JPH0825907A - Emergency use tire - Google Patents

Abstract

PURPOSE:To urge early replacement with a ground tire by limiting the repetition units of design elements, forming a tread pattern, to two or three kinds different in pitch length, and disposing the same elements continuously over a specified area to generate noise. CONSTITUTION:The tread is provided with linear main grooves 1 extended in the tire circumferential direction T, and lateral grooves 2 extended along the tire width direction between the main grooves 1 so as to partition blocks 3 to form a tread pattern P formed of block patterns. The minimum repetition units of design elements are limited to two or three kinds different in pitch length, and the same elements are continuously disposed over an area of at least 10% or more of the tire peripheral length. Pure tone of different frequency in reverse porportion to the pitch length in each area can be therefore generated in such a way that the difference based on the frequency difference is conspicuous. A driver can be thereby urged to early replacement with a ground tire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency tire which is used temporarily when a ground tire is punctured, and more specifically, it is a tire for emergency use after being used for an emergency purpose by actively generating noise. The present invention relates to an emergency tire designed to promote replacement with a ground tire.

[0002]

2. Description of the Related Art An emergency tire is a tire temporarily used for traveling to a repair place such as a nearby gas station when the ground tire is flat. For this reason, emergency tires are always stored in the luggage compartment and have a smaller diameter than grand tires so as not to occupy extra space or add extra weight load.
It is also designed to be narrow. It is not designed to withstand long-term use, and it is desirable to replace it with a ground tire as soon as possible after safety use has been completed. However, in reality, even after use for emergency purposes,
Since there are users who drive for a long time,
That measure was requested.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an emergency tire which has a structure for actively generating noise to prompt a driver to replace the tire with a ground tire at an early stage. To do.

[0004]

According to the present invention for achieving the above object, the minimum repeating unit of design elements constituting a tread pattern is two or three types having different pitch lengths, and the design elements are the same. The tire is characterized by being arranged so as to be continuous over at least 10% of the tire circumference.

As described above, the tread pattern design elements are limited to a few types having different pitch lengths,
Moreover, since the same design element is continuously arranged over a long region of 10% or more of the tire circumference, a pure tone having a frequency inversely proportional to the pitch length is generated while the same pitch length continues. Further, since pure tones having different frequencies are repeatedly generated for a fixed length, it is possible to positively generate a noticeable noise from the emergency tire during running.

Further, by setting the ratio of the maximum pitch length and the minimum pitch length of the two or three types of design elements to 1.1 or more, it is possible to increase the difference between the frequencies of pure tones and to make the noise more noticeable. it can. Therefore, it is possible to make the driver surely recognize that the emergency tire is mounted and promptly promptly to replace it with the ground tire. The tread pattern used in the present invention may be a block pattern, a rib pattern, a lug pattern, or a combination thereof, and any pattern used for pneumatic tires may be used.

Hereinafter, the structure of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an example of a tread pattern of an emergency tire of the present invention. Reference numeral 1 denotes three linear main grooves extending in the tire circumferential direction T on the tread surface, and a plurality of lateral grooves 2 are provided between the main grooves 1 along the tire width direction. A large number of blocks 3 are sectioned to form a tread pattern P consisting of block patterns. A sipe 4 is formed on the block 3 along the tire width direction.

The tread pattern P is formed by repeatedly arranging a plurality of types of design elements. In the present invention, the type of design element defined by the minimum repeating unit length has a different pitch length L. Two
The number of the elements is limited to three or three, and the same element is continuously arranged over a region covering at least 10% or more of the tire circumferential length.

FIG. 2 shows a case where two design elements having different pitch lengths are used. Design element A having _a longer pitch length L _a is continuously connected to 50% of the tire circumference.
And the design element B having the shorter pitch length L _b is continuously arranged in the area B corresponding to the remaining 50% of the tire circumference, and the tread pattern P
Is composed.

FIG. 3 shows a case where design elements having three types of pitch lengths are used. In addition to the design elements A and B having the above pitch lengths L _a and L _b , a pitch length L having an intermediate length is provided. Design element C consisting of _c
Are continuously arranged over the regions A, B, and C, each of which is ⅓ of the tire circumferential length. In both cases of FIG. 2 and FIG. 3, the area where the respective design elements are continuously arranged is set to be at least 10% of the tire circumferential length.

If the length of the consecutively arranged regions is less than 10%, the pure tone based on the design element cannot be distinguished so as to be distinguishable from the pure tones of different frequencies generated from other regions. The area length of the continuous sequence of each design element is preferably as shown in FIGS.
As shown in FIG. 5, it is preferable to arrange 50% or 1/3 of each design element so as to be substantially equal.

In the present invention, the types of design elements are limited to two types or three types, preferably two types. If there are more than three types of design elements, the frequency modulation effect between the design elements becomes too large, and it becomes difficult to make the noise generated from the emergency tires noticeably different. As described above, in the present invention, the number of types of design elements, which are the smallest repeating units constituting the tread pattern, is limited to two or three, and each design element has at least 10 tire circumferences of the same design element. %
Since they are arranged so as to be continuous, it is possible to generate pure tones with different frequencies that are inversely proportional to the pitch length in each region, and to repeatedly generate pure tones with different frequencies at fixed lengths. Can be a noticeable noise. That is, a high frequency pure tone is generated from the area of the design element having the shorter pitch length, and a low frequency pure tone is generated from the area of the design element having the longer pitch length, and the pure tones of different frequencies are constant. Since the noise is repeatedly generated for each length, it is possible to positively obtain a noticeable noise.

In the emergency tire of the present invention as described above, the ratio L _a / L of the maximum pitch length L _a and the minimum pitch length L _b among the two or three types of design elements.
_It is preferable that _b is at least 1.1 or more. It is preferably 1.1 to 2.0. If this pitch length ratio is smaller than 1.1, it is difficult to obtain a noticeable sound because the difference in frequency is small. When it exceeds 2.0, the area of the design element A having the maximum pitch length L _a and the minimum pitch length L _b
The rigidity difference with the area of the design element B consisting of becomes too large, which causes uneven wear on the tread surface.

Further, according to the present invention, the sipe density of the sipes 4 and the lateral groove density of the lateral grooves 2 within the pitch are changed according to the pitch length of the design element to increase the rigidity difference between the continuous regions of the respective design elements. Thus, the magnitude change of the pure tones generated alternately may be increased. When the density is increased, the rigidity is lowered and the level of pure tone generated can be lowered. Therefore, by adding a change in rigidity in addition to the frequency difference due to the pitch length, the noise generated from the emergency tire can be made more noticeable. The sipe density referred to here is the sum of the tire radial projection lengths of the sipes in the ground contact area of a specific pitch (JATMA standard conditions) divided by the pitch length, and the lateral groove density is The sum of the projected lengths of the lateral grooves in the tire radial direction is divided by the pitch length.

The present invention can be applied to a rib pattern, a lug pattern, etc., instead of the above-mentioned block pattern, and to an emergency tire comprising a tread pattern having a repeating unit of a conventionally known design element. It goes without saying that it can be applied.

[0016]

EXAMPLE The tire size was T125 / 70D14, the tread pattern was common to the block pattern shown in FIG. 1, and as shown in Table 1, two types of design elements A and B having different pitch lengths were continuously arranged. The tire 1 of the present invention, the tire 2 of the present invention in which three types of design elements A, B, and C having different pitch lengths are continuously arranged respectively, and the conventional tire in which only the design element A is continuously arranged are different in pitch length. Comparative tire 1 in which four types of design elements A, B, C, D are arranged continuously
Were manufactured as emergency tires.

A rim size of 14 × was applied to each of these test tires.
When mounted on a 4T rim, air pressure was set to 420 kpa, and a noise performance evaluation test was conducted under the following measurement conditions, the results shown in Table 1 were obtained. Noise performance Tire size 185 / 65R14 (Air pressure 200kpa,
Rim size 14 x 5 1 / 2J) Ground tires are mounted on the right front wheel of a front-wheel drive vehicle with a displacement of 1600cc, test tires are mounted on the right side of the vehicle, and the paved road surface is 60km / h.
The vehicle was driven at / h and the noise performance was evaluated by the feeling of the driver inside the vehicle. The evaluation results are shown as an average of 5 drivers trained in the noise test, ○ -1 stands out, ○ -2
Indicates that it stands out well, ○ -3 indicates that it stands out very well, and x indicates that it stands out.

[0018]

[Table 1] As is clear from Table 1, both the tires 1 and 2 of the present invention can generate more noticeable noise than the conventional tire and the comparative tire. In addition, the tire size and the tread pattern are the same as those described above, and as shown in Table 2, two types of design elements A and B of the present invention are manufactured by changing the ratio of continuously arranging them in the tire circumferential length. And a comparative tire 2 were manufactured. When these test tires were subjected to a noise performance evaluation test in the same manner as described above, the results shown in Table 2 were obtained.

[0019]

[Table 2] As is clear from Table 2, in order to generate a noticeable noise, it is understood that the continuous length of the design elements continuously arranged on the tire circumference should be 10% or more of the tire circumference. Further, in the above two types of design elements A and B, tires 5 and 6 of the present invention and comparative tire 3 in which the ratios of the maximum pitch length and the minimum pitch length were different as shown in Table 3 were manufactured. . When these test tires were subjected to a noise performance evaluation test by the same measurement method as described above,
The results shown in Table 3 were obtained.

Further, in the above-mentioned two types of design elements A and B, as shown in Table 4, the present invention in which the ratio of the maximum pitch length to the minimum pitch length is changed and the pattern rigidity (sipe density) is changed. Tires 7, 8 and 9 and comparative tire 4 were manufactured and subjected to a noise performance evaluation test by the same measurement method as described above. The results shown in Table 4 were obtained.

[0021]

[Table 3]

[0022]

[Table 4] As is clear from Tables 3 and 4, by setting the ratio of the maximum pitch length to the minimum pitch length to 1.1 or more, or by changing the sipe density to increase the pattern rigidity difference, a noticeable noise is generated. You can see that it can be generated.

[0023]

As described above, the emergency tire of the present invention limits the number of types of design elements, which are the minimum repeating units of the tread pattern, to two or three, and each of these elements has a tire circumference of 10 Since it is arranged continuously for more than%, pure tones having different frequencies inversely proportional to the length of the pitch length are generated in each region, and it is generated repeatedly by a constant length. The difference between pure tones based on the frequency difference can be prominently generated. Therefore, it is possible to promptly recognize the mounting of the emergency tire to the driver who is traveling and promptly promptly to replace it with the ground tire. Further, since the noise is generated due to the difference in frequency, the noise becomes louder especially when traveling at a high speed, and a warning can be given to reduce the speed, which does not seriously hinder safe traveling.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a tread pattern of an emergency tire of the present invention.

FIG. 2 is an explanatory diagram showing an example of a region in which two types of design elements having different pitch lengths are continuously arranged.

FIG. 3 is an explanatory diagram showing an example of a region in which three types of design elements having different pitch lengths are continuously arranged.

[Explanation of symbols]

1 Main groove 2 Lateral groove 3 Block 4 Sipe A, B, C Design element L Pitch length L _a Maximum pitch length L _b Minimum pitch length L _c Intermediate pitch length P Tread pattern

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B60C 23/04 B

Claims (2)

[Claims] 1. The minimum repeating unit of the design elements constituting the tread pattern is two or three types having different pitch lengths, and the same design element is continuous over at least 10% of the tire circumference. Emergency tires placed in. 2. The emergency tire according to claim 1, wherein the ratio of the maximum pitch length to the minimum pitch length of the design element is at least 1.1.