JP2008055878A - Molding die for runner with lug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to manufacture a runner with a plurality of types of lugs which can reduce the rolling of a vehicle body by arranging the rugs in a good balance. <P>SOLUTION: The runner die 2 for molding with the lug comprises a first die 21 having a recess 24 for forming a first long lug part and a first short lug part forming recess 25 formed at a first pitch P1, and a second die 22 having a recess 27 for forming a second long lug part and a recess 28 for forming a second short lug part formed at a second pitch P2. In the runner die 2 for molding with the lug, the first pitch P1 of the first die 21 is equalized to the second pitch P2 of the second die 22 so that, when the first die 21 and the second die 22 are opposed to one another and connected, they can be changed in the state to a first state A and a second state B. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mold for forming a traveling body with a lug such as a tire with a lug.

Conventionally, as a traveling body with a lug, there is a tire with a lug in which lugs are arranged in a staggered manner on a tread portion of the traveling body (see, for example, Patent Document 1). Specifically, in the traveling body with a lug, the first lug formed to be offset toward one side in the width direction of the traveling body main body and the second lug formed to be offset toward the other side in the width direction of the traveling body main body. The lugs are alternately formed in the circumferential direction of the traveling body main body.
Japanese Patent Laid-Open No. 9-109617

In a conventional traveling body with a lug, a first lug formed on one side in the width direction of the traveling body main body and a second lug formed on the other side of the traveling body main body are alternately formed. As a result, the first lug and the second lug hit the ground alternately during traveling, causing rolling of the vehicle body.
In order to prevent rolling of the vehicle body, it is necessary to arrange the lugs in a balanced manner with respect to the center in the width direction of the traveling body.
In order to manufacture a traveling body with a lug that can prevent such rolling of the vehicle body, a mold for forming the lug on the traveling body with a lug is required. This mold may be able to manufacture only one type of traveling body with lugs, particularly when the above-described lugs are arranged in a staggered arrangement.

  The present invention has been made in view of the above circumstances, and has a lug-equipped running body molding die capable of manufacturing a plurality of types of running bodies with lugs that can arrange lugs in a well-balanced manner and reduce rolling of the vehicle body. The purpose is to provide.

In order to solve the above problems, the present invention has taken the following technical means.
That is, the running body molding die with a lug according to the present invention has a first short lug portion having a short length in the width direction and a length in the width direction on one side in the width direction from the equatorial plane of the running body. The first short lug portion forming recesses and the first long lug portion forming recesses are alternately formed at a predetermined first pitch so that the long first long lug portions are alternately formed in the circumferential direction of the traveling body main body. It has the 1st metal mold | die formed.
Further, the running body molding die with lugs according to the present invention has a second short lug portion having a short length in the width direction and a length in the width direction on the other side portion in the width direction from the equator plane of the running body main body. The second short lug portion forming recesses and the second long lug portion forming recesses are alternately formed at a predetermined second pitch so that the long second lug portions are alternately formed in the circumferential direction of the traveling body main body. It has the 2nd metal mold | die formed.

The lug-equipped traveling body molding die is configured such that the first die and the second die are joined to face each other to form a cavity.
When the first mold and the second mold are joined, the running body forming mold with a lug has the first short lug portion forming recess of the first mold and the second mold of the second mold. A first state in which the second long lug portion forming concave portion is connected and the first long lug portion forming concave portion of the first mold is connected to the second short lug portion forming concave portion of the second mold; When the first mold and the second mold are joined, the first short lug portion forming concave portion of the first mold and the second short lug portion forming concave portion of the second mold are connected to each other. The first mold has a first mold so that the first long lug portion-forming recess and the second mold can be changed to a second state in which the second long lug-portion forming recess is connected. The first pitch and the second pitch of the second mold are made equal.

According to this, since the 1st pitch of the 1st metallic mold and the 2nd pitch of the 2nd metallic mold are made equal, a metallic mold is the 1st metallic mold or the 2nd metallic mold from the 1st state. By shifting the mold by one pitch, the state can be changed to the second state, and a lug-equipped traveling body having a different shape in each state can be manufactured.
In the traveling body with a lug formed in the first state, the first long lug portion is formed on one side in the width direction from the equator surface of the traveling body main body, and the first long lug portion is formed on the other side portion in the width direction from the equator surface. Two short lug portions are formed connected to the first long lug portion. Thereby, a 1st lug is formed in a traveling body main part.

Further, in the traveling body with a lug formed in the first state, the first short lug portion is formed on one side in the width direction from the equator plane of the traveling body main body, and the portion on the other side in the width direction from the equator plane. The second long lug portion is connected to the first short lug portion. Thereby, a 2nd lug is formed in a traveling body main part.
In the traveling body main body, the first lugs and the second lugs are alternately formed at an equal pitch.
The first lug has a first long lug portion formed on one side in the width direction from the equator plane of the traveling body, and a second short lug portion formed on the other side in the width direction from the equator surface. Therefore, when it hits the ground during traveling, the load of the vehicle body can be supported in a balanced manner by the first long lug portion and the second short lug portion.

The second lug has a first short lug portion formed on one side in the width direction from the equator plane of the traveling body, and a second long lug portion formed on the other side in the width direction from the equator surface. Therefore, when it hits the ground during traveling, the load of the vehicle body can be supported in a balanced manner by the first short lug portion and the second long lug portion.
Therefore, when the traveling body with a lug formed in the first state is mounted on the vehicle, the lug of the traveling body with the lug can support the load in a well-balanced manner, so that the traveling body with the lug is inclined during traveling. This can reduce the rolling of the vehicle body.

In the traveling body with a lug formed in the second state, the first long lug portion is formed on one side in the width direction from the equator plane of the traveling body main body, and the first long lug portion is formed on the other side in the width direction from the equator plane. A two long lug portion is formed connected to the first long lug portion. Thereby, a 1st lug is formed in a traveling body main part.
Further, in the traveling body with a lug molded in the second state, the first short lug portion is formed on one side in the width direction from the equator plane of the traveling body main body, and the portion on the other side in the width direction from the equator plane. The second short lug portion is connected to the first short lug portion. Thereby, a 2nd lug is formed in a traveling body main part.

Comparing the first lug and the second lug with the above configuration, the first lug is large and the second lug is small. The first lugs and the second lugs are alternately formed at an equal pitch.
The first lug has a first long lug portion formed on one side in the width direction from the equator plane of the traveling body main body, and a second long lug portion formed on the other side portion in the width direction. When the vehicle hits the ground, the load of the vehicle body can be supported in a balanced manner by the first long lug portion and the second long lug portion.
The second lug has a first short lug portion formed on one side in the width direction from the equatorial plane of the traveling body, and a second short lug portion formed on the other portion in the width direction from the equatorial plane. Therefore, when the vehicle hits the ground during traveling, the load of the vehicle body can be supported in a balanced manner by the first short lug portion and the second short lug portion.

Therefore, when the traveling body with a lug molded in the second state is mounted on the vehicle, the lug of the traveling body with the lug can support the load in a well-balanced manner, so that the traveling body with the lug does not tilt. The rolling of the vehicle body can be reduced.
As described above, the running body molding die with a lug according to the present invention can produce a plurality of types of running bodies with a lug that can reduce the rolling of the vehicle body by arranging the lugs in a balanced manner.
In addition, when the running body with a lug is molded in the second state, the first long lug portion and the second long lug portion are located with respect to the equatorial plane of the traveling body main body. The first long lug portion forming concave portion and the second long lug portion forming concave portion are formed symmetrically with respect to the joint portion between the first mold and the second mold so as to be symmetrical. It is characterized by.

According to this, as for the 1st lug of the traveling body with a lug formed by the metal mold for traveling body with a lug, the 1st long lug part and the 2nd long lug part are symmetrical with respect to the equatorial plane of a traveling body main part. Therefore, when the first lug hits the ground during traveling, the load of the vehicle body can be supported in a more balanced manner.
In addition, when the traveling body with a lug is molded in the second state, the first short lug portion and the second short lug portion are in contact with the equator plane of the traveling body main body. The first short lug portion forming concave portion and the second short lug portion forming concave portion are formed symmetrically with respect to the joint portion between the first mold and the second mold so as to be symmetrical. It is characterized by.

  According to this, as for the 2nd lug of the traveling body with a lug formed with the casting body shaping | molding die with a lug, a 1st short lug part and a 2nd short lug part are symmetrical with respect to the equatorial plane of a traveling body main body. Therefore, when the second lug hits the ground during traveling, the load on the vehicle body can be supported in a more balanced manner.

  According to the present invention, it is possible to manufacture a plurality of types of running bodies with lugs that can reduce the rolling of the vehicle body by arranging the lugs in a balanced manner.

The best mode for carrying out the present invention will be described below with reference to the drawings.
The lug-equipped traveling body 1 includes, for example, a lug-equipped tire that is attached to an axle of a work vehicle such as a tractor.
1 and 2 show a lug-equipped tire as an example of the lug-running body 1 formed by the lug-equipped running body molding die 2 according to the present invention.
1 and 2, a tread portion 4 formed of rubber or the like on the outer periphery of a traveling body main body 3 (referred to as a “tire main body” when the traveling body with a lug is a tire with a lug). have.

A plurality of lugs 5 are formed on the tread portion 4. The lugs 5 are formed at intervals in the circumferential direction of the traveling body main body 3.
Here, the “circumferential direction” refers to the circumferential direction of the tire body that is the traveling body 3. When the traveling body 1 with a lug is partially viewed from a plane as shown in FIGS. 1 and 2, the circumferential direction is a linear direction indicated by an arrow Y. In the present invention, the “width direction” refers to a direction (indicated by an arrow X in the drawing) parallel to the rotational axis direction of the traveling body 3. The “equatorial plane” refers to a virtual plane (indicated by symbol EP in the drawing) that passes through the center in the width direction of the traveling body 3 and is orthogonal to the circumferential direction Y. When the traveling body 1 with a lug is viewed from a plane, the equatorial plane EP is displayed in a straight line as shown in FIGS.

The lug 5 of the traveling body 1 with a lug shown in FIG. 1 includes a first lug 5 a formed so as to be offset from the equatorial plane EP of the traveling body 3 toward the one side in the width direction X, and an equatorial plane EP of the traveling body 3. To the other side of the width direction X and the second lug 5b formed to be offset.
When the traveling body 3 is divided into the part 7 on the one side in the width direction X and the part 8 on the other side from the equator plane EP, the part 7 on the one side in the width direction X has a length in the width direction X. Long first long lug portions 10 and first short lug portions 11 having a short length in the width direction X are alternately formed in the circumferential direction Y of the traveling body main body 3. The first long lug portion 10 and the first short lug portion 11 are formed at an equal pitch.

Further, a second long lug portion 13 having a long length in the width direction X and a second short portion having a short length in the width direction X are provided on a portion 8 on the other side in the width direction X from the equator plane EP of the traveling body 3. The lug portions 14 are alternately formed in the circumferential direction Y of the traveling body main body 3. The second long lug portion 13 and the second short lug portion 14 are formed at an equal pitch.
The length L1 in the width direction X of the first long lug portion 10 is substantially equal to the length in the width direction X of the portion 7 on the one side in the width direction X from the equator plane EP of the traveling body 3. Further, the length L2 in the width direction X of the second long lug portion 13 is substantially equal to the length in the width direction X of the portion 8 on the other side in the width direction X from the equator plane EP of the traveling body main body 3. The length in the width direction X of the portion 7 on the one side in the width direction X from the equator plane EP of the traveling body main body 3 and the width direction of the portion 8 on the other side in the width direction X from the equator plane EP of the traveling body main body 3. The length X is equal to half the length T (T / 2) in the width direction X of the traveling body 3. Here, the length T in the width direction X of the traveling body main body 3 refers to the distance in the width direction X from one sidewall portion 16a of the traveling body main body 3 to the other sidewall portion 16b.

The length L3 in the width direction X of the first short lug portion 11 is not less than 1/3 and less than 2/3 of the length in the width direction X of the portion 7 on the one side in the width direction X from the equator plane EP of the traveling body 3. It is desirable that That is, it is desirable that the length L3 of the first short lug portion 11 in the width direction X is 1/6 or more and less than 2/6 of the length T of the traveling body main body 3 in the width direction X.
The length L4 in the width direction X of the second short lug portion 14 is not less than 1/3 of the length in the width direction X of the portion 8 on the other side in the width direction X from the equator plane EP of the traveling body 3. It is desirable to be less than 3. That is, it is desirable that the length L4 in the width direction X of the second short lug portion 14 is not less than 1/3 and less than 2/6 of the length T in the width direction X of the traveling body main body 3.

As shown in FIG. 1, the first lug 5 a is formed by connecting a first long lug portion 10 and a second short lug portion 14. The first lug 5a can support the load of the vehicle body by the first long lug portion 10 and the second short lug portion 14 when the first lug 5a hits the ground during traveling.
The second lug 5 b is formed by connecting the first short lug portion 11 and the second long lug portion 13. Due to such a configuration, the second lug 5b can support the load of the vehicle body by the first short lug portion 11 and the second long lug portion 13 when it hits the ground during traveling.
In this way, each lug 5 (5a, 5b) can support the load of the vehicle body in a balanced manner on the left and right with the equatorial plane EP in between. Therefore, the traveling body 1 with lugs does not tilt during traveling, and vibration during traveling Can be reduced as much as possible. Thereby, the traveling body 1 with a lug can reduce rolling of the vehicle body of the traveling vehicle.

Further, in the traveling body 1 with a lug, the lengths L3 and L4 in the width direction X of the first short lug portion 11 and the second short lug portion 14 are 1/6 or more of the length T in the width direction X of the traveling body main body 2. By being less than / 6, a portion without the lug 5 is formed largely around the first short lug portion 11 and the second short lug portion 14, whereby the soil removal property of the traveling body 1 with the lug is improved. It will be expensive. Therefore, this traveling body 1 with a lug has little mud clogging between the lugs 5, and can exhibit sufficient tractive force.
In FIG. 1, the first long lug portion 10 of the first lug 5a is inclined at a predetermined angle θ1 with respect to the equator plane EP. The second short lug portion 14 of the first lug 5a is inclined at a predetermined angle θ2 with respect to the equator plane EP. The inclination angle θ1 of the first long lug portion 10 and the inclination angle θ2 of the second short lug portion 14 are equal.

In FIG. 1, the first short lug portion 11 of the second lug 5b is inclined at a predetermined angle θ3 with respect to the equatorial plane EP. Further, the second long lug portion 13 of the second lug 5b is inclined at a predetermined angle θ4 with respect to the equator plane EP. The inclination angle θ3 of the first short lug portion 11 and the inclination angle θ4 of the second long lug portion 13 are equal.
The traveling body 1 with a lug shown in FIG. 2 is different in the shape of the lug 5 from that of FIG. In the traveling body main body 3 of the traveling body with lugs 1, first lugs 5 a and second lugs 5 b are alternately formed in the circumferential direction Y. The first lug 5a and the second lug 5b are different in size. Comparing the first lug 5a and the second lug 5b, the first lug 5a is large and the second lug 5b is small.

The first lug 5 a has a shape in which the first long lug portion 10 and the second long lug portion 13 shown in FIG. 1 are connected. The first lug 5a has a symmetrical shape with respect to the equator plane EP in plan view.
The second lug 5b has a shape in which the first short lug portion 11 and the second short lug portion 14 shown in FIG. 1 are connected. The second lug 5b has a symmetrical shape with respect to the equatorial plane EP in plan view.
In this way, each lug 5 (5a, 5b) can support the load of the vehicle body in a balanced manner on the left and right with the equatorial plane EP in between, so that the traveling body 1 with a lug does not tilt during traveling, and vibration during traveling Can be reduced as much as possible. Thereby, the traveling body 1 with a lug can reduce rolling of the vehicle body.

Furthermore, since the 1st lug 5a is large, the 2nd lug 5b is formed small, and these are formed alternately by the traveling body 1 with a lug shown in FIG. 2, Therefore Around the 2nd lug 5b which is a small lug A portion where the lug 5 is not formed is formed large, and this configuration provides a high soil removal property. Therefore, this traveling body 1 with a lug has little mud clogging between the lugs 5, and can exhibit sufficient tractive force.
The above-described running body with lugs 1 (tires with lugs) is molded by the running body molding die 2 with lugs shown in FIGS. The mold 2 is divided into two. The lug-equipped traveling body molding die 2 includes a first die 21 and a second die 22. This lug-equipped traveling body molding die 2 is a set of a first mold 21 and a second mold 22, and the traveling body with lugs 1 shown in FIG. 1 and the traveling body with lugs shown in FIG. The two types of traveling bodies 1 with lugs can be formed.

  As shown in FIG. 3, the first mold 21 and the second mold 22 are formed in a cylindrical shape. The first mold 21 and the second mold 22 are joined to face each other, thereby forming a cavity inside thereof. The running body molding die 2 with a lug joins the first die 21 and the second die 22 and inserts a bladder (not shown) inside the first die 21 and the second die 22. The running body 1 with lugs is formed by vulcanizing raw rubber provided between the mold 22 and the bladder. In a state where the first mold 21 and the second mold 22 are joined, the cylindrical center direction of the molds 21 and 22 corresponds to the width direction X of the traveling body 1 with a lug. Hereinafter, the cylinder center direction of these molds 21 and 22 is referred to as “width direction X” of the traveling body molding mold 2 with lugs.

Further, the circumferential direction of the molds 21 and 22 corresponds to the circumferential direction Y of the traveling body main body 3. Hereinafter, the circumferential direction of these molds 21 and 22 is referred to as “circumferential direction Y” as in the case of the traveling body 1 with lugs.
The 1st metal mold | die 21 is for forming the 1st long lug part 10 and the 1st short lug part 11 of the lug 5 of the traveling body 1 with a lug mentioned above. As shown in FIGS. 4 to 6, a first long lug portion forming recess 24 and a first short lug portion 11 for forming the first long lug portion 10 are formed in the first mold 21. A first short lug portion forming recess 25 is provided for this purpose. The first long lug portion forming recess 24 is longer in the width direction X than the first short lug portion forming recess 25.

Further, the first long lug portion forming recesses 24 and the first short lug portion forming recesses 25 are alternately formed in the circumferential direction Y of the first mold 21. The first long lug portion forming concave portion 24 and the first short lug portion forming concave portion 25 are formed inside the first mold 21 at a predetermined pitch (hereinafter referred to as “first pitch P1”).
The 2nd metal mold | die 22 is for forming the 2nd long lug part 13 and the 2nd short lug part 14 among the lugs 5 of the traveling body 1 with a lug mentioned above. As shown in FIGS. 4 to 6, the second mold 22 is provided with a second long lug portion forming recess 27 for forming the second long lug portion 13 and a second short lug portion 14. A second short lug portion forming recess 28 is provided. The second long lug portion forming recess 27 is longer in the width direction X than the second short lug portion forming recess 28.

The second long lug portion forming recesses 27 and the second short lug portion forming recesses 28 are alternately formed in the circumferential direction Y of the second mold 22. The second long lug portion forming recesses 27 and the second short lug portion forming recesses 28 are formed inside the second mold 22 at a predetermined pitch (hereinafter referred to as “second pitch P2”).
The first pitch P1 and the second pitch P2 are equal. Therefore, when the first mold 21 and the second mold 22 are joined, the first long lug portion forming recess 24 and the first short lug portion forming recess formed in the first mold 21. 25, the second long lug portion forming concave portion 27 and the second short lug portion forming concave portion 28 formed in the second mold 22 are connected to each other.

As shown in FIG. 4, the running body molding die 2 with lugs according to the present invention includes a first long lug portion forming recess 24 of the first die 21 and a second short lug of the second die 22. The lug-equipped traveling body 1 shown in FIG. 1 can be molded in a state in which the part-forming recesses 28 are connected (hereinafter referred to as “first state A”). In the first state A, the first short lug portion forming recess 25 of the first mold 21 and the second long lug portion forming recess 27 of the second mold 22 are connected.
Further, as shown in FIG. 5, the lug-equipped traveling body molding die 2 according to the present invention includes a first long lug portion forming recess 24 of the first die 21 and a second die 22 of the second die 22. The traveling body 1 with a lug shown in FIG. 2 can be molded in a state in which the long lug portion forming recess 27 is connected (hereinafter referred to as “second state B”). In the second state B, the first short lug portion forming recess 25 of the first mold 21 and the second short lug portion forming recess 28 of the second mold 22 are connected.

Since the 1st pitch P1 of the 1st metal mold | die 21 and the 2nd pitch P2 of the 2nd metal mold | die 22 are equal, the running body shaping | molding metal mold | die 2 with a lug is the 2nd in the 1st state A. When the first mold 21 is shifted by one pitch in the circumferential direction Y with respect to the mold 22, the second state B is obtained. Further, when the first mold 21 is shifted by one pitch in the circumferential direction Y with respect to the second mold 22 in the second state B, the first state A is obtained.
Thus, the running body molding die 2 with a lug can be easily changed between the first state A and the second state B by shifting the first die 21 and the second die 22 by one pitch. Can be changed. Accordingly, a plurality of types (two types in this embodiment) of the traveling body with lugs 1 can be molded with one set of the traveling body forming molds 2 with lugs. As described above, the lug 5 formed by the lug-equipped running body molding die 2 can support the load of the vehicle body in a well-balanced manner, and the lug 5 is not tilted during traveling. Rolling can be reduced.

As shown in FIG. 6, when the first mold 21 and the second mold 22 are joined to each other, the running body forming mold 2 with a lug has an end surface of the first mold 21, The end surface of the second mold 22 is in close contact. This close contact portion appears as a boundary line between the first die 21 and the second die 22 when viewed from the inside of the lug-equipped running body molding die 2 as shown in FIGS. Hereinafter, this boundary line is referred to as “joint 30”.
The joint 30 is positioned at the center in the width direction X of the travel body molding die 2 with a lug in a state where the first die 21 and the second die 22 are joined. The joint portion 30 corresponds to the position of the equatorial plane EP of the traveling body with lugs 1 formed by the traveling body forming mold 2 with lugs. As shown in FIGS. 4 to 6, the joint portion 30 is shown linearly.

As shown in FIG. 6, the 1st metal mold | die 21 has the wall surface 32a for forming one side wall part 16a of the traveling body 1 with a lug. Moreover, the 2nd metal mold | die 22 has the wall surface 32b for forming the other side wall part 16b of the traveling body 1 with a lug. Each of the wall surfaces 32a and 32b is a curved surface curved in a circular arc shape when viewed in cross section.
In the wall surface 32 a of the first mold 21, the interval T1 from the position D1 farthest in the width direction X from the joint portion 30 to the joint portion 30 is half of the length T in the width direction X of the traveling body 3. It is equal to the length (T / 2).

Similarly, in the wall surface 32b of the second mold 22, the distance T2 from the position D2 farthest in the width direction X from the joint 30 to the joint 30 is the length T in the width direction X of the traveling body 3. Is equal to half the length (T / 2).
Hereinafter, the interval T1 is referred to as “the inner width T1 of the first mold 21”. The interval T2 is referred to as “the inner width T2 of the second mold 22”. The inner width T1 of the first mold 21 and the inner width T2 of the second mold 22 are equal.
The length K1 in the width direction X of the first short lug portion forming recess 25 of the first mold 21 is set to be 1/3 or more and less than 2/3 of the inner width T1 of the first mold 21. desirable. Further, the length K2 in the width direction X of the second short lug portion forming recess 28 of the second mold 22 is not less than 1/3 and less than 2/3 of the inner width T2 of the second mold 22. Is desirable.

By doing in this way, as above-mentioned, the traveling body 1 with a lug shape | molded by this running body shaping | molding die 2 with a lug has small vibration during driving | running | working, and also has high soil removal property, and traction force is enough. Will be able to demonstrate.
As shown in FIGS. 4 and 5, in the first long lug portion forming recess 24 of the first mold 21, the first long lug portion 10 is formed in the traveling body 1 with a lug at a predetermined inclination angle θ <b> 1. Thus, it is formed to be inclined at a predetermined angle θ1 with respect to the joint portion 30.
In addition, the first short lug portion forming recess 25 of the first mold 21 is formed with respect to the joint portion 30 so that the first short lug portion 11 is formed on the traveling body 1 with the lug at a predetermined inclination angle θ3. And inclined at a predetermined angle θ3.

As shown in FIGS. 4 and 5, in the second long lug portion forming recess 27 of the second mold 22, the second long lug portion 13 is formed in the traveling body 1 with the lug at a predetermined inclination angle θ <b> 4. As described above, it is inclined with respect to the joint portion 30 at a predetermined angle θ4.
Further, the second short lug portion forming concave portion 28 of the second mold 22 is formed with respect to the joint portion 30 so that the second short lug portion 14 is formed on the traveling body 1 with the lug at a predetermined inclination angle θ2. And inclined at a predetermined angle θ2.
As shown in FIG. 6, when the lug-equipped traveling body molding die 2 is in the second state B, the first long lug portion forming recess 24 of the first die 21 and the second die The second long lug portion forming concave portions 22 are symmetrical with respect to the joint portion 30 (line symmetry). Further, in the second state B, the first short lug portion forming concave portion 25 of the first mold 21 and the second short lug portion forming concave portion 28 of the second mold 22 are connected to the joint portion 30. Becomes symmetrical (line symmetry).

  As described above, the lug traveling body 1 formed in this state has the first long lug portion 10 and the second long lug portion 13 symmetrical with respect to the equatorial plane EP (see FIG. 2). Further, in the traveling body with lugs 1 molded in this state, the first short lug portion 11 and the second short lug portion 14 are symmetrical with respect to the equator plane EP.

  The present invention can be used for forming a traveling body with a lug such as a tire with a lug.

It is a partial top view of the traveling body with a lug shape | molded in the 1st state of the metal mold | die for traveling body with a lug. It is a partial top view of the traveling body with a lug shape | molded in the 2nd state of the metal mold | die for traveling body with a lug. It is a perspective view which shows the metal mold | die for running bodies with a lug. It is sectional drawing which shows the inside of the traveling body shaping die with a lug in a 1st state. It is sectional drawing which shows the inside of the traveling body shaping die with a lug in a 2nd state. It is CC arrow directional cross-sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Running body with lug 2 Running body molding die with lug 3 Running body main body 5 Lug 5a First lug 5b Second lug 7 A part of one side in the width direction of the traveling body main body 8 The other side in the width direction of the traveling body main body Part 10 first long lug part 11 first short lug part 13 second long lug part 14 second short lug part 21 first mold 22 second mold 24 first long lug part forming recess 25 first Short lug portion forming recess 27 Second long lug portion forming recess 28 Second short lug portion forming recess 30 Joint A First state B Second state P1 First pitch P2 Second pitch

Claims (3)

A first short lug portion having a short length in the width direction and a first long lug portion having a long length in the width direction are provided in a circumferential direction of the traveling body main body on one side in the width direction from the equator plane of the traveling body. The first short lug portion forming recesses and the first long lug portion forming recesses have first molds alternately formed at a predetermined first pitch so as to be alternately formed,
A second short lug portion having a short length in the width direction and a second long lug portion having a long length in the width direction are provided in the circumferential direction of the traveling body main body on the other side in the width direction from the equator plane of the traveling body. The second short lug portion forming recesses and the second long lug portion forming recesses have second molds alternately formed at a predetermined second pitch so as to be alternately formed,
The first mold and the second mold are joined to face each other to form a cavity, and the first mold and the second mold are joined when the first mold and the second mold are joined. The concave portion for forming the first short lug portion of the mold and the concave portion for forming the second long lug portion of the second die are connected, and the concave portion for forming the first long lug portion of the first die and the second die of the second die are connected. A first state in which the concave portion for forming the two short lugs is connected;
When the first mold and the second mold are joined, the first short lug portion forming recess of the first mold and the second short lug portion forming recess of the second mold are connected. And the state can be changed to the second state where the first long lug part forming recess of the first mold and the second long lug part forming recess of the second mold are connected,
A mold for forming a traveling body with a lug, wherein the first pitch of the first mold is equal to the second pitch of the second mold.   For forming the first long lug portion so that the first long lug portion and the second long lug portion are symmetric with respect to the equator plane of the traveling body body when the traveling body with a lug is molded in the second state. The run with a lug according to claim 1, wherein the recess and the recess for forming the second long lug portion are formed symmetrically with respect to the joint portion between the first mold and the second mold. Mold for body molding.   For forming the first short lug portion so that the first short lug portion and the second short lug portion are symmetrical with respect to the equator plane of the traveling body body when the traveling body with a lug is molded in the second state. The lug according to claim 1 or 2, wherein the concave portion and the concave portion for forming the second short lug portion are formed symmetrically with respect to the joint portion between the first die and the second die. Die for running body molding.

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