JP2004209949A - Mold clamping device and its control process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically engage an engaging part of a tie bar with a half nut even though a mold thickness is changed without providing tie bar position detecting means in a mold clamping device. <P>SOLUTION: In the mold clamping device 1 in which a core mold 4 is moved adjacent to or apart from a fixed mold 2 with mold opening/closing means, the engaging part 10 of the tie bar 8 provided so as to range along a piston 7a of a mold clamping cylinder 7 is engaged with the half nut 11 mounted on a board at the side where the mold clamping cylinder 7 is not provided, and mold clamping is carried out by the mold clamping cylinder 7, the mold clamping device is characterized by including operating means 12 wherein the half nut 11 is forwarded toward a forward completion position A in a half nut engaging step, engagement detecting means 13a which detect engagement of the half nut 11 with the engaging part 10, and tie bar position adjusting means 14 disposed to the mold clamping cylinder 7 or the tie bar 8 wherein the tie bar 8 is moved in a mold opening direction when an engagement signal is not outputted by the engagement detecting means 13a. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a movable mold is moved relative to a fixed mold by mold opening / closing means, and the movable mold and the fixed mold are clamped by a mold clamping cylinder disposed on one of the fixed platen and the movable platen. And a control method therefor.
[0002]
[Prior art]
The movable mold is moved with respect to the fixed mold by mold opening / closing means, and the movable mold and the fixed mold are clamped by a mold clamping cylinder disposed on one of the fixed plate and the movable plate. Devices are conventionally known. In the mold clamping device, the movable plate is moved at a relatively high speed by the mold opening / closing means, and at the mold closing completion position, the half nut arranged on one of the movable plate and the fixed plate is moved to the other of the movable plate and the fixed plate. Is engaged with the engaging portion of the tie bar disposed in the mold, and then the mold is clamped by the mold clamping cylinder. Therefore, when the mold to be mounted is changed, it is necessary to adjust the engagement position between the half nut and the tie bar according to the thickness of the mold. For this reason, conventionally, each mold clamping device has a unique mechanism. I have.
[0003]
For example, Patent Literature 1 discloses a mold clamping device that adjusts a mold thickness by rotating a driving motor and rotating each tie bar in synchronization to change a coupling position between a mold clamping piston and a moving screw of the tie bar. Has been described.
[0004]
[Patent Document 1]
JP-A-3-173612 (Claims 1, page 3, upper right column (action), FIG. 1)
[0005]
However, the one described in Patent Document 1 has a complicated structure in which a thread groove to be screwed with a tie bar is formed inside a mold clamping cylinder. Since the cylinder and the tie bar were separate bodies, there was a problem in strength. In addition, every time the mold is replaced, it is necessary for the operator to rotate the drive motor and perform the adjustment work to move the tie bar to the coupling position with the half nut, and accurate tie bar positioning can be performed automatically. Did not.
[0006]
Patent Literature 2 discloses a device provided with a driving unit that is connected to a ram of a mold clamping cylinder and moves the ram forward and backward when the ram is not under pressure. In Patent Document 2, a half nut and a tie bar are detected by signals from tie bar position detecting means for detecting individual positions in the moving direction of the tie bar and die plate position detecting means for detecting a position in the moving direction of the moving die plate. Is calculated so that the ring grooves are engaged.
[0007]
[Patent Document 2]
JP-A-8-276482 (Claim 1, FIG. 1)
[0008]
However, the one described in Patent Document 2 requires a tie-bar position detecting means, which leads to an increase in cost. Further, when a hydraulic cylinder is used as a driving means for moving the ram forward and backward, there is a problem that it is difficult to stop the ram at an accurate position. Further, there is a problem that the overall length of the mold clamping cylinder becomes longer because the ram is moved forward and backward in the mold clamping cylinder to adjust the position of the tie bar with respect to the half nut according to the mold used. .
[0009]
Patent Document 3 discloses a half-nut pressing step of pressing with a predetermined pressing force in a state where the engaging projection of the half nut is overlapped by a set distance with the engaging projection provided on the tie bar at the time of mold clamping. And closing the half nut by moving the tie bar in the mold closing direction after the completion of the half nut pressing step, thereby engaging the engagement protrusion of the half nut with the engagement protrusion of the tie bar to lock the mold. Has been described.
[0010]
[Patent Document 3]
Japanese Patent Application Laid-Open No. 10-296811 (Claims 1, (0020), FIGS. 1 and 3)
[0011]
However, the device described in Patent Document 3 also detects the position of the tie bar and engages the half nut similarly to Patent Document 2, and it is necessary to provide an encoder as a position detector of the mold clamping cylinder. Was. Further, the mold described in Patent Literature 3 uses any mold to always engage after the engagement projection provided on the tie bar and the engagement projection of the half nut are always overlapped. In such a case, there is a problem that extra time is required.
[0012]
[Problems to be solved by the invention]
In the present invention, in order to solve the above-described problem, the position of the tie bar with respect to the board on which the mold clamping cylinder is arranged is held at a fixed position by a simple mechanism, and the half nut is attached to the held tie bar. It is intended to be easily engaged. It is another object of the present invention to automatically engage the engagement portion of the tie bar with the half nut even when the thickness of the mold is changed without providing a tie bar position detecting unit. Another object is to reduce the overall length of the mold clamping cylinder.
[0013]
[Means for Solving the Problems]
In the mold clamping device according to the first aspect of the present invention, the movable mold is moved toward and away from the fixed mold by the mold opening / closing means, and the movable mold is moved to one of the fixed plate and the movable plate with the piston of the mold clamping cylinder. In a mold clamping device that engages an engaging portion of a tie bar that is continuously provided with a half nut provided on one of the fixed plate and the movable plate, and clamps the mold with the mold clamping cylinder, An actuating means for advancing the half nut toward the advance completion position in the process, an engagement detecting means for detecting the engagement between the half nut and the engaging portion, and a mold clamping cylinder or a tie bar; A tie bar position adjusting means for moving the tie bar in the mold opening direction when the engagement signal is not output by the detecting means is provided.
[0014]
According to a second aspect of the present invention, in the first aspect of the present invention, in the first aspect, a plurality of sets of a vertical surface with respect to the axial direction of the tie bar and a tapered surface that becomes thinner in the mold opening direction are alternately formed on the engaging portion. The half nut has a plurality of sets of vertical surfaces and inclined surfaces protruding in the mold opening direction corresponding to the engagement portions, which are alternately formed on the half nut. And an engagement detecting means for detecting the engagement between the half nut and the engaging portion at a position where the half nut is not present.
[0015]
According to a third aspect of the present invention, in the mold clamping device, the movable mold is moved toward and away from the fixed mold by the mold opening / closing means, and the movable mold is moved to one of the fixed plate and the movable plate with the piston of the mold cylinder. In a mold clamping device that engages an engaging portion of a tie bar and a half nut provided on one of the fixed platen and the movable platen and clamps the mold with the mold clamping cylinder, A first adjusting cylinder in which one of a rod or a cylinder portion is attached to a piston, a connecting member in which the other of the rod or the cylinder portion of the first adjusting cylinder is attached, and a mold in which one of the rod or the cylinder portion is attached to the connecting member A tie bar position adjusting means comprising a second adjusting cylinder to which the other of the rod and the cylinder portion is attached is provided on the board on which the tightening cylinder is arranged, and the tie bar position adjusting means In the half nut engaging step is characterized by holding the position of the tie bar and the piston of the first adjusting cylinder and the second adjusting cylinder as respective stroke end position.
[0016]
According to a fourth aspect of the present invention, there is provided a method of controlling a mold clamping device, comprising: moving a movable plate on which a movable mold is mounted with respect to a fixed plate on which a fixed die is mounted; An engaging portion formed on a tie bar connected to a piston of a mold clamping cylinder provided on one side engages a half nut provided on the other board with the board provided with the mold closing cylinder. In the method of controlling the mold clamping device that performs mold clamping with the mold clamping cylinder, when the engagement between the half nut and the engaging portion is confirmed in the half nut engaging step, the mold clamping is started as it is, and the engagement is not confirmed. Sometimes, the tie bar is moved in the mold opening direction to engage the engaging portion with the half nut, and then the mold is clamped by the mold clamping cylinder.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view of a partial cross section of the mold clamping device of the present invention. FIG. 2 is an enlarged view of the mold clamping device according to the present invention when the half nut and the tie bar engaging portion are engaged. 3 to 5 are operation explanatory diagrams showing a method of controlling the mold clamping device according to the present invention. FIG. 6 is a flowchart showing a method for controlling the mold clamping device of the present invention.
[0018]
A mold clamping device 1 such as an injection molding machine or a die-casting machine shown in FIG. A board 5 is provided. A mold opening / closing cylinder 6 as a mold opening / closing means for moving the movable mold 4 toward and away from the fixed mold 2 is fixed to both side surfaces of the fixed board 3, and a rod 6a of the mold opening / closing cylinder 6 is a movable board. 5 are fixed to both side surfaces. Further, near the four corners of the fixed platen 3, mold clamping cylinders 7 for clamping the fixed mold 2 and the movable mold 4 are provided, respectively. In this embodiment, the mold clamping cylinder 7 is a single-acting type in which an oil chamber 7b is formed only on the movable platen side of the piston 7a. A tie bar 8 is continuously provided on the movable platen side of the piston 7a, and the tie bar 8 is inserted into tie bar insertion holes 5a provided at four corners of the movable platen 5.
[0019]
The movable platen 5 is moved in parallel with the fixed platen 3 by being guided by a guide provided on a base plate (not shown) and the tie bar 8. The movable platen 5 is provided so that the position with respect to the fixed platen 3 can be detected by position detection means (not shown). In the present invention, the mold opening / closing means may be a combination of a servo motor and a ball screw as long as the movable platen is moved. In addition, the mold closing cylinder 7 may be of a backward type in which an oil chamber is also formed on the side opposite to the movable platen. Furthermore, the mold clamping cylinder 7 may be provided with the tie bar 8 connected to the movable platen 5 and facing the fixed platen 3.
[0020]
Locking devices 9 are fixed to both sides of the tie bar insertion holes 5a on the opposite side 5b of the fixed platen of the movable platen 5, respectively. In the present invention, the locking device 9 is provided on the other board than the board on which the mold clamping cylinder 7 is provided. In this embodiment, the locking device 9 includes a pair of half nuts 11 and a lock cylinder 12 in which a rod is fixed to each of the half nuts 11. Then, the half nut 11 is advanced toward the advance completion position A indicated by the two-dot chain line in FIG. 2 by the lock cylinder 12 as the operating means, and is engaged with the engagement portion 10 of the tie bar 8. In the lock cylinder 12, the forward limit switch 13a which is an engagement detecting means for detecting that the half nut 11 is engaged with the engagement portion 10, and the half nut 11 is disengaged from the engagement portion 10 and moved to the retreat side. And a retreat-side limit switch 13b for detecting that the half-nut 11 has started to move forward from the retreat side.
[0021]
In this embodiment, the half nut 11 has a semicircular concave portion at the portion engaged with the inner engaging portion 10. As shown in FIG. 2, a plurality of sets of protrusions 11 d are formed including a vertical surface 11 a with respect to the axial direction of the tie bar 8, a parallel surface 11 b with respect to the axial direction, and an inclined surface 11 c that protrudes in the mold opening direction. It has a serrated cross section. A parallel surface 11e with respect to the axial direction of the tie bar 8 is also formed between the inclined surface 11c and the next vertical surface 11a, and a concave portion 11f is formed from the inclined surface 11c, the parallel surface 11e, and the next vertical surface 11a. . However, the shape of the half nut 11 is not limited to the above, and may be any shape as long as it can be engaged with the engagement portion 10 of the tie bar 8 described later. For example, the tie bar 8 may be formed with a plurality of sets of irregularities consisting of only a plane perpendicular to the axial direction and a plane parallel to the axial direction, or may be formed in a screw shape, and the number of the convex portions 11d or the concave portions 11f may be one. .
[0022]
An engaging portion 10 is formed on the outer peripheral portion 8a of the tie bar 8 connected to the mold clamping cylinder 7. The engaging portion 10 is a portion to which the half nut 11 of the above-described locking device 9 is engaged. The engaging portion 10 is used when the mold having the maximum mold thickness that can be formed by the mold clamping device 1 is attached, and when the mold having the minimum mold thickness is attached. The tie bar 8 is formed to have a predetermined length along the axial direction of the tie bar 8 so that the half nut 11 can engage with the tie bar 8 in any case where the tie bar 8 is attached. The shape of the engaging portion 10 according to this embodiment corresponds to the half nut 11 described above, and includes a vertical surface 10a with respect to the axial direction of the tie bar 8, a parallel surface 10b with respect to the axial direction, and a mold opening direction. It has a saw-tooth cross-section in which a plurality of sets of concave portions 10d each formed of a tapered inclined surface 10c that becomes thinner and thinner are formed. A parallel surface 10e with respect to the axial direction of the tie bar 8 is also formed between the inclined surface 10c and the next vertical surface 10a, and a convex portion 10f is formed from the inclined surface 10c, the parallel surface 10e, and the next vertical surface 10a. I have.
[0023]
In this embodiment, the parallel surface 11e formed in the concave portion 11f of the half nut 11 is formed longer in the mold opening and closing direction than the parallel surface 11b formed in the convex portion 11d. When the half nut 11 is engaged with the portion 10 at different positions according to the thickness of the mold, the probability that the protrusion 11d of the half nut 11 is engaged with the recess 10d of the engagement portion 10 is increased. Has become. The surface of the half nut 11 and / or the engagement portion 10 may be hardened.
[0024]
Next, the tie bar position adjusting means 14 of the mold clamping device 1 will be described. The tie bar position adjusting means 14 keeps the position of the tie bar 8 at a fixed position in the half nut engaging step, and when the advanced half nut 11 cannot be It has a function for adjusting the position. A rod 15a of a backward adjustment type first adjustment cylinder 15 is fixed to a rear end surface 7c of the piston 7a of the mold clamping cylinder 7 opposite to the movable platen. The cylinder portion 15b of the first adjustment cylinder 15 is fixed to one end of a connecting member 16 provided in a direction parallel to the fixed platen 3 on the side opposite to the fixed platen. Further, a cylinder portion 17b of a reversing type second adjustment cylinder 17 is fixed to a position inside the mold clamping cylinder 7 on the anti-movable platen side surface 3a of the fixed platen 3, and the rod 17a of the second adjustment cylinder 17 is The other end of the connecting member 16 is fixed to the fixed platen side. Needless to say, the position detecting means of the movable platen 5, the limit switch, each cylinder and the like in the mold clamping device 1 are connected to control means (not shown) and controlled via the control means.
[0025]
The reason why the tie bar position adjusting means 14 in this embodiment is composed of two backward-acting cylinders, the first adjusting cylinder 15 and the second adjusting cylinder 17, is that both cylinders are closed and closed cylinders, respectively. This is because the position of the tie bar 8 is held by holding the tie bar 8 at the side stroke end position. If only the first adjusting cylinder 15 is provided and the tie bar 8 is held at the stroke end position on the cylinder side of the first adjusting cylinder 15, the half nut 11 and the engaging portion 10 do not move the tie bar 8 as described later. , The pressure increase stroke of the mold clamping cylinder 7 cannot be secured. If only the second adjusting cylinder 17 is provided and the tie bar 8 is held at the stroke end position of the second adjusting cylinder 17 on the cylinder side, the half nut 11 and the engaging portion 10 cannot be engaged as described later. When it is necessary to move the tie bar 8 in the mold opening direction, the tie bar 8 cannot be moved.
[0026]
In this embodiment, the tie bar position adjusting means 14 is attached to each mold clamping cylinder 7, but one tie bar position adjusting means 14 may be attached to a plurality of mold clamping cylinders 7. One second adjusting cylinder 17 may be attached to the plurality of first adjusting cylinders 15 fixed to the piston 7a of the mold clamping cylinder 7 via the connecting member 16. The tie bar position adjusting means 14 may be constituted by a motor and a feed screw. Further, the tie bar position adjusting means 14 fixes the tie bar holder on the base on the side opposite to the fixed board of the movable board 5, and is disposed between the holder and the tie bar 8 when the tie bar 8 is inserted through the holder. You may.
[0027]
Next, a control method of the mold clamping device 1 of the present invention will be described with reference to the operation explanatory diagrams of FIGS. 3 to 5 and the flowchart of FIG. In the mold closing step shown in FIG. 3, the piston 15c of the first adjusting cylinder 15 of the tie bar position adjusting means 14 is held at the cylinder end stroke position on the side opposite to the fixed platen, and the piston 17c of the second adjusting cylinder 17 is The tie bar 8 is held at the cylinder-side stroke end position on the fixed board side, and is held in a fixed state with respect to the fixed board 3. Then, the movable platen 5 is moved by contracting the mold opening / closing cylinder 6 in the retreating direction (step 1).
[0028]
Next, in the half nut engaging step (1) shown in FIG. 3, when the position of the movable platen 5 reaches the lock cylinder advance start position on the mold opening side by a predetermined interval from the mold clamping completion position (step 2), the actuation means Then, the rod of the lock cylinder 12 and the half nut 11 start moving forward (step 3). Then, the engagement between the half nut 11 and the engaging portion 10 is confirmed based on whether or not the half nut 11 is detected by the forward limit switch 13a (step 4). At this time, when the position of the half nut 11 exceeds the engagement detection position B of the forward limit switch 13a indicated by a dashed line in FIG. 2, the inclined surface 11c of the half nut 11 and the inclined surface 10c of the engagement portion 10 are shifted. If the contact is made, it is determined that the half nut 11 has been engaged, and an engagement signal is sent from the forward limit switch 13a to the control means (in the case of Y in step 4). At this time, the half nut 11 is constantly pressed by the lock cylinder 12 toward the forward completion position A indicated by a two-dot chain line in FIG. Regarding the engagement detection position B of the forward limit switch 13a, the vertical surface 11a of the half nut 11 and the vertical surface 10a of the engagement portion 10 are overlapped (the parallel surface 11b of the half nut 11 is 10 is in a state of entering the axial center side of the tie bar 8 from the parallel surface 10e of the tie bar 8), and is set at a position where the half nut does not reach the forward completion position.
[0029]
Also, in the half nut engaging step (2) shown in FIG. 3, the parallel side 11b of the convex portion 11d of the half nut 11 and the parallel surface 10e of the convex portion 10f of the engaging portion 10 come into contact with each other. If the engagement between the half nut 11 and the engagement portion 10 has not been confirmed even after the predetermined time has elapsed since the limit switch 13b was turned off (Step 4 is N), the tie bar position adjusting means 14 The first adjusting cylinder 15 is advanced, and the tie bar 8 is moved in the mold opening direction (step 5). Then, the parallel surface 10e of the engaging portion 10 moves in the mold opening direction, the contact of the convex portion 11d of the half nut 11 with the parallel surface 11b is released, and the convex portion of the half nut 11 continuously pressed by the lock cylinder 12. The portion 11d is fitted into the concave portion 10d of the engaging portion 10. When the half nut 11 advances, the engagement of the half nut 11 is confirmed by the limit switch 13a, and at the same time, the advance of the first adjusting cylinder 15 is stopped. At this time, the reason why the tie bar 8 is moved in the mold opening direction, not in the mold closing direction, is to move the tie bar 8 in the mold opening direction with respect to the vertical surface 11 a of the half nut 11. This is because it is possible to move to a position where the vertical surface 10a contacts with a short moving distance.
[0030]
As described above, the start of the movement of the half nut 11 by the lock cylinder 12 is started just before the mold closing completion position for the purpose of shortening the time, but the engagement between the half nut 11 and the engaging portion 10 is almost completed at the mold closing completion position. When the completion of mold closing is confirmed before and after the engagement of the half nut 11 is confirmed (step 6), the tie bar 8 is moved in the mold clamping direction, and the process proceeds to the mold clamping step. Although not described in the flow chart at this time, if the mold closing completion position cannot be confirmed even after the lapse of a predetermined time, there is a possibility that a foreign object or the like may be caught between the molds. The control of the fastening device 1 is stopped.
[0031]
In the mold clamping step (1) shown in FIG. 4, first, a gap C (see FIG. 2) between a vertical surface 10 a that is a pressing surface of the engagement portion 10 and a vertical surface 11 a that is a pressed surface of the half nut 11. The second adjustment cylinder 17 is also used to move the piston 7a of the mold clamping cylinder 7 so that the two are brought into contact with each other and the force of the mold clamping cylinder 7 is quickly transmitted to the movable platen 5. . The rod 17a of the second adjusting cylinder 17 is advanced (Step 7), and at the same time, the operating oil is also supplied to the oil chamber 7b of the mold clamping cylinder 7 to operate the mold clamping cylinder 7 (Step 8). At this time, the first adjustment cylinder 15 is held at that position, and the forward force of the second adjustment cylinder 17 is transmitted to the piston 7a of the mold clamping cylinder 7.
[0032]
Then, in the mold clamping step (2) shown in FIG. 4, after the vertical surface 10 a of the engaging portion 10 comes into contact with the vertical surface 11 a of the half nut 11, the operation of the first adjustment cylinder 15 and the second adjustment cylinder 17 is performed. Oil is released to a tank (not shown), both cylinders are set free, and the mold is clamped only by the mold clamping cylinder 7. The reason why the first adjusting cylinder 15 and the second adjusting cylinder 17 are made free is to absorb the subsequent pressure increasing stroke of the mold clamping cylinder 7. Then, when the movable mold 4 and the fixed mold 2 are completely clamped and the pressure increase is completed (step 9), molten resin is injected and filled into the cavity formed between the molds by an injection device (not shown) ( Step 10), followed by cooling and solidification. When a predetermined time has elapsed and the mold clamping time has elapsed (step 11), the hydraulic oil in the oil chamber 7b of the mold clamping cylinder 7 is released to the tank as shown in FIG. Perform (Step 12).
[0033]
Then, in the half nut releasing step shown in FIG. 5, the lock cylinder 12 is retracted, and the half nut 11 is released from the engaging portion 10 (step 13). At this time, the first adjustment cylinder 15 may be slightly advanced to make it easier to detach the half nut 11 from the engagement portion 10. Then, if the removal of the half nut 11 from the engaging portion 10 is confirmed by detecting the retreat-side limit switch 13b (step 14), the mold opening / closing cylinder 6 is advanced in the mold opening process shown in FIG. Step 15) The movable mold 4 is moved in the mold opening direction to release the movable mold 4 from the molded product. Thereafter, the movable platen 5 is moved to the mold opening completion position (step 16). The mold clamping cylinder 7 is of a backward movement type, the mold clamping cylinder 7 is movable in the mold opening direction, and a mold opening step of releasing the movable mold 4 and the molded product by the mold clamping cylinder 7 is performed first. It may be. In that case, the half nut releasing step is performed after the mold opening step, and the mold opening and closing cylinder 6 performs the mold opening again.
[0034]
In the tie-bar position adjustment step shown in FIG. 5, when the molded product is being taken out at the mold opening completion position, the operating oil is supplied to the rod-side oil chamber of the first adjustment cylinder 15 and the first adjustment is performed. The rod 15a of the cylinder 15 is held at the cylinder end stroke end position (step 17), and at about the same time hydraulic fluid is supplied to the rod-side oil chamber of the second adjustment cylinder 17, and the rod 17a of the second adjustment cylinder 17 is also moved to the cylinder side. The piston 7a and the tie bar 8 of the mold clamping cylinder 7 are held at fixed positions with respect to the fixed platen 3 by being held at the stroke end position (step 18). The tie bar 8 may be held in the tie bar position adjustment step by holding the first adjustment cylinder 15 at the rod-side stroke end position and holding the second adjustment cylinder 17 at the rod-side stroke end position. In that case, the second adjustment cylinder 17 is used when it is necessary to move the tie bar 8 to the mold opening side in the half nut engagement step, and the first adjustment cylinder 15 is used at the start of mold clamping.
[0035]
Next, the setting of the mold thickness when the mold used in the mold clamping apparatus 1 of the present invention is changed will be described. When setting the mold thickness, the lock cylinder 12 is retracted, and the first adjustment cylinder 15 and the second adjustment cylinder 17 are each held at the cylinder-side stroke end position. Then, a value smaller than the actual mold thickness is input from an input screen (not shown), and the mold is closed. Then, when the movable mold 4 and the fixed mold 2 come into contact with each other, a difference between the input value and the above-described value is displayed on the display screen. input. Then, the corrected input value of the thickness of the mold is used for control as a mold clamping completion position, but the position of the tie bar 8 is not adjusted by setting the mold thickness.
[0036]
Next, another embodiment of the present invention will be described. In this example, the basic arrangement of the mold clamping device and the configuration of the tie bar position adjusting means 14 are the same as those in the above-described embodiment. However, a combination of a servomotor and a ball screw is used as the mold opening / closing means. When the mold is closed, the servomotor is driven, and the position of the movable platen 5 is detected using an encoder attached to the servomotor. Then, the movable platen 5 is stopped at a position where the convex portion 11d of the half nut 11 advances forward to the advance completion position A and engages with the concave portion 10d of the engaging portion 10 of the tie bar 8 held by the fixed platen 3. Then, the half nut 11 is engaged with the engagement portion 10. In this embodiment, since the engagement position of the half nut 11 is almost before the mold closing completion position, it is necessary to stop the movable platen 5 once or largely reduce the speed at that position as described above. is there.
[0037]
Further, still another embodiment of the present invention will be described. Also in this example, the basic arrangement of the mold clamping device and the configuration of the tie bar position adjusting means 14 are the same as those in the above-described embodiment. In still another embodiment, the locking device 9 attached to the movable platen 5 is movable with respect to the movable platen 5 in the mold opening and closing direction. Specifically, the half nut 11 has a contact surface that presses the side 5b of the movable plate 5 opposite the fixed plate, and is held on the movable plate 5 by a spring fixed to a portion other than the contact surface. A shaft fixed to the spring is screwed to the movable platen 5, the shaft of the spring is rotatable by a motor via a pulley and a belt, and the shaft and the spring are provided so as to be adjustable in the mold opening and closing direction. As a result, when the thickness of the mold used is changed, the shaft and the spring are moved in the mold opening / closing direction, and the relative positions of the half nut 11 and the movable platen 5 are changed. Then, at the mold closing completion position, the convex portion 11d of the half nut 11 can be engaged with the concave portion 10d of the engaging portion 10 without making contact with the concave portion 10d. When the mold is clamped, the spring is contracted, so that the half nut 11 abuts and is pressed against the side 5b of the movable platen 5 opposite to the fixed platen. In the above, the position of the half nut 11 may be adjusted by a hydraulic cylinder instead of a spring or a motor.
[0038]
In the present invention, the position of the tie bar 8 connected to the piston 7a of the mold clamping cylinder 7 can be held at a fixed position by the tie bar position adjusting means 14, although the above-described other embodiments are merely examples. With such a mechanism, various modes in which the engaging portion 10 and the half nut 11 are engaged without providing the tie bar position detecting means as in the related art can be applied.
[0039]
【The invention's effect】
According to the first aspect of the present invention, the movable die is moved toward or away from the fixed die by the die opening / closing means, and the tie bar is provided on one of the fixed plate and the movable plate so as to be connected to the piston of the mold clamping cylinder. In the mold clamping device which engages the half nut provided on either one of the fixed platen and the movable platen, and clamps the mold with the mold clamping cylinder, the half nut is engaged in the half nut engaging step. Actuating means for advancing toward the forward completion position, engagement detecting means for detecting the engagement between the half nut and the engaging portion, and engagement means provided on the mold clamping cylinder or the tie bar. Since the tie bar position adjusting means for moving the tie bar in the mold opening direction when no signal is output is provided, the half nut can be moved in any state with respect to the engagement portion of the tie bar. It is possible to focus. Also, since the half nut is engaged with the engaging portion by moving to the mold opening side, the half nut and the engaging portion are engaged at a position where the vertical surface of the half nut is close to the vertical surface of the engaging portion. And the time until the mold is clamped by the mold clamping cylinder can be shortened.
[0040]
According to a second aspect of the present invention, in the first aspect, a plurality of pairs of a vertical surface with respect to the axial direction of the tie bar and a tapered surface that becomes thinner in the mold opening direction are formed alternately on the engagement portion. On the other hand, in the half nut, a plurality of sets of vertical surfaces and inclined surfaces protruding toward the mold opening direction are formed alternately in correspondence with the engaging portions, and the half nut is located at a position not reaching the half nut advance completion position. And the engagement detecting means for detecting the engagement of the engagement portion, so that even if the half nut and the engagement portion are not completely engaged but slightly engaged, the By moving the tie bar, the half nut and the engaging portion are completely engaged, and it is possible to directly shift to mold clamping.
[0041]
According to a third aspect of the present invention, the movable mold is moved toward and away from the fixed mold by the mold opening / closing means, and the tie bar is connected to one of the fixed plate and the movable plate with the piston of the mold clamping cylinder. And a half nut provided on the other of the fixed platen and the movable platen, and clamping the mold by the mold clamping cylinder. A first adjustment cylinder to which one of the parts is attached, a connecting member to which the other of the rod or the cylinder part of the first adjusting cylinder is attached, and a clamping cylinder to which one of the rod or the cylinder part is attached to the connecting member Tie bar position adjusting means comprising a second adjusting cylinder in which the other of the rod or the cylinder portion is attached to the disc having been mounted, and the tie bar position adjusting means In the slot engagement step, the pistons of the first adjustment cylinder and the second adjustment cylinder are each used as a stroke end position to hold the position of the tie bar, so that the position of the tie bar can be fixed at a fixed position by a simple mechanism. Thus, the engagement portion between the half nut and the tie bar can be engaged without providing the tie bar position detecting means. Further, the mold clamping cylinder can always be clamped from a fixed position even if the mold thickness of the mold used is changed, so that the length of the mold clamping cylinder can be shortened.
[0042]
According to claim 4 of the present invention, the movable plate on which the movable mold is mounted is moved with respect to the fixed plate on which the fixed die is mounted, and the mold clamp provided on one of the fixed plate and the movable plate. An engaging portion formed on a tie bar connected to the piston of the cylinder is engaged with a half nut provided on the other plate of the plate on which the mold clamping cylinder is provided, and the mold is clamped by the mold clamping cylinder. In the method of controlling the mold clamping device, when the engagement between the half nut and the engaging portion is confirmed in the half nut engaging step, the mold clamping is started as it is, and when the engagement is not confirmed, the tie bar is moved in the mold opening direction. Then, after the engaging portion and the half nut are engaged, the mold is clamped by the mold clamping cylinder.
[Brief description of the drawings]
FIG. 1 is a plan view showing a partial cross section of a mold clamping device according to the present invention.
FIG. 2 is an enlarged view of a mold clamping device according to the present invention when a half nut and a tie bar are engaged with each other.
FIG. 3 is an operation explanatory view (a mold closing step, a half nut engaging step (1), and a half nut engaging step (2)) illustrating a control method of the mold clamping device of the present invention.
FIG. 4 is an operation explanatory view (a mold clamping step (1), a mold clamping step (2), and a depressurizing step) illustrating a control method of the mold clamping device of the present invention.
FIG. 5 is an operation explanatory view (half-nut releasing step, mold opening step, tie-bar position adjusting step) showing a control method of the mold clamping device of the present invention.
FIG. 6 is a flowchart illustrating a control method of the mold clamping device according to the present invention.
[Explanation of symbols]
1 ……… Mold clamping device
2 ……… Fixed mold
3 ... fixed board
3a: anti-movable plate side
4 ……… Movable mold
5 movable board
5a tie bar insertion hole
5b …… anti-fixing plate side
6 …… Mold opening and closing cylinder
6a, 15a, 17a ... rod
7 ……… Clamping cylinder
7a, 15c, 17c ... Piston
7b ... oil chamber
7c Rear end face
8 ...... Tie bar
8a ...... Outer circumference
9 Locking device
10 Engagement part
10a, 11a ... vertical surface
10b, 10e, 11b, 11e ... parallel plane
10c, 11c ... slope
10d, 11f ... recess
10f, 11d ... convex part
11 Half-nut
12 Lock cylinder (actuation means)
13a ... Forward limit switch (engagement detection means)
13b …… Reverse limit switch
14 tie bar position adjustment means
15 ...... First adjustment cylinder
15b, 17b ... cylinder part
16 ...... Connecting member
17 ... second adjustment cylinder
A ……… Advance completion position
B: Engagement detection position
C ……… Gap

Claims (4)

A fixed platen on which a fixed mold is mounted,
A movable plate on which a movable mold is mounted facing the fixed plate,
Mold opening and closing means for moving the movable mold toward and away from the fixed mold,
A mold clamping cylinder disposed on one of a fixed platen and a movable platen for clamping the fixed mold and the movable mold,
A tie bar connected to the piston of the mold clamping cylinder;
An engaging portion formed in an outer peripheral portion of the tie bar in an axial direction;
A board provided with a mold clamping cylinder, a half nut provided on the other board and engaged with the engaging portion,
In the mold clamping device consisting of
Actuating means for advancing the half nut toward the forward completion position in the half nut engaging step,
Engagement detection means for detecting the engagement between the half nut and the engagement portion,
A mold clamping device provided with the mold clamping cylinder or the tie bar, and a tie bar position adjusting means for moving the tie bar in the mold opening direction when the engagement signal is not output by the engagement detecting means. . An engaging portion formed with a plurality of sets of concave portions each having at least a concave surface including a vertical surface with respect to the axial direction of the tie bar and a tapered surface that becomes thinner in the mold opening direction.
A half nut in which a plurality of sets of convex portions formed of at least a vertical surface corresponding to the engaging portion and an inclined surface protruding toward the mold opening direction are formed,
2. The mold clamping device according to claim 1, further comprising an engagement detecting means for detecting engagement between the half nut and the engagement portion at a position where the half nut does not reach the forward completion position. A fixed platen on which a fixed mold is mounted,
A movable plate on which a movable mold is mounted facing the fixed plate,
Mold opening and closing means for moving the movable mold toward and away from the fixed mold,
A mold clamping cylinder disposed on one of a fixed platen and a movable platen for clamping the fixed mold and the movable mold,
A tie bar connected to the piston of the mold clamping cylinder;
An engaging portion formed in an outer peripheral portion of the tie bar in an axial direction;
A board provided with a mold clamping cylinder, a half nut provided on the other board and engaged with the engaging portion,
In the mold clamping device consisting of
A first adjusting cylinder in which one of a rod and a cylinder portion is attached to a piston of the mold clamping cylinder,
A connecting member to which the other of the rod or the cylinder part of the first adjustment cylinder is attached,
A tie bar position adjusting means comprising a second adjusting cylinder having one of a rod or a cylinder portion attached to the connecting member and one of the rod or the cylinder portion attached to a board on which the mold clamping cylinder is provided and one of the rod or the cylinder portion is provided,
By the tie bar position adjusting means,
A mold clamping device, wherein in a half nut engagement step, the positions of the tie bars are held by setting the pistons of the first adjustment cylinder and the second adjustment cylinder as stroke end positions. Move the movable plate with the movable mold attached to the fixed plate with the fixed mold attached,
An engaging portion formed on a tie bar connected to a piston of a mold clamping cylinder disposed on one of the fixed platen and the movable platen,
The board provided with the mold clamping cylinder is engaged with a half nut provided on the other board,
In a control method of a mold clamping device that performs mold clamping by the mold clamping cylinder,
When the engagement between the half nut and the engaging portion is confirmed in the half nut engaging step, mold clamping is started as it is,
When the engagement is not confirmed, move the tie bar in the mold opening direction,
Engage the engagement portion and the half nut,
A method for controlling a mold clamping device, comprising clamping the mold by the mold clamping cylinder.

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