JPH02229009A - Method of manufacturing cushion rubber crossing gate for vehicle - Google Patents

Abstract

PURPOSE:To enable the cushion rubber of crossing gate for a vehicle to be manufactured, in the nature of being less generated air bubble and having a long life time by making polyurethane into powder or particulate matter previously, and inputting it into a die after mixing with additives, and performing, while heating, degassing and molding, and then vulcanization- reacting it by vulcanization iron pot. CONSTITUTION:A main material is finished by the primary reaction as polyurethane, and in a state of powder or particulate matter. And, it is added and mixed with additives, and then inputted into a die. Since the material shows a thermoplastic property within the die at the heated condition, the air in the particles of the material is degassed completely by repeating the compression and decompression of pressing pressure. After that, it is taken out of the die and given a burring treatment, and besides left in the vulcanization pot for 24 hours for instance, and a manufacture is completed then. Inasmuch as the degassing is conducted sufficiently by repeating compression and decompression, it is noted that the degassing may be sufficient even in the molding for a cushion rubber such as being in a complicated shape having grooves 12 in upper and lower part thereof. Thus, the fatigue failure strength in the repeated compression loads between the end surface 2a of a cylinder and the flange surface 8 of the cylinder shaft is improved, and the life time thereof is prolonged, and, as a result, it may bring about the drop of impact noise and vibration due to the deformation effect of the grooves 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a cushioning rubber for a vehicle circuit breaker such as a unit switch or a high speed circuit breaker.

[Conventional technology]

Figure 4 is a side view of a general unit switch, and Figure 5 is a side view of a typical unit switch.
It is a partial sectional view of the figure.

In these figures, a cushioning rubber 1 made of polyurethane
is attached to the upper end surface 2a of the cylinder 2. The cylinder shaft 3 slides up and down by air pressure from the solenoid valve 4. When the cylinder is turned on, the cylinder shaft 3 slides upward,
Contactor 6 (6a, 6b) makes contact. When released, the solenoid valve 4 is electrically turned off and the air inside the cylinder 2 escapes to the outside, while the cylinder shaft 3 falls downward due to the force of the spring 7, and the flange surface 8 of the cylinder shaft 3 meets the cushioning rubber 1. It has a colliding structure.

Conventionally, a method for manufacturing the cushioning rubber 1 in a circuit breaker having the general structure as described above involves the following steps.

That is, a liquid main raw material and a crosslinking agent are heated, mixed and stirred, and the liquid is injected dropwise into a mold, subjected to secondary vulcanization, and then removed from the mold and subjected to secondary vulcanization in a vulcanization pot. We obtain the buffer GoJ.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, since the (ne(-1) is in liquid form and is poured into the mold, it is possible that some air bubbles may remain inside the buffer gol, even if air is injected and vacuum degassed. For this reason, there was a problem in that the bubbles 5 would collapse due to repeated compressive loads due to the release operation of the position switch, which would cause cracks to develop in the shock absorbers J and 1, resulting in a shortened lifespan. .

An object of the present invention is to provide a method for manufacturing a cushioning rubber for a vehicle circuit breaker, which has a long life and has a long life, with less generation of bubbles during the polyurethane molding process.

[Means to solve the problem]

A method for manufacturing a buffer for a vehicle circuit breaker according to the present invention includes: a cylinder and a cylinder shaft for inserting a contact; a spring for releasing the contact; In a method for manufacturing an annular buffer rubber made of polyurethane that is interposed between the flange surface of a cylinder shaft and the polyurethane, the polyurethane is powdered or granulated in advance, mixed with additives, and then put into a mold. , Pressurization and depressurization are repeated in the mold while heating to defoam and mold, and then the molded object is removed from the mold,
The buffer rubber is obtained by carrying out a force-flow reaction in a vulcanization pot.

[Effect]

Before molding, polyurethane has already undergone a primary reaction as polyurethane, and additives are mixed with the powder or granules before being put into a mold, and pressure is applied and depressurized within the mold while heating. Repeat ~3 times to ensure air bubbles are completely removed. Thereafter, the vulcanization reaction is completed in a vulcanization pot.

[Example J Figure 1 is a half sectional view showing the shape of the Y-shaped rubber based on the manufacturing method of the example, Figure 2 is a plan view of the first time, and the process diagram showing the manufacturing method of the example in the third section. It is.

1 and 2, the annular cushioning rubber 11 is different in that it has grooves 12 (12a, 12b) extending northward and at right angles to each other, but the other features are the same as those in FIGS. 4 and 5. The situation is the same.

FIG. 3 shows the process of manufacturing the product shown in FIG. 1, in which the main raw material is in the form of powder or granules after the primary reaction as polyurethane. Additives are added to this, mixed, and then poured into a mold. Since the material exhibits hot wire plasticity in the mold in a heated state, the air existing between the grains of the raw material is completely degassed by repeating the press pressure 11 and pressure reduction. Thereafter, the product is removed from the mold, subjected to a burr removal process, and left in a vulcanization kettle for 24 hours to complete the product.

According to this manufacturing method, degassing is sufficiently performed by repeating pressurization and depressurization, so as shown in FIGS. 1 and 2.
Even when molding a buffer rubber 11 having a complicated shape, such as having grooves 12 at the bottom, degassing is sufficient. Therefore, the fatigue fracture strength under repeated compressive loads between the end surface 2a of the cylinder and the flange surface 8 of the cylinder shaft is improved, the life is extended, and impact noise due to the deformation of the groove 12 is reduced.
This also leads to a reduction in vibration. With conventional devices that inject liquid materials, when the shape is complex, there is a tendency for the number of bubbles to increase.

〔Effect of the invention〕

The method for producing a buffer rubber for a vehicle circuit breaker according to the present invention includes the steps of: preparing the polyurethane in powder or granular form in advance, mixing it with additives, putting it into a mold, and pressurizing it in the mold while heating it. and depressurization are repeated to degas and mold.
Thereafter, the molded object was taken out of the mold and subjected to a linear flow reaction in a vulcanization pot to obtain the buffer rubber, so that the degassing by repeated pressurization and depressurization in the mold was sufficient. This has the effect that no air bubbles remain in the completed annular cushioning rubber, improving the fatigue fracture strength of the circuit breaker against repeated compressive loads, and extending the life of the circuit breaker. Even in the case of a complicated shape, the air is removed sufficiently, so that impact noise and vibration can be reduced by, for example, providing grooves on both end faces of the cushioning rubber.

4. A detailed explanation of the V-side Figure 1 is a one-sided sectional view showing the shape of the cushioning rubber based on the manufacturing method of the example, Figure 2 is a plan view of Figure 1, and Figure 3 is the manufacturing method of the example. FIG. 4 is a (j14J side view) of a general unit switch, and FIG. 5 is a partial sectional view of FIG. 4.

Claims (1)

[Claims] 1) A circuit breaker consisting of a cylinder and a cylinder shaft for inserting a contact, and a spring for releasing the contact, is interposed between the end face of the cylinder and the flange face of the cylinder shaft, and is made of polyurethane. In the method for manufacturing an annular buffer rubber, the polyurethane is made into powder or granules in advance, mixed with additives, then put into a mold, and repeatedly pressurized and depressurized in the mold while being heated. manufacturing a cushioning rubber for a circuit breaker for a vehicle, characterized in that the molded object is degassed and molded, and then the molded object is taken out from the mold, and subjected to a flow reaction in a vulcanization pot to obtain the cushioning rubber. Method.