JP2792707B2 - Positioning device for the upper clamp of the bladder in the central mechanism of the tire vulcanizer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for positioning a bladder upper clamp portion in a center mechanism of a tire vulcanizer.

(Prior Art) In a tire vulcanizer, when vulcanizing and molding a green tire, a hot pressurized medium is supplied into a bladder supported scalably by an upper clamp portion and a lower clamp portion of a central mechanism,
The bladder is in contact with the inner surface of the green tire in the mold to perform vulcanization molding.

This central mechanism bladder is a consumable item, usually 7-10
If you use it for about a day, you need to replace it. Also, when changing the size of the tire to be molded, it is necessary to replace the bladder.

Therefore, as a technique for easily and efficiently performing the work at the time of replacement, a center mechanism as disclosed in Japanese Patent Publication No. 1-36409 has been conventionally provided.

(Problems to be Solved by the Invention) In this conventional central mechanism, when a green tire is put in a mold and a hot pressurized medium is put in a bladder and molded, the upper clamp portion is lowered by a central fluid cylinder, Since the upper clamp portion is positioned by being brought into contact with the spacer, it is necessary to manage various spacers and to disassemble the upper clamp portion each time it is replaced.

In other words, the height of the bladder, especially at the time of molding, the height of the bladder differs depending on the tire size / the size of the green tire, and since the molding state greatly affects the uniformity of the tire, its management is very important. is there. However, conventionally, a spacer for regulating the stroke of the upper clamp portion is provided, and the upper clamp portion is brought into contact with the upper end of the spacer to position the upper portion of the bladder.

Therefore, every time the tire size is changed, the spacer must be changed to one having a different length, and it is necessary to manage various spacers, disassemble the upper clamp portion, and the like. For this reason, in recent years, in a situation where the size of the special tire is large, the size of the tire is frequently replaced, and the replacement frequency of the spacer is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and has as its object to enable easy and reliable positioning by electrical processing without using mechanical means such as a spacer.

(Means for Solving the Problems) According to the present invention, an upper clamp portion 3 for clamping an upper portion of a bladder 2 is provided at an upper end of a piston rod 18, and a central hydraulic pressure cylinder 15 is used to move the upper clamp portion 3 through the piston rod 18. In the central mechanism of the tire vulcanizer in which the upper clamp 3 is moved up and down, a detector 19 for detecting the amount of vertical movement of the piston 17 and stopping the upper clamp portion 3 at a predetermined position.
Is provided in the fluid pressure cylinder 15, and the detector 19 includes a detector main body 20 fixed to the lower end of the cylinder main body 16, and the main body 20.
A rod 21 that is inserted into an axial guide hole 23 formed in the piston 17 and the piston rod 18 by extending further,
A magnet 22 provided in the piston 17 in a non-contact state with the rod 21
, And is configured to electrically extract the amount of movement of the piston 17 on the detector body 20 side as a change in the resistance.

(Operation) The fluid pressure cylinder 15 is operated, and the piston rod 18
, The upper clamp portion 3 moves downward. At this time, the detector 19 has detected the amount of movement of the upper clamp unit 3 and when it reaches a predetermined position, the hydraulic cylinder 15
Stop the operation of. Therefore, when the tire size is changed, if the set position is changed accordingly, the upper clamp portion 3 can be easily and reliably positioned at a predetermined position.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the upper part of FIG. 1, the left half and the right half have different tire sizes and operating states, respectively.

In FIG. 1, 1 is a green tire, 2 is a molding bladder, and is supported by an upper clamp portion 3 and a lower clamp portion 4 so as to be detachable and expandable. 5 is a mold,
It comprises an upper die 6, an upper bead die 7, a lower die 8, a lower bead die 9, and the like. The upper mold 6 and the upper bead mold 7 are provided on an upper platen (not shown) provided to be vertically movable, and the lower mold 8 is provided on a lower platen 10.
Each is attached to. Reference numeral 11 denotes a guide cylinder, and this guide cylinder 11 is attached to the lower platen 10. Numeral 12 denotes an elevating cylinder, which is fitted inside the guide cylinder 11 so as to be vertically movable, and a lower bead die 9 is detachably screwed to an upper end portion. The elevating cylinder 12 is vertically movably supported by a fluid pressure cylinder (not shown). This lifting cylinder 12
A support ring 13 for supporting the lower clamp portion 4 is internally fitted therein so as to be vertically movable. The support ring 13 is vertically movable within the elevating cylinder 12 by a hydraulic cylinder (not shown), and a hydraulic cylinder 15 is attached to the center of the lower surface of the support ring 13 via a support cylinder 14. The fluid pressure cylinder 15 is for moving the upper clamp portion 3 up and down, and includes a cylinder body 16, a piston 17 and a piston rod 18. The cylinder body 16 is fixed to the lower end of the support cylinder 14, and the piston rod 18 is attached to the support cylinder 14,
The upper clamp part 3 is detachably attached to the upper end of the piston rod 18 by bolts or the like so as to protrude above the lower clamp part 4 through the support ring 13 and the like. Reference numeral 19 denotes a detector for detecting the amount of vertical movement of the piston rod 18, for example, a linear transducer is used. As shown in FIG. 2, the detector 19 includes a main body 20, a fixed rod 21, and a magnet 22. The main body 20 is fixed to a lower end of the cylinder main body 16, and the fixed rod 21 is fixed to the main body 20. At the same time, the piston 17 is slidably inserted into a guide hole 23 formed at the center of the piston 17 and the piston rod 18, and the magnet 22 is embedded in the piston 17 concentrically with the fixed rod 21. The detector 19 electrically changes the moving distance of the magnet 22 on the fixed rod 21, that is, the moving amount of the piston 17 and the piston rod 18 as a change in the resistance of the detector body 20. Has become.

The detector 19 is connected to a comparator 25 together with a position setting device 24 as shown in FIG. When the tire size is changed, the position setting device 24 is moved to the upper clamp portion 3 according to the size.
Is set electrically. Comparator 25
Is for comparing the set position with the detected position, and providing a stop signal to the control valve 26 of the fluid pressure cylinder 15 when they match.

Next, the operation will be described. At the time of vulcanization molding, the green tire 1 is first placed on the lower mold 8 and then the fluid pressure cylinder 15
Is moved in the contraction direction to move the piston rod 18 upward, thereby lowering the upper clamp portion 3.
At this time, since the piston 17 moves downward, the fixed rod
The position of the magnet 22 with respect to 21 is lowered, and an electric signal corresponding to the amount of movement is output from the main body 20 side of the detector 19.
Therefore, if the position of the upper clamp unit 3 is set in advance by the setting unit 24, the detection position detected by the detector 19 and the setting unit
The comparator 25 compares the set value with the setting value 24, and when they match, the comparator 25 outputs a stop signal. Therefore, the control valve 26 returns to neutral, and the fluid pressure cylinder 15 stops the contraction operation. As a result, the upper clamp portion 3 automatically stops at a predetermined position. Then, a low-pressure heat-pressure medium is supplied into the bladder 2, and the bladder 2 is abutted on the inner surface of the green tire 1 as shown in the upper right half of FIG. Next, after lowering the upper mold 6 and performing mold clamping, a high-pressure heat-pressure medium is again supplied into the bladder 2 to perform vulcanization molding of the green tire 1.

Since this vulcanization molding is performed with a heat and pressure medium, the detector 19
There is a possibility that abnormalities may be detected due to the occurrence of the steam or the rod 21 being worn or damaged.

Therefore, in the present invention, the detector 19 provided on the fluid pressure cylinder 15 includes a detector main body 20 fixed to the lower end of the cylinder main body 16, and an axial center formed on the piston 17 and the piston rod 18 extending from the main body 20. Rod 21 inserted in the guide hole 23 in the direction, and the piston 17 in a non-contact state with the rod 21.
And a magnet 22 provided therein.
The detector body 20 is configured to electrically extract the amount of movement as a change in the resistance on the detector body 20 side.
Is less likely to be violated by steam or the like, so that direct detection is accurate and more durable, and the magnet 22 and the rod 21
Is in a non-contact state, so that it does not cause abnormality detection due to the occurrence of wear, scratches, etc., and since the magnet 22 only needs to be provided on the piston 17, the cost can be reduced irrespective of the cylinder stroke. is there.

When removing the vulcanized tire after vulcanization molding, the hydraulic cylinder 15 is operated in the extension direction, and the upper clamp portion 3 is pushed upward by the piston rod 18. Then, as shown in the upper left half of FIG. 1, the bladder 2 extends in the vertical direction, and when the support ring 13 is lowered by a hydraulic cylinder (not shown), the lower clamp portion of the bladder supported by the support ring 13 4 and the upper clamp part 3
Since the bladder 2 descends while keeping its shape as shown in the upper left half of FIG. 1, the vulcanized tire on the lower mold 8 can be easily taken out.

When changing the tire size,
Replace the clamp ring of the lower clamp part 4, the bladder 2 and the like with ones suitable for the size. In this case, since the height of the upper part of the bladder also changes, the position is set in advance by the setting device 24. Then, the upper clamp unit 3 is automatically stopped at a predetermined position after the replacement by the fluid pressure cylinder 15. Therefore, it is not necessary to replace the spacer as in the related art, and the upper portion of the bladder can be simply and reliably positioned only by electrical processing.

In the embodiment, a linear transducer is illustrated as the detector 19, but the detector 19 is not limited to this.

(Effects of the Invention) According to the present invention, a detector for detecting the amount of vertical movement of the piston 17 and stopping the upper clamp portion 3 at a predetermined position.
Since the hydraulic cylinder 19 is provided, the upper clamp portion 3 can be easily and reliably positioned by electrical processing as compared with the conventional one using the spacer, and the work efficiency at the time of size change is remarkably improved. In addition, troublesome spacer management and the like become unnecessary.

Further, in the present invention, the displacement (movement amount) of the piston 17 is determined by a magnet.
Since the change in electric resistance is directly detected as the change in electric resistance via the cylinder 22, the magnet 22 need only be provided on the piston 17 so that the cost is reduced irrespective of the cylinder stroke.
Since the rod 22 and the rod 21 are not in contact with each other, they do not cause abnormal detection due to the occurrence of wear, scratches, etc., and the detector 19 is not exposed to steam, etc. It will be excellent in property.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a cutaway side view of the essential parts, and FIG. 3 is a block diagram of the same. DESCRIPTION OF SYMBOLS 1 ... Green tire, 2 ... Bladder, 3 ... Upper clamp part, 4 ... Lower clamp part, 5 ... Mold, 15 ... Fluid pressure cylinder, 17 ... Piston, 18 ... Piston rod, 19 …… Detector, 20 …… Main body, 21 …… Fixed rod, 22
……magnet.

Claims (1)

(57) [Claims] An upper clamp portion (3) for clamping an upper portion of a bladder (2) is provided at an upper end of a piston rod (18),
In the center mechanism of the tire vulcanizer, the upper clamp section (3) is moved up and down by a central fluid pressure cylinder (15) via the piston rod (18), and the vertical movement amount of the piston (17) is detected. The fluid pressure cylinder (15) is provided with a detector (19) for stopping the upper clamp part (3) at a predetermined position, and the detector (19) is fixed to the lower end of the cylinder body (16). A detector body (20) and a rod (21) extending from the body (20) and inserted into an axial guide hole (23) formed in a piston (17) and a piston rod (18). And a magnet (22) provided in the piston (17) in a non-contact state with the rod (21), and a movement amount of the piston (17) is detected by a detector body (20).
A positioning device for an upper clamp portion of a bladder in a center mechanism of a tire vulcanizer, which is configured to electrically take out a change in a resistor on a side thereof.