JPS63259247A - Connecting pin of driving chain for tenter clip - Google Patents

Abstract

PURPOSE:To improve the permeability of lubricating oil and to prevent abnormal abrasion by forming a plurality of oil grooves or streaks on the surface of a connecting pin, conducting surface hardening heat treatment or direct quenching, and then dry-coating the surface with solid lubricating material. CONSTITUTION:A connecting pin 51 is provided with a plurality of oil grooves or steaks 52 at the middle portion thereof, which have a groove depth of about 0.15mm, a groove pitch of about 1.5mm and an angle of inclination of 30 deg., and the surface thereof is dry-coated with a solid lubricant such as MOS2 or the like. A manufacturing method thereof comprises the steps of outer diameter working, forming oil grooves 52 by knurling, conducting surface hardening heat treatment by gas nitriding or direct quenching and polishing the outside diameter. Subsequently, degreasing and chemical conversion coating are conducted, and drying is conducted. After that, the surface is dry-coated with MOS2 or the like, and finally the connecting pin is heated to be hardened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a connecting pin of a drive chain 7 to which a tenter clip for clipping a film is attached, for example in a transverse stretching machine.

FIG. 5 shows a chain row on one side of a horizontal stretching machine, and the chain row 11 is composed of a large number of drive chains 712, such as an upper drive sprocket 13 and a lower idler block.
It is run by 14. The horizontal stretching machine uses this chain row 1.
1 are arranged in two rows in the left-right direction, and the intervals between the chain rows are widened, for example, at the top. The film enters from below and is clipped by a tenter clip (not shown) fixed above the drive chain 712, and then stretched in the transverse direction as it moves upward.

Next, an example of a tenter clip will be described with reference to FIGS. 3 and 4. In FIG. 3, the driving chain 721 mainly includes a chain box 22, a link plate 23, a roller 24, a connecting pin 25, and the like. The two link plates 23 are connected by a bushing 26 fixed thereto, and the vertical connecting pin 25 fixed to the chain pox 22 is inserted into the bush 26 to form a fitting part, so that the chain pox 22 and link plate 23 are connected to form an endless chain. The connecting pin 25 supports the roller 24 via a bush 26 in the middle.

In addition, in FIG. 3, the upper link plate 23 has a fourth
As shown in the figure, a substantially semicircular hole 27 for lubricating oil is formed on the outer periphery of the bushing 26, and both of the two sleeve holes 27 are located in the oil groove 27A.

The tenter clip body 2 is attached to the top surface of the chain box 22.
8 is fixed by a bolt (not shown), and a lip blade 31 is attached to this which can be freely rotated around a pin 30 by a lever 29.
1 is in the position shown, clips a film (not shown) between it and the clip body 28. The A guide rail 36 fixed to the frame 35 and the B guide rail 37 fixed thereto have roller pins 3 fixed to the chain pox 22.
The driving chain 721 is guided in its travel by contact with guide rollers 39 to 41 rotatably supported vertically on the clip body 8 and guide rollers 42 and 43 rotatably supported on the clip body 28.

A mounting member 45 is fixed to the A guide rail 36, and a nozzle 46 with an inner diameter of about 0.5 mm is attached to the mounting member 45. A drive check 721 is connected to the drive chain 721 through which lubricating oil under pressure flows from the nozzle 46. It is ejected in the form of a thread onto the surface of the upper link plate 23 (in FIG. 3) at the position shown as the shaded area in FIG. At this time, since the lubricating oil is viscous, it does not scatter, but rather the thread-like lubricating oil adheres to the link plate 23 as if being pulled. The lubricating oil that has adhered to the thread-like or band-like surface of the link plate 23 in this way is transferred to the sprocket 1 by the drive chain 721.
When passing through the third class (see Figure 5), the link plate 23 receives centrifugal force and moves along the upper surface of the link plate 23 to its center, reaching the connecting pin 25 and lubricating the connecting pin 25 and bush 26. On the other hand, the lubricating oil flowing into the oil groove 27A also reaches the connecting bottle 25 through the sleeve hole 27 and the sleeve hole (not shown) of the bushing 26.

[Prior Art] As shown in Fig. 2, conventional connecting bottles are made by hardening 545C steel to a hardness of about 45° HRC.
The outer periphery forming the fitting part with the bush 26 (see Figure 3) was polished. Note that the hole on the left is a hole for a pin for fixing this connecting bottle to the link plate 23.

However, the drive chain for the tenter clip used in the horizontal stretching machine generates a chain tension of 500 to 1000 kg, and a high surface pressure is applied to the friction surface of the coupling bottle that makes up the bush and the fitting part, and lubricating oil is applied to the entire friction surface. It was difficult for oil to penetrate and form an oil film. As a result, the parts of the friction surface where the surface pressure was particularly high caused fretting corosion accompanied by "galling" and the formation of red rust, which stopped the wear of the connecting bottle. In particular, new connected bottles have a rough surface roughness of about 2 to 45 and are "scorched".
It was easy to wake up.

In addition, if the lubricating oil has poor permeability, it is difficult to exchange old and new oil, and the old lubricating oil remains stagnant, causing carbonization and loss of lubrication function while driving under high-temperature hot wind. Furthermore, synthetic high-temperature oils are used as lubricating oils, but strong extreme pressure additives are restricted so as not to affect products such as films and sheets. The load capacity was relatively low, which was a factor in reducing wear. In recent years, as the running speed of the drive chain 7 has increased to more than 250 m/min, the life of the connecting bottle has been significantly reduced due to wear, and it has been desired to improve this problem.

[Object of the Invention] The present invention has been made from this viewpoint, and its object is to provide a tenter that improves the permeability of lubricating oil to the fitting part between the bushing and the connecting bottle, and prevents abnormal wear due to lack of oil film. An object of the present invention is to provide a connecting bin for a drive chain for a clip.

[Summary of the Invention] The connecting bottle of the drive chain for tenter clips of the present invention has a plurality of oil grooves or grooves formed on the surface of the connecting bottle that constitutes the fitting part with the bushing, and has been subjected to surface hardening heat treatment or It is characterized by being coated with a dry coat of solid lubricant after sub-quenching.

[Embodiment of the Invention] Hereinafter, FIG. 1 showing an embodiment of the present invention will be described. The connecting pin 51 that constitutes the fitting part with the bush 26 (see Fig. 3) is made of SACM645 steel, for example, and has a groove depth of about 0.15 mm in the middle part and a groove pitch of about 1.5 mm. Oil groove or groove 52 with a corner of about 30'
A plurality of are provided, and the diameter after rotation is about 18 mm. And after rotation, MO32 (molybdenum disulfide)
etc. as a solid lubricant for dry neat coating.

Note that 53 is a pin hole for fixing the connecting pin 51 to the link plate 23 (see FIG. 3).

The above-mentioned method of manufacturing the connecting pin 51 is as follows: First, after the outer diameter is processed, oil grooves etc. are formed by knurling using a thread rolling machine or lathe.
After that, the outer diameter is rotated after surface hardening heat treatment by gas nitriding or sub-quenching. After degreasing, chemical conversion coating treatment, dry explosion, dry coat coating such as MOS2, etc. Heat and harden.

[Effects of the Invention] As explained above, the connecting pin of the drive chain for tenter clips of the present invention has a plurality of oil grooves formed on the outer periphery of the connecting bottle and is subjected to surface heat hardening treatment to increase hardness. Dry coated with solid lubricant. As a result, the lubricating oil permeated the entire friction surface of the connecting pin, improving wear resistance. In particular, the occurrence of "galling" during initial wear has been reduced, and the break-in period has been significantly shortened. In addition, the ease of replacing old and new oil has been improved, and there is almost no carbon sludge, and even if the lubricating oil film breaks down, the lubricating action of the solid lubricant prevents abnormalities such as galling. The wear condition at a chain running speed of 350 m/min and a running time of 1000 hours was investigated. The results are as follows, showing that the performance improved.

[Brief explanation of the drawing]

FIG. 1 is a side view of an embodiment of the present invention, FIG. 2 is a side view of a conventional example, FIGS. 3 and 4 are examples of tenter clips, and FIG. 3 is a partially sectional side view. Figure i4 is a plan view of the chain pox and link plate, and Figure 5 is a schematic plan view of one chain row. 26... Bush, 51... Connecting bottle, 52...
Oil groove or groove.

Claims (1)

[Claims] The connecting pin that constitutes the fitting part with the bush has a plurality of oil grooves or grooves formed on its surface, and is characterized by being dry-coated with a solid lubricant after being subjected to surface hardening heat treatment or deep hardening. Connecting pin for drive chain for tenter clip.