JPH07174653A - Vehicle provided with internal-pressure alarm device - Google Patents

Abstract

PURPOSE:To perform a detection with high accuracy and to increase the reliability of the alarm of an internal pressure by detecting a reduction in the internal pressure on the basis of an increase in the number of revolutions due to a reduction in the circumferential length of a tire and producing a breaker from a cord which is rich in elasticity. CONSTITUTION:In a radial tire 5, a breaker 3 which reinforces a carcass 1 at the inside of a tread 2 is made from a cord 4 which is rich is elastisity. A number-of- revolutions detection mechanism 8 in which a revolution meter 9 has been attached to every tire 5 receives the signal of the revolution meter 9, it compares and judges the number of revolutions of every tire 5, it specifies the tire 5 in which the number of revolutions is especially large, it judges a reduction in a pressure, and an alarm mechanism 7 issues an alarm by means of sound, light or the like. In addition, it is preferable that the cord 4 is a steel cord or made of an organic fiber, and its kind can be combined with a change in the angle of the breaker. Consequently, without spoiling the characteristic of the tire 5, it is possible to manufacture the tire 5 in which the stretch in the circumferential direction of the tire can be set at 1 to 5% with reference to an internal pressure of 1kg/cm<2>. Thereby, the change rate of a circumferential length due to the reduction in the pressure is large, and a drop in the internal pressure can be detected with high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle equipped with an internal pressure alarm device. More specifically, the present invention relates to a vehicle including an internal pressure drop detection mechanism that detects a decrease in internal pressure from an increase in rotation speed due to a decrease in tire circumference, and an internal pressure alarm device that can accurately detect a change in circumference due to pressure reduction. .

[0002]

2. Description of the Related Art At present, a tire internal pressure drop detecting mechanism measures a decrease in tire internal pressure mainly as an increase in the rotational speed of the tire. This is based on the principle that the tire circumference decreases as the internal pressure decreases, and the rotational speed increases when traveling at the same speed or traveling the same distance. The structure of a general radial tire will be described with reference to FIG.

In the radial tire, the cord (thread) of the carcass 1 corresponding to the basic skeleton of the tire is radial (radial).
It is stretched out. The breaker 3 is wound around the outer periphery of the tread portion 2 in a rattle shape.
The breaker 3 usually has a structure in which the cords 4 cross each other at a constant angle with respect to the circumferential direction. Further, a reinforcing band containing organic fiber cords substantially parallel to the circumferential direction may be appropriately added as a reinforcing structure band. Steel is usually used as the material of the cord 4 in many cases (steel radial tire).

However, the current radial tire has a very strong rigidity in the circumferential direction and has an internal pressure of 1 kg / cm ² (for example, a passenger car tire has a normal internal pressure of 2 kg / cm ² ).
Even if it is reduced, the perimeter is reduced only by 0.05 to 0.5%. With a radial tire, the distance traveled by one rotation of the tire is approximately proportional to the tire circumference. Therefore, for example, when traveling the same distance, the rotation speed of the tire is also 0.05 to 0.
Although it increases by about 5%, there is a problem that it is very difficult to accurately measure such an increase in the number of revolutions. This is because there is a difference between the inner and outer wheels when traveling on a curve, and the number of revolutions also changes due to the influence of load movement during traveling and slip due to driving braking.

In view of the above circumstances, the present invention is provided with an internal pressure alarm device capable of accurately detecting the change in tire circumference due to depressurization and increasing the reliability of the internal pressure alarm. The purpose is to provide a vehicle.

[0006]

A vehicle equipped with an internal pressure alarm device according to the present invention comprises: (a) an internal pressure drop detecting mechanism for detecting a decrease in internal pressure due to an increase in rotational speed due to a decrease in tire circumference.
(B) The internal pressure drop detection mechanism is equipped with an alarm mechanism that issues an alarm when it detects a reduced pressure, and a breaker for reinforcing the carcass inside the tread is equipped with a radial tire made of a highly elastic cord. It is characterized by that.

The elongation of the radial tire in the tire circumferential direction is 1% or more and 5% or more with respect to an internal pressure of 1 kg / cm ² .
The following is preferable.

[0008]

In the vehicle equipped with the internal pressure warning device of the present invention, the vehicle is equipped with the internal pressure drop detecting mechanism for detecting the decrease in the internal pressure due to the increase in the number of revolutions due to the decrease in the tire circumferential length, which serves as a rattle for the radial carcass. Since the breaker is made of a stretchable cord to greatly change the circumferential length due to pressure reduction, the vehicle has an internal pressure warning device with high warning accuracy.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle equipped with the internal pressure alarm device of the present invention will be described below. FIG. 1 is an explanatory view of a vehicle equipped with the internal pressure alarm device of the present invention. The difference from the prior art of the present invention is that a vehicle equipped with an internal pressure alarm device 6 is provided with a breaker 3 for reinforcing the carcass 1 inside a tread portion 2, and a radial tire 5 made of a cord 4 having a very high elasticity. Is the point attached. The internal pressure alarm device 6 includes an alarm mechanism 7 and a rotation speed detection mechanism 8.

The rotation speed detection mechanism 8 which is an internal pressure drop detection mechanism includes a tachometer 9 used for measuring speed, for example. The tachometer 9 is attached to each tire 5, and the rotation speed detection mechanism 8 receives a signal from the tachometer 9 to compare and judge the rotation speed of each tire, and identifies the tire 5 having a particularly large rotation speed to reduce the pressure. Make a decision. When the rotation speed detection mechanism 8 determines that the pressure is reduced, the alarm mechanism 7 issues an alarm.

The alarm mechanism 7 informs the driver of abnormality by sound, light, or a combination thereof, and can use a buzzer, a meter, a warning light and the like.

As the highly elastic cord 4 used for the breaker 3 of the tire 5, a steel cord (high elongation cord), rayon, polyester,
It is preferred to use organic fibers such as nylon. It is also possible to combine the type of the cord and the breaker angle appropriately changed. This is because, for example, the rigidity in the circumferential direction can be reduced by increasing the breaker angle in the circumferential direction. Then, the tire circumferential extension is reduced to an internal pressure of 1 kg / cm ² without impairing the characteristics of the radial tire (the deformation of the contact surface during cornering is small and the tread surface contacts the ground uniformly, so that the exercise performance is great). On the other hand, a radial tire having a content of 1% or more and 5% or less can be manufactured. With such a tire, it is possible to detect the tire rotation difference and issue an alarm regarding the decrease in the internal pressure relatively easily even with the existing internal pressure alarm device.

The tire circumferential extension is 1 kg / c of internal pressure.
If it is less than 1% with respect to m ² , it is difficult to detect a decrease in internal pressure without improving the present problems. On the other hand, 5%
Above that, the tire will no longer have the characteristics of a radial tire, and wear resistance and steering stability will deteriorate, which is not preferable.

Next, the tire of the present invention will be described based on examples, but the present invention is not limited to such examples as a matter of course.

[0015]

[Table 1]

Table 1 shows that the breaker is made of steel cord (high elongation cord) (Example 1), polyester (Example 2), nylon (Example 3) and polyester (Example 4). , Compared with a conventional steel product (comparative example). The tire size is 195 mm wide, the flatness ratio (cross section height / tire width) 65%, and the wheel diameter is 15 inches.
The breaker structure is a two-piece breaker structure.

The normal internal pressure of the circumferential extension is 2 kg.
/ Cm ² was reduced to 1 kg / cm ² , and the length in the circumferential direction at the crown portion was measured at each internal pressure, and the elongation in the circumferential direction per 1 kgf / cm ^{2 of} internal pressure was taken.

From Table 1, the circumferential elongations of Examples 1 to 4 are:
It is clearly larger than 0.21% of the comparative example, and is 1% or more and 5% or less.

Table 2 is a table in which the tires of Examples 1 to 4 were equipped with an internal pressure warning mechanism, the changes in the tire rotational speed due to the pressure reduction were measured, and the tires were compared with the conventional tire (comparative example).

[0020]

[Table 2]

In Table 2, the air pressure at the normal internal pressure is 2
1 kgf / cm ² which is 1 kgf / cm ² less than the normal internal pressure of the air pressure on the right side of the front wheel when decompressing.
The cm ² was compared with the rotational speeds of other tires, and it was examined whether or not there was a detectable difference. The number of rotations indicates the number of rotations when running on a straight course for 1 km.

In the comparative example, the number of revolutions on the right side of the front wheel at the time of pressure reduction is
It is only 1.4 times higher than the normal internal pressure. Therefore, even if the average value 522.1 is compared with the rotation speed 523.3 on the right side of the front wheel, the difference is only 1.2. Therefore, the pressure is reduced from the comparison with the rotation speed of the tire running at another normal internal pressure. It is almost impossible or unclear to determine which tire has a tire. However, in Examples 1 to 4, the number of rotations to the right of the front wheel increased by about 10 times. For example, in the first embodiment, the number of rotations to the right of the front wheel is 517.6 when the normal internal pressure is set to 530.
4 and 12.8 times, which is 9.9 times more than the average of 520.5, and it is clearly detected that it is increased compared to other tires.

[0023]

As described above, the vehicle equipped with the internal pressure alarm device of the present invention is provided with the internal pressure drop detecting mechanism for detecting the decrease in the internal pressure due to the increase in the number of revolutions due to the decrease in the tire circumferential length. The breaker of No. 1 was made with a cord having elasticity. Therefore, the change rate of the circumference due to the pressure reduction is large, and the decrease in the internal pressure is accurately detected, so that the vehicle can be provided with the highly reliable internal pressure alarm device.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a vehicle equipped with an internal pressure warning device of the present invention.

[Explanation of symbols]

 1 Carcass 2 Tread part 3 Breaker 4 Code 5 Tire 6 Internal pressure alarm device 7 Alarm mechanism 8 Rotation speed detection mechanism

Claims (2)

[Claims] 1. An internal pressure drop detecting mechanism for detecting a decrease in internal pressure from an increase in the number of revolutions due to a decrease in tire circumference.
(B) A vehicle provided with an internal pressure alarm device including an alarm mechanism that issues an alarm when the internal pressure drop detection mechanism detects a pressure reduction, wherein a breaker that reinforces the carcass inside the tread portion is made of a highly elastic cord. A vehicle equipped with an internal pressure warning device, which is equipped with radial tires. 2. A vehicle provided with an internal pressure alarm device according to claim 1, wherein the radial tire has a tire circumferential elongation of 1% or more and 5% or less with respect to an internal pressure of 1 kg / cm ² .