JPH0872113A - Tie bar extraction device in mold clamping device - Google Patents

Abstract

PURPOSE: To obtain a tie bar extraction device in a mold clamping device, that can shift an upper tie bar to a position where it does not interfere with a mold loading/unloading operation without providing a special driver in addition to an intrinsic driver required for actuating a mold clamping device. CONSTITUTION: At least one of tie bars 164a mounted upward of a mold 152 is provided with a first connecting and fixing means 180 that can engage/ disengage the tie bar with/from a movable die plate 158 on the opposite side to a mold of the movable die plate 158 as well as a second connecting and fixing means 165a that can engage/disengage the tie bar with/from a stationary die plate 154 on the opposite side to a mold of the stationary die plate 154. Therefore, each of the other tie bars is fixed to the stationary die plate 154 at one end thereof and provided with a first connecting and fixing means that can engage/disengage the tie bar with/from the movable die plate 158 at the other end thereof on the opposite side to the mold of the movable die plate 158.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device applied to an injection molding machine, a press machine or the like that clamps a mold in a horizontal direction. The present invention relates to a tie bar removing device in a mold clamping device that can be removed to the extent that there is no hindrance to the attachment and removal of.

[0002]

2. Description of the Related Art FIG.
The tie bar extraction device in the mold clamping device described in Japanese Patent Laid-Open No. 2-30370 is shown. In the figure, machine base 1
A fixed die plate 102 is attached to one end of 01, and a link housing 103 is attached to the other end thereof, and four connecting tie bars 104 and 105 are horizontally mounted between them. A movable die plate 106 is arranged between the fixed die plate 102 and the link housing 103. The link housing 103 and the movable die plate 106 are connected by a link mechanism 107, and the movable die plate 106 can be moved forward and backward with respect to the fixed die plate 102 by operating the link mechanism 107 by a mold clamping cylinder 108. It is like this. As a result, the molds (not shown) attached to the fixed die plate 102 and the movable die plate 106 can be clamped and opened. By the way, in this apparatus, the threaded portion of the lower tie bar 105 on the mold clamping cylinder 108 side is higher than the threaded portion of the upper tie bar 104.
The distance S when pulling out 04 is increased. The upper tie bar 10 is attached to the end surface of the upper fixed die plate 102 side nut 109 fixed to the fixed die plate 102.
Rotation stopper 110 such as rotation stopper pin for stopping rotation of 4
Is detachably attached. On the other hand, the lower fixed die plate 102 side nut 111 is not provided with a rotation stopper.

Next, on the link housing 103 side, a nut 11 with a die height adjusting device which is a nut with a rotating device.
2, 113 are provided. Each of the nuts 112, 1
13 is a case 11 fixed to the link housing
2a and 113a and nuts 112b and 1 in which the outer sides are rotatably fitted to the cases 112a and 113a and the inner surfaces are threaded with the tie bars 104 and 105, respectively.
Although not shown, the nuts 112b and 113b are connected to a rotation transmission mechanism such as a chain, so that the nuts 112b and 113b can rotate. Therefore, in this case, the nuts 112 and 113 with the die height adjusting device, which are nuts with the rotating device, are provided.
When the nuts 112b and 113b are rotated by the rotation transmission mechanism, the link housing 103 and the movable die plate 106 move forward and backward along the tie bars 104 and 105 on the machine base 101, and the fixed die plate 102 and the movable die plate. The distance from the plate 106 can be adjusted according to the size of the mold. Further, in the die height adjusting device, the upper nut 112b and the upper tie bar 104 are integrally attached by a connecting tool 114 such as a key plate, and the connecting bearing 114 such as the key plate is detachable. I am able to wear it. On the other hand, the lower nut 113b is not provided with the connector 114. The nuts 112 and 11
The rotation device 3 is not limited to the chain drive, but may be rotationally driven by another known method.

Here, when the tie bar is to be removed in response to the attachment and detachment of the mold, first, the key plate connector 114 is attached to the tie bar to be removed within the upper tie bar 104, and the nut 112b and the tie bar are attached. Similarly, the rotation stopper 110 on the side of the fixed die plate 102 for the tie bar which is also to be removed is removed, and in this state, the nuts 112b and 113b of the nuts 112 and 113 with the die height adjusting device are placed in the reverse of the hands of the watch. When rotated in the direction, the nut 113 b moves along the threaded portion of the tie bar 105 and the link housing 103 and the movable die plate 10.
Move to the left with 6. On the other hand, the tie bar to which the coupling tool 114 is attached in the upper tie bar 104 and which is integrated with the nut 112b is rotated by the nut 112b and fixed to the fixed die plate 102.
9 and moves to the left in the drawing together with the link housing 103 and the moving die plate 106. Thus,
Of the upper tie bars 104, the tie bar that is intended to be pulled out goes out from the screw of the nut 109 while rotating, and the work of attaching and detaching the mold to and from the fixed die plate 102 can be performed without being disturbed by the upper tie bars 104. It can be carried out.

[0005]

In this case, however, the rotation of the nuts 112b and 113b required to move the upper tie bar 104 together with the link housing 103 and the movable die plate 106 to the left in the drawing requires the mold clamping device to rotate. A relatively large power rotary drive which is completely unnecessary for operation is required separately from the drive of the mold clamping device, which has a drawback that the production cost of the mold clamping device is significantly increased.
Further, the tie bar 105 becomes longer, and the threaded portion also becomes longer by the thread length S, which increases the manufacturing cost. Further, since a large force is applied to the threaded portion, it is necessary to make the lead angle small. Therefore, when the tie bar 104 is pulled out, there is a problem that the lead angle is small and the pulling time becomes long. Therefore, the present invention, without providing a special drive device other than the original drive device necessary for operating the mold clamping device,
An object of the present invention is to provide a tie bar removing device in a mold clamping device that can shift the upper tie bar to a position that does not hinder the work of mounting and removing the mold, and is intended to solve the above conventional problems.

[0006]

Therefore, according to the present invention, a fixed die plate for holding a fixed die, a movable die plate for holding a movable die, and an advance / retreat operation of the movable die plate with respect to the fixed die plate. Means and a plurality of tie bars for clamping the moving die plate and the fixed die plate by coupling and fixing the moving die plate after the moving die plate approaches the fixed die plate and the fixed die and the moving die are closed. In the mold clamping device, at least one of the tie bars above the mold among the tie bars is
A movable die plate and a tie bar are provided on the opposite side of the movable die plate from the mold, and the first coupling and fixing means is detachable from the movable die plate. The other tie bar has a second coupling and fixing means, and one end of the other tie bar is fixed to the fixed die plate, and the other end of the other tie bar is opposite to the die of the moving die plate. A fixed die plate which has a fixing means, and which holds a fixed mold;
A movable die plate for holding the movable die, a means for moving the movable die plate forward and backward with respect to the fixed die plate, and a movable die plate approaching the fixed die plate to close the fixed die and the movable die. After that, in a mold clamping device comprising a movable die plate and a fixed die plate, which are combined and fixed to perform mold clamping, at least one of the tie bars above the mold among the tie bars is a fixed die. The fixing die plate and the tie bar are detachable from the plate on the side opposite to the mold, and the movable die plate and the tie bar are detachable from the mold on the opposite side. The other tie bar has a joining and fixing means, one end of which is fixed to the moving die plate and the other end of which is opposite the mold of the fixed die plate to the moving die plate and the tie bar. Are those comprising a engagement detachable first coupling fixing means is for a means for these issues resolved.

[0007]

In the tie bar removing device of the mold clamping device configured as described above, the die is mounted and removed on the fixed die plate, and the upper tie bar is mounted on the fixed die plate. The case of removing will be described. In this case, first, the first coupling and fixing means on the movable die plate is released, and the means for moving the movable die plate forward and backward relative to the fixed die plate is used.
The movable die plate is brought close to the fixed die plate, and the fixed die and the movable die are closed. Then, the fixed mold and the movable mold are combined, and the movable mold and the movable die plate are separated. Next, while the first connecting and fixing means for the lower tie bar is in the released state, the first connecting and fixing means for the upper tie bar is connected and fixed, and the second connecting and fixing means for the upper tie bar is released. In this state, when the moving die plate is moved in a direction away from the fixed die plate corresponding to the mold opening using a means for moving the moving die plate forward and backward with respect to the fixed die plate, the upper tie bar comes out of the fixed die plate. As a result, with the upper tie bar removed from the fixed die plate, it is possible to easily attach and detach the die to and from the fixed die plate. In this state where the upper tie bar is removed from the fixed die plate, the upper tie bar is slidably supported between the movable die plate and the fixed die plate by the supporting means attached to the movable die plate, and the upper tie bar is in a cantilever state. Prevents it from bending under its own weight.

Next, in the tie bar removing device of the mold clamping device, in the tie bar removing device according to claim 3, wherein the die is mounted and removed on the moving die plate, the case of extracting the upper tie bar from the moving die plate will be described. To do. In this case, the first on the fixed die plate
The movable die plate is moved closer to the fixed die plate by using the means for releasing the coupling and fixing means and moving the movable die plate forward and backward with respect to the fixed die plate, and the fixed die and the movable die are closed. Then, the fixed mold and the movable mold are combined, and the fixed mold and the fixed die plate are separated. Next, the first connecting and fixing means for the lower tie bar is released, the first connecting and fixing means for the upper tie bar is connected and fixed, and the second connecting and fixing means for the upper tie bar is released. In this state, when the moving die plate is moved in the direction away from the fixed die plate corresponding to the mold opening by using the means for moving the moving die plate forward and backward with respect to the fixed die plate, the upper tie bar is removed from the moving die plate.
As a result, with the upper tie bar removed from the moving die plate, it is possible to easily attach and detach the mold to and from the moving die plate. In this manner, when the upper tie bar is removed from the movable die plate, the upper tie bar is slidably supported between the movable die plate and the fixed die plate by the supporting means attached to the fixed die plate, and the upper side tie bar is in a cantilevered state. It prevents the tie bar from bending under its own weight.

[0009]

1 is a front view showing a mold clamping device according to a first embodiment of the present invention, FIG. 2 is a front view showing the upper tie bar withdrawn state, and FIG. FIG. 4 is an enlarged view of a main part of FIG. 1, and FIG. 4 is an explanatory view showing a released state of the half nut. In FIG. 1, reference numeral 150 denotes a base on which the mold clamping device is mounted and fixed, and a fixed die plate 154 for mounting a fixed mold 152 is fixed to one end of the base 150. Reference numeral 158 denotes a movable die plate, a movable die 156 is attached to the fixed die plate 154 side, and a slide shoe 159 is integrally attached to a leg portion thereof, and a guide rail 151 provided on the base 150.
It is mounted so that it can move forward and backward along. The guide portion of the movable die plate 158 may be a sliding slide, a rolling guide, or may be floated by air or magnetic force. In FIG. 2, hydraulic cylinders 160 for generating a mold clamping force after mold closing are provided at four corners of the moving die plate 158.
The hydraulic cylinder 160 has an oil chamber 161 indicated by (A) and (B) with a ram 162 interposed therebetween as described later.
A, 161B. As shown in an enlarged view in FIG. 3, the ram 162 has a multi-stage outer circumference with large, medium, and small diameters, and insertion holes 174 for inserting the upper tie bar 164a and the lower tie bar 164b are formed through the shaft center. , When the mold clamping pressure is increased, pressure oil is sent to the one oil chamber 161A to move it to the left in FIG.
63 is brought into contact with the half nut 180 as the first coupling and fixing means, and the half nut 180 is attached to the tie bar 164.
The half nut 180 can be further pushed leftward in a state of being meshed with a and 164b to generate a mold clamping force. Also, the half nut 180 of the ram 162
The stopper pin 193 is fixed to the side and the stopper pin 1
93 penetrates the shaft center portion 191 of the sprocket 190, and a double nut 192 is attached to the tip of the ram 162.
The dimension l between the mounting surface of the stopper pin 193 and the double nut 192 can be finely adjusted. That is, the moving width (cylinder stroke) of the ram 162 is determined by setting the dimension l.

One end 164a is fixed by a half nut 165a as a second coupling and fixing means, and the die plate 154 is fixed.
Is an upper tie bar detachably fixed to the 164b
Fixed one end with nut 165b
It is a lower tie bar fixed to. And each tie bar 1
A threaded portion 172 is formed at a tip end of each of 64a and 164b over a predetermined length, and this threaded portion 172 also meshes with a half nut 180 provided on the back side of the moving die plate 158 during mold clamping. Reference numeral 166 denotes a die opening / closing cylinder attached to the fixed die plate 154 or the moving die plate 158, which moves the moving die plate 158 forward and backward. Therefore, the tip of the rod 170 of the mold opening / closing cylinder 166 is fixed to the movable die plate 158 or the fixed die plate 154.

Reference numerals 175 and 176 denote movable die plates 158.
A packing presser fixed to the front and rear of the portion constituting the mold clamping cylinder, and a guide bar 177 for supporting the half nut 180 so that the half nut 180 can move forward and backward is fixed to the packing presser 175 on the back side of the moving die plate 158. At the same time, a screw hole 182 is provided near the inner peripheral portion thereof. As shown in FIG. 4, half nuts 180 a and 180 b, which are nuts divided and opposed to each other, are slidably supported via a bracket 178 on a guide bar 177 fixed to the packing retainer 175. Is always biased by a spring 179 so as to be pressed against the tip portion 163 of the ram 162. The half nut 180 can be opened and closed left and right by an opening and closing mechanism (not shown) along the guide bar 181 fixed to the bracket 178, and is closed during the mold clamping to engage with the threaded portion 172 of the tie bar 164. 1
90 is threaded on the outer periphery of the boss, and packing retainer 175
The sprocket is screwed into the screw hole 182 provided near the inner circumference of the sprocket. The sprocket 190 is driven by a chain drive device such as a stepping motor (not shown),
It moves back and forth through the chain 195 in the direction shown by the arrow in FIG.

In the illustrated example, the movable die plate (tie bar) and the fixed die plate are connected and fixed by means of the tip screw portion of the tie bar and the half nut on the fixed die plate side. The invention is not limited to this example. For example, although not shown, one or more circumferential grooves are formed at the tip portion of the tie bar, and the half nut is replaced with the circumferential groove that engages and disengages with the circumferential groove. Further, the coupling and fixing means can be configured with a locking block provided with one or more protrusions. In short, the coupling and fixing means in the present invention may be one that can surely engage and disengage the tip end of the tie bar at the set position, and one end of which is constituted by a gripping member that is movable against the ram and is movable with the ram. However, the present invention is not limited to the above embodiment. Further, the moving die plate 158 is provided with a supporting means 201 for slidably supporting the moving die plate 158 of the upper tie bar 164a and the fixed die plate 154 via the bush 200 (FIG. 2).

Next, in the tie bar removing device in the mold clamping device configured as described above, the fixed die plate 15 is used.
A case where the upper tie bar 164a is pulled out from above 4 will be described. In this case, first, the first connecting and fixing means on the moving die plate 158, in this case, means for engaging and disengaging the half nut 180 and the tie bars 164a, 164b, is released to fix the moving die plate 158 to the fixed die plate. The mold opening / closing cylinder 166, which is a means for moving the dies 154 forward and backward, is moved backward to move the movable die plate 158.
The fixed die 152 and the fixed die 152.
And the moving die 156 are closed. And fixed mold 15
The moving die 156 and the moving die plate 158 are separated by connecting the moving die 156 and the moving die 156 by means not shown.
Next, while keeping the first coupling and fixing means for the lower tie bar 164b in the released state, the half nut 180 of the first coupling and fixing means for the upper tie bar 164a is closed and coupled, and the half of the second coupling and fixing means for the upper tie bar 164a is fixed. Release the nut 165a.

In this state, when the mold opening / closing cylinder 166 is operated to move forward to move the movable die plate 158 in the direction away from the fixed die plate 154 corresponding to the mold opening,
The upper tie bar 164a comes off from the fixed die plate 154. As a result, with the upper tie bar 164a removed from the fixed die plate 154, it is possible to easily attach and detach the molds 152 and 156 to and from the fixed die plate 154 without being disturbed by the upper tie bar 164a. In this manner, when the upper tie bar 164a is removed from the fixed die plate 154, the upper tie bar 164a is moved by the supporting means 201 attached to the moving die plate 158.
8 and a fixed die plate 154 are slidably supported,
The cantilevered upper tie bar 164a is prevented from bending due to its own weight.

Next, of the tie bar removing device in the mold clamping device, the structure of the second embodiment of the present invention for mounting and removing the mold on the moving die plate will be described with reference to FIGS. FIG. 5 shows a typical embodiment of the present invention, in which 150 is a base for mounting and fixing the main mold clamping device,
A fixed die plate 154 for mounting the fixed mold 152 is fixed to one end of the base 150. Reference numeral 158 denotes a movable die plate, a movable die 156 is attached to the fixed die plate 154 side, and a slide shoe 159 is integrally attached to a leg portion of the movable die 154, and a guide rail 151 provided on the base 150. It is mounted so that it can move forward and backward. The guide portion of the movable die plate 158 may be a sliding slide, a rolling guide, or may be floated by air or magnetic force. Next, in FIG. 6, hydraulic cylinders 160 for generating a mold clamping force after mold closing are formed at four corners of the fixed die plate 154, and the hydraulic cylinders 160 have an oil chamber 161A inside with a ram 162 interposed therebetween as described later. , 161B. The ram 162 has a large outer circumference as in the case of the enlarged view of the ram 162 in FIG. 3 of the first embodiment.
The tie bar 164a has an insertion hole 174 penetrating the shaft center, which is formed in multiple stages with medium and small diameters. When the mold clamping pressure is increased, pressure oil is sent to the one oil chamber 161A to move to the right in FIG. The half nut 180 is moved and brought into contact with the half nut 180 as the first coupling and fixing means, and the half nut 180 is further pushed rightward with the half nut 180 meshing with the tie bar 164a to generate a mold clamping force. .

A stopper pin 193 is fixed to the half nut 180 side of the ram 162.
Numeral 93 penetrates the shaft center portion 191 of the sprocket 190, and a double nut 192 is attached to the tip of the ram 162.
The dimension l between the mounting surface of the stopper pin 193 and the double nut 192 can be finely adjusted. That is, the width of movement of the ram (cylinder stroke) is determined by setting the dimension l. 164a is an upper tie bar whose one end is detachably fixed to the moving die plate 158 by a half nut 165a as a second coupling and fixing means, and 164b is a lower side whose one end is fixed to the moving die plate 158 by a nut 165b. It is a tie bar. A threaded portion 172 is formed over a predetermined length at the tip of each tie bar 164a, 164b, and this threaded portion 172 also meshes with a half nut 180 provided on the back side of the fixed die plate 154 during mold clamping. Reference numeral 166 denotes a die opening / closing cylinder attached to the fixed die plate 154 or the moving die plate 158, which moves the moving die plate 158 forward and backward.
Therefore, the tip of the rod 170 of the mold opening / closing cylinder 166 is
It is fixed to the movable die plate 158 or the fixed die plate 154.

175 and 176 are fixed die plates 154.
A packing presser fixed to the front and rear of the portion forming the mold clamping cylinder, and a guide bar 177 for supporting the half nut 180 so that it can move forward and backward is fixed to the packing presser 176 on the back surface side of the fixed die plate 154. In addition, a screw hole 182 is provided near the inner peripheral portion thereof. Guide bar 1 fixed to this packing retainer 176
A bracket 178 is provided with a half nut 180 in which a nut is divided into two and opposed to each other as shown in FIG. 4 of the first embodiment.
The half nut 180 is slidably supported via a spring 179, and the half nut 180 is constantly supported by a spring 179.
It is urged to press against. The half nut 180 can be opened and closed to the left and right along the guide bar 181 fixed to the bracket 178 by an opening and closing mechanism (not shown), and is closed during mold clamping to engage with the threaded portion 172 of each tie bar 164a, 164b.

A screw 190 is provided on the outer circumference of the boss, and the screw hole 18 is provided near the inner circumference of the packing retainer 176.
It is a sprocket screwed into 2. The sprocket 190 is moved back and forth in a direction indicated by an arrow in FIG. 6 via a chain 195 by a chain drive device such as a stepping motor (not shown). In the illustrated example, the movable die plate (tie bar) and the fixed die plate are connected and fixed by means of the tip screw portion of the tie bar and the half nut on the fixed die plate side. However, the present invention is not limited to this, as described in the first embodiment. Further, the fixed die plate 154 is provided with support means 201 for slidably supporting the movable die plate 158 of the upper tie bar 164a and the fixed die plate 154 via the bush 200.

Next, in the tie bar removing device in the mold clamping device thus configured, the moving die plate 15
A case where the upper tie bar 164a is pulled out from above will be described. In this case, first, the first connecting and fixing means on the fixed die plate 154, that is, the means for engaging and disengaging the half nut 180 and the tie bars 164a, 164b, is released to move the movable die plate 158 to the fixed die plate. The mold opening / closing cylinder 166, which is a means for advancing and retracting with respect to 154, is moved backward to bring the movable die plate 158 close to the fixed die plate 154, and the fixed die 152 and the movable die 156 are closed. And the moving mold 156
The fixed mold 152 and the fixed die plate 154 are separated by connecting the fixed mold 152 and the fixed mold 152 by means not shown. Next, while keeping the first coupling and fixing means for the lower tie bar 164b in the released state, the first coupling and fixing means for the upper tie bar 164a is coupled and fixed, and the half nut 165a of the second coupling and fixing means for the upper tie bar is released.
In this state, the mold opening / closing cylinder 166 is operated to move forward,
When the movable die plate 158 is moved in the direction of separating from the fixed die plate 154 corresponding to the mold opening, the upper tie bar 164a comes out of the movable die plate 158. As a result, the moving tie plate 158 and the upper tie bar 164 are
With a removed, the molds 152, 156 can be easily attached to and removed from the movable die plate 158 without being obstructed by the upper tie bar 164a. In this manner, with the upper tie bar 164a removed from the moving die plate 158, the upper tie bar 1
64a is slidably supported between the movable die plate 158 and the fixed die plate 154 by the supporting means 201 attached to the fixed die plate 154, and prevents the cantilevered upper tie bar 164a from sagging by its own weight. ing.

[0020]

As described above in detail, according to the present invention, when the tie bar corresponding to the attachment and detachment of the die is removed, the forward / backward moving die opening / closing cylinder of the movable die plate corresponding to the die opening / closing can be used. Therefore, it is not necessary to specially provide a driving device such as a tie bar rotating device for moving the tie bar or a hydraulic cylinder, and the tie bar removing device in the mold clamping device can be manufactured at low cost. Further, by providing a coupling means for the fixed die plate and the movable die plate at both ends of the upper tie bar, it is possible to disperse the heavy die and the upper tie bar with moment load on the movable die plate and the fixed die plate, Therefore, the fixed die plate and the movable die plate are not overloaded.

[Brief description of drawings]

FIG. 1 is a partial sectional front view showing a mold closed state according to a first embodiment of a tie bar removing device of the present invention.

FIG. 2 is a front view showing a state where the upper tie bar of FIG. 1 is removed.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is an explanatory diagram showing a released state of the half nut in FIG. 1.

FIG. 5 is a partial sectional front view showing a mold closed state according to a second embodiment of the tie bar removing device of the present invention.

FIG. 6 is a front view showing a state where the upper tie bar of FIG. 5 is removed.

FIG. 7 is a front view showing a mold closed state in a conventional tie bar removing device.

[Explanation of symbols]

 152 Fixed mold 154 Fixed die plate 156 Moving mold 158 Moving die plate 164a Upper tie bar 164b Lower tie bar 165a Half nut (second coupling fixing means) 166 Mold opening / closing cylinder 180 Half nut (first coupling fixing means) 200 Bush 201 Supporting means

Claims (5)

[Claims] 1. A fixed die plate for holding a fixed die, a movable die plate for holding a movable die, means for moving the movable die plate forward and backward with respect to the fixed die plate, and the movable die plate is fixed. A mold clamping device comprising a plurality of tie bars for clamping the movable die plate and the fixed die plate by fixing the movable die and the movable die close to each other after approaching the die plate and closing the die, At least one of the tie bars above the mold has a first coupling and fixing means for detaching the movable die plate and the tie bar on a side opposite to the mold of the movable die plate, and a metal of the fixed die plate. The other side of the tie bar is fixed to the fixed die plate and the other end is movable. On the opposite side of the die plate from the mold,
A tie bar removing device in a mold clamping device, comprising a first coupling and fixing means capable of engaging and disengaging a movable die plate and a tie bar. 2. The moving die plate is provided with supporting means for slidably supporting between the moving die plate of the upper tie bar and the fixed die plate.
Tie bar removing device in the described mold clamping device. 3. A fixed die plate holding a fixed die, a movable die plate holding a movable die, a means for moving the movable die plate forward and backward with respect to the fixed die plate, and the movable die plate is fixed. A mold clamping device comprising a tie bar that closes a movable die and a fixed die plate after the stationary die and the movable die are closed by approaching the die plate, and the die is one of the tie bars. At least one tie bar of the tie bar above the mold has a first coupling and fixing means for detaching the fixed die plate and the tie bar on the side opposite to the mold of the fixed die plate, and a mold of the movable die plate. On the opposite side, the movable die plate and the tie bar have a detachable second coupling and fixing means, and the other tie bar has one end fixed to the movable die plate and the other end fixed to the fixed die plate. A tie bar removing device in a mold clamping device, comprising a first coupling / fixing means capable of engaging and disengaging a moving die plate and a tie bar on the side of the plate opposite to the mold. 4. The fixed die plate is provided with a support means for slidably supporting between the movable die plate of the upper tie bar and the fixed die plate.
Tie bar removing device in the described mold clamping device. 5. A detachable second connecting and fixing means is detachably connected and fixed to a groove portion including a screw formed at an end portion of the tie bar and the groove portion so as to prevent movement of the tie bar in an extension direction by a hydraulic cylinder. The tie bar removing device in the mold clamping device according to any one of claims 1 to 4, wherein the tie bar extracting device is formed by a half nut.