JP6108479B2 - Hydraulic oil tank or auxiliary oil tank for injection molding machine - Google Patents

Description

  The present invention is provided in an injection molding machine having a hydraulic system that supplies hydraulic oil to control a hydraulic cylinder device, and supplies the hydraulic oil to and from a cylinder chamber of the hydraulic cylinder device. It relates to a tank or auxiliary oil tank.

  In general, an injection molding machine is equipped with a mold clamping device that opens and closes and molds a mold device composed of a fixed mold and a movable mold, and flows into a cavity space in the mold apparatus. A molding material made of resin or metal in a possible state is injection-filled. For example, if the molding material is a thermoplastic resin material, an injection device for injecting and filling a molten resin material that has been plasticized and melted (hereinafter referred to as a molten resin) is provided. After the molding material is injected and filled in and solidified, the molding device is opened and the molding cycle for taking out the molded product is repeated to continuously mass-produce the molded product as a product.

  In order to shorten the molding cycle time, the mold clamping device of the injection molding machine is designed to speed up the mold opening and closing operations and to generate a large mold clamping force in the mold clamping operation. There is a configuration that is divided into a mold opening / closing drive device that performs an opening / closing operation and a mold clamping cylinder device that performs a mold clamping operation.

  In the mold clamping device of the injection molding machine disclosed in Patent Document 1, a fixed platen fixed on the machine base to which a fixed mold is attached, and a tie bar coupled to the fixed platen are supported so as to be slightly slidable with respect to the machine base. A mold clamping device comprising a support platen (back platen) and a movable platen to which a movable mold is attached and moved between a fixed platen and a support platen, such as a servo motor and a ball screw mechanism Discloses a mold clamping device having a mold opening / closing drive device including an electric actuator and a mold clamping cylinder device including a hydraulic actuator such as a hydraulic cylinder.

  In the mold clamping device, a mold clamping shaft (working shaft) that is a nut and is fixed to the back of the movable platen is fixed to a screw shaft that is rotated by a servo motor. The nut of the mold clamping shaft is screwed so that the movable platen moves forward and backward at high speed, and the mold clamping cylinder device supports the mold clamping cylinder supported by the support platen and the mold clamping shaft that slides inside the cylinder. A high-pressure mold clamping force is applied to the movable platen by supplying high-pressure hydraulic fluid from a hydraulic pressure generation source to the mold oil chamber (cylinder chamber) formed in step S2.

  Further, the mold clamping device has an auxiliary storage tank (auxiliary oil tank) connected to the mold clamping chamber of the mold clamping cylinder device via a prefill valve, and performs mold closing operation with the mold opening / closing drive device. When the hydraulic fluid stored in the auxiliary reservoir is supplied to be sucked into the enlarged mold clamping chamber through the opened prefill valve, and the mold clamping cylinder device performs the mold clamping operation. By simply closing the prefill valve and supplying a small amount of hydraulic fluid from the tank device (main oil tank) to the mold clamping chamber with a hydraulic pump that is the source of hydraulic pressure, the mold is quickly placed on the movable platen via the mold clamping shaft. A clamping force is applied, and then the pressure is released from the mold clamping chamber by the mold clamping cylinder device, and when the mold opening operation is performed by the mold opening / closing drive device, it is reduced through the opened prefill valve. Auxiliary hydraulic fluid discharged from mold clamping chamber It is adapted to the reservoir to Tomeso.

  In such a mold clamping device, particularly when a mold opening operation is performed at a high speed, the mold clamping chamber is quickly reduced by moving the mold clamping shaft through the mold clamping cylinder at a high speed. In some cases, the hydraulic fluid that has been depressurized flows into the connected auxiliary storage tank vigorously, and the liquid level of the hydraulic hydraulic fluid undulates in the auxiliary storage tank, causing bubbles to enter.

  In the bubble mixing prevention device disclosed in Patent Document 2, a box-shaped baffle member having a plurality of holes is disposed on an upper portion of a discharge port opened in a hydraulic oil tank in a hydraulic device, particularly an injection molding machine, and a flat plate is disposed on the upper portion. The baffle member is disposed and the hydraulic oil pushed back into the hydraulic oil tank from the cylinder through the discharge port is rectified by a plurality of holes provided in the baffle member, and further, the liquid level is obtained by the flat plate on the baffle member. By changing the flow of hydraulic oil toward the so-called horizontal flow in the horizontal direction, entrainment of bubbles can be prevented and smooth operation of the hydraulic equipment is not hindered, and the operating capacity as a hydraulic equipment is sufficient Is disclosed.

International Publication No. 2004/024417 Japanese Utility Model Publication No. 61-018242

  However, in the hydraulic oil tank including the conventional auxiliary oil tank, the hydraulic oil is formed in the tank when the hydraulic oil is supplied to and discharged from the cylinder chamber of the hydraulic cylinder device of the injection molding machine through the supply / discharge hole. A baffle member is provided in the upper part of the supply / discharge hole, and the hydraulic oil collides with the baffle member to change the flow of the hydraulic oil in the lateral direction, that is, the direction of the hydraulic oil flow toward the inner surface of the hydraulic oil tank. However, if the flow rate of the hydraulic oil cannot be sufficiently reduced, the hydraulic oil collides with the inner surface of the hydraulic oil tank, and the flow of the hydraulic oil is changed again above the hydraulic oil tank along the inner surface. As a result, the liquid level in the hydraulic oil tank may greatly swell and air bubbles may be mixed.

  Therefore, in the case of forming a supply / discharge hole in the bottom surface of a conventional hydraulic oil tank, for example, the depth of the tank is increased, that is, the height of the tank is increased, and the amount of hydraulic oil stored is increased. Therefore, it is necessary to prevent the bubbles from being mixed so as to suppress the undulation of the liquid level of the hydraulic oil. As a result, the mold clamping device is increased in size. Especially when the hydraulic oil tank is connected to the cylinder chamber of the hydraulic cylinder device without supplying the hydraulic pressure source and has a hydraulic circuit for supplying and discharging hydraulic oil, the hydraulic oil tank is arranged above the hydraulic cylinder device. As a result, the overall height of the mold clamping device becomes large.

  Therefore, in the hydraulic oil tank or auxiliary oil tank of the injection molding machine of the present invention, even if the amount of hydraulic oil stored in these tanks is small, the hydraulic oil flowing into these tanks is quickly and gently decelerated. Therefore, by suppressing the undulation of the liquid level and preventing air bubbles from being mixed into the hydraulic oil stored in these tanks, the operation of the hydraulic cylinder device is stabilized and the height of the tank and the entire device is increased. The purpose is to reduce dimensions and reduce size.

  The hydraulic oil tank for an injection molding machine according to the present invention is provided in an injection molding machine having a hydraulic system for controlling a hydraulic cylinder device, and has a supply / discharge hole for supplying and discharging hydraulic oil to / from a cylinder chamber of the hydraulic cylinder device. In the hydraulic oil tank formed, at least two flat baffle plates provided so as to be arranged at different heights on the upper side of the supply / discharge hole opened on the bottom surface, and immediately above the opening of the supply / discharge hole And a hollow baffle plate fixed between the two flat baffle plates and fixed around the entire inner surface so that the hollow through hole is located.

  Further, in the auxiliary oil tank of the injection molding machine according to the present invention, the auxiliary oil tank having a discharge hole for discharging the excess hydraulic oil exceeding a predetermined storage amount to the main oil tank of the hydraulic system. The flat baffle plate arranged at the top of the flat baffle plate is disposed above the liquid level when the hydraulic oil has the predetermined storage amount. The hollow baffle plate arranged at the top of the hollow baffle plate may be arranged at the level of the liquid level when the hydraulic oil has the predetermined storage amount.

  In the auxiliary oil tank of the injection molding machine of the present invention, the tank is partitioned into at least two oil storage chambers, and at the height that allows the excess hydraulic oil to overflow into the adjacent oil chamber. A partition plate and one of the oil chambers formed by partitioning with the partition plate, the supply and discharge holes are formed in the bottom surface, and one hollow baffle plate is attached to the upper side of the partition plate. Of the oil storage chamber formed by being arranged at a height and being partitioned by the partition plate, and a main oil storage chamber in which the two flat baffle plates are arranged across the hollow baffle plate The auxiliary oil is discharged to the outside from the discharge hole that forms the surplus hydraulic oil exceeding the predetermined storage amount of the main oil storage chamber that overflows beyond the partition plate. And a room.

  Further, in the auxiliary oil tank of the injection molding machine according to the present invention, the hydraulic cylinder device is a mold clamping cylinder device provided in a mold clamping device of the injection molding machine, and an operating shaft connected to the movable platen is a hydraulic piston. The mold clamping cylinder supported by the back platen is a hydraulic cylinder, and when the movable platen is opened and closed by another hydraulic actuator or another electric actuator, the operation is performed between the cylinder chamber of the mold clamping cylinder. It is good to supply and discharge oil.

  In the hydraulic oil tank or auxiliary oil tank of the injection molding machine of the present invention, even when the amount of hydraulic oil stored in these tanks is small, the hydraulic oil stored in these tanks is supplied and discharged. In addition, it is possible to reduce the height of the tank and to reduce the height dimension by preventing the bubbles from entering the liquid surface by suppressing the undulation of the liquid level. Enables miniaturization and reduction of height dimension.

It is sectional drawing of the longitudinal direction which shows the outline of the mold clamping apparatus of the injection molding machine which has an auxiliary oil tank of this invention. FIG. 2 is a longitudinal sectional view schematically showing a mold clamping cylinder device in the mold clamping device shown in FIG. 1. It is EE arrow sectional drawing of the clamping cylinder apparatus shown by FIG. FIG. 3 is a longitudinal sectional view schematically showing the state of hydraulic oil in an auxiliary tank immediately after the start of a mold opening process for opening a closed mold apparatus in the mold clamping cylinder apparatus shown in FIG. 2. FIG. 5 is a cross-sectional view of the mold clamping cylinder device shown in FIG. FIG. 3 is a longitudinal sectional view schematically showing a state of hydraulic oil in an auxiliary tank immediately before completion of a mold opening process for opening a mold device in the mold clamping cylinder device shown in FIG. 2. It is GG arrow sectional drawing of the mold clamping cylinder apparatus shown by FIG. In the auxiliary oil tank shown in FIG. 3, (a) is a cross-sectional view taken along arrow AA, (b) is a cross-sectional view taken along arrow BB, (c) is a cross-sectional view taken along arrow CC, and FIG. 4D is a cross-sectional view taken along the line DD.

  The hydraulic oil tank or auxiliary oil tank of the injection molding machine of the present invention will be described by taking the auxiliary oil tank of the mold clamping device of the injection molding machine shown in FIGS. 1 to 8 as an example of the embodiment.

  A mold clamping device 1 for an injection molding machine shown in FIGS. 1 to 7 includes a stationary platen 5 fixed on a machine base 11, a back platen 6 that is connected by a tie bar 8 and slightly slides on the machine base 11. And a movable platen 7 which is supported on and guided by a guide rail 9 mounted on the guide block 10 and fixed on the machine base 11 and moves back and forth between the fixed platen 5 and the back platen 6. In the mold apparatus 12, the fixed mold 12 a is fixed to the fixed platen 5, and the movable mold 12 b is fixed to the movable platen 7. The movable platen 7 is fixed with a working shaft 31 having a hollow shaft center portion. The operating shaft 31 has one end fixed to the back surface of the movable platen 7 and the other end formed with a piston head 31a that slides in a clamping cylinder 32 serving as a hydraulic cylinder and a ball screw shaft serving as a ball screw mechanism. A nut 22 that is screwed onto 21 is fixed. The movable platen 7 may have a guide bush serving as a guide hole through which the tie bar 8 passes, and the movement of the movable platen 7 may be guided using the tie bar 8.

  In the mold opening and closing process, the movable platen 7 advances and retreats toward the fixed platen 5 so as to open and close the mold apparatus 12 by the mold opening and closing drive device 2, and the mold closing cylinder apparatus 3 moves the mold apparatus 12 in the mold closed state. A mold clamping force is generated by trying to advance toward the fixed platen 5 so as to tighten.

  The mold opening / closing drive device 2 is an electric actuator, and is rotatably supported by a rotary bearing 26 at a rear end portion of a mold clamping cylinder 32 (described later) whose one end is fixed to the back surface of the back platen 6. The rotation drive of the electric motor 23 is transmitted through the pulleys 24, 24 and the belt 25, and the other end of the ball screw shaft 21 is screwed into a nut 22 fixed to the operating shaft 31 so as not to rotate. Thus, the movable platen 7 is moved forward and backward together with the operating shaft 31 toward the fixed platen 5 so that the mold opening / closing operation can be performed at a high speed.

  The mold clamping cylinder device 3 is a hydraulic actuator, and slidably inserts an operating shaft 31 having a piston head 31a formed in a mold clamping cylinder 32 supported by the back platen 6, for example, a single-acting cylinder The cylinder chamber 32a of the mold clamping cylinder 32 (in the embodiment, the piston head side oil chamber 32a on the mold clamping side) is supplied with high pressure from the main oil tank 14 via a hydraulic pressure source 15 such as a hydraulic pump. The clamping operation can be performed at a high pressure by pressing the movable mold 12b against the fixed mold 12a via the movable platen 7 by the working shaft 31 that moves forward with the hydraulic oil 13. Note that the cylinder chamber 32a of the mold clamping cylinder 32 is connected to the hydraulic pressure generation source 15 and the main oil tank 14 via the direction switching valve 16, for example, and switched to the hydraulic pressure generation source 15 (P port) side. When the hydraulic oil 13 is supplied and switched to the main oil tank 14 (T port) side, the compressed hydraulic oil 13 in the cylinder chamber 32a is discharged to the main oil tank 14, thereby the cylinder chamber 32a. The pressure inside is released, i.e. depressurized. Note that the hydraulic circuit shown in the figure is schematically illustrated and is not limited thereto.

  In such a mold clamping apparatus 1, for example, when the mold opening / closing drive apparatus 2 performs a mold opening or closing operation, the operation shaft 31 moves back and forth, and the volume of the cylinder chamber 32 a of the mold clamping cylinder 32 increases or decreases. The auxiliary oil tank 4 is connected to the cylinder chamber 32a via the prefill valve 33 and supplies the hydraulic oil 13 to and from the cylinder chamber 32a. When the mold is closed, the prefill valve 33 is opened. The auxiliary oil tank 4 and the cylinder chamber 32a communicate with each other, and the hydraulic oil 13 stored in the auxiliary oil tank 4 is supplied to the cylinder chamber 32a so that the prefill valve 33 can be used during mold clamping. The backflow from the cylinder chamber 32a to the auxiliary oil tank 4 is prevented and the hydraulic oil 13 in the main oil tank 14 is slightly pressurized after being pressurized by the hydraulic pressure source 15 into the cylinder chamber 32a of the clamping cylinder 32. And to be able to quickly start mold clamping by only supplying high pressure hydraulic fluid 13 quantities. In such a mold clamping device 1, when the mold is opened, the cylinder chamber 32a of the mold clamping cylinder 32 is depressurized immediately before, for example, the directional switching valve 16 or the like, and then the prefill valve 33 is opened. Thus, the cylinder chamber 32 a and the auxiliary oil tank 4 communicate with each other, and the hydraulic oil 13 in the cylinder chamber 32 a is discharged toward the auxiliary oil tank 4. When the mold is clamped or when the mold is depressurized, the operating shaft 31 advances and retreats although it is a short distance. Therefore, the ball screw shaft of the mold opening / closing drive device to which the nut 22 fixed to the operating shaft 31 is screwed. The movement of the operating shaft 31 is not hindered by keeping the state 21 freely rotatable. Further, the direction switching valve 16 may be switched to a shut-off state that is not connected to either the hydraulic pressure generation source 15 side or the main oil tank 14 side while the prefill valve 33 is open, or the direction switching valve 16. If the flow path resistance of the piping that returns the hydraulic oil 13 to the main oil tank 14 is large and the amount of the hydraulic oil 13 that returns to the main oil tank 14 is small, the main pressure continues from the above-described pressure release operation. The state switched to the oil tank 14 side may be maintained.

  The auxiliary oil tank 4 is divided into a main oil storage chamber 41 and a sub oil storage chamber 42 by a partition plate 43. The main oil storage chamber 41 is discharged from the cylinder chamber 32a of the mold clamping cylinder 32, with a supply / discharge hole 41a formed in the bottom surface communicating with the cylinder chamber 32a of the mold clamping cylinder 32 via the prefill valve 33. The coming hydraulic oil 13 is stored, and the stored hydraulic oil 13 is supplied so that the cylinder chamber 32a sucks it. The auxiliary oil storage chamber 42 discharges the excess hydraulic oil 13 that overflows from the main oil storage chamber 41 beyond the partition plate 43 to the main oil tank 14 through a discharge hole 42a that forms on the bottom surface. Further, the air in the auxiliary oil tank 4 is pressurized or negative pressure by the hydraulic oil 13 supplied and discharged from the cylinder chamber 32a of the clamping cylinder 32 during the mold opening / closing operation. An air breather 48 is provided for supplying and discharging air from the outside of the auxiliary oil tank 4 so as to bring the internal pressure of the auxiliary oil tank 4 to normal pressure so as not to be in a state.

  From here, the specific configuration of the present invention will be described. The auxiliary oil tank 4 of the mold clamping device 1 shown in FIG. 1 to FIG. 8 decelerates the flow velocity of the hydraulic oil 13 by changing the flow direction of the hydraulic oil 13 flowing into the main oil storage chamber 41 from the supply / discharge hole 41a. It is equipped with a “bubble prevention mechanism” that prevents the bubbles from mixing by preventing the liquid surface from wobbling. The bubble prevention mechanism 44 can reduce the height of the auxiliary oil tank 4 and the overall size of the auxiliary oil tank 4. The bubble prevention mechanism 44 is mainly composed of two flat baffle plates 45 and 45 and a hollow baffle plate 46. The flat baffle plates 45, 45 are arranged at different heights from the supply / discharge hole 41a so as to cover the upper side of the supply / discharge hole 41a. The hollow baffle plates 46 are arranged so as to alternate between the two flat baffle plates 45, 45 in the height direction. More specifically, the hollow baffle plate 46 is fixed over the entire circumference of the inner side surface of the main oil storage chamber 41 so that the hollow through hole 46a is positioned above the supply / discharge hole 41a. ing.

  The lower flat baffle plate 45 closest to the supply / discharge hole 41a is fixed to the bottom surface of the main oil storage chamber 41 with a predetermined gap by a spacer member 47. Further, the flat baffle plate 45 disposed on the flat baffle plate 45 is fixed to the flat baffle plates 45 and 45 facing each other with a spacer member 47 with a predetermined gap therebetween. The fixing of the flat baffle plates 45, 45 is not limited to the fixing means by the spacer member 47, and an appropriate fixing means may be adopted.

  The hollow baffle plate 46 is preferably disposed on the upper side 43a of the partition plate 43, that is, at the height of the liquid level 13a when the maximum amount of hydraulic oil 13 can be stored in the main oil storage chamber 41. Further, the flat baffle plate 45 disposed at a position higher than the hollow baffle plate 46 may be disposed at a height exceeding the upper side 43a of the partition plate 43, that is, stored in the main oil storage chamber 41. The hydraulic fluid 13 may be disposed at a height that exceeds the height of the liquid level 13a when the maximum amount of hydraulic oil 13 is stored. Preferably, the distance g from the liquid level 13a is 5 mm to 15 mm above. More preferably, the distance g from the liquid surface 13a is more than 10 mm above the liquid surface 13a.

  The flat baffle plate 45 and the hollow baffle plate 46 are the first flat baffle plate 45 facing the supply / discharge hole 41a from the supply / discharge hole 41a on the bottom surface with respect to the height direction position of the main oil storage chamber 41. Between the flat baffle plate 45 and the hollow baffle plate 46 facing each other, and the flat baffle plates 45, 45 facing each other through the opening portion of the hollow through hole 46 a formed in the hollow baffle plate 46. Between these, it arrange | positions leaving the space used as the flow path through which the hydraulic oil 13 flows. When facing the flat baffle plate 45 and the hollow baffle plate 46 facing each other, the plate surface 45a of the flat baffle plate 45 is more than the opening of the hollow through hole 46a of the hollow baffle plate 46. It is good to form large or the same. Further, the plurality of flat baffle plates 45, 45 may be formed such that the flat baffle plate 45 arranged on the upper side has the same or larger vertical and horizontal dimensions of the plate surface 45a. . Further, a plurality of small holes are formed at appropriate positions in the flat baffle plate 45 and the hollow baffle plate 46, and for example, a plurality of small holes 45b are formed in the flat baffle plate 45 as shown in FIG. In order to prevent bubbles from being mixed into the hydraulic oil 13 by further reducing the flow velocity of the hydraulic oil 13 and suppressing the undulation of the liquid level of the hydraulic oil 13 in the main oil storage chamber 41. You may do it.

  Three or more flat baffle plates 45 may be provided at different height positions. Even when three or more flat baffle plates 45 are provided, the height of the liquid surface 13a when the flat baffle plate 45 at the highest position is the maximum storage amount of the hydraulic oil 13 that can be stored in the main oil storage chamber 41 is set. Preferably, the distance g from the liquid surface 13a is preferably arranged on the upper side by a dimension of 5 mm to 15 mm, and more preferably the distance from the liquid surface 13a. It is more preferable that g is arranged on the upper side by a dimension of about 10 mm.

  Two or more hollow baffle plates 46 may be provided at different height positions. When two or more hollow baffle plates 46 are provided, the highest hollow baffle plate 46 is preferably fixed to the height 43 a of the upper side of the partition plate 43.

  In the mold clamping device 1 having such an auxiliary oil tank 4, the operating shaft 31 moved by the mold opening / closing drive device 2 discharges the hydraulic oil 13 in the cylinder chamber 32 a of the mold clamping cylinder 32 so as to be ejected, When the hydraulic oil 13 is supplied to the auxiliary oil tank 4 from the supply / discharge hole 41a through the opened prefill valve 33, first, the hydraulic oil 13 collides with the flat baffle plate 45 directly above the supply / discharge hole 41a. Then, the direction in which the hydraulic oil 13 flows changes to the horizontal direction, that is, the direction in which the hydraulic oil 13 is distributed from the supply / discharge hole 41a toward the entire circumference of the inner side surface of the main oil storage chamber 41 (FIGS. 4, 5 and 8B). )) Next, the hydraulic oil 13 collides with the inner side surface of the main oil storage chamber 41, and the direction in which the hydraulic oil 13 flows changes along the inner side surface to the upward hollow baffle plate 46, This time, the hydraulic oil 13 collides with the hollow baffle plate 46. Thus, the direction in which the hydraulic oil 13 flows changes to the horizontal direction, that is, the direction toward the approximate center of the main oil storage chamber 41 (FIG. 8C), and finally the hydraulic oil 13 at the approximate center of the main oil storage chamber 41. After colliding with each other, the flow of the hydraulic oil 13 changes in the upward direction, and after colliding with the flat baffle plate 45 at the highest position, the flow speed of the hydraulic oil 13 is also reduced, the undulation is small and the liquid level is reduced. 13a will not be violated (FIGS. 6, 7 and 8D). Moreover, since the flow path of the hydraulic oil 13 is formed so as to be dispersed in the width direction of the main oil storage chamber 41, the main oil storage chamber 41 is increased in height, and a large amount is added to the main oil storage chamber 41. Even if the hydraulic oil is not stored, the hydraulic oil 13 can be quickly and gently decelerated even with less hydraulic oil 13 than before, and the auxiliary oil tank 4 can be reduced in size and the height of the auxiliary oil tank 4 can be reduced. Enable.

  The hydraulic oil tank or the auxiliary oil tank of the present invention has been described by taking the embodiment of the auxiliary oil tank 4 as an example. However, the hydraulic oil tank is not limited to the auxiliary oil tank 4 as long as it is a hydraulic oil tank, and other main oil tanks 14 and the like. It is also possible to apply to other hydraulic oil tanks. Further, the hydraulic oil tank or the auxiliary oil tank of the present invention has been described by taking the embodiment of the horizontal mold clamping device 1 as an example. However, the movable platen and the back platen are connected by a tie bar and arranged between the platens. The present invention can also be applied to various mold clamping devices such as a vertical mold clamping device having a mold opening / closing drive device and a mold clamping cylinder device device between a fixed platen and a back platen. The hydraulic oil tank or the auxiliary oil tank of the present invention has been described by taking the embodiment of the mold clamping device 1 having the mold opening / closing drive device 2 driven by an electric actuator as an example, but is driven by various actuators such as a hydraulic actuator. The present invention can also be applied to a mold clamping device having a mold opening / closing drive device.

  The present invention is a variety of injection molding machines for injection molding of molding materials such as resin and metal, and is used for injection molding machines having hydraulic systems that supply hydraulic oil and control hydraulic cylinder devices, particularly for mold clamping devices. it can. According to the present invention, it is possible to reduce the height of these tanks and to reduce the height of these tanks while suppressing the undulation of the liquid level of the hydraulic oil stored in the hydraulic oil tank or auxiliary oil tank, and the entire apparatus Can contribute to the development of injection molding machines.

1 Horizontal mold clamping device for injection molding machine 2 Mold opening / closing drive device 3 Mold clamping cylinder device 4 Auxiliary oil tank (hydraulic oil tank)
5 fixed platen 6 back platen 7 movable platen 8 tie bar 9 guide rail 10 guide block 11 machine base 12 mold device 12a fixed side mold 12b movable side mold 13 hydraulic oil 13a hydraulic oil is stored in the main oil storage chamber at the maximum Level 14 when heated Main oil tank (hydraulic oil tank)
DESCRIPTION OF SYMBOLS 15 Hydraulic pressure source 16 Direction switching valve 21 Ball screw shaft 22 Nut 23 Electric motor 24 Pulley 25 Belt 26 Rotary bearing 31 Actuation shaft 31a Piston head 32 Clamping cylinder 32a Cylinder chamber 33 Prefill valve 41 Main oil storage chamber 41a Supply / exhaust hole 42 Sub-oil storage chamber 42a Discharge hole 43 Partition plate 43a Upper side 44 of partition plate Bubble prevention mechanism 45 Flat baffle plate (bubble prevention mechanism)
45a Plate surface 45b of flat baffle plate Multiple small holes 46 Hollow baffle plate (bubble prevention mechanism)
46a Hollow through-hole 47 formed in hollow baffle plate 47 Spacer member 48 Air breather

Claims (4)

  A hydraulic oil tank that is provided in an injection molding machine having a hydraulic system for controlling a hydraulic cylinder device, and that forms a supply / discharge hole for supplying and discharging hydraulic oil to and from the cylinder chamber of the hydraulic cylinder device, and is opened at the bottom. And at least two flat baffle plates provided at different heights on the upper side of the supply / discharge hole, and an inner surface so that a hollow through hole is positioned immediately above the opening of the supply / discharge hole. A hydraulic oil tank for an injection molding machine, comprising: a hollow baffle plate fixed over the entire circumference and disposed between the two flat baffle plates.   The hydraulic oil tank is an auxiliary oil tank having a discharge hole for discharging excess hydraulic oil exceeding a predetermined storage amount to the main oil tank of the hydraulic system, and is the first of the flat baffle plates. The flat baffle plate disposed above is disposed above the liquid level when the hydraulic oil has the predetermined storage amount, and is disposed at the top of the hollow baffle plate. The auxiliary oil tank for an injection molding machine according to claim 1, wherein the hollow baffle plate is disposed at a liquid level when the hydraulic oil has the predetermined storage amount.   The tank is partitioned into at least two oil storage chambers, and the partition plate is formed at a height that allows the excess hydraulic oil to overflow into the adjacent oil chamber, and is partitioned by the partition plate. One of the oil chambers, the supply / discharge hole is formed on the bottom surface, one hollow baffle plate is disposed at the height of the upper side of the partition plate, and the hollow baffle plate is sandwiched therebetween And one of the oil storage chambers formed by partitioning with the partition plate and overflowing beyond the partition plate. The auxiliary oil storage chamber for discharging the surplus hydraulic oil exceeding the predetermined storage amount of the main oil storage chamber coming from the discharge hole formed on the bottom surface to the outside. The auxiliary oil tank for the injection molding machine described.   The hydraulic cylinder device is a mold clamping cylinder device provided in a mold clamping device of an injection molding machine, wherein an operating shaft connected to a movable platen is a hydraulic piston, and a mold clamping cylinder supported by a back platen is hydraulically operated. The hydraulic oil is supplied to and discharged from a cylinder chamber of the clamping cylinder when the movable platen is opened and closed by another hydraulic actuator or another electric actuator. An auxiliary oil tank for a mold clamping device of an injection molding machine according to claim 3.

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