JPS6212117Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a chain tensioning device installed in a chain case, etc., and is constructed by arranging two chain tensioners in a stacked state. It is about improvement.

(b) Prior art A chain tensioning device that widens the effective buffering range by providing two arc-shaped chain tensioners in a stacked state has been known.
This is already known as seen in Publication No. 56180.

However, in this known method, the first chain tension, which contacts the chain, and the second chain tension, which is disposed on the back side of the chain, normally contact each other only at the pivot joint, and are not pivoted. Since the arc-shaped parts other than the section are configured to be spaced apart from each other at appropriate intervals up to the free end, under normal conditions, only the tension of the first chain presses the chain, and the amount of chain displacement exceeds the spacing. For the first time, it comes into close contact with the second chain tension, and a synergistic compressive action is performed between the two.

Therefore, a sudden difference occurs between the elastic force until the first chain tension comes into close contact with the second chain tension, and the elastic force exerted from the stage when both chain tensions come into close contact. There is a problem in that it is not possible to smoothly and continuously change the load change that is applied impulsively at the start of rotation, etc., and as a result, the pulsation of the chain cannot be prevented and abnormal vibration noise is generated.

(c) Problems that the invention aims to solve Therefore, the present invention is a chain tensioning device with a structure in which the chain tensioning is provided in a double structure to widen the effective buffering range, but it is also designed to prevent shock chain displacement such as at the start of rotation. The object of the present invention is to provide a device that can reliably receive the force and exert the elastic force against the chain while changing continuously without any steps.

(d) Means to solve the problem Chain 5 rotating from the drive shaft 1 side to the driven shaft 3 side
The support shaft 9 is bent in a winding manner using the same material in the form of a long flat strip, and the upper and lower arcuate portions are connected to the support shaft 9 from approximately half of the arcuate portion. A first chain tension 7 and a second chain tension 8 are formed in which the circular arc-shaped portions on the sides overlap and contact each other, and the other free end side is gradually expanded and separated, and the end portions 7a and 8a are spaced apart from each other. This is a chain tensioning device for a chain case, characterized in that it is formed as follows.

(E) Effect: The first chain tension and the second chain tension provided in two stacks.
Chain tension means that the part where the support shaft is bent in a winding manner and the approximate center of the arc-shaped part is in normal overlapping contact, and the part from the contact part to the free end is a gradual opening that separates. The chain is provided in an expanded shape so that the chain is normally compressed by the abutting and overlapping parts, so that it can accurately absorb the impact load at the start of rotation, and also reduce the elastic force against the chain. The changes are made to be continuous without any steps.

(F) Embodiments The present invention will be described in detail below based on embodiments shown in the drawings.

Referring to FIG. 1, 1 is a drive shaft, 2 is a drive sprocket, 3 is a driven shaft, 4 is a driven roller (driven sprocket, driven roller, etc.), 5 is a chain, and 6 is a chain tensioning device. The tensioning device 6 is the first
It is composed of a chain tensioner 7 and a second chain tensioner 8, and the middle portion of the arc-shaped portion of the first chain tensioner 7 is in contact with the roller 5a of the chain 5.

As shown in FIG.
a and a second chain tension 8 located on the back side of the first chain tension 7, and the bent part is connected to a support shaft (bolt 9) and rotatably fixed to the chain case 10.

The arcuate portion of the second chain tension 8 has a greater degree of curvature than that of the first chain tension 7, and the end (free end 8a) of the second chain tension 8 is the end of the first chain tension 7. (The free end 7a) is located closer to the support shaft 9, and the area between the pivot portion of the second chain tension 8 (the attachment portion to the support shaft 9) and the approximate center of the arc-shaped portion is , is configured to gradually expand and expand, coming into contact with the back surface of the arc-shaped portion of the first chain tensioner 7, and separating from the substantially central portion between the free ends 7a and 8a.

(g) Effects of the invention Since it is only necessary to process the same material, material management costs and processing man-hours can be reduced.

Because of the difference in perspective, the elastic force can be better managed, and since they are made of the same material, the elastic force of one of the two is more easily transmitted to the other than in the past.

The spring force of the first chain tension and the second chain tension can be gradually expanded and expanded, and the spring force can be adjusted (exchanged) by changing the length.

Therefore, maintaining the chain in an appropriate tension state by elastically deforming the chain when it comes into contact with the chain is similar to conventional chain tensioning, but in the chain tensioning device of the present invention, the chain tensioning device elastically deforms due to contact with the chain. The circular arc-shaped portion of the first chain tensioner 7 that comes into contact with
Since it is in contact with the second chain tension 8 between the pivot point and the approximately central part, the first chain tension and the second chain tension act together to prevent an impactful chain displacement such as when the chain starts rotating. It is reliably received by the elastic force exerted, and thereafter the chain is well buffered by the displacement of the portion of the first chain tension 7 near the free end and the portion of the second chain tension 8 near the free end. In other words, in the conventional double structure chain tensioning device in which arc-shaped parts other than the pivot joint parts are provided at appropriate intervals, the first
Since there is a sudden change between the elastic force at the stage until the chain tension comes into close contact with the second chain tension and the elastic force exerted after the chain tension comes into close contact, the change in the amount of deflection of the chain tension as a whole occurs during the contact stage. This creates a step and prevents a continuous linear change, which causes the chain to pulsate at the step change part, causing vibration and abnormal noise. Since the arc-shaped parts of the first chain tension and the second chain tension are normally in contact between the pivot point and the approximate center, the amount of deflection of the entire chain tension changes continuously in a straight line without any steps. As a result, tension can be applied to the chain without causing pulsation, and smooth operation can be achieved.

Therefore, according to the present invention, the problems occurring in the conventional devices can be solved and the intended purpose can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing a chain case equipped with the chain tensioning device of the present invention, and FIG. 2 is a partially enlarged view showing the main parts thereof. 6... Chain tensioning device, 7... First chain tensioning, 8... Second chain tensioning, 10... Chain case.

Claims (1)

[Scope of utility model registration request] Chain 5 rotating from the drive shaft 1 side to the driven shaft 3 side
The support shaft 9 is bent in a winding manner using the same material in the form of a long flat strip, and the upper and lower arcuate portions are connected to the support shaft 9 from approximately half of the arcuate portion. A first chain tension 7 and a second chain tension 8 are formed in which the circular arc-shaped portions on the sides overlap and contact each other, and the other free end side is gradually expanded and separated, and the end portions 7a and 8a are spaced apart from each other. A chain tensioning device for a chain case, characterized in that the chain tensioning device is formed in a chain case.