JPH0430339B2 - - Google Patents

Description

[Detailed description of the invention] TECHNICAL FIELD This invention relates to tire forming drums.

Generally, a tire forming drum has various constituent members attached to its outer periphery, and is configured so that its diameter can be expanded or contracted in order to pull out these constituent members.The mechanism for such expansion/contraction is as follows: For example, Special Publication No. 55-31734 or Special Publication No. 51-
One disclosed in Publication No. 19871 is known.

The former (Japanese Patent Publication No. 55-31734) supplies compressed air to two air chambers in a cylindrical ring that is slidably provided along the main axis of a tire forming drum (hereinafter simply referred to as drum). By discharging the drum, the cylindrical ring slides and the drum is expanded and contracted via a link mechanism provided between the cylindrical ring and the drum. Since the settings cannot be made accurately, there is a problem in that it is not possible to meet the demand for an increase in the number of steps for setting the drum outer diameter such as stitching diameter, pasting diameter, pull-out diameter, etc. due to the recent increase in the number of tire component parts.

The latter (Japanese Patent Publication No. 51-19871) has a double structure for the main shaft of the drum, consisting of an outer shaft and a central shaft that is slidable at the center of the drum. The drum is expanded and contracted via a link mechanism installed between the drum, but the structure is complex and the center shaft is driven by a drive mechanism installed outside the drum, making it difficult to replace the drum. The problem is that each drum needs to be reset each time, which increases cycle time and reduces efficiency.

This invention was made in view of these conventional problems, and aims to provide an efficient tire forming drum that has a simple structure, a large number of outer diameter setting stages, and has the following characteristics: However,
A cylindrical ring that circumscribes the main shaft coaxially and slidably in the axial direction; a disk-shaped partition plate that is fixed to the main shaft and slides on the inner peripheral surface of the cylindrical ring to define a secret chamber within the cylindrical ring; one or more pistons between the main shaft and the inner peripheral surface of the cylindrical ring and/or the main shaft so as to be able to move in the axial direction and define an airtight chamber within the cylindrical ring; A complex stopper that restricts the movement of the cylindrical ring and the piston through a series of connecting members, and a drum that is arranged concentrically surrounding the outer periphery of the cylindrical ring and that is divided into multiple parts in the circumferential direction and whose diameter can be expanded and contracted. a motion conversion mechanism interposed between the main body, the cylindrical ring and the drum main body, which converts the axial movement of the cylindrical ring into a radial movement and transmits the radial movement to the drum main body, thereby expanding and contracting the diameter of the drum main body; A tire forming drum includes a pressure fluid supply mechanism that gradually expands and contracts the diameter of a drum body by individually supplying pressure fluid to airtight chambers and moving a cylindrical ring in predetermined strokes.

The present invention will be explained below based on the drawings. FIG. 1 is a front cross-sectional view showing an embodiment of a tire forming drum according to the present invention, with the upper half showing the state at maximum expansion and the lower half showing the state at maximum contraction. 1
1 is a main shaft of a rotatable tire building drum having a base end 1a supported in a cantilever manner by a bearing means (not shown), and has a large diameter part 1b and a small diameter part 1c. Reference numeral 2 denotes a disk-shaped partition plate fixed to the step between the large diameter portion 1b and the small diameter portion 1c of the main shaft 1, and having an outer diameter larger than that of the large diameter portion 1b. 3 is provided concentrically with the main shaft 1 and the partition plate 2, and has a closed end 3a at one axial end in sliding contact with the large diameter portion 1b of the main shaft 1, and an inner peripheral surface 3c in sliding contact with the outer peripheral surface 2a of the partition plate 2, It is a cylindrical ring that can slide in the direction of the axis O of the main shaft 1. One end of a plurality of arms 4 extending parallel to the main shaft 1 is fixed to the open end 3b of the cylindrical ring 3, and a stopper 6 is fixed to the other end of the arm 4 via a stopper holder 5. . As the cylindrical ring 3 moves, this stopper 6 comes into contact with a stopper holder of another stopper, which will be described later.
It has a function of defining the movement range of the cylindrical ring 3 in the direction of the main shaft base end 1a (rightward in the figure). A
is an airtight chamber formed by the cylindrical ring 3, the partition plate 2, and the large diameter portion 1b of the main shaft 1. 7,8
are disc-shaped guide members fixed to the base end and the distal end of the main shaft 1, respectively, and surfaces 7a and 8a facing each other are flat and constitute guide surfaces perpendicular to the axis O of the main shaft 1. Reference numeral 9 denotes a cylindrical drum body disposed concentrically surrounding the outer periphery of the cylindrical ring 3. This drum body 9 is equally divided in the circumferential direction, and each divided piece 9a has sliding surfaces 9b, 9b provided at both ends in the axial direction, and radially extends along the guide surfaces 7a, 8a of the guide members 7, 8. By sliding in synchronization with the direction, the diameter of the entire drum body 9 is expanded or contracted. The inner peripheral surface of each divided piece 9a is provided with inclined surfaces 10 and 11 that approach the axis O as it goes from the distal end side to the proximal end side of the main shaft 1. Guide members 13a and 13b for linear movement are attached. 14 is formed on the outer peripheral surface of the cylindrical ring 3, and the inclined surface 10 of each divided piece 9a of the drum body 9,
It is a conical protrusion having an inclined surface 15 parallel to 11. On the inclined surface 15 of this protrusion 14, the same number of linear movement guide slide tips 16 as the drum body divided pieces 9a are fixed at equal intervals, and each slide tip 16 is fixed to the corresponding divided piece 9a.
It is slidably fitted into the guide rail of the guide member 13b of a. A slider 17 is fixed to the closed end 3a of the cylindrical ring 3 via a sleeve 18, and is slidable along the main shaft 1 at one end of the cylindrical ring 3. The outer circumferential surface 17a of the slider 17 is formed parallel to the inclined surfaces 10 and 11 of each divided piece 9a of the drum body 9, and the same number of slide chips 19 as the divided pieces 9a are arranged at equal intervals on this outer circumferential surface 17a. Fixed. Each slide tip 19 has a guide member 13a on the inclined surface 10 of the corresponding divided piece 9a.
It is slidably fitted into the guide rail of. the inclined surfaces 10 and 11, the guide members 13a and 13b,
The protrusion 14 on the outer peripheral surface of the cylindrical ring 3, the slide tips 16, 19, and the slider 17 are combined to convert the movement of the cylindrical ring 3 in the direction of the axis O into a radial movement and transmit it to the drum body 9. It constitutes a motion conversion mechanism 20 that expands or contracts the diameter of the main body 9. 21 has a large diameter part 21a and a small diameter part 21b, and is in sliding contact with the main shaft 1 on the inner peripheral surface, and also has a large diameter part 21a and a small diameter part 21b.
The first piston is in sliding contact with the inner circumferential surface 3c of the cylindrical ring 3 on the outer circumferential surface of 1a, and is slidable in the direction of the axis O. A concave portion 2 is formed in the end surface 21c of the large diameter portion 21a of the first piston 21 that can come into contact with the partition plate 2.
2 is formed, and this recess 22 is the partition plate 2.
Together with the small diameter portion 1c of the main shaft 1 and the cylindrical ring 3, an airtight chamber B is formed. One end of an arm 23 is fixed to the tip of the small diameter portion 21b of the first piston 21. This arm 23 is slidably fitted into a groove 24 formed at the tip of the main shaft 1 in the direction of the axis O, and a stopper 26 is fixed to the other end of the arm 23 via a stopper holder 25. . This stopper 26 has the function of coming into contact with the distal end surface 1d of the main shaft 1 as the first piston 21 moves, and defining the range of movement of the first piston 21 in the direction of the main shaft base end 1a. 27 has a large diameter part 27a and a small diameter part 27b like the first piston 21, and has an inner circumferential surface in sliding contact with the small diameter part 21b of the first piston 21, and an outer circumferential surface of the large diameter part 27a in contact with the inner diameter of the cylindrical ring 3. This is a second piston that is in sliding contact with the circumferential surface 3c and is slidable in the direction of the axis O. This second piston 27
The large diameter portion 27a of the first piston 21
A recess 28 is formed in the end surface 27c that can come into contact with the first piston 1a, and the recess 28 forms an airtight chamber c together with the large diameter part 21a and the small diameter part 21b of the first piston 21 and the cylindrical ring 3. . At the tip of the small diameter portion 27b of the second piston 27, an axial groove (not shown) is formed in the main shaft 1 with a predetermined angular phase shift in the circumferential direction from the groove 24 into which the arm 23 of the first piston 21 is fitted. ) is fixed at one end of the arm 29 which is slidably fitted into the arm 2.
A stopper 31 is fixed to the other end of 9 via a stopper holder 30. The arm 4 and the stopper holder 5, the arm 23 and the stopper holder 25, the arm 29 and the stopper holder 30 are collectively referred to as a connecting member. This stopper 31 is the second piston 27
The first piston 21 and the second piston 27 have the function of coming into contact with the stopper holder 25 as the first piston 21 and the second piston 27 move, thereby defining the movement range of the second piston 27 in the direction of the main shaft base end 1a. The range of movement in the direction of the tip of the main shaft is such that the tips of the small diameter portions 21b, 27b of both pistons 21, 27 are
It is defined by contacting the A cover plate 32 is fixed to the open end 3b of the cylindrical ring 3 to seal it, and is in sliding contact with the small diameter portion 27b of the second piston 27. A recess 33 is formed in an end surface 32a of the cover plate 32 that can come into contact with the large diameter portion 27a of the second piston 27.
Large diameter portion 27a and small diameter portion 27 of piston 27
b, further forms an airtight chamber D together with the cylindrical ring 3. Further, this cover plate 32 is connected to the second piston 27.
It has a function as a stopper that defines the range of movement of the cylindrical ring 3 in the direction of the main shaft base end 1a by coming into contact with it. The range of movement of the cylindrical ring 3 toward the tip of the main shaft is defined by the closed end 3a of the cylindrical ring 3 coming into contact with the partition plate 2. Each of the airtight chambers A, B, C, and D is connected to a pressure fluid source (not shown) through separate hoses (not shown) each having a switching valve in the middle, and is supplied with pressure fluid individually. It is becoming more and more excreted. These hoses, switching valves, and pressure fluid sources are combined to constitute a pressure fluid supply mechanism.

Next, the operation will be explained based on FIGS. 2 to 4.
Now, the pressure fluid is discharged from the airtight chamber A, and the airtight chamber B,
Pressure fluid is supplied to C and D, and the cylindrical ring 3 is in the state where it has reached the stroke end on the tip side of the main shaft 1, that is, in the first stage where the diameter of the drum body 9 of the tire forming drum is the smallest. State (first
(state shown in the lower half of the figure). In this state, first, the pressure fluid in the airtight chamber D is discharged by the pressure fluid supply mechanism, and the pressure fluid in the airtight chamber A is discharged.
When pressure fluid is supplied to the cylindrical ring 3, as shown in FIG. 2, the cylindrical ring 3 slides toward the base end of the main shaft 1 by a predetermined stroke, and the stopper 6 comes into contact with the stopper holder 30 of the second piston 27 and stops. do. Even if the stopper 6 of the cylindrical ring 3 comes into contact with the second piston 27, the second piston 27 does not move because the airtight chambers B and C are filled with pressure fluid. This cylindrical ring 3
Due to the wedge action of the slide tips 16 and 19 that slide within the guide rails of the guide members 13a and 13b of each divided piece 9a of the drum body 9, each divided piece 9a is moved between the guide members 7 and 8. Guide surface 7
a, 8a radially outward by a predetermined distance corresponding to the sliding distance of the cylindrical ring 3 synchronously. As a result, the entire drum body 9 is divided into each divided piece 9a.
The outer diameter increases by twice the sliding distance in the direction perpendicular to the axis. This is the second stage state. Next, when the pressure fluid in the airtight chamber C is discharged and further pressure fluid is supplied to the airtight chamber A, as shown in FIG. It further slides toward the side by a predetermined stroke, and the stopper 6 of the cylindrical ring 3 comes into contact with the stopper holder 25 of the first piston 21 via the stopper 31 of the second piston 27 and the stopper holder 30, and stops. Stopper 31 of this second piston 27
Even if they come into contact with each other, the first piston 21 does not move because the airtight chamber B is filled with pressure fluid. With the further sliding of this cylindrical ring 3,
The outer diameter of the entire drum body 9 is further expanded by a predetermined dimension. This is the third stage state. Next, the pressure fluid in the airtight chamber B is discharged, and the pressure fluid is supplied to the airtight chambers C and A. By that,
The first piston 21 slides toward the spindle base end 1a side until the stopper 26 comes into contact with the tip end surface 1d of the spindle 1, and the cylindrical ring 3 further moves toward the spindle base end 1a side by a predetermined distance while pressing the second piston 27. The stroke slides and stops. As a result, the outer diameter of the entire drum body 9 is further enlarged by a predetermined dimension. This state is the fourth
This is the fourth stage state shown in the figure. Next, airtight room B
When the pressure fluid is discharged and the pressure fluid is supplied to the airtight chamber A, the cylindrical ring 3 slides a predetermined stroke toward the main shaft base end 1a side while pressing the second piston 27, and the second piston 27 stoppa 3
1 comes into contact with the stopper holder 25 of the first piston 21, thereby reaching the stroke end on the main shaft base end 1a side and stopping. As a result, the drum body 9 is in the fifth stage state, which is the most enlarged state. This state is shown in the upper half of FIG. As described above, by individually supplying and discharging pressure fluid to the airtight chambers A, B, C, and D, the diameter of the drum body 9 can be reduced from the first stage (the most reduced state) to the fifth stage (the most reduced state). It is possible to scale to any state up to the most enlarged state. In addition, the drum body 9
The number of expansion/contraction stages can be adjusted by increasing or decreasing the number of pistons. That is, since the airtight chambers are formed on both sides of the first and second pistons 21 and 27 and on both sides of the partition plate 2, the number of airtight chambers is (number of pistons + 2), and the number of diameter expansion/contraction stages of the drum body 9 is (pistons). number + 3). In the embodiment described above, the number of pistons is the first piston 21 and the second piston 21.
Since there are two pistons 27, the airtight chamber is 2+2.
= 4 chambers (A, B, C, D), and the number of expansion/contraction stages is 2+3=5 stages. In addition, the outer diameter dimension of the drum body 9 at each stage is determined by the stroke of the cylindrical ring 3 between each stage, in other words, the mounting position of the stoppers 6, 26, 31 on the arms 4, 23, 29, and the inclined surfaces 10, 11, It can be adjusted by appropriately setting the angles of 15 and 17a.

As explained above, according to this invention,
The outer diameter of the drum body of the tire-forming drum can be set in multiple stages, making it easy to adapt to the stitching diameter, pasting diameter, pulling diameter, etc. of multiple types of tires of different sizes. Compared to a tire-building drum equipped with a tire-building drum, it is possible to provide a tire-building drum with a simpler structure, shorter cycle time, and higher efficiency.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the tire forming drum according to the present invention, in which the upper half is a front sectional view showing the drum body when it is at its maximum expansion, and the lower half is a front sectional view showing the drum body when it is at its maximum contraction. , FIGS. 2 to 4 are front sectional views showing the main parts of the tire forming drum shown in FIG. 1 in different expansion and contraction states. DESCRIPTION OF SYMBOLS 1... Main shaft of tire forming drum, 2... Partition plate, 3... Cylindrical ring, 9... Drum body, 20
...Movement conversion mechanism, 21...First piston, 27
...Second piston, A, B, C, D...airtight chamber.

Claims (1)

[Claims] 1. A cylindrical ring that circumscribes the main shaft coaxially and slidably in the axial direction, a disk-shaped partition plate that is fixed to the main shaft and slides on the inner peripheral surface of the cylindrical ring to define an airtight chamber within the cylindrical ring, and the cylindrical ring. and the main shaft, one or more pistons that are in axially movable sliding contact with the inner circumferential surface of the cylindrical ring and/or the main shaft and define an airtight chamber within the cylindrical ring, and each of the cylindrical ring and the piston. a plurality of stoppers that restrict the movement of the cylindrical ring and the piston through connecting members connected to the cylindrical ring; a motion conversion mechanism that is interposed between the drum body, the cylindrical ring, and the drum body, converts the axial movement of the cylindrical ring into radial movement, transmits the radial movement to the drum body, and expands and contracts the diameter of the drum body; A tire characterized by comprising: a pressure fluid supply mechanism that gradually expands and contracts the diameter of the drum body by supplying pressure fluid to each airtight chamber individually and moving the cylindrical ring in predetermined strokes. molded drum.