JP2831681B2 - Wheel having hollow portion and method of manufacturing the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel having lugs projecting from the outermost periphery of a tire body provided with a hollow portion therein, and a method of manufacturing the same.

[Conventional technology and its problems]

Conventionally, a method of manufacturing a wheel in which a tire is integrally formed around a rim as disclosed in Japanese Patent Application Laid-Open No. 63-260408 has been disclosed. However, the prior art has a lug projecting from the outermost periphery of a tire body. Since the portion is formed only of rubber, stress applied to the lug when traveling on a hard road is concentrated on the base of the lug, and there is a problem that the base of the lug is cracked and damaged. In addition, there is also a problem that the rubber does not spread sufficiently due to the trapping of air in the portion of the mold where the lugs are formed during rubber molding, and the lugs are chipped at the leading end.

[Means and Method for Solving the Problems] In order to solve the above problems, the present invention provides a wheel in which a lug 102 projects from the outermost periphery of a tire body 101 provided with a hollow portion 108 therein. At least inside the base portion, a hollow portion 108 ′ communicating with the hollow portion 108 is provided as a wheel. As a method for manufacturing the wheel, the outermost periphery of the tire body portion 101 having the hollow portion 108 therein is provided. The molds 11 and 12 that form the outer surface of the lug 102 protruding from them are provided with suction portions 31 and 31 ′, and the mold 20 that forms the hollow portion 108 is provided with a protrusion 46 that presses the inner surface of the lug 102. A method of manufacturing a wheel having a hollow portion in which a hollow portion 108 ′ communicating with the hollow portion 108 is formed inside the base of the lug 102 while being pressed by the protrusion 46 and sucked from the suction portions 31, 31 ′ of the molds 11, 12. It is what it was.

[Function and effect of the invention]

According to the present invention, pressing is performed by the projection 46 of the mold 20 and the mold is pressed.
A lug projecting from the outermost periphery of the tire body 101 with a hollow portion 108 provided inside while sucking from the suction portions 31 and 31 'of 11 and 12.
Since the cavity 108 ′ communicating with the hollow 108 is formed inside the base of the lug 102, the lug 102 is neatly molded to its tip, and the conventional problem is solved to manufacture a wheel having a hollow. be able to. And the wheels are
The stress on the lug 102 is reduced by the presence of the cavity 108 '.
102 is absorbed by the bending of the entire base, and is absorbed by the hollow part 108 because the hollow part 108 'communicates with the hollow part 108. Less likely to break. In addition, the presence of the hollow portion 108 'and the hollow portion 108 improves the cushioning property and the running performance as a wheel.

〔Example〕

A method of manufacturing a wheel according to an embodiment of the present invention will be described in detail with reference to the drawings.

First, a hydraulic press forming apparatus 1 for press forming wheels
Will be described. Reference numeral 2 denotes a machine frame constituted by fixing columnar frames 5 at four corners of a pedestal 3 and an upper frame 4 provided on the floor surface. Reference numeral 6 denotes a vertical moving frame having through holes 7 at four corners.
It is mounted in a state of penetrating. Numeral 8 denotes a hydraulic device for moving up and down along the cylindrical frames 5 of the vertical moving frame 6. The upper portion of the hydraulic piston 9 is fixed to the lower surface of the vertical moving frame 6. Reference numerals 10 and 10 denote left and right rails fixedly provided on the upper surface of the vertical moving frame 6, and are mounted thereon so that the lower die 11 for wheel forming can move in the ero direction. Reference numeral 12 denotes an upper die for molding wheels, which is fixed to the lower surface of the upper frame 4 with bolts.

13a and 13b are flexible pipes that supply steam having a temperature of 140 to 200 ° C. and a pressure of 12 kg / cm ² into the lower mold 11 and the upper mold 12, and the lower mold 11 and the upper mold 12 are The temperature is maintained at 140-200 ° C, which is a temperature for vulcanizing raw rubber in a short time.

Numeral 14 denotes a temperature control cabinet installed on the floor below the left and right rails 10, 10, in which an electric heater 15 and a cooling device 16 are provided. Reference numerals 17 and 17 denote left and right rails provided between the inside and outside of the temperature control chamber 14, and a grip 18
Is mounted so that it can move along the rails. Then, while the operator places the core mold 20 on the upper surface of the moving table 19, the moving table 19 is moved along the left and right rails 17 The core mold 20 can be stored together with the moving table 19 in the temperature control chamber 14. Reference numeral 22 denotes a lid (door) that opens and closes the entrance of the temperature control cabinet 14 by being inserted and removed in the vertical direction. However, the temperature control cabinet 14 houses the core mold 20 therein, and by the action of the electric heater 15 and the cooling device 16, the temperature can be raised to a temperature of 70 ° C. to 110 ° C. at which raw rubber can be molded and vulcanized in a short time. Subtype 20
Is configured to regulate the temperature.

Reference numeral 23 denotes a nozzle mounted at the tip of a bendable pipe 24, which has a temperature of 140 to 200 ° C. and a pressure of 12 kg / c from the tip.
It is configured so that m ² water vapor can be ejected. A pipe 24 'is provided at the base of the pipe 24, and the nozzle 23
The configuration is such that the state can be switched between a state in which water vapor is ejected from the tip of the pipe and a state in which the water vapor is shut off to release the inside of the pipe 24 to the atmosphere.

 Here, the lower mold 11 will be described in detail.

The lower mold 11 is configured by fixing a base 11a and a mold 11b with bolts 11c.

Reference numeral 25 denotes a mold engraved on the upper surface of the mold part 11b, and a part 26 and a lug 102 for forming a tire body 101 of the wheel 100 described later.
The outer shape of the rubber tire, such as a portion 27 for forming the rubber tire and a portion 28 for forming the spoke covering portion 103, is carved, and the surface thereof is formed as a rough surface.

Reference numeral 29 denotes a support pin that penetrates a hole 105 of a boss 104 of the wheel 100 described later, and is fixed to the center of the upper surface of the base 11a. Reference numeral 30 denotes a spoke supporting portion that supports a spoke 106 of the wheel 100 described later, and is provided at three places on the upper surface of the mold portion 11b. However, the support pins 29 and the three spoke supports 30 ...
In this configuration, the rim 107 of the wheel 100 can be positioned at a predetermined position of the mold portion 25. Note that a movable support 30a that can move up and down is provided at the center of the spoke support 30 and is urged in the upward direction by a spring 30b.

Reference numerals 31 ... are through holes as suction portions formed at the bottom of the portion 27 of the mold portion 11b where the lug 102 is formed. Reference numeral 32 denotes a through hole formed in the upper surface and the side surface of the base 11a, and a pipe 33 is provided on a side surface portion thereof. Numerals 34 and 34 denote seals.
It is provided in a circular groove carved on the upper surface of a. However, the pipe 33 is connected to a vacuum pump, a vacuum is applied between the seals 34, 34, and when the raw rubber is placed on the mold 25 and the press forming is performed, the through holes 31 are made to have a negative pressure to form the lug 102. Rubber spreads to the bottom corner.

Reference numeral 35 denotes a hole provided in the outer peripheral portion of the mold 25, and is provided so that the rubber spreads to the outer peripheral corner of the mold when raw rubber is placed on the mold 25 and press-molded.

50 ... are thin pins provided on the bottom of the mold 25,
When raw rubber is placed on 25, the raw rubber is inserted to prevent the raw rubber from shifting.

Reference numeral 36 denotes a hole provided inside the base 11a, and a bendable pipe 13a for supplying steam having a temperature of 140 to 200 ° C. and a pressure of 12 kg / cm ² is connected to the hole inlet 36a. ,
The water vapor is introduced into the hole 36 and discharged from the hole outlet 36b through a bendable pipe 13a '. The temperature of the lower mold 11 is maintained at 140 to 200 ° C. for vulcanizing raw rubber.

37a are holes provided at the four corners of the lower die 11, and are provided so that the positioning fitting pins 38 provided on the upper die 12 described later are fitted therein. 37b are through holes provided in the lower mold 11, and are provided so that positioning fitting pins 43 provided in the core mold 20, which will be described later, are fitted therein.

39 has a temperature of 140 to 200 ° C. and a pressure of 12 kg / cm ² from the tip
A vertical groove 39a into which the cylindrical portion 23a of the nozzle 23 is inserted, a lateral groove 39b into which the flange 23b of the nozzle 23 is inserted, and the jet pipe 23 of the nozzle 23 are provided on the upper surface thereof.
A vertical groove 39c into which c is inserted is provided. Numeral 40 is a groove for fitting the ejection pipe 23 of the nozzle 23c provided on the upper surface of the mold portion 11b.

 Next, the upper mold 12 will be described in detail.

The upper mold 12 is configured by fixing a base 12a and a mold 12b with bolts 12c.

Reference numeral 25 'denotes a mold engraved on the lower surface of the mold part 12b, and a part 26' for forming a tire body 101 of the wheel 100 described later and a lug.
A portion 27 'for forming 102, a portion 28' for forming the spoke covering portion 103, and the like are carved, and the surface thereof is formed as a rough surface.

Reference numeral 41 denotes a hole into which the tip of the support pin 29 is fitted.
It is provided at the center of the lower surface of 12a.

31 'are through holes as suction portions formed at the bottom of the portion 27' of the mold portion 12b where the lug 102 is formed. 32 'is base 12
This is a through hole formed in the upper surface and the side surface of a, and a pipe 33 'is provided in a side surface side portion thereof. 34 '
Reference numeral 34 'denotes a seal, which is provided in a circular groove carved on the lower surface of the base 12a with the opening of the through holes 31'... And 32 'interposed therebetween. However, the pipe 33 'is connected to a vacuum pump to make a vacuum between the seals 34' and 34 '.
The rubber extends to the bottom corner of the portion 27 'for molding 102.

35 'is a hole provided on the outer peripheral portion of the mold 41,
The rubber is provided so as to extend to the outer corners of the mold when press-molding raw rubber.

Reference numeral 36 'denotes a hole provided in the base 12a, and a flexible pipe 13b for supplying steam having a temperature of 140 to 200 ° C. and a pressure of 12 kg / cm ² is connected to the hole inlet 36'. The water vapor is introduced into the hole 36 'and discharged from the hole outlet 36b' through the bendable pipe 13b'.The temperature of the upper mold 12 is maintained at 140 to 200 ° C. at which the raw rubber is vulcanized. ing.

38 are fitting pins provided at the four corners of the upper mold 12 and penetrate through through holes 42 provided at the four corners of the core mold 20 described later;
The lower mold 11 is provided so as to fit into the hole 37a.

Reference numeral 39 'denotes a holding table provided opposite the table 39 on which the nozzle 23 is set. The nozzle 23 is held by the table 39 and the pressing table 39 'at the time of press molding, and the tip of the ejection pipe 23c projects and protrudes into the space formed by the dies 25 and 25'.

Reference numeral 30 'denotes a spoke supporting portion which supports the spoke 106 in cooperation with the spoke supporting portion 30 of the lower mold 11, and is provided at three places on the lower surface of the mold portion 12b. A movable support 30a 'is provided at the center of the spoke support 30' so as to be movable up and down, and is urged downward by a spring 30b '.

Next, the core mold 20 will be described. On the upper and lower surfaces, a part 45 for forming a hollow part 108 of a tire body 101 of the wheel 100 described later, and a lug 102 for the lower mold 11 and the upper mold 12 are formed. The protrusions 46 press the rubber into the 27 and 27 'so that the rubber spreads to the bottom corners when press-molding the parts 27 and 27'
(A cavity 108 ′ inside the lug 102 pressed by the projections 46 is formed in communication with the hollow 108.) And a fitting recess 123 into which the rim 107 of the wheel 100 enters. If the amount of protrusion of the molded parts 47 (parts 47 and L _1, becomes also L ₁ radius of the rim in recess 123, the radius L ₁ of the rim in recess 123
It is set so as is smaller than the radius L ₂ of the rim 107. ), A portion 48 for forming a concave portion into which the spoke 106 of the wheel 100 enters, and an outer peripheral portion and an inner peripheral portion of two half-shaped tire pieces 130 formed by the lower mold 11 and the upper mold 12. A mold 44 comprising annular groove portions 60 and 61 for forming joints E ₁ and E ₂ to be joined.
44 is carved. The surfaces of the molds 44 are subjected to a silicon baking treatment (or a fluorine coating treatment), so that the rubber after molding is easily separated.

51 are thin pins provided on the upper surface of the mold 44,
When raw rubber is placed on 44, the raw rubber is inserted to prevent the raw rubber from shifting.

42 ... are through holes through which the fitting pins 38 ... of the upper die 12 pass, 43 ...
Are positioning fitting pins that fit into the through holes 37b provided in the lower mold 11.

Reference numerals 49 and 49 denote left and right suspension portions for hanging wires and the like of the lift device when the core mold 20 is detached from the lower mold 11 and lifted.

Next, the temperature for vulcanizing the raw rubber in a short time is 140 to 200 ° C.
Core mold 20 adjusted to a temperature of 70 to 110 ° C, which can mold lower rubber 11 and upper mold 12 and raw rubber that have been heated to a temperature and does not vulcanize in a short time
A method of forming the wheel 100 using the hydraulic press forming apparatus 1 having the following will be described.

First, an iron tubular boss for mounting wheels on the axle
Wheel body 110 in which 104 and an annular rim 107 made of an iron pipe are welded and connected to spokes 106 made of three iron pipes.
Prepare The boss 104 and the spokes 106 are reinforced iron plates
Reinforced connection at 109.

Then, an adhesive A for attaching rubber and an adhesive B for attaching iron are applied to the entire wheel body 110, and after drying, the adhesive A for attaching rubber is applied to a circle of the spoke 106 with a portion covered with rubber. Apply to the annular rim 107. Next, the annular rim 1
07 A solution obtained by dissolving rubber in a solvent is applied to the outer periphery, a natural rubber C having good adhesiveness in a band shape is adhered thereon, and a solution in which rubber is dissolved in a solvent is applied thereon.

Next, the lower die 11 is moved from the position facing the upper die 12 to the left and right rails.
Move in the direction of B above 10.10 and position it at the tip of left and right rail 10.10. And, in advance, the wheels 10
It is possible to mold the band-shaped raw rubber D cut in accordance with the pitch between the lugs 102 and 102 at a temperature of 70 which does not cure in a short time.
The preheated to ~ 110 ° C is placed on the mold 25 of the lower mold 11. At this time, the band-shaped raw rubber D is locked with the pin 50 so that the cut is located in the middle of the portions 27, 27 on which the lugs 102 are formed, and the raw rubber is positioned exactly on the 27.

Then, the core mold 20 is taken out from the temperature control cabinet 14, and is put on the lower mold 11 such that the fitting pins 43 are fitted into the through holes 37b provided in the lower mold 11.

Then, the band-shaped raw rubber D is also placed on the mold 44 on the upper surface of the core mold 20. At this time, in the same manner as when the belt-shaped raw rubber D is placed on the lower mold 11, the cut is located in the middle of the projections 46, 46 for forming the lugs 102, so that the raw rubber is just positioned on the projections 46. Then, the band-shaped raw rubber D is locked by the pin 51.

Then, the lower mold 11 on which the core mold 20 is stacked is moved to the left and right rails 10.
Move the upper part of the upper die 12 to the position facing the upper die 12 so that the alignment fitting pins 38 of the upper die 12 pass through the through holes 42 of the core die 20 to the holes 37a of the lower die 11. So that it fits
Hydraulic device 8 until upper mold 12, core mold 20 and lower mold 11 come into close contact
Is operated to move the vertical moving frame 6 upward. The pressing pressure between the dies at that time is about 100 to 120 kg / cm ² and the molding is performed for about 2 minutes. Then, the belt-shaped raw rubber D is press-formed at 25 · 25 ′ · 44 · 44, and the tire body 101 of the wheel 100, the lug 102
, A spoke covering portion 103, and a rim fitting recess 123 into which the rim 107 enters. At this time, the lugs 102 are pressed by the protrusions 46 formed on the core mold 20 and the lower mold 11 and the upper mold 12 are pressed.
The portions 27 for forming the lugs 102 of the lower die 11 and the upper die 12 are sucked by a vacuum pump from the through holes 31 formed in the bottom of the lugs 102 of the lower die 11. The rubber spreads to the bottom corner of 27 '… and is molded neatly. Then, the vertical frame 6 is moved downward by the hydraulic device 8 to separate the upper mold 12 and the core mold 20, and then the lower mold 11 is placed on the left and right rails 10, 10 while the core mold 20 is stacked. To the left and right rails 10 and 10 to the end. Then, the core mold 20 is separated from the lower mold 12 by the lift device, and the core mold 20 is stored in the temperature control cabinet 14 again. At this time, the surfaces of the molds 44 and 44 of the core mold 20 are subjected to silicon baking treatment (or fluorine coating treatment) so that the rubber after molding is easily separated and the molds of the lower mold 11 and the upper mold 12 are formed. Due to the fact that the surface of 25 ・ 25 ′ is treated as a rough surface and rubber is difficult to separate,
The formed half-split tire pieces 130 remain in the lower mold 11 and the upper mold 12, respectively.

In this way, as shown in FIG.
130 is molded, but the joint allowances E ₁ and E _{2 of} each of the half-shaped tire pieces 130 to 130 project from the joint surface between the lower mold 11 and the upper mold 12 (the core mold 20 is Part formed by the annular groove portions 60 and 61). Since the joining margins E ₁ and E ₂ are not yet vulcanized since they are molded by the core mold 20, the vulcanization is performed by joining the half-split tire pieces 130 and 130 together in the next step. And the two half-split tire pieces 130, 130 are firmly adhered and formed. The shape of the bonding margins E ₁ is the outer circumferential side of the tire inner side reduce its projecting amount d ₂ of the tire are formed on the projection amount d ₁ is larger inclined. that is,
When joining the two half-shaped tire pieces 130 and 130 together, the outer peripheral side that touches the lower mold 11 and the upper mold 12 and affects the outer surface that is undergoing vulcanization is less protruding as necessary for bonding The amount is such that wrinkles and streaks do not enter the surface by not applying too much pressing force to the surface of the outer surface where vulcanization is progressing at the time of joining, and contact the lower mold 11 and the upper mold 12. The unvulcanized inner side has a large projecting amount so that a sufficient adhesive force can be obtained in which excess rubber is formed in the hollow portion 108 to form a raised portion 111 at the time of joining.

Next, the hole 105 of the boss 104 of the wheel body 110 having the belt-shaped raw rubber C adhered to the outer periphery of the annular rim 107 is inserted into the support pin 29 of the lower mold 11 to support the spoke 106 on the spoke support 30. Thus, the rim 107 of the wheel main body 110 is positioned in the rim fitting recess 123 into which the rim 107 of the half-shaped tire pieces 130, 130 of the lower mold 11 enters.

Then, the lower mold 11 is moved again on the left and right rails 10 in the direction A so as to face the upper mold 12, and the tip of the injection pipe 23c of the nozzle 23 has a hollow portion of the half-shaped tire piece 130. Install the nozzle 23 on the base 39 of the lower mold 11 so as to be located at 108, and
The hydraulic device 8 is operated until the upper die 12 and the lower die 11 come into close contact with each other so that the alignment pins 38 of the 12 fit into the holes 37a of the lower die 11, and the vertical moving frame 6 is moved upward. Let it. The press pressure between the two dies 11 and 12 at that time may be larger than the pressure of steam 12 g / cm ² ejected from the tip of the nozzle 23,
In this embodiment, it is set to about 100 to 120 kg / cm ² .

Then, by operating the valve 24 ′ of the pipe 24, steam having a temperature of 140 to 200 ° C. and a pressure of 12 kg / cm ² is ejected from the tip of the nozzle 23.

Then, the tire pieces 130 and 130 are vulcanized from the outer surface by the heat of the lower mold 11 and the upper mold 12 (temperature of 140 to 200 ° C.), and the nozzle
The inside of the tire is vulcanized with the steam of 140 to 200 ° C spouted from 23, and the whole tire is vulcanized in 5 to 10 minutes.

In this case, the radius L ₁ of the rim in recess 123 of the tire pieces 130, 130 which rim 107 enters the so formed smaller than the radius L ₂ of the rim 107, the rubber is pressed by the rim 107 at the time of pressing, the rim 107 And the tire pieces 130 are accurately bonded to each other. Further, a part of the excess rubber pressed by the rim 107 rises toward the hollow portion 108 and adheres tightly to the band-shaped raw rubber C adhered to the rim 107, so that high-pressure steam can be put into the hollow portion 108. This prevents the water vapor from entering between the rubber and the rim 107. Therefore, the rim 107 and the tire piece 130
・ Adhesion with 130 becomes very strong.

In addition, air that has entered the rubber inside the tire pieces 130, 130 (air enters the rubber when rolling the rubber) or gas generated inside the rubber due to heat expands at the temperature applied during vulcanization. This is suppressed by the high pressure of the water vapor contained in the hollow portion 108, so that a stable and uniform rubber structure is obtained and a good-quality tire is formed. Then, by the high pressure of the water vapor contained in the hollow portion 108, the rubber bulged in the hollow portion 108 by being pressed by the rim 107 or the band-shaped raw rubber C bonded to the rim 107 is pressed against the rim 107, The 107 and the tire pieces 130 are further firmly adhered.

In this way, after steam of 140 to 200 ° C. is ejected from the nozzle 23 and vulcanization is performed for 5 to 10 minutes, the ejection of steam is stopped by operating the valve 24 ′, and the steam in the hollow portion 108 is released to the atmosphere. After leaving the inside of the hollow portion 108 at atmospheric pressure for about 1 minute while opening it inside, the upper and lower dies 12 and 11 are separated by moving the vertical moving frame 6 downward by the hydraulic device 8 to separate the nozzle. twenty three
After removing the lower mold 11, the lower mold 11 is moved on the left and right rails 10 and 10 in the direction B, pulled out to the tip of the left and right rails 10 and 10, and the wheel 100 is taken out from the lower mold 11.

Then, the hole 112 formed in the outer peripheral portion of the tire by the ejection pipe 23C of the nozzle 23 is closed by press-fitting a cylindrical rubber 113 having a diameter larger than the diameter of the hole 112, and the lower mold 11 and the upper mold 12 are closed. A cylindrical rubber portion protruding laterally from the lug 102 formed when excess rubber is fitted into the through holes 31... 31 ′ formed in the bottoms of the portions 27. 114… is cut off from the root part and removed. In addition, lower mold 11 and upper mold 12
The cylindrical rubber portions 115 protruding laterally from the lugs 102 formed by fitting excess rubber into the holes 35 provided in the holes at the time of molding.
May be left as it is because its projection amount is small, but if it adversely affects the performance as a wheel, it is cut off from its root.

In this way, the wheels as shown in FIGS.
Although the tire 100 is made, the hollow part 108 is formed inside the tire body 101, so that when it is mounted on a running vehicle body, the cushion is good and the running performance is good. Also, even if a small hole is made by a nail or the like being stuck in the tire body 101, the hollow portion 1
Since the interior of 08 is originally at atmospheric pressure, there is no problem and the vehicle can continue running without being unable to run as with conventional high-pressure pneumatic wheels. This is because the shape of the tire body 101 and the lug 102 of the wheel 100 manufactured as described above supports the traveling vehicle body almost in the same manner as a solid tire even if there is a hollow portion 108 inside. It is. More specifically, the thickness t of the portion 120 (the lower portion of the hollow portion 108) of the tire body 101 that adheres to the rim 107 is formed to be thicker than the thickness t 'of the upper portion 121 of the air passage portion 108. The upper portion 121 of the thin hollow portion 108 is deformed by the reaction force of the load of the traveling vehicle body received from the road surface to exert a good cushioning property of the wheel 100, but the bending more than necessary is thicker. It is blocked by a portion (lower portion of the hollow portion) 120 of the tire body 101 to be mounted on the rim 107. Therefore, the tire of the wheel 100 has a hollow portion inside while exhibiting good cushioning properties.
Despite having 108, it can support the running body almost in the same way as a solid tire.

In particular, since the cavity 108 'communicating with the hollow 108 is provided inside the base of the lug 102, the stress applied to the lug 102 is caused by the bending of the entire base of the lug 102 due to the presence of the cavity 108'. The cavity 1 is absorbed into the cavity 108 and
Since 08 'is communicated and absorbed in the hollow portion 108, the base of the lug is less likely to be cracked and damaged, and the presence of the hollow portion 108' and the hollow portion 108 improves cushioning. The running performance as a wheel is good.

In the above embodiment, the cavity 108 'inside the lug 102 is provided at the base of the lug 102, but when a large lug is provided, the cavity 108' is provided up to the tip of the lug 102. Needless to say, it is good.

Finally, the boss 104, the spokes 106, and the reinforcing iron plate 109 of the wheel 100 are colored with black paint of the same color as rubber, and one side of the annular groove 122 formed on the side of the tire (the traveling vehicle body). Applying a paint such as yellow or white only to the outer side surface when mounting on the vehicle increases the commercial value and the direction of rotation of the wheel 100 is specified by the shape of the lug 102 (agricultural machinery Most of the lug-equipped wheels have a fixed rotation direction when mounted on the vehicle body.) When the vehicle is mounted on the vehicle body, only the outer side is coated with a paint that is prominent in a ring shape. Incorrect mounting direction can be prevented.

[Brief description of the drawings]

Figure shows one embodiment of the present invention, a side view of FIG. 1 is a hydraulic press forming apparatus, FIG. 2 is a plan view of the lower mold 11, FIG. 3 is a second view S ₁ - S ₁ sectional view, FIG. 4 is a view of FIG.
S ₂ -S ₂ sectional view, Fig. 5 F arrow view of FIG. 2, FIG. 6 is a bottom view of the upper mold 12, FIG. 7 is S ₃ -S ₃ cross-sectional view of FIG. 6, 8 figure S ₄ -S ₄ cross-sectional view of FIG. 6, FIG. 9 is a plan view of the medium-sized 20, the
10 Figure S ₅ -S ₅ cross-sectional view of FIG. 9, FIG. 11 S ₆ of FIG. 9 -S ₆
FIG. 12 is a sectional view taken along the line S ₇ -S _{7 of} FIG. 9, and FIG.
S ₈ -S ₈ cross-sectional view of FIG, Fig. 14 acts explanatory cross-sectional view at the time of molding,
FIG. 15 is a perspective view of the belt-shaped raw rubber D, FIG. 16 is a side view of the wheel main body 110 to which the raw rubber C is adhered, and FIG.
Partially sectional side view of the 00, FIG. 18 is a plan view of FIG. 17, FIG. 19 is a S ₉ -S ₉ sectional view of FIG. 17. In the figure, reference numeral 1 denotes a hydraulic press forming apparatus, 11 denotes a lower die, 12 denotes an upper die, 20 denotes a core die, 23 denotes a nozzle, 31 and 31 'denote through holes (suction parts), 46 denotes a protrusion, 100 Is a wheel, 101 is a tire body, 10
2 is a lug, 103 is a spoke covering portion, 104 is a boss, 106 is a spoke, 107 is a rim, 108 is a hollow portion, 108 'is a hollow portion, 123 is a rim fitting recess, and 130 is a tire piece.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoru Satoru 3-6-1, Matsuhama-cho, Fukuyama-shi, Hiroshima Fukuyama Rubber Industries Co., Ltd. References JP-A-61-129602 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60B 15/02 B29C 33/04 B29C 33/42

Claims (2)

(57) [Claims] 1. A wheel having a lug 102 protruding from the outermost periphery of a tire body 101 having a hollow portion 108 therein.
A hollow portion 108 'communicating with the hollow portion 108 at least inside the base portion. 2. Molds 11 and 12 for molding the outer surfaces of lugs 102 projecting from the outermost periphery of a tire body 101 having hollow portions 108 therein.
The mold 20 for forming the hollow part 108 is provided with a projection 46 for pressing the inner surface of the lug 102, and the suction part 31
A hollow portion 108 'communicating with the hollow portion 108 is formed inside the base of the lug 102 while being pressed by the protrusions 46 and sucked from the suction portions 31 and 31' of the molds 11 and 12. A method for manufacturing a wheel having: