WO2024106540A1

WO2024106540A1 - Forming device

Info

Publication number: WO2024106540A1
Application number: PCT/JP2023/041500
Authority: WO
Inventors: 悠生山▲崎▼; 博成佐々木
Original assignee: 芝浦機械株式会社
Priority date: 2022-11-18
Filing date: 2023-11-17
Publication date: 2024-05-23
Also published as: JP2024073894A

Abstract

This forming device comprises: a tie bar including a recessed mold-clamping groove portion; a movable die plate; and a pair of mold-clamping split nuts which include a convex protruding portion and are provided on the movable die plate, the pair of mold-clamping split nuts being configured such that, in a state in which molds are clamped together, the protruding portion meshes with the mold-clamping groove portion to regulate movement of the movable die plate relative to the tie bar. The protruding portion is formed such that, when viewed from a direction orthogonal to the tie bar, a tip-end portion, which is the part of the protruding portion that is introduced into the mold-clamping groove portion first, tapers on both sides in the direction in which the tie bar extends.

Description

Molding Equipment

This invention relates to a molding device equipped with a split nut for clamping.

　Forming devices equipped with split nuts for clamping are known in the past. Such split nuts for clamping are disclosed, for example, in Japanese Utility Model Application Publication No. 2-40112.

The above-mentioned Japanese Utility Model Application Publication No. 2-40112 discloses a molding device including a pair of split nuts provided on a platen to which a movable die is attached, and a tie rod having a groove. The split nuts have a protrusion that engages with the groove. The platen is configured such that movement relative to the tie rod is restricted by the protrusion engaging with the groove. When viewed from a direction perpendicular to the tie rod, the protrusion extends from the base of the protrusion to the tip in a direction perpendicular to the direction in which the tie bar extends (the radial direction of the tie bar). The groove is formed in a concave shape corresponding to the protrusion. In other words, the protrusion and the groove are surfaces that are arranged opposite each other in a meshed state, and have surfaces that extend in a direction perpendicular to the direction in which the tie bar extends.

Japanese Utility Model Application Publication No. 2-40112

In the molding device of the above-mentioned Japanese Utility Model Application Publication No. 2-40112, the protrusions and grooves each have surfaces that are arranged opposite each other in an interlocking state and that extend in a direction perpendicular to the direction in which the tie bars extend. For this reason, high precision is required in positioning the protrusions relative to the grooves in the direction in which the tie bars extend so that the protrusions do not interfere with the grooves when transitioning from a non-interlocking state to an interlocking state. For this reason, there has been a demand for a method that makes it easier to position the protrusions relative to the grooves in the direction in which the tie bars extend.

This invention was made to solve the above problems, and one object of the invention is to provide a molding device that can easily position the protruding portion of the clamping split nut relative to the clamping groove of the tie bar in the direction in which the tie bar extends.

In order to achieve the above object, a molding device in one aspect of the present invention comprises a tie bar including a concave clamping groove, a movable die plate that moves along the tie bar while holding a movable die, and a pair of clamping split nuts provided on the movable die plate that include convex protrusions and are configured to restrict the movement of the movable die plate relative to the tie bar by engaging the protrusions with the clamping groove when the die is closed, and the protrusions are formed so that, when viewed from a direction perpendicular to the tie bar, the tip portion, which is the portion of the protrusion that is first introduced inside the clamping groove, is tapered on both sides in the direction in which the tie bar extends.

In one aspect of the present invention, as described above, the molding device includes a convex protrusion, and is configured to restrict the movement of the movable die plate relative to the tie bar by engaging the protrusion with the clamping groove when the die is closed, and a pair of clamping split nuts are provided on the movable die plate, and the protrusion is formed so that its tip is tapered on both sides in the direction in which the tie bar extends when viewed from a direction perpendicular to the tie bar. As a result, since the tip of the protrusion is tapered on both sides in the direction in which the tie bar extends, a large tolerance range (so-called play) in the direction in which the tie bar extends in which the protrusion can engage with the clamping groove when engaging with the clamping groove can be secured, compared to a conventional configuration in which the protrusion has a surface on one side of the direction in which the tie bar extends that extends perpendicular to the direction in which the tie bar extends. That is, even if the meshing position of the protrusion with respect to the mold clamping groove is shifted from the target position in the direction in which the tie bar extends, the protrusion can be guided (slid) to the target position by meshing with the tie bar on either side of the tapered tie bar in the direction in which the protrusion extends. Therefore, the positioning of the protrusion of the mold clamping split nut with respect to the mold clamping groove of the tie bar in the direction in which the tie bar extends can be easily performed. In addition, since the protrusion can be guided (slid) to the target position by meshing with the tie bar on either side of the tapered tie bar in the direction in which the protrusion extends, the gap between the protrusion and the mold clamping groove in the direction in which the tie bar extends can be reduced. Therefore, when closing one of the gaps on both sides of the protrusion in the direction in which the tie bar extends after the meshing state, there is almost no need to move (accelerate) the protrusion with respect to the tie bar, so that the impact when the protrusion comes into contact with the tie bar when the gap is closed can be reduced. Furthermore, since the protrusion can be guided (slid) to the desired position as described above, it is possible to prevent the protrusion from colliding with the convex portion between the adjacent clamping grooves of the tie bar during engagement.

In the molding device according to the above aspect, preferably, the protruding portion of the clamping split nut has an arc-shaped tip, tapering on both sides in the direction in which the tie bar extends. With this configuration, the arc-shaped tip makes it easier to guide (slide) the protruding portion to the desired position in the direction in which the tie bar extends when engaging. This makes it easier to position the protruding portion of the clamping split nut relative to the clamping groove of the tie bar in the direction in which the tie bar extends. Also, compared to when the tip of the protruding portion is sharp, the arc-shaped tip makes it possible to suppress damage to the protruding portion due to cracks or breakage.

In the molding device according to the above aspect, preferably, the protruding portion of the split nut for mold clamping has a nut-side tapered surface provided on both sides of the tip when viewed from a direction perpendicular to the tie bar, and is formed so as to taper toward the tip by the nut-side tapered surface, and the mold clamping groove of the tie bar has a tie-bar-side tapered surface arranged substantially parallel to the nut-side tapered surface. With this configuration, the protruding portion can be guided (slid into) to the desired position when engaging in the direction in which the tie bar extends, not only by the tip of the protruding portion but also by the nut-side tapered surface tapered toward the tip of the protruding portion. Therefore, it is easier to position the protruding portion of the split nut for mold clamping relative to the mold clamping groove of the tie bar in the direction in which the tie bar extends. In addition, the nut-side tapered surface and the tie-bar-side tapered surface are substantially parallel to each other, so that a large contact area between the protruding portion of the split nut for mold clamping and the mold clamping groove of the tie bar can be secured. Therefore, it is possible to suppress the occurrence of damage such as cracks and breaks caused by the application of large stress to the split nut for mold clamping and the tie bar.

In this case, the inclination angle of each of the nut side tapered surface and the tie bar side tapered surface relative to the radial direction of the tie bar is preferably greater than 0 degrees and less than 10 degrees. With this configuration, the nut side tapered surface and the tie bar side tapered surface are each formed with a relatively small inclination angle, so that when the movable die plate receives a force in a direction away from the fixed die plate during injection of molten metal into the die, the component of the force in the opening direction acting on the pair of clamping split nuts can be reduced.

In the above-mentioned configuration in which the protruding portion of the clamping split nut has a nut-side tapered surface and the clamping groove of the tie bar has a tie-bar-side tapered surface, preferably, when viewed from a direction perpendicular to the tie bar, the protruding portion of the clamping split nut and the clamping groove are each formed so that one side portion in the direction in which the tie bar extends and the other side portion are symmetrical with respect to the center line in the direction in which the tie bar extends of each of the protruding portion of the clamping split nut and the clamping groove. With this configuration, the protruding portion can be stably guided (slid into) the desired position during engagement on both the one side and the other side in the direction in which the tie bar extends.

In the molding device according to the above aspect, preferably, the clamping split nut is provided between adjacent protrusions when viewed from a direction perpendicular to the tie bar and includes a recess with an arc-shaped bottom, and the tie bar is provided at the outer circumferential end of the tie bar and includes a flat surface that forms a space between the recess of the clamping split nut when viewed from a direction perpendicular to the tie bar. With this configuration, the space allows the protrusion of the clamping split nut and the clamping groove of the tie bar to be roughly engaged between the adjacent protrusions. This makes it easier to position the protrusion of the clamping split nut relative to the clamping groove of the tie bar in the direction in which the tie bar extends.

In this case, preferably, a chamfer is provided on the edge of the flat surface of the tie bar when viewed from a direction perpendicular to the tie bar. With this configuration, the protrusion can be guided (slid into) the target position in the direction in which the tie bar extends when engaging, not only by the tip of the protrusion, but also by the chamfer of the tie bar. This makes it even easier to position the protrusion of the clamping split nut relative to the clamping groove of the tie bar in the direction in which the tie bar extends.

In the molding device according to the above aspect, preferably, in an engaged state in which the clamping split nut is engaged with the clamping groove, the total gap between the protruding portion of the clamping split nut and the protruding portion of the clamping groove in the direction in which the tie bar extends is 0.2 mm or more and 0.5 mm or less. With this configuration, the total gap between the protruding portion and the protruding portion of the clamping groove in the direction in which the tie bar extends can be made relatively small, so that the operation of closing the gap before the injection of molten metal into the mold can be carried out in a relatively short time.

In the molding device according to the above aspect, preferably, in an engaged state in which the clamping split nut is engaged with the clamping groove, the total gap between the protruding portion of the clamping split nut and the clamping groove in the direction in which the tie bar extends is smaller than the gap between the protruding portion of the clamping split nut and the clamping groove in the radial direction of the tie bar. With this configuration, the total gap between the protruding portion and the clamping groove in the direction in which the tie bar extends can be made relatively small, so that the operation of closing the gap before the injection of molten metal into the mold can be performed in a relatively short time. Also, in the engaged state, the gap between the protruding portion of the clamping split nut and the clamping groove in the radial direction of the tie bar can be made relatively large, so that the collision between the protruding portion and the clamping groove in the radial direction of the tie bar can be avoided.

The molding device according to the above aspect preferably further comprises a die plate drive device including a servo motor and a movement mechanism driven by the servo motor to move the clamping split nut together with the moving die plate in the direction in which the tie bar extends, and a control unit that controls the clamping split nut to engage with the clamping groove when the servo motor is turned off after the clamping split nut is moved by the servo motor and the movement mechanism to a predetermined position where the clamping split nut and the clamping groove face each other in the radial direction of the tie bar. With this configuration, by turning off the servo motor, the engagement can be performed without restricting the position of the protrusion in the direction in which the tie bar extends, so that the positioning of the protrusion of the clamping split nut relative to the clamping groove of the tie bar in the direction in which the tie bar extends can be more easily performed.

As described above, according to the present invention, it is possible to easily position the protruding portion of the clamping split nut relative to the clamping groove of the tie bar in the direction in which the tie bar extends.

1 is a schematic side view showing an overall configuration of a molding apparatus according to an embodiment. FIG. 2 is a perspective view showing a tie bar of a molding apparatus and a clamping split nut of a clamping apparatus according to an embodiment. 3 is a cross-sectional view taken along line III-III in FIG. 2.

Below, an embodiment of the present invention will be described with reference to the drawings.

[Embodiment]
The configuration of a molding apparatus 100 according to an embodiment will be described with reference to Figures 1 to 3. The molding apparatus 100 according to the embodiment is configured by a die-casting machine.

In each figure, the direction in which the tie bar 10 extends is indicated as the X direction. Within the X direction, the direction from the movable die M2 to the fixed die M1 is indicated as the X1 direction, and the opposite direction is indicated as the X2 direction.

In each figure, the movement direction of the clamping split nut 3 is indicated by the Z direction. The Z direction is perpendicular to the X direction and is also the up-down direction. Within the Z direction, the upper side is indicated by the Z1 direction, and the lower side is indicated by the Z2 direction.

In each figure, the direction perpendicular to both the X and Z directions is indicated as the Y direction.

In each figure, the radial direction of the tie bar 10 (the direction perpendicular to the tie bar 10) is indicated by R. In other words, the direction perpendicular to the center line C1 of the tie bar 10 is indicated by R.

In each figure, the circumferential direction of the tie bar 10 is indicated by RO.

(Schematic configuration of molding device)
1 is a horizontal molding machine that performs molding by horizontally reciprocating a movable die M2 relative to a fixed die M1. The molding device 100 is configured to manufacture a molded product by injecting molten metal into a cavity in the die M and solidifying it.

The molding device 100 includes an injection device 101, a molding device main body 102 to which a mold M is attached, a mold clamping device 103 having a split nut 3 for clamping, and a control unit 104.

One clamping device 103 is provided for each tie bar 10. Each clamping device 103 has a pair of clamping split nuts 3. The pair of clamping split nuts 3 are configured to restrict the movement of the moving die plate 12 relative to the tie bar 10 by engaging with the clamping groove portion 10a of the tie bar 10 when the die M is closed.

(Configuration of the injection device)
The injection device 101 includes a cylindrical sleeve 101a, a plunger 101b, and a plunger drive device (not shown).

The sleeve 101a has a pouring port 101c at the top. The sleeve 101a is configured so that, when the mold M is closed, molten metal is poured through the pouring port 101c by a pouring device including a ladle.

The plunger 101b is configured to be movable back and forth within the sleeve 101a. The plunger 101b is moved by a plunger drive device. The plunger 101b is configured to move forward (in the X2 direction) with molten metal poured into the sleeve 101a, thereby injecting the molten metal into a cavity in the mold M.

(Configuration of molding device body)
The molding device main body 102 includes a plurality of tie bars 10, a fixed die plate 11, a movable die plate 12, a die plate driving device 13 for the movable die plate 12, and a release agent application device 14.

The tie bar 10 includes a concave clamping groove 10a. The clamping groove 10a is formed at the end of the tie bar 10 in the X2 direction. A plurality of clamping grooves 10a are provided and aligned in the X direction. The clamping grooves 10a extend in the circumferential direction of the tie bar 10.

As an example, the radius r1 of the tie bar 10 is 80 mm. In other words, the distance (r1) from the center line C1 of the tie bar 10 to the outer circumferential surface 10b of the tie bar 10 is 80 mm.

The fixed die plate 11 is configured to hold the fixed die M1. As an example, the fixed die M1 is fixed to the fixed die plate 11 by a clamp member. The above-mentioned injection device 101 is provided on the fixed die plate 11. Furthermore, the cylinder portion 15b of the clamping cylinder 15 is integrally provided on the fixed die plate 11. Furthermore, the piston portion 15a of the clamping cylinder 15 is integrally provided on the tie bar 10.

More specifically, one clamping cylinder 15 is provided for each tie bar 10. As an example, the clamping cylinder 15 is a hydraulic cylinder. The clamping cylinder 15 has a piston portion 15a and a cylindrical cylinder portion 15b that covers the piston portion 15a. The piston portion 15a is formed by the tie bar 10 itself. The head portion of the piston portion 15a is disposed near the end of the tie bar 10 on the X1 direction side, which is the opposite side to the clamping groove portion 10a side. The cylinder portion 15b is formed by the fixed die plate 11 itself.

The clamping cylinder 15 is configured to close the mold M, move the pair of clamping split nuts 3 in the Z direction to engage with the tie bar 10, and then move the piston portion 15a in the X1 direction to clamp the mold M. In detail, the clamping cylinder 15 is configured to move the tie bar 10 having the piston portion 15a and the clamping groove portion 10a in the X1 direction. As a result, the clamping cylinder 15 is configured to press the pair of clamping split nuts 3 (movable die plate 12) in the X1 direction with the clamping groove portion 10a, and to restrict the movement of the movable die plate 12 in the direction away from the fixed mold M1 by the clamping groove portion 10a when the molten metal is injected.

The movable die plate 12 is configured to move along the tie bars 10 while holding the movable die M2. As an example, the movable die M2 is fixed to the movable die plate 12 by a clamp member. The movable die plate 12 is provided with a clamping device 103. In detail, the clamping device 103 is fixed to the surface of the movable die plate 12 on the X2 direction side by a fixing member such as a bolt.

The drive of the die plate drive device 13 is controlled by the control unit 104. The die plate drive device 13 supports the moving die plate 12 from below, and is configured to move the moving die plate 12 forward and backward in the X direction along the tie bars 10.

The die plate driving device 13 includes a servo motor 13a and a moving mechanism 13b driven by the servo motor 13a. The moving mechanism 13b is configured so that the moving die plate 12 is installed from above and moves the clamping split nut 3 together with the moving die plate 12 in the direction in which the tie bar 10 extends (X direction). The moving mechanism 13b includes a ball screw and is a feed mechanism that feeds the clamping split nut 3 (die plate driving device 13) in the X direction. The moving mechanism 13b is driven by the servo motor 13a and is configured so that the clamping split nut 3 (die plate driving device 13) can be accurately positioned in the X direction. The moving die plate 12 is moved by the die plate driving device 13 between the mold opening position shown in FIG. 1 and the mold closing position where the moving die M2 and the fixed die M1 are in contact or close to each other.

The die plate drive device 13 is configured to move the clamping split nut 3 to a predetermined position where the clamping split nut 3 and the clamping groove 10a face each other in the radial direction of the tie bar 10 using the servo motor 13a and the movement mechanism 13b. After that, with the servo motor 13a turned off, the clamping device 103 is configured to move the clamping split nut 3 in the Z direction using the split nut drive unit 2 to engage with the clamping groove 10a.

The coating device 14 is configured to coat the mold release agent on the mold M that is in an open state by the die plate driving device 13. The coating device 14 is equipped with an injection nozzle that sprays the mold release agent and a nozzle moving device that moves the injection nozzle.

(Configuration of the mold clamping device)
The mold clamping device 103 includes a split nut drive unit 2 and a pair of split nuts 3 for mold clamping.

The split nut drive unit 2 shown in Figures 2 and 3 is controlled by the control unit 104. As one example, the split nut drive unit 2 includes a fluid-driven or electric motor-driven cylinder, and is configured to move the split nut drive unit 2 in the Z direction as the cylinder expands and contracts.

A pair of clamping split nuts 3 are provided on the movable die plate 12. Therefore, the clamping split nuts 3 move in the X direction together with the movable die plate 12 by the die plate drive device 13. The pair of clamping split nuts 3 are arranged to face each other in the Z direction with the tie bar 10 in between. The clamping split nuts 3 include a convex protrusion 30 (tooth portion).

In detail, the protrusion 30 is provided on the surface facing the outer peripheral surface 10b of the tie bar 10. The protrusion 30 protrudes toward the center line C1 of the tie bar 10. A plurality of protrusions 30 are provided so as to be aligned in the X direction at the same pitch P as the clamping groove 10a of the tie bar 10. The pitch P refers to the interval at which adjacent protrusions 30 are repeatedly arranged in the direction in which the tie bar 10 extends (X direction). As an example, the pitch P is 25 mm.

When engaged with the tie bar 10, the protrusion 30 extends in the circumferential direction of the tie bar 10. The clamping split nut 3 is configured such that when the die M is closed, the protrusion 30 engages with the clamping groove 10a, thereby restricting the movement of the moving die plate 12 relative to the tie bar 10.

Referring to FIG. 3, when viewed from a direction perpendicular to the tie bar 10, the protrusion 30 is formed so that the tip 31, which is the portion of the protrusion 30 that is first introduced into the inside of the mold clamping groove 10a, tapers on both sides in the direction in which the tie bar 10 extends (X direction).

The protruding portion 30 of the split nut 3 for mold clamping is formed so that the tip 31 is arc-shaped and tapers on both sides in the direction in which the tie bar 10 extends. In detail, the protruding portion 30 of the split nut 3 for mold clamping is formed so that the tip 31 is arc-shaped. "Arc-shaped" includes not only a perfect circle shape, but also a shape close to a perfect circle that follows a perfect circle (such as an ellipse).

As an example, the radius r2 of the arc-shaped tip 31 of the protrusion 30 is 6.0 mm. When viewed from a direction perpendicular to the tie bar 10 (direction R), the tip 31 of the protrusion 30 has a slight straight surface that is parallel to the center line C1 at the tip position that is closest to the center line C1 of the tie bar 10. The protrusion does not have to have a straight surface.

The clamping groove 10a of the tie bar 10 with which the protrusion 30 engages is formed in a shape that is approximately similar to the protrusion 30. In detail, the clamping groove 10a is formed as an arc-shaped recess, similar to the tip 31 of the protrusion 30. As an example, the radius r3 of the arc-shaped clamping groove 10a is 5.8 mm. Note that the radius r3 may be greater than the radius r2.

When viewed from a direction perpendicular to the tie bar 10 (direction R), the protruding portion 30 of the clamping split nut 3 has nut-side tapered surfaces 32 provided on both sides of the tip portion 31. The protruding portion 30 is formed so as to taper toward the tip portion 31 by the nut-side tapered surfaces 32. The inclination angle θ of the nut-side tapered surfaces 32 relative to the radial direction of the tie bar 10 is greater than 0 degrees and less than 10 degrees. As a specific example, the inclination angle θ is 2 degrees.

Furthermore, the clamping groove portion 10a of the tie bar 10 has a tie bar side tapered surface 10c that is arranged facing and approximately parallel to the nut side tapered surface 32 in the engaged state. The inclination angle of the tie bar side tapered surface 10c with respect to the radial direction (R direction) of the tie bar 10 is the same as the inclination angle θ of the nut side tapered surface 32.

When viewed from a direction perpendicular to the tie bar 10 (R direction), the protrusion 30 of the split nut 3 for mold clamping is formed so that one side portion A1 in the direction in which the tie bar 10 extends (X direction) and the other side portion A2 are symmetrical with respect to the center line C2 of the direction in which the tie bar 10 extends of the protrusion 30 of the split nut 3 for mold clamping. In short, as shown in Figure 3, in a drawing in which the X direction extends left and right, the protrusion 30 is formed in an equally convex shape on both the left and right.

Similarly, when viewed from a direction perpendicular to the tie bar 10 (R direction), the clamping groove 10a is formed so that one side portion B1 in the direction in which the tie bar 10 extends and the other side portion B2 are symmetrical with respect to the center line C2 of the direction in which the tie bar 10 extends (X direction) of the clamping groove 10a. In short, as shown in Figure 3, in a drawing in which the X direction extends left and right, the clamping groove 10a is formed in an equally concave shape on both the left and right.

A space S is formed between adjacent protrusions 30 of the tie bar 10. In detail, the clamping split nut 3 includes a recess 33 with an arc-shaped bottom portion, which is provided between adjacent protrusions 30 when viewed from a direction perpendicular to the tie bar 10 (direction R). The tie bar 10 includes a flat surface 10d that is provided at the outer circumferential end of the tie bar 10 and forms a space S between the recess 33 of the clamping split nut 3 when viewed from a direction perpendicular to the tie bar 10.

When viewed from a direction perpendicular to the tie bar 10, a chamfered portion 10e is provided on the edge portion (both ends in the X direction) of the flat surface 10d of the tie bar 10. As an example, the chamfered portion 10e is formed by R-chamfering. As an example, the radius r4 of the chamfered portion 10e is 0.5 mm.

When the mold clamping split nut 3 is engaged with the mold clamping groove 10a, a gap is formed between the mold clamping split nut 3 and the mold clamping groove 10a.

In detail, as one example, in the engaged state, the total gap L1 (= L1a + L1b) between the protrusion 30 of the clamping split nut 3 and the clamping groove 10a in the direction in which the tie bar 10 extends is 0.2 mm or more and 0.5 mm or less. As a specific example, the gap L1 is 0.3 mm.

Furthermore, in the meshed state, the total gap L1 between the protrusion 30 of the clamping split nut 3 and the clamping groove 10a on both sides of the protrusion 30 in the direction in which the tie bar 10 extends is smaller than the gap L2 between the protrusion 30 of the clamping split nut 3 and the clamping groove 10a in the radial direction (R direction) of the tie bar 10. As a specific example, when the gap L1 is 0.3 mm, the gap L2 is 0.5 mm.

(Configuration of the control unit)
As an example, the control unit 104 includes a CPU (Central Processing Unit), a memory, etc., and is configured as a control panel. The control unit 104 is configured to control the driving of the die plate driving device 13 and the mold clamping device 103.

In detail, the control unit 104 is configured to use the servo motor 13a and movement mechanism 13b of the die plate drive unit 13 to move the split nut 3 for mold clamping to a predetermined position where the split nut 3 for mold clamping and the groove 10a for mold clamping face each other in the radial direction (R direction) of the tie bar 10, and then, with the servo motor 13a turned off, control the split nut drive unit 2 of the clamping device 103 to engage the split nut 3 for mold clamping with the groove 10a for mold clamping.

(Method of engagement between mold clamping split nut and mold clamping groove)
The procedure for engaging the mold clamping split nut 3 with the mold clamping groove portion 10a will be described with reference to Figs.

First, in a non-engaged state where the clamping split nut 3 and the clamping groove 10a are not engaged, the clamping device 103 is moved in the X direction together with the movable die plate 12 by the die plate driving device 13. As a result, the clamping split nut 3 is positioned at a predetermined position in the radial direction (R direction) of the tie bar 10 where the clamping split nut 3 and the clamping groove 10a face each other.

Next, the servo motor 13a of the die plate drive device 13 is turned off. In other words, the state in which the servo motor 13a constrains the position of the clamping split nut 3 in the X direction is released, and a servo-free state is established.

Next, the split nut drive unit 2 transitions from a non-engaged state to an engaged state. That is, the clamping split nut 3 (protrusion 30) is moved in the Z direction toward the clamping groove 10a of the tie bar 10. At this time, even if the protrusion 30 is displaced in the X direction from the predetermined position where it should be placed relative to the clamping groove 10a, the arc-shaped tip 31 and the nut side tapered surfaces 32 on both sides in the X direction are brought into contact with the convex parts between the clamping grooves 10a, so that the protrusion 30 is guided (slid into) to a predetermined position where it engages with the clamping groove 10a in the direction in which the tie bar 10 extends.

Next, the clamping split nut 3 is moved slightly in the X1 direction relative to the tie bar 10 by the clamping cylinder 15, filling the gap L1b. In this state, molten metal is injected into the mold M. Note that the gap L1b is extremely small. Because of this, the clamping split nut 3 is almost in contact with the clamping groove 10a, and so when the gap L1b is filled and becomes zero, the impact applied to the clamping split nut 3 and the clamping groove 10a is extremely small.

(Effects of the embodiment)
In this embodiment, the following effects can be obtained.

As described above, this embodiment includes a convex protrusion 30, and is configured to restrict the movement of the movable die plate 12 relative to the tie bar 10 by engaging the protrusion 30 with the clamping groove 10a when the die M is closed, and a pair of clamping split nuts 3 are provided on the movable die plate 12, and the protrusion 30 is formed so that the tip 31 tapers on both sides in the direction in which the tie bar 10 extends when viewed from a direction perpendicular to the tie bar 10. As a result, the tip 31 of the protrusion 30 is formed so as to taper on both sides in the direction in which the tie bar 10 extends, and therefore, compared to a conventional configuration in which the protrusion has a surface on one side of the direction in which the tie bar extends that extends perpendicular to the direction in which the tie bar extends, a large tolerance range (so-called play) in the direction in which the tie bar 10 extends in which the protrusion 30 can engage with the clamping groove 10a can be secured. That is, even if the engagement position of the protrusion 30 with respect to the clamping groove 10a is shifted from the target position in the direction in which the tie bar 10 extends, the protrusion 30 can be guided (slid) to the target position by engaging with the tie bar 10 while contacting either surface of the protrusion 30 in the direction in which the tie bar 10 extends. Therefore, the positioning of the protrusion 30 of the clamping split nut 3 with respect to the clamping groove 10a of the tie bar 10 in the direction in which the tie bar 10 extends can be easily performed. In addition, since the protrusion 30 can be guided (slid) to the target position by engaging with either surface of the protrusion 30 in the direction in which the tie bar 10 extends while contacting the tie bar 10, the gap between the protrusion 30 and the clamping groove 10a in the direction in which the tie bar 10 extends can be reduced. Therefore, when closing one of the gaps L1a, L1b on both sides of the protrusion 30 in the direction in which the tie bar 10 extends after the engagement is achieved, there is almost no need to move (accelerate) the protrusion 30 relative to the tie bar 10, so the impact when the protrusion 30 comes into contact with the tie bar 10 when the gap L1b is closed can be kept small. In addition, since the protrusion 30 can be guided (slid) to the desired position as described above, it is possible to avoid the protrusion colliding with the convex portion between the adjacent clamping grooves 10a of the tie bar 10 during engagement.

In this embodiment, as described above, the protrusion 30 of the clamping split nut 3 is formed so that the tip 31 is arc-shaped and tapered on both sides in the extension direction of the tie bar 10. This makes it easier to guide (slide) the protrusion 30 to the desired position when engaging in the extension direction of the tie bar 10 by the arc-shaped tip 31. This makes it easier to position the protrusion 30 of the clamping split nut 3 relative to the clamping groove 10a of the tie bar 10 in the extension direction of the tie bar 10. Furthermore, compared to when the tip of the protrusion is sharp, the arc-shaped tip 31 can suppress damage to the protrusion 30 due to cracks or breakage.

In this embodiment, as described above, the protrusion 30 of the clamping split nut 3 has nut-side tapered surfaces 32 provided on both sides of the tip 31 when viewed from a direction perpendicular to the tie bar 10, and is formed so as to taper toward the tip 31 by the nut-side tapered surfaces 32, and the clamping groove 10a of the tie bar 10 has a tie bar-side tapered surface 10c arranged substantially parallel to and facing the nut-side tapered surface 32. As a result, not only the tip 31 of the protrusion 30 but also the nut-side tapered surface 32 tapering toward the tip 31 of the protrusion 30 can guide (slide) the protrusion 30 to the desired position during engagement in the direction in which the tie bar 10 extends. This makes it easier to position the protrusion 30 of the clamping split nut 3 relative to the clamping groove 10a of the tie bar 10 in the direction in which the tie bar 10 extends. In addition, the nut side tapered surface 32 and the tie bar 10 side tapered surface, which are approximately parallel to each other, ensure a large contact area between the protrusion 30 of the clamping split nut 3 and the clamping groove 10a of the tie bar 10. This makes it possible to prevent damage such as cracks and breaks caused by large stress acting on the clamping split nut 3 and the tie bar 10.

In this embodiment, as described above, the inclination angle θ of each of the nut side tapered surface 32 and the tie bar side tapered surface 10c relative to the radial direction of the tie bar 10 is greater than 0 degrees and less than 10 degrees. As a result, each of the nut side tapered surface 32 and the tie bar side tapered surface 10c is formed at a relatively small inclination angle θ, so that when the movable die plate 12 receives a force in a direction away from the fixed die plate 11 during injection of molten metal into the die M, the component of the force in the opening direction acting on the pair of clamping split nuts 3 can be reduced.

As described above, in this embodiment, when viewed from a direction perpendicular to the tie bar 10, the protrusion 30 of the split nut 3 for mold clamping and the groove 10a for mold clamping are formed such that the portions A1, B1 on one side in the direction in which the tie bar 10 extends and the portions A2, B2 on the other side are symmetrical with respect to the center line C2 in the direction in which the tie bar 10 extends of each of the protrusion 30 of the split nut 3 for mold clamping and the groove 10a for mold clamping. This allows the protrusion 30 to be stably guided (slid into) the desired position during engagement on both the one side and the other side in the direction in which the tie bar 10 extends.

In this embodiment, as described above, the clamping split nut 3 includes a recess 33 with an arc-shaped bottom portion, which is provided between adjacent protrusions 30 when viewed from a direction perpendicular to the tie bar 10, and the tie bar 10 includes a flat surface 10d that is provided at the outer circumferential end of the tie bar 10 and forms a space S between the recess 33 of the clamping split nut 3 when viewed from a direction perpendicular to the tie bar 10. This allows the protrusion 30 of the clamping split nut 3 and the clamping groove 10a of the tie bar 10 to be roughly engaged between the adjacent protrusions 30 by the space S. This makes it easier to position the protrusion 30 of the clamping split nut 3 relative to the clamping groove 10a of the tie bar 10 in the direction in which the tie bar 10 extends.

In this embodiment, as described above, when viewed from a direction perpendicular to the tie bar 10, a chamfered portion 10e is provided on the edge portion of the flat surface 10d of the tie bar 10. This allows the protrusion 30 to be guided (slid into) the desired position during engagement in the direction in which the tie bar 10 extends, not just by the tip 31 of the protrusion 30, but also by the chamfered portion 10e of the tie bar 10. This makes it even easier to position the protrusion 30 of the clamping split nut 3 relative to the clamping groove 10a of the tie bar 10 in the direction in which the tie bar 10 extends.

In this embodiment, as described above, in the engaged state in which the mold clamping split nut 3 is engaged with the mold clamping groove 10a, the total gap L1 between the protruding portion 30 of the mold clamping split nut 3 and the mold clamping groove 10a in the direction in which the tie bar 10 extends is 0.2 mm or more and 0.5 mm or less. This makes it possible to make the total gap L1 between the protruding portion 30 and the mold clamping groove 10a in the direction in which the tie bar 10 extends relatively small, so that the operation of closing the gap L1 before the injection of molten metal into the mold M can be performed in a relatively short time.

In this embodiment, as described above, in the engaged state in which the clamping split nut 3 is engaged with the clamping groove 10a, the total gap L1 between the protruding portion 30 of the clamping split nut 3 and the clamping groove 10a in the direction in which the tie bar 10 extends is smaller than the gap L2 between the protruding portion 30 of the clamping split nut 3 and the clamping groove 10a in the radial direction of the tie bar 10. This makes it possible to make the total gap L1 between the protruding portion 30 and the clamping groove 10a in the direction in which the tie bar 10 extends relatively small, so that the operation of closing the gap L1 before the injection of molten metal into the mold M can be performed in a relatively short time. In addition, in the engaged state, the gap L2 between the protrusion 30 of the clamping split nut 3 and the clamping groove 10a in the radial direction of the tie bar 10 can be made relatively large, so that it is possible to avoid collision between the protrusion 30 and the clamping groove 10a in the radial direction of the tie bar 10.

As described above, this embodiment further includes a die plate drive device 13 including a servo motor 13a and a moving mechanism 13b that is driven by the servo motor 13a to move the clamping split nut 3 together with the moving die plate 12 in the direction in which the tie bar 10 extends, and a control unit 104 that controls the clamping split nut 3 to engage with the clamping groove 10a with the servo motor 13a turned off after the clamping split nut 3 is moved to a predetermined position where the clamping split nut 3 and the clamping groove 10a face each other in the radial direction of the tie bar 10 by the servo motor 13a and the moving mechanism 13b. As a result, by turning off the servo motor 13a, engagement can be performed without restricting the position of the protrusion 30 in the direction in which the tie bar 10 extends, so that the positioning of the protrusion 30 of the clamping split nut 3 relative to the clamping groove 10a of the tie bar 10 in the direction in which the tie bar 10 extends can be more easily performed.

[Modification]
The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

For example, in the above embodiment, an example was shown in which the molding device was configured as a die-casting machine, but the present invention is not limited to this. In the present invention, the molding device may be configured as an injection molding device that injects resin, etc.

In the above embodiment, an example was shown in which the molding device was configured as a horizontal molding device, but the present invention is not limited to this. In the present invention, the molding device may also be configured as a vertical molding device.

In the above embodiment, the tip of the protrusion is formed in an arc shape, but the present invention is not limited to this. In the present invention, the tip of the protrusion may be formed in an elliptical arc shape, etc. In addition, the tip of the protrusion may be an inclined surface, etc., rather than an arc shape.

In the above embodiment, an example was shown in which the recess between adjacent protrusions was formed in an arc shape, but the present invention is not limited to this. In the present invention, the recess between adjacent protrusions may be formed in an elliptical arc shape, or the like. In addition, the recess between adjacent protrusions may be formed in an inclined surface, rather than an arc shape.

In addition, in the above embodiment, an example was shown in which the inclination angle of each of the nut side tapered surface and the tie bar side tapered surface relative to the radial direction of the tie bar is greater than 0 degrees and less than 10 degrees, but the present invention is not limited to this. In the present invention, the inclination angle of each of the nut side tapered surface and the tie bar side tapered surface relative to the radial direction of the tie bar may be 10 degrees or more.

In addition, in the above embodiment, an example was shown in which the total gap between the protruding portion of the clamping split nut and the protruding portion of the clamping groove in the direction in which the tie bar extends when the clamping split nut is in an engaged state with the clamping groove is 0.2 mm or more and 0.5 mm or less, but the present invention is not limited to this. In the present invention, the total gap between the protruding portion of the clamping split nut and the protruding portion of the clamping groove in the direction in which the tie bar extends when the clamping split nut is in an engaged state with the clamping groove may be less than 0.2 mm or greater than 0.5 mm.

In addition, in the above embodiment, an example was shown in which the total gap between the protruding portion of the clamping split nut and the protruding portion of the clamping groove in the direction in which the tie bar extends is smaller than the gap between the protruding portion of the clamping split nut and the clamping groove in the radial direction of the tie bar, but the present invention is not limited to this. In the present invention, in the engaged state in which the clamping split nut is engaged with the clamping groove, the total gap between the protruding portion of the clamping split nut and the protruding portion of the clamping groove in the direction in which the tie bar extends may be larger than or the same size as the gap between the protruding portion of the clamping split nut and the clamping groove in the radial direction of the tie bar.

In the above embodiment, an example was shown in which the protrusions and clamping grooves of the clamping split nut are formed so that one side portion in the direction in which the tie bar extends and the other side portion are symmetrical with respect to the center line C2 (see FIG. 3) when viewed from a direction perpendicular to the tie bar, but the present invention is not limited to this. In the present invention, the protrusions and clamping grooves of the clamping split nut may be asymmetric with respect to the center line C2 (see FIG. 3) when viewed from a direction perpendicular to the tie bar.

In the above embodiment, an example was shown in which the chamfered portion was formed by R chamfering, but the present invention is not limited to this. In the present invention, the chamfered portion may also be formed by C chamfering.

Description of the Reference Signs 3 Split nut for mold clamping 10 Tie bar 10a Mold clamping groove 10c Tie bar side tapered surface 10e Chamfered portion 10d Flat surface 12 Moving die plate 13 Die plate drive device 13a Servo motor 13b Moving mechanism 30 Protrusion 31 Tip 32 Nut side tapered surface 33 Recess 100 Molding device 104 Control unit A1 One side portion (in the direction in which the tie bar of the split nut for mold clamping extends) A2 The other side portion (in the direction in which the tie bar of the split nut for mold clamping extends) B1 One side portion (in the direction in which the tie bar of the groove for mold clamping extends) B2 The other side portion (in the direction in which the tie bar of the groove for mold clamping extends) C2 Center line (of tie bar) L1 Gap L2 (total of both sides of the protruding portion of the split nut for mold clamping and the protruding portion of the mold clamping groove in the direction in which the tie bar extends) Gap (between the protruding portion of the split nut for mold clamping and the mold clamping groove in the radial direction of the tie bar) M Mold M2 Movable mold S Space θ Inclination angle (of the nut side tapered surface and the tie bar side tapered surface with respect to the radial direction of the tie bar)

Claims

a tie bar including a concave clamping groove;
A movable die plate that moves along the tie bars while holding a movable die;
a pair of clamping split nuts provided on the movable die plate, the pair including a convex protrusion and configured to restrict movement of the movable die plate relative to the tie bar by engaging the protrusion with the clamping groove when the die is closed;
a molding apparatus in which, when viewed from a direction perpendicular to the tie bar, a tip portion of the protrusion, which is the part of the protrusion that is first introduced into the inside of the mold clamping groove portion, is formed so as to taper on both sides in the direction in which the tie bar extends.
The molding device according to claim 1, wherein the protruding portion of the clamping split nut is formed so that the tip end is arc-shaped and tapered on both sides in the direction in which the tie bar extends.
The protruding portion of the mold clamping split nut has a nut side tapered surface provided on both sides of the tip portion when viewed from a direction perpendicular to the tie bar, and is formed so as to taper toward the tip portion by the nut side tapered surface,
The molding apparatus according to claim 1 , wherein the mold clamping groove of the tie bar has a tie bar side tapered surface disposed substantially parallel to and facing the nut side tapered surface.
The molding device of claim 3, wherein the inclination angle of each of the nut side tapered surface and the tie bar side tapered surface relative to the radial direction of the tie bar is greater than 0 degrees and less than 10 degrees.
The molding device according to claim 3, wherein, when viewed from a direction perpendicular to the tie bar, the protrusions and the clamping grooves of the clamping split nut are formed such that one side portion in the direction in which the tie bar extends and the other side portion are symmetrical with respect to the center line of the direction in which the tie bar extends of each of the protrusions and the clamping grooves of the clamping split nut.
The split nut for mold clamping includes a recess provided between adjacent protruding portions when viewed from a direction perpendicular to the tie bar, the recess having a bottom portion formed in an arc shape,
The molding apparatus according to claim 1 , wherein the tie bar includes a flat surface provided at an outer circumferential end of the tie bar, the flat surface forming a space between the flat surface and the recess of the mold clamping split nut when viewed from a direction perpendicular to the tie bar.
The molding device according to claim 6, wherein a chamfer is provided on the edge portion of the flat surface of the tie bar when viewed from a direction perpendicular to the tie bar.
The molding device according to claim 1, wherein, in an engaged state in which the clamping split nut is engaged with the clamping groove, the total gap between the protrusion of the clamping split nut and the clamping groove in the direction in which the tie bar extends is 0.2 mm or more and 0.5 mm or less.
The molding device according to claim 1, wherein, in an engaged state in which the clamping split nut is engaged with the clamping groove, the total gap between the protrusion of the clamping split nut and the clamping groove in the direction in which the tie bar extends is smaller than the gap between the protrusion of the clamping split nut and the clamping groove in the radial direction of the tie bar.
A die plate drive device including a servo motor and a moving mechanism driven by the servo motor to move the split nuts for die clamping together with the movable die plate in the direction in which the tie bars extend;
2. The molding apparatus according to claim 1, further comprising a control unit that controls the clamping split nut to engage with the clamping groove portion while turning off the servo motor, after the servo motor and the moving mechanism have moved the clamping split nut to a predetermined position where the clamping split nut and the clamping groove portion face each other in the radial direction of the tie bar.