JPS6347053A - Grinding method for multi-groove belt - Google Patents

Abstract

PURPOSE:To enable cutting grooves quickly on a cylindrical element and eliminate a drop in configuration precision by finding the shrinkage factor of the element after cutting multi-grooves and forming the multi grooves by the use of a grinding stone for cutting the multi-grooves with predetermined groove intervals enlarged depending upon said shrinkage factor. CONSTITUTION:Shrinkage appearing when many V-grooves are processed and formed on a cylindrical element 1 for forming a multi-groove belt, depends upon the types and the arrangement directions of fiber embedded in the boundary wall of the element 1, an elastomer material forming the element and the like. So far as the same material is used, a shrinkage factor falls within an approximately constant range. Also, the fiber, the elastomer material and the like once set, rarely undergo a change and the shrinkage factor of the element 1 is approximately constant in a practical sense. Also, the shrinkage of the element 1 occurs uniformly over the entire length thereof. In this respect, the sectional form of grooves to be formed and the intervals thereof are enlarged and set on the element 1 with due consideration of said shrinkage factor, and the grooves are cut according to the intervals so set. Consequently, predetermined intervals and groove shape are obtained after the cutting work.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for grinding a multi-thread belt.
This invention relates to a method for grinding a multi-thread belt with accurate groove pinch spacing.

[Conventional technology]

As a small high horsepower power transmission belt, 3
~Multi-striped belt (poly V) consisting of four parallel V-shaped grooves
(sometimes referred to as a belt) is well known.

This multi-thread belt has a transmission efficiency equivalent to that of a large number of belts wound in parallel, and is therefore preferably used as a small-sized, high-power transmission belt as described above.

By the way, when molding the above-mentioned multi-thread belt, a cylindrical mold with a long axial length from which a large number of multi-thread belts can be cut is embedded with the necessary reinforcing core and molded with an elastomer material, and the outer surface of this cylindrical mold is In this method, a method is adopted in which a large number of V-grooves are simultaneously ground and formed at a constant pitch interval in parallel, and then this cylindrical mold is cut into a ring shape for each predetermined number of grooves, and the inner and outer surfaces of this ring-shaped cut body are inverted. Therefore, it is generally used as a multi-thread belt.

However, when grinding a large number of V-grooves on the outer surface of the cylindrical blank as described above, the cylindrical blank contracts in the axial direction due to the grinding, resulting in a phenomenon in which the groove pinch interval of the multi-filament heald becomes inaccurate.

The reason for this is that shrinkage-preventing fibers are embedded mainly in the axial direction within the peripheral wall thickness of the cylindrical mold, but these fibers are cut during V-groove grinding, which causes the shrinkage-preventing effect to disappear. This is thought to be due to the contraction force originally possessed by the cylindrical vibration being exerted.

In order to solve this problem, conventionally when grinding a cylindrical machine, as shown in Figure 5, finishing is done in the grinding process of rough finishing (indicated by the chain line in the figure) and finishing (indicated by the solid line in the figure). Increase the cutting allowance during grinding (Δd in the diagram)
This prevents errors caused by intermediate shrinkage (in the direction of arrow X).

[Problems with conventional technology]

However, in the above method, the grinding amount for finish grinding inevitably increases, so the grinding process takes a lot of time, making it impossible to improve manufacturing efficiency, and since the grinding allowance is large, material is wasted accordingly. Furthermore, the grinding process takes longer, making it easier for the grinding wheel to become clogged.
At the same time, there were various problems such as the generation of frictional heat during grinding, which could lead to deterioration in the quality of the heald.

[Problems solved by the invention]

The present invention has been made in view of the above-mentioned problems, with the object of providing a method for grinding a multi-threaded belt that can quickly grind grooves on a cylindrical vibration belt and that does not reduce shape accuracy due to shrinkage.

[Technology to solve problems]

That is, in the method of grinding a multi-striped heald according to the present invention, the shrinkage rate of the cylindrical vibration after multi-slot grinding is obtained, and the predetermined groove spacing is expanded according to the shrinkage rate to obtain the groove spacing. This method is characterized by forming multi-groove grooves using a multi-groove grinding wheel.

[Effect]

In this invention, a conventionally known means is employed as the means for manufacturing the multi-thread belt itself.

The shrinkage that occurs when a large number of VLs are ground and formed on a cylindrical material for forming a multi-filament heddle varies depending on the type of fibers embedded in the peripheral wall of the cylindrical material, the arrangement direction, the elastomer material used to form the cylindrical material, etc. Different, but under the same materials used,
The shrinkage rate falls within a nearly constant range.

Furthermore, with regard to fibers, elastomer materials, etc., once set at -, there is almost no change, so in practice, the above-mentioned shrinkage rate of cylindrical vibration is almost constant.

On the other hand, contraction in cylindrical vibration occurs uniformly over the entire length.

Therefore, taking the above-mentioned shrinkage rate into consideration, the cross-sectional shape of the groove to be ground in a cylindrical pattern and the groove interval are set to be enlarged, and the groove is ground at the dimensional interval.

That is, for example, if the shrinkage rate of the cylindrical vibration after multi-groove molding is 0.
If it is 7%, the interval of grinding blades for multi-groove forming is
The shape is enlarged by 0.7%, and multiple grooves are formed by grinding with this grinding blade.

Therefore, after grinding, the cylindrical vibration contracts, resulting in a predetermined groove spacing and shape.

〔Example〕

Next, the present invention will be explained in detail.

FIG. 1 is a side view of a grinding device used to carry out the method of the invention.

As a cylindrical swing for multi-thread healds for automobile auxiliary equipment, length 30
01. Molding an elastomer cylindrical mold 1 with a thickness of 6 fl, in which fibers are embedded in a row in the heald width direction in a cushion rubber member that will serve as a multi-groove ground surface, and this is wound between pulleys IA and 18. The number of grooves to be rotated and ground at the same time is 75,
A multi-slot groove was ground and formed using the grinding wheel 2 with a pinch interval of 3.56 mm, and the amount of contraction of the cylindrical vibration at this time was measured to be 0.67 mm and 1.87 mm, and the average amount of contraction was 1.35 inches.
I got +.

Therefore, as the arrangement spacing of the grindstones forming the multi-groove grooves, the above groove spacing is 3.56 tm, and the average shrinkage amount is 1.35 x 1.
/' 15 increments, i.e. 3.56 + 1.35
x 1/75-3.56+0.018 =3.578
(drunk) and used this grindstone to grind the same cylindrical mold surface as above.

As a result, it was confirmed that the difference between the cylinder after shrinkage and the finishing whetstone was 0.52u or less.

In FIG. 1, reference numeral 2 indicates a finishing grindstone, which is used to finish the grooves after grinding with the rough finishing grindstone 2.

Further, each of the grindstones 2.2' is movable in the direction of the arrow, and is constructed so that it can be moved forward or backward as appropriate for each grinding process.

Since cylindrical vibration is made of elastomer material, it is inevitable that the amount of shrinkage will vary depending on the product, but normally the permissible range of the deviation angle of the groove shape (α in Figure 2) of this type of multi-lead belt is , as shown in Fig. 4, α≦2°. Therefore, if the interval between the rough finishing whetstones 2 is set to the above average value, the shape of the ground groove will be the same as the groove of the finishing whetstone and the cylinder after grinding. The deviation of the groove falls within the numerical range of ΔW≦0.811'Ii.

〔effect〕

As explained above, in this invention, grooves are formed at intervals enlarged by an amount that takes into account the shrinkage rate of the cylindrical vibration, and the shape after rough grinding is controlled, so that good groove grinding can be achieved in finish grinding. The time required for grinding is greatly reduced, and
Because the grinding time is shortened, less frictional heat is generated, and deterioration due to heat can be prevented, making the production of this type of belt extremely easy to manage.

[Brief explanation of the drawing]

Fig. 1 is a side view of a grinding device used in carrying out the present invention, Figs. 2, 3, and 4 are explanatory views of the operation of the present invention, and Fig. 5 is an explanatory view of the conventional manufacturing method. . pu2tJ 73m '7'41Z/ 5m 4:=U-χ'

Claims (1)

[Claims] (1) A cylindrical mold for forming a multi-striped belt is molded, V grooves are ground and formed on the outer surface of the cylindrical mold at equal pitch intervals, and then the cylindrical mold is cut into rings at a fixed number of grooves to form the multi-striped belt. In the cutting method, the shrinkage rate of the cylindrical mold after multi-groove grinding is obtained, and a predetermined groove spacing is expanded according to the shrinkage rate using a multi-groove grinding wheel whose groove spacing is obtained. A method for grinding a multi-striped belt characterized by forming multi-striped grooves.