JPH0323841Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a new proposal for a paddy wheel.

Conventionally, paddy wheels used for agricultural machinery such as rice transplanters have been of the type that is integrally molded with a rim 2 embedded in a hard rubber tire body 1, as shown in Figure 1 (cross-sectional view). However, in recent years, pneumatic tires using tubes have been adopted because they are lightweight and have improved cushioning properties.

By the way, such pneumatic tires have the problem of becoming unusable due to puncture accidents, which reduces work efficiency.

The present invention aims to solve the above problems, and its features include a rib partition dividing the inside center of the rubber tire in the vertical direction into two, and a symmetrical annular cavity connected in the circumferential direction via the partition. A rim supported by spokes is embedded and fixed in the annular cavity and the rubber of the inner peripheral surface of the rubber tire.

An example of implementing the present invention will be described below based on the drawings.

FIG. 2 is a partially cutaway front view of the paddy wheel according to the present invention, and FIG. 3 is an enlarged sectional view of the same portion.

As seen in the drawing, the present invention provides a rib partition wall S that bisects the tire body 1 in the longitudinal direction, and creates bilaterally symmetrical annular cavities 3, 3 that continue in the circumferential direction via the partition wall 2. It is a composition.

In other words, a foil core body consisting of a rim supported by bosses and spokes (the circumferential surface that will be bonded to the rubber is pre-adhesive treated), a reinforcing plate, etc. is inserted into the molding molds that are opposed above and below. At the same time, a partially vulcanized compounded rubber as described below is interposed between the foil core (rim outer periphery) and the mold cavity and press vulcanized. At this stage, the vulcanized compounded rubber is prepared by mixing predetermined compounded chemicals in advance, and is formed into a cylindrical shape with a predetermined wall thickness using an extruder, etc., and is then cut into a predetermined length and joined at both ends. For this connection, a rib partition made of the same material is interposed to divide the inside of the cylinder into two, and a foaming agent is filled in each of the two halves of the cavity.

After that, press vulcanization is carried out using a conventionally known method, in which the blowing agent generates decomposed gas at the vulcanization temperature along with heating, and the cavities 3, 3 filled with decomposed gas are secured inside. At the same time, the rubber on the circumferential surface is pressed against the inner wall of the cavity. At this time, a lug is formed on the side surface of the vulcanized rubber, and at the same time, the adhesion to the rim 4 is ensured firmly.

Next, the pressurized state of the mold is released and the product is taken out. However, before taking out the product, the thermal decomposition gas in the tire cavities 3, 3 is removed by inserting, for example, a syringe needle, to bring it to almost normal pressure, and the press pressure is removed. After that, both molds are opened and the product is taken out. By the way, in this case, after the product is cooled, the pressure inside the cavities 3, 3 will be negative, so air will be injected later to bring the insides of the cavities 3, 3 to a normal pressure or a slightly pressurized state. For this purpose, it is convenient to create a navel body on the rubber tire.

Although it is preferable in the present invention to make the insides of the cavities 3, 3 slightly pressurized, it is also possible to maintain atmospheric pressure at all times by drilling a small hole that communicates with the atmosphere from the cavities 3, 3. No problem. Note that the rib partition wall S at the central position is extremely effective in providing strong cushioning properties.

In the above example, the cross section of the rim 4 is circular, but Figs. 4 and 5 show examples in which a deformed shape such as a flat ellipse or an anchor shape is embedded. It is something that can be designed. In addition, in the drawing, 5 is a lug and 6 is a wing plate.

The rubber tire of this invention has a central longitudinal rib partition wall S.
Due to the synergistic effect of this and the internal pressure of the symmetrical cavities 3 and 3 that sandwich it, it is sufficiently supported and does not buckle, and is also lighter and has higher cushioning properties than the conventional solid type. It is durable and has excellent durability.

In addition, there is no possibility of punctures and troubles during operation.

[Brief explanation of the drawing]

Figure 1 is a partial sectional view of a conventional product, Figure 2 is a partially cutaway front view of the paddy wheel of the present invention, Figure 3 is an enlarged sectional view of the same part, and Figures 4 and 5 are of other examples. FIG. 1... Tire body, S... Rib bulkhead, 3... Cavity, 5... Lug.

Claims (1)

[Claims for Utility Model Registration] (1) A rib partition dividing the inside center of the rubber tire in the vertical direction into two, and a symmetrical annular cavity that continues in the circumferential direction via the partition, and that the annular cavity and the rubber tire A rice paddy wheel characterized by a rim supported by spokes embedded and fixed in the rubber material on the inner circumferential surface. (2) A paddy field wheel according to claim 1 of the utility model registration claim, characterized in that reinforcing lugs protruding from the left and right outer surfaces of the rubber tire are formed.