Have
A plurality of holding portions for holding one extension portion of the torsion coil spring fitted to the cylindrical portion are formed on the base body at intervals in the longitudinal direction of the one extension portion.
A chain tensioner characterized by that.
In claim 1,
As the holding part, a first holding part that holds a tip part of the one extension part, and a second holding part that holds the one extension part in a portion closer to the cylindrical part than the first holding part, Have
The first holding portion includes a wall portion that is formed so as to form a gap with the base body and restricts displacement of the one extension portion in a direction away from the base body.
A chain tensioner characterized by that.
In claim 2,
The first holding portion is erected from the base body, and is formed in an approximately L shape in which one side is open or an arch shape in which both sides are closed,
The one extension part has a tip bending part extending in the same direction as the cylindrical part while being held by the first holding part,
The gap between the wall portion and the base body is smaller than the length of the tip bending portion,
A chain tensioner characterized by that.
In any one of Claims 1 thru | or 3,
The second holding portion is erected from the base body, and an inclined surface on which the one extension portion can get over when the torsion coil spring is attached to the main body member, and the one extension portion is the inclined surface. A chain tensioner, characterized in that the chain tensioner is formed as a protrusion having a restriction wall portion for restricting the reversal after overcoming.
In claim 4,
The chain tensioner according to claim 1, wherein the second holding portion includes a pair of left and right protrusions, and the one extension portion is sandwiched from the left and right by the pair of protrusions.
In claim 4,
The second holding portion has another projection in addition to the one projection, and the one extension is sandwiched from the left and right by the one projection and the other projection. A chain tensioner characterized by that.
The main body member in a direction in which the shoe surface is pressed against the chain with respect to the main body member that has a shoe surface that is slid with respect to the chain and is swingably attached to the attached member. A torsion coil spring mounting structure for a chain tensioner that holds a torsion coil spring that oscillates and biases
The main body member has a base on which a shoe wall surface constituting the shoe surface is erected at an outer peripheral edge portion, and a spiral portion of the torsion coil spring that is erected from the base and is fitted to the attached member. A cylindrical portion that becomes a swingable mounting portion,
A plurality of holding portions for holding one extension portion of the torsion coil spring fitted to the cylindrical portion are formed on the base body at intervals in the longitudinal direction of the one extension portion,
As the holding part, a first holding part that holds a tip part of the one extension part, and a second holding part that holds the one extension part in a portion closer to the cylindrical part than the first holding part, Have
The first holding portion includes a wall portion that is formed so as to form a gap with the base body and restricts displacement of the one extension portion in a direction away from the base body,
The first holding portion is erected from the base body, and is formed in an approximately L shape in which one side is open or an arch shape in which both sides are closed,
The one extension portion has a tip bending portion extending in the same direction as the cylindrical portion while being held by the first holding portion,
The gap between the wall portion and the base is made smaller than the length of the tip bending portion,
The second holding portion is erected from the base body, and an inclined surface on which the one extension portion can get over when the torsion coil spring is attached to the main body member, and the one extension portion is the inclined surface. Is formed as a projecting body having a regulating wall portion that regulates the reversal after overcoming,
When the torsion coil spring is attached to the main body member, after the front end bent portion of the one extension portion passes below the wall portion in the first holding portion, the inclined surface in the second holding portion is moved. It is performed by fitting the spiral part to the cylindrical part while getting over
A structure for mounting a torsion coil spring of a chain tensioner characterized by that.