JP4410639B2 - Mold fastening device - Google Patents

Description

  The present invention relates to a device for fastening a mold in a molding machine such as a press machine or an injection molding machine. More specifically, when disassembling / assembling, a fixed mold and a movable mold can be integrated to greatly streamline the work. The present invention relates to a mold fastening device.

For operations such as press machines and injection molding machines, when the mold is installed on the machine or when the mold is removed from the machine, the fixed mold, the movable mold, and the main mold are disassembled into a single unit before the factory. It is transported to and stored in the storage location.
In addition, when the mold is large, a crane is used for attaching / detaching to / from the machine. Therefore, careful work is taken so as not to damage the mold.
In addition, fixed molds and movable molds should be managed as a set, but in many factories they are stored separately.
As described above, when the molding die is not stored in a separated state, the fixed die and the movable die are integrated by hand tightening after taking appropriate time.
Further, since it is necessary to use a fastening device different from the original mold clamping, a large instrument / volume is required. There exists patent document 1 as a prior art. This is a device for locking a pair of molds, and the force required for locking is small, but the force required for separation can be increased.

Further, there is Patent Document 2 as a prior art of a self-clamping die apparatus.
The mold apparatus 10 of Document 2 includes a mold body 12 in which plates 18, 19, and 20 are combined and integrated with pins, and a lock mechanism 16 provided inside the body. The locking mechanism includes a force generating device 54 and a tie rod device 52 for locking.
The force generator is configured by laminating a spring washer 91 on a shaft 100, and a tie rod 56 is arranged in series with the shaft 100 so as to be locked. The actuator device acts from the rear end of the shaft 100 and the front end portion of the tie rod 56 at the position where the mold apparatus 10 is in the liquid injection position or the product take-out position. The spring overlapped with the shaft 100 is pressed in a compressing direction, and after being pressed, engaged with the cross groove at the front end of the tie rod 56, the tie rod 56 is turned 90 degrees to disengage from the shaft 100. . [Explanation symbols are the same as in Patent Document 2]
JP 2001-88132 A JP-A-5-345338

When installing and removing a mold from a molding machine with a movable mold and a fixed mold separated, it takes a lot of time and damages part of the mold during the work. It was happening.
In addition, a dedicated stand for transportation and storage is required, which causes a problem that the storage space becomes large. In addition, preparation of a dedicated fastener for fastening and storing a pair of molds has been a problem of unexpected cost generation and space securing.
Further, in order to transport a large-sized mold as a unit, the conventional fastening device has a problem that the fastening force is insufficient.

The pair of mold fastening devices disclosed in Patent Literature 1 and Patent Literature 2 is for securing the clamping pressure required at the time of molding. Therefore, it is not applicable as a fastening device that fastens a pair of molds together and then removes them from the molding machine for transportation and storage.
When these fastening devices are employed in a transportation fastening device, the universal locking device of Patent Document 1 has a problem that the gripping force is too small to be applied to a mold having a large mass. The fasteners used in injection molds have a problem that a force generating device for locking force and a lock bolt turning mechanism are required, and a space is required on the molding machine to install them. It was.

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to perform a dog pressing operation in which a pair of molds of a fixed mold and a movable mold are integrated. It is possible to install and remove from the main mold by embedding and integrating the fastening mechanism including a boosting mechanism that can obtain a large fastening force into the mold. It is an object of the present invention to provide a mold fastening device capable of improving and greatly rationalizing the transportation and storage of molds.

The mold fastening apparatus according to claim 1 is an apparatus for fastening a fixed mold and a movable mold in a molding machine, and is provided in one of the fixed mold and the movable mold. A gripped portion;
A clamp device that is provided on any other mold and grips the gripped portion and pulls it toward the other mold;
A shaft movable in a direction approaching and separating from the one mold by pressing the shaft end dog portion from the opposite surface of the contact surface of the other mold;
A plurality of gripping portions for gripping releasably closing said gripped portion of said being engaged connected to an end portion of one of the mold side is provided on one of the mold the said shaft,
A biasing means for constantly biasing the shaft in a direction away from the one mold;
An inner peripheral surface that holds the outer periphery of the gripping portion in a state of gripping the gripped portion when the shaft moves in a direction away from the one mold is formed in a cylindrical shape, and the shaft is one mold And a restricting means in which a groove having a diameter larger than that of the inner peripheral surface is formed so that the grip end of the grip portion is fitted to release the grip of the gripped portion. The mold can be carried as an integral mold.

According to the first aspect of the present invention, when the gripping portion and the gripped portion are provided and clamped on the pair of molds of the movable mold and the fixed mold, for example, the direction in which the movable mold moves and contacts the fixed mold A movable shaft is provided at the end of the movable mold, and a gripping part that can be opened and closed is provided at the end of the movable mold, and the movable mold is always tightened with a biasing means in the direction in which the movable mold contacts the fixed mold. When a movable mold is brought into close contact with a force, a restricting means for positioning on the contact surface is provided.
The clamped and paired molds can be removed and transported from the molding machine as they are, so that handling and storage are easy.

  The mold fastening device according to claim 2, wherein an outer periphery of the restricting means is provided so as to protrude from the other mold toward the one mold, and the portion facing the restricting means in the one mold. And a slightly larger hole having the same shape as the outer periphery of the body of the restricting means is formed, and the gripped portion is attached to the bottom of the hole, and when one mold and the other mold are fastened, By positioning the means and the hole, positioning on the contact surface between one mold and the other mold is performed.

  According to the second aspect of the present invention, the fixed mold and the movable mold are brought into contact with each other at the same position each time, and a member such as a dedicated independent pin for mutual positioning is not used but provided on the shaft portion of the gripping shaft that moves forward and backward. For example, the holding portion is guided by the inner diameter surface of the restricting means provided so as to protrude from the end face of the fixed mold, and the slightly larger reference hole provided in the end face of the other die contacting the outer peripheral face of the restricting means. It is designed to be fitted and positioned so that the positioning when the pair of molds are in contact and the fastening operation of the gripping tool can be performed simultaneously.

The mold fastening device according to claim 3 is:
It said shaft comprises a first shaft outer peripheral annular groove in the mold side end of the one with the always biased in a direction to be spaced apart from the mold of the one is provided by the biasing means,
With engaging coupling the gripper to the one of the mold side, the other cylindrical portion in which a plurality of holes on the same circumference in the mold side is Kezu設is axially moved to the first axis A second shaft to be fitted,
A plurality of rolling elements having a diameter larger than the wall thickness of the cylindrical portion fitted in the plurality of holes so as to be able to roll;
An inner peripheral annular groove having a larger diameter than the inner peripheral surface is engraved on the inner peripheral surface of the restricting means at a position corresponding to the rolling element ,
The outer circumferential annular groove of the first shaft has a groove bottom portion in which the sum of the groove depth and the thickness of the cylindrical portion of the second shaft is larger than the diameter of the rolling element, and from the middle of the outer circumferential groove. A male taper portion is formed that is connected to the outer diameter of the end on one mold side by a conical surface,
The inner circumferential annular groove of the restricting means has a groove bottom portion in which the sum of the groove depth and the thickness of the cylindrical portion is less than the diameter of the rolling element, and the cylinder extends from the groove bottom to the one mold side. A female taper portion connected by a conical surface is formed on the inner peripheral surface,
A force-increasing mechanism comprising the male taper portion, the female taper portion, and the rolling element is configured.

According to the invention of claim 3, the engagement surface between the second shaft interlocked with the collet of the gripping portion and the first shaft always urged in the axial direction is a tapered portion made of a conical surface. Further, a rolling element is interposed between these taper portions to increase the biasing force applied to the first shaft and transmit it to the second shaft to strengthen the fastening force of the collet that grips the pull stud of the gripped portion. It makes it possible.
The opening of the collet and the release of the fastening force can be operated by pressing the dog portion of the first shaft from the back of the mold with a pressing member (not shown) provided in the main body mold. Here, the mold back surface means the side surface opposite to the abutting surface.

  The mold fastening device according to claim 4, wherein the rolling element is a barrel-shaped rolling element in which the trunk is swollen, and a radius of curvature of the trunk part passing through the axis is larger than a groove bottom radius of the inner circumferential groove. It is formed slightly smaller.

  According to invention of Claim 4, by making a rolling element into a barrel-shaped rolling element, the stress to the contact surface in a barrel-shaped rolling element, the male taper part of a 1st axis | shaft, and the female taper part of a 2nd axis | shaft Concentration is relaxed and the generation of indentation can be prevented, so that the lifetime can be maintained for a long time.

  The mold fastening device according to claim 5, wherein the conical surface of the male taper portion has an arc having a radius larger than a cross-sectional radius of the barrel-shaped rolling element on an axial section of the first shaft. It is formed on a rotating surface rotated about an axis of 1.

  According to invention of Claim 5, it is a contact surface of a barrel-shaped rolling element and a male taper surface, Comprising: Of the male taper part which the outer diameter surface of the barrel-shaped rolling element in the axial cross section of a barrel-shaped rolling element contacts The self-locking function is strengthened by forming a conical surface on the rotating surface obtained by rotating an arc having a radius larger than the sectional radius of the barrel-shaped rolling element on the axial section of the first axis around the first axis. In addition, the ability to prevent the mold from being disengaged even when a large force is applied from the outside is high.

  As a result of solving the problem by the above-mentioned means, the mold fastening device of the present invention has the following effects.

  The invention according to claim 1 has an effect that the fixed mold and the movable mold are fastened and integrated, and the mounting and removing from the main mold can be greatly rationalized in terms of transportation and storage of the mold. Have.

  According to the second aspect of the present invention, accurate positioning and repeated fastening after contact between the fixed mold and the movable mold are simultaneously performed at the same position, so that the fastener is compact and space-saving. Has the effect of achieving.

  In the third aspect of the present invention, a transmission mechanism composed of a male and female tapered portion and a rolling element is provided between the fixed mold and the movable mold to form a force-increasing mechanism, so that a larger fastening force can be obtained. It has the effect that it becomes possible.

  The invention according to claim 4 has an effect that the surface pressure is reduced and no indentation is generated, and the life can be extended by interposing a barrel-shaped rolling element between the rolling surfaces of the male tapered portion and the female tapered portion. Have.

  According to a fifth aspect of the present invention, the male tapered portion rotates a conical surface around an arc having a radius larger than the cross-sectional radius of the barrel-shaped rolling element on the axial section of the first axis around the first axis. It has an effect that the stability of the self-lock function is good because it is formed on the rotating surface, and there is almost no effect on the fastening force even if some disturbance is applied to the molds that are fastened to a pair Have

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an overall explanatory view of a mold fastening device including a clamping device of the present invention, and is an example of a mold fastening device used for integrally fastening a fixed die and a movable die in a molding machine. FIG. 2 is a cross-sectional explanatory view of the mold fastening device of the present invention. FIG. 3 is an explanatory diagram of a clamped state of the self-locking mechanism in the mold fastening device of FIG. FIG. 4 is an explanatory view of an unclamped state of the self-locking mechanism in the mold fastening device of FIG.

  In FIG. 1, a fixed mold 1 and a movable mold 2 facing each other are fixed to a fixed side platen 3, a fixed side main mold 5 fixed to the movable side platen 4, and a movable side main mold 6 by a mold lock cylinder 7. ing. The mold fastening device 8 is a fastening device capable of integrating both molds when the contact surface 1a of the fixed mold and the contact surface 2a of the movable mold 2 are in contact.

  The integrated mold shown in FIG. 1 includes a gripping portion 10 including a shaft 9 that can move in a direction in which the contact surface approaches and separates from the fixed mold 1, and a biasing means 11 that constantly biases the gripping force, A gripped portion 12 is provided on the movable mold 2. Further, a restricting means 13 is provided for restricting the direction orthogonal to the contact surface when the fixed mold 1 and the movable mold 2 are in contact. The cylinder 16 provided in the fixed mold 1 as the restricting means 13 is engaged with the reference hole 2b formed in the movable mold 2 so that both molds can always be positioned at the same position.

In FIG. 2, the fixed mold 1 and the movable mold 2 can be fitted into a reference hole 2 b provided in the movable mold 2 so that the fixed mold 1 and the movable mold 2 are always in contact at the same place without being laterally displaced on the contact surface. The cylindrical body 16 having a protruding portion is fixed to be concentric with the reference counterbore 1b and the reference hole 2b of the fixed mold 1. A pull stud 17, which is a gripped portion, is fixed to the base portion of the reference hole 2 b of the movable mold 2.

The cylindrical portion 18b of the second shaft 18 that is slidable forward and backward on the axis of the cylindrical body 16 is fitted with the hole 16a of the cylindrical body 16 as a guide hole.
One end of the second shaft 18 on the projecting end side of the cylindrical body 16 is formed in a shaft shape that can guide the collet 19 that holds the head portion 17a of the pull stud 17 with the groove portion 18a. A plurality of collets 19 are mounted on the outer periphery of the groove 18a, and one end is bundled by a ring-shaped spring 20, so that the other end is pressed against the inner peripheral surface 16a by the collet claw 19a according to the diameter of the hole of the cylindrical body 16. Yes. When the collet 19 moves in the axial direction and has a small diameter, the collet 19 closes and clamps the shaft head 17a. When the diameter increases and the collet claw 19a opens and enters the groove 16c, the collet claw 19a does not grip the head 17a. .

The other end of the second shaft 18 is formed in a cylindrical portion 18 b whose outer diameter is guided by a hole 16 a near the flange surface of the cylindrical body 16. A first shaft 21 that engages with the cylindrical portion 18b of the second shaft 18 and is constantly urged in the direction of the back surface 1c of the fixed mold to apply a clamping force is provided in series on the concentricity of the second shaft 18. It has been. The first shaft 21 and the second shaft 18 are connected via a rolling element 22. As for the 1st axis | shaft 21, the grooved front-end | tip part of the side engaged with the 2nd axis | shaft 18 is guided by the internal diameter hole of the cylindrical part 18b.

  On the first shaft 21, a disc spring 23 of biasing means for biasing in the direction of the back surface 1c of the fixed mold 1 is laid so as to be movable on the shaft. One end (front end) of the disc spring is in contact with the rear end surface (anti-projecting end) of the cylindrical body 16 via a washer 24, and the rear end of the disc spring group formed by overlapping is a screw at the end of the shaft of the first shaft 21. It abuts against the end face of the nut 25 to be screwed.

  A dog 27 for operating the first shaft 21 is provided at the shaft end. When the nut 25 is screwed in, the disc spring group is compressed, and the reaction force constantly biases the first shaft 21 in the back direction. Even after the nut 25 is screwed in, a certain amount of bending allowance remains in the disc spring group.

Next, the engaging portion between the first shaft 21 and the second shaft 18 will be described.
3 and 4, the first shaft 21 and the second shaft 18 are connected via a rolling element 22. The plurality of rolling elements 22 are fitted into holes 18c that are intermittently processed in the cylindrical portion 18b, and the cylindrical portion 18b functions as a holder. In FIG. 3, the ring-shaped groove 21a formed at the tip portion of the first shaft 21 is used as the inner guide surface of the rolling element 22, and the groove 16b formed on the inner diameter side of the cylindrical body 16 is engaged as the outer guide surface. Yes. The groove 16 b is formed on the inner diameter side of the collars 26 and 28.

Next, the mechanism of the engaging portion will be described.
In FIG. 2, the ring-shaped groove 21 a on the inner guide surface of the rolling element 22 is formed in an arc shape on a plane passing through the axis of the first shaft 21. The groove depth is equal to the radius of the rolling element 22.
Further, an arc having a radius larger than the cross-sectional radius of the rolling element 22 on the shaft cross section of the shaft 21 is rotated around the first axis from the position about half the groove depth to the outer diameter of the shaft 21. A conical surface 21b which is a rotating surface is formed. This rotating surface is called a male taper portion.
In addition, here, it is not necessarily limited to the circular arc, but may be a smooth curved line having a substantially circular arc shape, and the tangent line of the portion in contact with the rolling element 22 from the outer diameter of the shaft 21 toward the groove 21a and the shaft 21 Any shape can be used as long as the angle between the axis and the axis becomes loose.

  While the collet 19 is pressed on the nut 25 side of the first shaft 21, the first shaft 21 moves in the direction of the contact surface of the mold, compresses the disc spring group, and pulls the second shaft 18 into the pull stud. Move closer to 17. The collet 19 also moves in the same direction, and the collet claw 19a opens and does not grip the head 17a of the pull stud 17. At this time, since the first shaft 21 moves in the direction of the pull stud 17, the rolling element 22 has a conical surface 21b larger than the rolling element radius of the first shaft 21, the cage surface 18c of the cylindrical portion 18b, and the collar. 26, the rolling elements 22 are kept floating in the holes of the cage.

  When the pressure on the nut 25 is released, the first shaft 21 moves away from the pull stud 17. Since the rolling element 22 is sandwiched between the male and female taper portions, the second shaft 18 is also pulled in the same direction so that the collet claw 19a is accommodated in the hole 16a, and the collet 19 is closed and grips the head 17a of the pull stud 17. At this time, the force that pulls the head portion 17a in the direction of the fixed mold 1 is not the compression reaction force of the disc spring group, but the rolling element 22 has an arc surface larger than the rolling element radius of the first shaft 21 and a conical surface of the collar 26. The force is increased by the wedge effect caused by being held by 26a.

Therefore, even if the total mass of the fixed mold 1 and the movable mold 2 is increased, the fastening force when integrated can be increased. Further, when the fastening force over the mold separation force were energizing the disc spring occurs, because the arc-shaped as in the first axis 21 is inclined surface 21b, the disc spring is compressed above fastening force, the first since the shaft 21 is the rolling element 22 moves in the axial direction moves toward loose inclination of the inclined surface 21b, axial force becomes to be dispersed in the radial direction of the component force, become self-locking Mold integration will not be lost. For this reason, it is safe and easy to handle the integrated mold in the exchange during the molding operation and the storage and storage operation during the replacement.

Next, the operation of this embodiment will be described.
In FIG. 2, when the dog 27 is pushed in by pressing means (not shown) provided on the stationary main mold 5, the disc spring 23 is compressed and the first shaft 21 moves toward the end of the mold. The tip of the shaft 21 in the pushing direction is formed in the shape shown in FIG. The rolling element 22 falls into the slack portion of the shaft 21, and the state shown in FIG. Therefore, since the second shaft 18 can slide through the hole 16a of the cylindrical body 16, the collet 19 also slides the inner diameter of the cylindrical body 16 in the axial direction, and the collet claw 19a fits into the groove 16c having a large diameter. At this time, since the inner diameter of the collet claw 19a is larger than the outer diameter of the head 17a of the pull stud 17, the pull stud 17 can be unclamped.

  In this state, the integrated mold is mounted on the fixed main mold 5 and the movable main mold 6, the fixed mold 1 and the movable mold 2 are locked by the mold lock cylinder 7, and the fixed main mold 5 This is possible by operating the dog 27 with a pressing member provided on the side.

  When the molding operation is completed and the die is integrated when the used die is removed from the machine, the pull stud 17 of the other die is inserted into the collet 19 while the dog 27 remains pushed. When the dog 27 is retracted without the pressing force, the first shaft 21 is also retracted by the force of the disc spring 23, the second shaft 18 connected by the rolling element 22 is retracted, and the claw 19A of the collet 19 is the cylinder. The head 17A of the pull stud 17 is gripped and pulled while sliding through the 16 holes 16a.

  Since the pull stud 17 is fixed to one of the molds and does not move, the second shaft 18 is also fixed through the collet 19, and when only the first shaft 21 is retracted, the rolling element 22 is It is pushed out from the slack portion of the first shaft 21 and rides on the inclined shaft 21 b of the first shaft 21. The rolled-up rolling element 22 is increased by the conical surface 21 b and the conical surface 26 a of the collar 26, and pulls the second shaft 18 with a force greater than the spring force of the disc spring 23.

Next, an external force for separating the clamped mold acts in a direction to release the engagement between the pull stud 17 and the collet 19.
That is, the pull stud 17, collet 19, second shaft 18, rolling element 22, first shaft 21, nut 25, and disc spring 23 act in sequence to generate a fastening force for the disc reaction compression die. ing. The second shaft 18 presses the rolling element 22 against the conical surface 26a of the collar 26 and the conical surface 21b of the first shaft 21. The reaction force of the inclined surface of the collar 26 causes the first shaft 21 to exert an external force in the axial direction. Does not hang.

  In particular, the conical surface of the female taper portion is a concave conical surface and is brought into contact with an arc having a larger radius than the barrel-shaped rolling element. When some external force is applied to release the clamp of the integral mold and the pull stud 17 is pulled out against the clamping force of the disc spring, the rolling element 22 is pushed from the male tapered surface. A force pushed in the axial direction along the concave conical surface of the collar 26 acts.

  At this time, as the rolling element 22 moves in the axial direction, the first shaft 21 moves in the direction in which the pull stud 17 moves away from the second shaft, but at this time, the conical surface 21b. Thus, the angle between the tangent of the portion in contact with the rolling element 22 and the axis is forced to move in a loose direction. Therefore, the first shaft 21 is prevented from moving in the direction of decreasing the amount of compression of the disc spring 23, which leads to weakening the urging force of the disc spring 23, and the boosting effect is not weakened, and the self-locking function is achieved. Maintained.

Since the external force for removing the clamp is self-locked as described above, the rolling element 22 is pressed against the collar 26 and the male taper portion of the first shaft 21, so that the contact surface is not indented. Stress is reduced. The diameter of the rolling element 22 should be larger.
By introducing a barrel-shaped rolling element into the rolling element, the allowable load capacity is dramatically increased, and the breaking load of the pull stud 17, the collet 19, the second shaft 18, and the first shaft 21 can be compared with that of the die. It has become possible to reduce the size and life of the equipment.

Compared to conventional fastening devices that use steel balls, it has several times the clamping ability, and a self-locking mechanism can further improve safety.
By adopting a cylindrical body, it can be used as a reference pin, saving space and reducing parts.

BRIEF DESCRIPTION OF THE DRAWINGS It is whole explanatory drawing of the metal mold fastening apparatus containing the clamp apparatus of this invention, Comprising: It is the metal mold fastening apparatus example used for the integrated fastening of the fixed metal mold | die and a movable metal mold | die in a molding machine. It is a section explanatory view of the metallic mold fastening device of the present invention. It is explanatory drawing of the clamped state of the self-locking mechanism in the metal mold fastening apparatus of FIG. It is explanatory drawing of the unclamped state of the self-locking mechanism in the metal mold fastening apparatus of FIG.

Explanation of symbols

1 fixed mold 2 movable mold 3 fixed side platen 4 movable side platen 5 fixed side main mold 6 movable side main mold 7 mold lock cylinder 8 mold fastening device 10 gripping part 11 biasing means 12 gripped part 13 regulating means 16 cylinder 17 pull stud 18 second shaft 19 collet 20 ring-shaped spring 21 first shaft 22 rolling element 23 disc spring 24 washer 25 nut 26, 28 collar

Claims (5)

An apparatus for fastening a fixed mold and a movable mold in a molding machine, a gripped portion provided on one of the fixed mold and the movable mold,
A clamp device that is provided on any other mold and grips the gripped portion and pulls it toward the other mold;
A shaft movable in a direction approaching and separating from the one mold by pressing the shaft end dog portion from the opposite surface of the contact surface of the other mold;
A plurality of gripping portions for gripping releasably closing said gripped portion of said being engaged connected to an end portion of one of the mold side is provided on one of the mold the said shaft,
A biasing means for constantly biasing the shaft in a direction away from the one mold;
An inner peripheral surface that holds the outer periphery of the gripping portion in a state of gripping the gripped portion when the shaft moves in a direction away from the one mold is formed in a cylindrical shape, and the shaft is one mold And a regulating means in which a groove having a larger diameter than the inner peripheral surface is formed, in which the gripping portion shaft end is fitted by movement to the side and the gripping of the gripped portion is released .
A mold fastening device characterized in that a fixed mold and a movable mold can be carried as a single mold.
  The outer periphery of the restricting means is provided so as to protrude from the other mold to the one mold side, and a portion of the one mold facing the restricting means has the same shape as the outer periphery of the main body of the restricting means and slightly A large hole is formed, and the gripped portion is attached to the bottom of the hole, and when the one mold and the other mold are fastened, the restricting means and the hole engage with each other. 2. The mold fastening apparatus according to claim 1, wherein positioning is performed on a contact surface between the mold and the other mold. The axis is
A first shaft which is an outer peripheral annular groove provided in the mold-side end portion of the one with the always biased in a direction to be spaced apart from the mold of the one by the biasing means,
With engaging coupling the gripper to the one of the mold side, the other cylindrical portion in which a plurality of holes on the same circumference in the mold side is Kezu設is axially moved to the first axis A second shaft to be fitted,
A plurality of rolling elements having a diameter larger than the wall thickness of the cylindrical portion fitted in the plurality of holes so as to be able to roll;
An inner peripheral annular groove having a larger diameter than the inner peripheral surface is engraved on the inner peripheral surface of the restricting means at a position corresponding to the rolling element ,
The outer circumferential annular groove of the first shaft has a groove bottom portion in which the sum of the groove depth and the thickness of the cylindrical portion of the second shaft is larger than the diameter of the rolling element, and from the middle of the outer circumferential groove. A male taper portion is formed that is connected to the outer diameter of the end on one mold side by a conical surface,
The inner circumferential annular groove of the restricting means has a groove bottom portion in which the sum of the groove depth and the thickness of the cylindrical portion is less than the diameter of the rolling element, and the cylinder extends from the groove bottom to the one mold side. A female taper portion connected by a conical surface is formed on the inner peripheral surface,
3. The mold fastening device according to claim 1, wherein a force-increasing mechanism including the male taper portion, the female taper portion, and the rolling element is configured.
  The rolling element according to claim 3, wherein the rolling element is a barrel-shaped rolling element having a swollen body, and a radius of curvature of a body part passing through an axis thereof is formed slightly smaller than a groove bottom radius of the inner circumferential annular groove. Mold fastening device. The conical surface of the male taper portion is formed on a rotation surface obtained by rotating an arc having a radius larger than the cross-sectional radius of the barrel-shaped rolling element on the axial cross section of the first shaft around the first axis. The mold fastening apparatus according to claim 3 or 4, wherein the mold fastening apparatus is formed.