JPH08254253A - Chain tensioner - Google Patents

Abstract

PURPOSE: To facilitate integral molding and form a thick-walled rib so as to improve the strength easily. CONSTITUTION: In a chain tensioner 1 provided with a tensioner main body 6 having a slide-contact face 8 on which a part of a chain between chain wheels comes into slide-contact and a rib 7 along the direction crossing the tensioner main body 6, an insert member 5 having a drop prevention plate section 11 and a reinforcing plate section 12 which crosses the drop prevention plate section 11 integrally is used to arrange the drop prevention plate section 11 in parallel with the slide-contact face 8 and the reinforcing plate section 12 along the rib 7 so that insert molding is carried out by using the insert member 5 as a core material and synthetic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is widely applied to a chain or the like for transmitting a rotational force to a cam shaft of automobiles and motorcycles, and is used for preventing vibration of a chain wound around a chain wheel. The present invention relates to a resin chain tensioner that requires wear resistance.

[0002]

2. Description of the Related Art A conventional chain tensioner is disclosed in Japanese Utility Model Laid-Open No. 3952/1993. As shown in FIGS. 10 and 11, the chain tensioner 30 includes a pair of L-shaped side engaging pieces 36 and 37 that engage from both sides of a metal arm 31 serving as a base.
The shoe 32 is made of synthetic resin and has a U-shaped end hook piece 34 that engages with the chain traveling start end portion 31a of the arm 31.

[0003]

In the case of such a conventional chain tensioner 30, the sliding contact surface 4 with which the chain C slides contacts.
5 uses a synthetic resin shoe 32 having a metal arm 31 and a metal arm 31 which is separate from the shoe 32.
In order to assemble the shoe 32 made of synthetic resin into 1, the U-shaped end hook piece 34 to be engaged is required, and it is difficult to secure the strength of the end hook piece 34. there were.

Further, as shown in FIG. 12, when the chain tensioner 40 is integrally injection-molded with synthetic resin,
The thickness of the rib 43 is 6 with respect to the thickness of the tensioner main body 44.
If it is 0% or more, a recess 46 called a sink mark is generated in the portion of the sliding contact surface 45 with which the chain slides.
In order to prevent the recess 46 from being formed, there is a problem that the thickness of the rib 43 is limited and sufficient strength cannot be secured.

The present invention has been made in view of the above-mentioned conventional drawbacks. A metal arm and a U-shaped end hook piece are not required, and ribs are made thick to easily improve strength. It is an object of the present invention to provide a chain tensioner that can be integrally molded.

[0006]

In order to achieve the above object, the present invention according to claim 1 provides a tensioner main body having a sliding contact surface with which a portion of the chain between the chain wheels slides, and the tensioner main body. In a chain tensioner provided with a rib for reinforcing, a sink preventive plate portion and an insert member integrally having a reinforcing plate portion along a direction intersecting with the sink mark preventive plate portion are used, and the sink preventive plate portion is slidably contacted. It is characterized in that the reinforcing plate portion is arranged substantially parallel to the surface and along the rib, and the insert member is insert-molded with a synthetic resin as a core material. Further, the invention according to claim 2 is the chain tensioner according to claim 1, wherein the insert member is made of a synthetic resin reinforced with glass fiber, and the insert resin is insert-molded with the same synthetic resin as the synthetic resin of the insert member. It is characterized by having done.

[0007]

The present invention uses an insert member integrally having a sink mark prevention plate portion and a reinforcing plate portion along a direction intersecting with the sink mark prevention plate portion, and the sink mark prevention plate portion is almost on the sliding contact surface with which the chain slides. Place the reinforcing plate along the ribs in parallel,
By using insert material as the core material and insert molding with synthetic resin, even if the rib is thick, the sink preventive plate part can prevent sink marks and the rib can be made thick, and the reinforcing plate part sufficiently reinforces To be able to do.

[0008]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing an example of a usage state of a chain tensioner. Chain tensioner 1
Is a chain 4 wrapped around the chain wheels 2 and 3
Is arranged at a portion separated from the chain wheels 2 and 3 and is used to prevent the chain 4 from being vibrated by being pressed from the outside.

FIG. 2 is a perspective view showing a chain tensioner according to an embodiment of the present invention, and FIG. 3 is a cross sectional view thereof. The chain tensioner 1 uses the insert member 5 as a core material, insert-molds a polyamide resin selected from 66 nylon and 46 nylon, which are commercially available under the trade name nylon, and forms a sliding contact surface 8 with which the chain 4 slides. The tensioner main body 6 has a rib 7 extending in a direction intersecting the tensioner main body 6 substantially at right angles.

In the chain tensioner 1, the sink prevention plate portion 11 of the insert member 5 is arranged substantially parallel to the sliding contact surface 8 and the reinforcing plate portion 12 of the insert member 5 is arranged along the rib 7. The entire tensioner body 6 including the sliding contact surface 8 is bent in a convex shape with a small curvature with respect to the corresponding portion of the chain 4.

Further, the chain tensioner 1 integrally includes both guides 9 and 9 which are formed on both sides of the tensioner main body 6 and which extend substantially at right angles to the sliding contact surface 8 and which are continuous in the longitudinal direction with a uniform rectangular cross section. The chain 4 is guided by the two guides 9, 9.

FIG. 4 is a perspective view showing an insert member according to an embodiment of the present invention. The insert member 5 is manufactured by extruding a steel plate, and as shown in FIG. 3, a sink prevention plate portion 11 having a width narrower than that of the tensioner body 6 and a direction intersecting the sink prevention plate portion 11 at a substantially right angle. Both reinforcing plate portions 1 having a cross-sectional dimension that fits up to the middle position of the rib 7 along
2 and 12, which form a channel having a U-shaped cross section.

Most of the insert member 5 is embedded in polyamide resin so that the sink mark preventing plate portion 11 is located substantially in the center of the tensioner body 6, and as shown in FIG. 2, it is injection-molded with resin. Both ends 13 and 14 project from both ends of the tensioner body 6 and the rib 7.

A method of forming the chain tensioner according to the above embodiment of the present invention will be described. The insert member 5 is manufactured by extrusion along the longitudinal direction of the chain tensioner 1.

As shown in FIG. 5, an injection molding die 16 is provided.
The insert member 5 is fixed to the mold 16 at a predetermined position corresponding to the recessed portion 17 forming the cavity. In this case, since the insert member 5 is fixed to the mold at both end portions 13 and 14, the both end portions 13 and 14 are projected after the injection molding of the chain tensioner 1. Since the sliding contact surface 8 is not formed, there is no problem in the performance of the chain tensioner 1.

The chain tensioner 1 is completed by injection molding with a polyamide resin selected from 66 nylon, 46 nylon and the like.

According to the above embodiment of the present invention, since the insert member 5 made of an inexpensive steel plate of extrusion molding is used as the core material to insert-mold the chain tensioner 1, the entire chain tensioner can be assembled without using the shoe as a separate body. It can be molded at low cost as an integrated one, and the insert member 5
Since the sink prevention plate portion 11 prevents the sink of the sliding contact surface 8,
Without considering the relationship with the thickness of the tensioner body 6,
Since the rib 7 can be made thick, the strength of the chain tensioner 1 can be sufficiently improved.

In this case, the steel plate insert member 5 is also used.
Since the reinforcing plate portion 12 of (1) functions as a reinforcing material, the synthetic resin material used for the chain tensioner 1 can use a resin having high slidability even if the strength is greatly reduced at high temperatures.

The insert member 5 may be formed by press forming from a steel plate. Instead of the steel plate, the insert member 5 is made of a polyamide resin reinforced by embedding glass fibers, and the chain tensioner is made of a polyamide resin of the same quality as the synthetic resin forming the insert member 5. 1 may be insert-molded. In this case, since the same quality material is integrally molded, there is an advantage that the bondability between the insert member 5 and the polyamide resin around it is significantly improved.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. For example, FIGS. 6 to 8 show modified examples of the above-described embodiment, the same reference numerals are given to the same portions, and duplicate description will be omitted. As shown in FIG. 6, a glass reinforced plastic having a T-shaped cross section can be adopted as the insert member 5.

The cross-sectional shape of the insert member 5 is a T-shaped cross section of two sheets as shown in FIG. 7, and the reinforcing plate 12 is processed as shown in FIG.
b may be provided to improve the bonding strength with the surrounding synthetic resin, and as shown in FIG. 9, it is also possible to form a hollow pipe having a quadrangular cross section.

[0022]

According to the first aspect of the present invention, the sink mark prevention plate portion and the reinforcement plate portion along the direction intersecting with the sink mark prevention plate portion are integrally used, and the sink mark prevention plate portion is chained. The reinforcing plate portion is arranged substantially parallel to the sliding contact surface where the sliding contact is made, and the reinforcing plate portion is arranged along the rib, and the insert member is formed by insert molding with a synthetic resin, so that the sink mark preventing plate portion can be formed even if the rib is thick. Since the sink mark is prevented from occurring, the rib can be made thicker, and it is possible to sufficiently reinforce with the reinforcing plate portion, and it is possible to integrally form the entire chain tensioner by using the insert member as a core material. . In the present invention according to claim 2, the insert member is made of a synthetic resin reinforced with glass fiber, and the insert member and the surrounding synthetic resin are formed by insert molding with the same synthetic resin as the synthetic resin of the insert member. The bondability of is significantly improved.

[Brief description of drawings]

FIG. 1 is a side view showing an example of a usage state of a chain tensioner.

FIG. 2 is a perspective view showing a chain tensioner according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of the chain tensioner according to the embodiment of the present invention.

FIG. 4 is a perspective view showing an insert member according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a method for manufacturing the chain tensioner according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a modified example of the insert member according to the above embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a modified example of the insert member according to the above embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a modified example of the insert member according to the above embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a modified example of the insert member according to the above embodiment of the present invention.

FIG. 10 is a side view showing a conventional chain tensioner.

11 is a cross-sectional view of FIG.

FIG. 12 is a cross-sectional view showing another conventional chain tensioner.

[Explanation of symbols]

 1 Chain Tensioner 2, 3 Chain Wheel 4 Chain 5 Insert Member 6 Tensioner Main Body 7 Rib 8 Sliding Surface 11 Sink Prevention Plate 12 Reinforcement Plate 16 Mold 17 Recess

Claims (2)

[Claims] 1. A sink tension preventing plate portion and a sink preventing plate portion in a chain tensioner having a tensioner main body having a sliding contact surface with which a portion of the chain between the chain wheels slides, and a rib for reinforcing the tensioner main body. Using an insert member integrally having a reinforcing plate portion along a direction intersecting with, the sink mark preventing portion is substantially parallel to the sliding contact surface,
A chain tensioner characterized in that the reinforcing plate portion is arranged along the rib, and the insert member is used as a core material and insert-molded with a synthetic resin. 2. The chain tensioner according to claim 1, wherein the insert member is made of a synthetic resin reinforced with glass fiber, and is insert-molded with a synthetic resin of the same quality as the synthetic resin of the insert member.