JP5196521B2 - Method for controlling expansion / contraction of molding drum and method for manufacturing tire having the expansion / contraction control method - Google Patents

Description

  The present invention relates to a molding drum expansion / contraction control method, and more particularly, to a molding drum expansion / contraction control method for changing the expansion / contraction amount of a molding drum in accordance with a change in inner diameter of a tire constituent member, and a tire manufacturing method including the expansion / contraction control method. .

  In a conventional molding drum, tire constituent members such as an inner liner and a carcass are wound on the outer peripheral surface of the drum, and a carcass band having different dimensions is formed by expanding and contracting the outer diameter of the drum ( Patent Document 1).

In this conventional molding drum, when the molding drum diameter is changed in accordance with the change in the dimensions of the tire constituent members, the diameter (minimum diameter) of the drum when the drum is most contracted is measured, and the measured value is compared with the measured value. Then, using the drum diameter expansion / contraction ratio (drum expansion / reduction amount per motor rotation) calculated at the time of designing the drum, the amount of motor rotation required to reach the target drum diameter (expansion diameter) is set. doing.
Therefore, if there is a difference between the actual drum expansion / contraction ratio of the molding drum in the tire molding apparatus and that at the time of the above design, the expansion / contraction characteristic diagram shown in FIG. 4 (the amount of rotation of the molding drum motor and the drum diameter) As shown in the graph showing the relationship with the amount of enlargement and the relationship based on the design value), the actual enlargement increases as the amount of rotation of the motor increases, that is, as the target diameter of the forming drum increases. The diameter and the calculated enlarged diameter (that is, the set enlarged diameter) deviate from each other.

Actually, since the drum expansion / contraction ratio of the molding drum device is unlikely to be as designed, when a tire is manufactured using a plurality of molding drum devices, the molding drum is added to the tire manufactured by each molding device. A subtle dimensional difference due to the difference in diameter of the tire occurs, and the quality of the product tire varies.
JP 2003-89158 A

  The present invention has been made in view of the above-described problems in the conventional expansion / contraction control of the molding drum of a tire, and the expansion / contraction diameter of the molding drum is always constant regardless of the tire molding apparatus, thereby varying the tire quality. It is to prevent the occurrence of.

The invention according to claim 1 is a control method for controlling expansion / contraction of the diameter of the molding drum around which the tire constituent member is wound by an expansion / contraction driving device, and measuring each of the diameter at the time of reduction and the diameter at the time of expansion of the molding drum. When the ratio of the scaling measuring a rotation amount of the drive source of the drive unit, the diameter difference between the amount of rotation during the time of the scaling of the diameter of the building drum between expansion and contraction of the diameter of the building drum based on the steps of calculating a drum diameter-Chijimihi before SL drive source, it has, according to the computed drum diameter-Chijimihi, characterized by driving and controlling the drive source.
The invention of claim 2 is the scaling method of controlling a building drum according to claim 1, characterized by having a step of storing a drum diameter-contraction ratio before SL drive source.
According to a third aspect of the present invention, in the molding drum expansion / contraction control method according to the first aspect, the diameter at the time of reduction in the step of measuring the diameter at the time of reduction and the diameter at the time of expansion of the molding drum is the minimum diameter. The enlarged diameter is the maximum diameter.
A fourth aspect of the present invention, the scaling method of controlling a building drum according to any of claims 1 to 3, wherein the driving source is characterized by Ru Oh the drive motor.
The invention of claim 5 is a method for producing a tire, characterized by having a scaling control method has been formed drum according to any one of claims 1 to 4.

(Function)
In the present invention, the measurement of the diameter of the molding drum, which has been performed only at the minimum diameter of the conventional molding drum, is also performed at the expanded diameter, preferably the maximum expanded diameter, and from the amount of rotation of the drive source of the expansion / contraction drive device in the meantime, The expansion / contraction ratio of the molding drum (the ratio of the difference in diameter between the reduction and expansion of the molding drum and the amount of rotation ) is obtained, and the drive of the expansion / contraction driving device necessary to obtain a desired expansion diameter based on this ratio The amount of rotation of the source is calculated and set in the control device of the drive source.
The above processing is performed for each tire forming apparatus using the above processing.

According to the present invention, the measured value of the two points of the diameter (reduced diameter) when the molding drum is reduced and the diameter (expanded diameter) when enlarged, and the measured amount of rotation of the drive source between the reduced and enlarged diameters. Because the expansion / contraction ratio of the molding drum is obtained from the value, and the rotation amount of the drive source for each tire molding device is set based on the expansion / contraction ratio, even if there is a difference in the drum expansion / contraction ratio of each molding drum, it does not matter In any molding drum, it is possible to always obtain the same target drum diameter. Further, by adopting the tire manufacturing method having this expansion / contraction control method, the quality of the product tire does not vary.

An embodiment of the molding drum expansion / contraction control method of the present invention will be described.
In the present embodiment, the tire molding apparatus described in Patent Document 1 is used.
That is, FIG. 1 is a view showing a band molding drum, which is an embodiment of a molding drum of a tire molding apparatus, in a cross section along the axis.
A band molding drum according to an embodiment of the present invention includes a hollow fixed shaft 1 and a plurality of segments 2 arranged radially around the fixed shaft 1. The fixed shaft 1 includes an expansion / contraction drive device. As a part, for example, a screw shaft 3 that is rotationally driven by a drive motor such as a servomotor is arranged coaxially.

  Two inclined surfaces 10 that are inclined downward in the figure from both sides of the segment toward the center thereof are formed inside the segment 2. A pair of tapered cones 5 arranged to face each other are screw-engaged with the screw shaft 3, and the tapered surface 6 is in contact with the inclined surface 10 through a linear motion guide 11.

  That is, a female screw member 8 is fixed to the taper cone 5 through a slit 9 provided at intervals in the circumferential direction of the fixed shaft 1, and the female screw member 8 is provided on the screw shaft 3. The lead angles that are spaced apart from each other are screwed into a pair of male screw portions 7 whose directions are opposite to each other.

In the expansion / contraction driving device, when the screw shaft 3 is rotated by the drive motor M (see FIG. 2), the male screw member 7 integrated therewith is rotated, and the tapered cone 5 is moved together with the female screw member 8 screwed into the male screw member 7. Move in the direction of approaching or separating in the axial direction.
When the tapered cone 5 moves, the tapered surface 6 of the tapered cone 5 advances and retracts the segment 2 in the radial direction via the linear motion guide 11 and the inclined surface 10. That is, the diameter of the segment 2 arranged in an annular shape expands and contracts following the displacement of the taper cone 5.
A pair of flange-shaped guide members 4 that guide the segment 2 when the segment 2 expands or contracts are attached to the fixed shaft 1.
As described above, the segment 2 expands / contracts according to the rotation and stop of the screw shaft 3, or stops and is positioned at a required position, and the carcass member and other winding members are placed on the outer peripheral surface of the segment 2 at that position. Wrap.

FIG. 2 is a perspective view of the tire molding apparatus 20 including the band molding drum 21 as viewed obliquely from above.
The tire molding apparatus 20 includes a band molding drum 21, a drive motor M that rotationally drives the band molding drum 21 and the screw shaft 3, and a drive control unit 22 that houses a transmission mechanism and a control unit.

In this embodiment, when molding the winding member of the tire of a different size using the band molding drum 21, expansion / contraction control is performed in order to accurately perform the expansion / contraction of the band molding drum 21.
Next, this enlargement / reduction control will be described.
FIG. 3 shows an expansion / contraction characteristic curve of the band forming drum 21 based on the first expansion / contraction control.
That is, in order to set the diameter of the band forming drum 21 according to the present embodiment, first, the minimum diameter D1 of the drum and the diameter D2 at the time of arbitrary expansion are measured and the difference D (indicated by B in the figure) is obtained. At the same time, the amount of rotation N (indicated by A in the figure) of the drive motor M is actually measured.

From these measured values, the amount of expansion / contraction of the band molding drum 21 in the tire molding apparatus 20 per rotation of the drive motor M, that is, the actual drum diameter expansion / contraction ratio: ΔD,
(Expression) ΔD = (D2−D1) / N (that is, B / A)
Ask for. Here, the diameter D2 at the time of expansion / contraction is arbitrary, but it is desirable to use the value at the time of maximum expansion because accuracy is further improved.
The molding drum expansion / contraction ratio is stored in the storage unit of the control unit of the tire molding apparatus 20. Here, the control unit includes a microcomputer, a ROM that stores a program for molding and the like, and a RAM that is a storage unit that stores the molding drum expansion / contraction ratio and the like, an input unit, a display unit, and the like. It is preferable to comprise.

  By obtaining ΔD in this way, the amount of expansion / contraction required when the carcass band size is changed can be set by the amount of rotation of the drive motor using the drum diameter expansion / contraction ratio calculated from the above-described actual measurement values. Therefore, even if there is a difference in the expansion / contraction ratio of the actual drum diameter between the molding apparatuses, the influence can be eliminated.

That is, when the size of the carcass wound around the molding drum is changed, when the changed size is input to the control unit of the tire molding device 20, the control unit corresponds to the input size of the molding drum. The rotation amount of the drive motor for the molding drum is calculated based on the drum diameter expansion / contraction ratio according to the present embodiment, and the drive motor is controlled to rotate by the rotation amount.
Thus, by calculating and controlling the expansion / contraction amount of the band molding drum 21 for each tire molding device 20, the obtained expansion / contraction amount is always constant regardless of the tire molding device 20.
Therefore, as the amount of rotation of the drive motor increases as in the past, that is, as the molding drum expands in diameter, the diameter of the molding drum, and thus the diameter of the manufactured tire, varies for each tire molding device. Therefore, it is possible to always obtain a tire with no variation in quality.

As described above, in the present embodiment, the screw transmission device that is rotationally driven by the drive motor as the expansion / contraction drive device has been described, but the present invention is not necessarily limited thereto. For example, another well-known drive device such as a gear transmission device or a transmission device using a link mechanism can be used for the expansion / contraction drive device.
In the above description, a drive motor is used as a drive source of the expansion / contraction drive device. However, the drive motor is not limited to an electric motor, and may be a hydraulic motor. Other drive sources such as hydraulic pressure and air pressure are used. A pressure drive source may be used.

It is a figure shown in the cross section which follows the axis line of a band shaping | molding drum. It is a perspective view of the shaping | molding apparatus provided with the band type drum. It is a diagram (enlargement / reduction characteristic diagram) showing the relationship between the rotation amount of the motor of the molding drum and the expansion amount of the drum diameter. It is a diagram (enlargement / reduction characteristic diagram) showing the relationship between the rotation amount of the motor of the conventional molding drum and the expansion amount of the drum diameter, and the relationship based on the design value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fixed axis | shaft, 2 ... Segment, 3 ... Screw shaft, 4 ... Guide member, 5 ... Tapered cone, 6 ... Tapered surface, 7 ... Male screw part, 8 ... -Female screw member, 9 ... slit, 10 ... inclined surface, 11 ... linear motion guide, 20 ... tire molding device, 21 ... band molding drum, 22 ... drive control unit, M ... Drive motors.

Claims (5)

A control method for controlling expansion / contraction of a diameter of a molding drum around which a tire constituent member is wound by an expansion / contraction driving device,
Measuring the diameter at the time of reduction and the diameter at the time of expansion of the molding drum,
Measuring the amount of rotation of the drive source of the expansion / contraction drive device between the reduction and expansion of the diameter of the molding drum;
On the basis of the ratio of the diameter difference between the amount of rotation during expansion and time of reduction of the diameter of the building drum, comprising the steps of: calculating a drum diameter-Chijimihi before Symbol driving source, a,
A molding drum expansion / contraction control method, wherein the drive source is driven and controlled according to the calculated drum diameter expansion / contraction ratio . In the molding drum expansion / contraction control method according to claim 1,
Scaling method of controlling a molding drum, characterized in that it comprises a step of storing a drum diameter-contraction ratio before SL drive source. In the molding drum expansion / contraction control method according to claim 1,
A molding drum expansion / contraction control method characterized in that the diameter at the time of reduction in the step of measuring the diameter at the time of reduction and the diameter at the time of expansion of the molding drum is the minimum diameter, and the diameter at the time of expansion is the maximum diameter. In the molding drum expansion / contraction control method according to any one of claims 1 to 3,
Scaling control method of the molding drum the driving source, wherein the Ru Oh the drive motor. Method of manufacturing a tire characterized by having a scaling control method has been formed drum according to any one of claims 1 to 4.

Images