JPH02204024A - Method and device for grinding tire tread - Google Patents

Abstract

PURPOSE:To improve the efficiency as well as the saving of power in the grinding work of a tire tread by a method wherein grinding is effected once or twice in accordance with the amount of remaining tread. CONSTITUTION:When the result of measurement (radius R of a tire 2) is sent from a measuring means 38, a control means 41 obtains a difference between the result of measurement and a predetermined finishing value and, thereafter, compares the difference with a set value. When the difference is lower than the set value, prestored one-time grinding program is called out and an one-time grinding signal is sent to servomotors 19, 20 through cables 42, 43. As a result, a rasp 28, rotated by the driving of another motor 29, is moved along the locus of one-time grinding. On the other hand, when the difference has exceeded the set value, a prestored two-time grinding program is called out and a two- time grinding signal is sent to the servomotors 19, 22. As a result, the rotating rasp 28 is reciprocated axially along the locus of two-time grinding whereby a tread 3 may be ground by two times reciprocally.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tire tread grinding method and apparatus for grinding the tread of a used tire in order to form a base tire for a retreaded tire.

Yoroi Mryo 1 In recent years, while reducing the cost of automobile tires,
As a measure to restore the driving performance of tires, used treads (camelback) have been replaced, ie, retreaded.

In order to retread such tires, it is necessary to remove the tread of the used tire by grinding it.

Conventionally, such tire tread grinding is carried out by attaching a used tire to a grinding machine that has one rasp, a beeling knife, and one rasp, and then grinding the tread of the used tire while rotating the rasp. The tread of the used tire is ground twice in total by running it back and forth along the contour, or by running the grinding knife in advance followed by the rasb. Grinding the tread twice with a rub or beeing knife in this way ensures that even if the amount of tread wear is small and there is a large amount of remaining tread, this remaining tread can be reliably removed to achieve the finished diameter. This is to obtain a new tire.

However, in such conventional methods, the tread is ground twice in total, so if the amount of remaining trays and dors mentioned above is small, the tread is not ground at all in the first grinding. As a result, there is a problem in that a large amount of operating time and power for the grinding operation is wasted.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tire tread grinding method and apparatus that can improve the efficiency of tire tread grinding work and save power.

Therefore, the purpose is to first measure the outer diameter equivalent value of a used tire, calculate the difference between the measurement result and a predetermined finishing value, and when the value is less than the set value, 1. A step of sending a grinding signal twice to a grinding machine when the number exceeds a set value, and grinding the tread of the used tire once or twice by the grinding machine based on the grinding signal. Second, a measuring means for measuring the outer diameter equivalent value of the used tire, and a measurement result sent from the measuring means and a predetermined finish value. and a control means for emitting a grinding signal once when the number is less than a set value and twice when the number exceeds the set value, and using the grinding signal from the control means. This can be achieved by a tire tread grinding apparatus equipped with a grinding machine that grinds the tread of a finished tire once or twice.

January First, the outer diameter equivalent value of the used tire is measured using a measuring means. Here, what is the outer diameter equivalent value?

The outer diameter, circumference length, radius, etc. can be easily converted to the outer diameter by adding, subtracting, multiplying, or dividing a certain number.The zeroth order is a value equivalent to the outer diameter, and the control means was sent from the measuring means. After determining the difference between the measurement result and a predetermined -E value, the difference is compared with the set value. When the difference is less than the set value, that is, when the amount of remaining tread is small,
The control means sends a grinding signal to the grinding machine once, and if the difference exceeds a set value, that is, when the amount of remaining tread is large, the control means sends a grinding signal to the grinding machine twice. . As a result, the grinding machine grinds the tread of the used tire only once or twice, based on the grinding signal, until the tread of the used tire reaches the finished value.

In this way, the grinding is performed only once or twice depending on the amount of remaining tread, so that the efficiency of the grinding work can be improved and power can be saved.

1 example Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1.2, l is a grinding machine for grinding the tread 3 of a used pneumatic tire 2, and this grinding machine 1 has a circular frame 4.

The frame 4 includes a rim 7 that supports one bead portion 8 of the tire 2 from the inside via a support 5, and a rim 7 that can move toward and away from the rim 7 by the operation of a cylinder 8, and when approaching the rim 7. A rim 9 supporting the other bead portion 6 of the tire 2 from the inside is rotatably supported, and the tire 2 supported by being sandwiched from both sides by these rims 7, 8 and the rims 7, S is driven by a motor IO. rotated at low speed. A lifter 15 is installed directly below the rim 7, θ, and this lifter 15 holds the tire 2 placed thereon on the rim. , 8 until the axis of rotation of the tire 2 becomes coaxial with the axis of the tire 2. A support stand IB connected to the frame 4 is installed in front of the frame 4, and a lower stand 18 that moves parallel to the axis of the tire 2 while being guided by a rail 17 is supported on this support stand te-h. There is. This lower stand 1
B is screwed onto a screw shaft (not shown) connected to the servo motor 19, and is reciprocated in the left-right direction by rotation of this screw shaft. The Tfi stand 18 supports an upper stand 21 that moves in a direction perpendicular to the lower stand 18, that is, in the front-back direction while being guided by a rail 20. This F side stand 21 is supported by a screw shaft 23 connected to a servo motor 22. As a result, the side stand 21 is screwed into the
It can reciprocate backwards. (-A vertical rotary shaft 27 is rotatably supported through a bearing 26 at the rear of the side stand 21, and a disk-shaped shaft 27 is provided with a large number of grinding protrusions on the outer periphery at the top end of the rotary shaft 27. The last rub 28 is fixed.

Further, a motor 23 is attached to the front part of the L side stand 21,
The driving force of this motor:a is transmitted to the rotating shaft 27 via the belt 30 L2, and when the motor 29 is activated, the rasp 28 rotates around the vertical axis together with the rotating shaft 27, causing the tread 3 of the tire 2 to rotate. to grind. Frame 4 mentioned above. Rim 7, 9. Lifter 15. Support stand 113
, the f-side stand 18, the servo motor 18, the upper stand 21, the servo motor 22, the rub 28, and the motor 2G constitute the grinding machine 1 as a whole. A cylinder 32 that is parallel to the normal line to the tire 2 and inclined at an acute angle with respect to the perpendicular line is attached to the bracket 31 fixed to the upper part of the frame 4,
A movable plate 35 is attached to the tip of the piston rod 33 of the cylinder 32 to which the top end of a rod 34 parallel to the cylinder 32 is fixed. A touch roller 36 is rotatably supported at the lower end of the rod 34, and this touch roller 3B comes into contact with the outer periphery of the tread 3 when the piston rod 33 of the cylinder 32 is retracted. 37 is a linear scale, and this linear scale 37 measures the outer diameter equivalent value of the tire 2, here the radius, by detecting the amount of movement of the moving plate 35, that is, the amount of movement of the touch roller 36. In this example, the soil of the tire 2.

Since the distance from the outer periphery of the touch roller 36 to the axis of the tire 2 at the standby position is determined in advance, the distance M that the touch roller 36 moves from the standby position until it contacts the tread 3 of the tire 2 is Linear scale 3
7 and subtracting the distance 1111M from the distance ML. In this embodiment, the radius R as described above is measured at three or more locations on the circumference while the tire 2 is intermittently rotated, and the average value is taken to ensure accuracy. The aforementioned cylinder 32 and touch roller 36
, the linear scale 37 as a whole constitutes a measuring means 38 for measuring the equivalent value of the outer diameter of the tire 2, here the radius R. 41 is a control means such as a computer, and this control means 41 is connected to the servo motor +9.22 and the linear scale 37 via cables 42, 43, and 44. This control means 41 controls the measurement results sent from the measurement means 38 via the cable 44, that is, the tire 2
From the radius R of, a predetermined and stored finish value N,
In other words, the radius of the tire at the end of regular grinding,
After subtracting the difference P between these, this difference P is set as a predetermined and stored setting value Q, a boundary value for whether to grind once or twice, for example, 5■. compare. When the difference P is less than the set value Q, the control means 41 calls a pre-stored one-time grinding program and sends one-time grinding signals to the cable 42 based on the program.
．． 43 to the servo motor IS, 22 to control the movement trajectory of the rasp 28 for one-time grinding as shown in FIG. 3. On the other hand, when the difference P exceeds the set value Q,
A pre-stored two-time grinding program is called up, and a two-time grinding signal based on the program is sent to the servo motor 19.22 via the cable 42.43.The movement locus of the sprocket 28 is shown in FIG. control for two-time grinding.

Next, the operation of one embodiment of the present invention will be explained.

First, a used pneumatic tire 2 is carried into the grinding machine 1 and placed on the lifter 15.Next, the lifter 15 is operated to rotate the tire 2 so that its axis is the rim. , 8, actuate the cylinder 8 to bring the rim 9 closer to the rim 7, and then move the rim 9 closer to the rim 7. , 9 to sandwich and support the tire 2 from both sides, the cylinder 3
The touch roller 3e is lowered from the standby position until it contacts the tread 3 of the tire 2 by retracting the piston rod 33 of the tire 2. At this time, since the distance is determined in advance,
By measuring the moving distance #M of the touch roller 38 using the linear scale 37, the radius R1 of the tire 2, that is, the equivalent value of the outer diameter can be measured.

Here, such measurement of the radius R of the tire 2 is based on the tire 2.
This is performed at three or more points on the circumference while being rotated intermittently by the motor 10, and the average value is sent to the control means 41 via the cable 44. control! '-it 41
is the measurement result from the measuring means 38, that is, the radius R of the tire 2.
When the grinding result R is sent, the difference P between the grinding result R and the predetermined and stored finish value N is determined, and then the Pth is compared with the predetermined and stored set value Q. When the difference P is less than the set value Q or F, that is, when the amount of remaining tread is small and the remaining tread can be reliably removed by one grinding, the control means 41 uses a one-time grinding program stored in advance. is called, and one-time grinding signals are sequentially sent to the servo motors 18, 22 via the cables 42, 43 based on the program. As a result, the servo motors 13, 22 are activated, and the rasp 28, which is being driven and rotated by the motor 29, is moved along a locus for one-time grinding as shown in FIG. As a result, the remaining tread of the tire 2 is reliably removed, and the radius R of the tire 2 becomes the finished value N. On the other hand, when the difference P exceeds the set value Q, that is, when the amount of remaining tread is large and two grinding operations are required in order to reliably remove the remaining tread, the control means 41 stores the information in advance. A two-time grinding program is called, and two-time grinding signals are sequentially sent to the servo motors 19 and 22 based on the program. As a result, the rotating rubb 2
8 reciprocates in the axial direction along a twice-grinding locus as shown in FIG. 4, and grinds the tread 3 twice overlappingly. As a result, the remaining tread of the tire 2 is reliably removed, and the radius R of the tire 2 becomes the finished value N. In this way, grinding is performed only once or twice depending on the amount of remaining tread, so that the efficiency of the grinding work can be improved and furthermore, power can be saved.

FIG. 5 is a diagram showing another embodiment of the invention. In this embodiment, the grinding machine is provided with one rasp 28 and one beering knife 51. and,
When grinding the tread once in such a grinding machine, only the rub 28 is moved along the illustrated trajectory, while when grinding the tread 3 twice, the beering knife 51 is moved. First, the rasp 28 is moved along the illustrated trajectory, and then the rasp 28 is moved along the illustrated trajectory. Note that the other configurations and operations are the same as those of the previous embodiment.

In the above embodiment, the radius R of the tire 2 was measured as the equivalent value of the outer diameter of the tire 2, but in this invention, the diameter (the outer diameter itself) or the circumference length as the equivalent value of the outer diameter of the tire 2. It may also be possible to measure
For such measurement, a contact type sensor may be used as in the embodiment, but a non-contact type sensor such as a charging sensor may also be used.

As explained above, according to the present invention, it is possible to improve the efficiency of the grinding operation and also to save power.

[Brief explanation of the drawing]

Fig. 1 is an overall schematic front view showing one embodiment of the present invention, Fig. 2 is a similar side view, Fig. 3 is a side cross-sectional view showing the movement locus of the rub during one-time grinding, and Fig. 4 is FIG. 5 is a side cross-sectional view showing the movement locus of the rasp during round grinding, and FIG. 5 is a side cross-sectional view showing the movement locus of the rasp and beering knife according to another embodiment of the present invention. l...Grinding machine 2...Used tire 3
...Tread 38...Measuring means 41...
Control means patent applicant Brideston Co., Ltd. Agent Patent attorney Ta 1) Toshio l...Grinding machine 38...Measuring means 2nd...Used tire diagram diagram diagram diagram

Claims (2)

[Claims] (1) A process of measuring the outer diameter equivalent value of a used tire,
A step of determining the difference between the measurement result and a predetermined finishing value, and sending a grinding signal once to the grinding machine when the difference is less than a set value, and sending a grinding signal twice when the difference exceeds the set value. and a step of grinding the tread of the used tire once or twice using a grinding machine based on the grinding signal;
A method for grinding a tire tread, comprising: (2) Calculate the difference between the measurement result sent from the measuring means and the predetermined finishing value by using a measuring means to measure the equivalent value of the outer diameter of the used tire, and if the difference is less than the set value, 1
a control means for emitting a two-time grinding signal when the difference exceeds a set value; and a control means for grinding the tread of the used tire once or twice based on the grinding signal from the control means. A tire tread grinding device comprising a grinding machine.