JP7564040B2 - Injection Molding Machine - Google Patents

Description

The present invention relates to an injection molding machine.

As an example of this type of injection molding machine that has been used in the past, the configuration shown in the following Patent Document 1 can be cited. That is, a conventional injection molding machine has a fixed platen that supports a fixed mold, a movable platen that supports a movable mold, and an intermediate mold support frame that is arranged between the fixed platen and the movable platen and rotatably supports an intermediate mold. The movable platen and the intermediate mold support frame are provided so as to be movable forward and backward with respect to the fixed platen. A plurality of first core molds are protruding from one of the front and rear surfaces of the intermediate mold, and a plurality of second core molds are protruding from the other. In a clamped state, resin is filled into the void between the first core mold and the fixed mold, and injection molding of the preform is performed. When the resin is cooled to a predetermined temperature, the mold is opened and the intermediate mold is rotated 180°. After that, the mold is clamped again, and the first core mold with the preform attached is inserted into the movable mold for blowing, and air is sprayed to perform blow molding. At this time, resin is filled into the void between the second core mold and the fixed mold, and injection molding of the preform is performed. Blow molding and injection molding can be done simultaneously.

The movable mold has multiple split molds that can be separated in the mold width direction. The following Patent Document 2 shows a structure for guiding the movement of the split molds. That is, each of the multiple split molds has a first partial mold and a second partial mold. The first and second partial molds are moved in opposite directions along the mold width direction when each split mold is separated. The first partial molds of each split mold are connected to each other by a first connecting rod, and the second partial molds of each split mold are connected to each other by a second connecting rod. The first and second connecting rods are longitudinal members extending in the mold width direction, and have steps on their opposing surfaces. The first and second connecting rods are arranged so that their respective steps engage with each other and their opposing surfaces are in surface contact with each other, and are configured to guide each other's movement in the mold width direction.

JP 2018-167579 A Japanese Patent Application Publication No. 59-67020

In conventional injection molding machines such as those described above, the movement of the split mold is guided by the first and second connecting rods. However, because the opposing surfaces of the first and second connecting rods are in surface contact with each other, a relatively large sliding resistance is generated, and the driving force required to move the split mold is large.

The present invention was made to solve the above problems, and its purpose is to provide an injection molding machine that can reduce the driving force required to move the split mold.

The injection molding machine according to the present invention comprises a fixed platen that supports a fixed mold, and a movable platen that is movable back and forth relative to the fixed platen and supports a pair of split molds that can be separated in a direction perpendicular to the direction of advance and retreat. The movable platen has a guide that guides the movement of the split molds. The guide has a guide rail attached to the movable platen so as to extend in a direction perpendicular to the direction of advance and retreat, sliders attached to each of the pair of split molds, and rolling elements held by the sliders. The rolling elements roll on a rolling surface provided on the guide rail, so that the split molds can move together with the sliders and the rolling elements in a direction perpendicular to the direction of advance and retreat.

According to the injection molding machine of the present invention, the split mold can be moved in the mold width direction together with the slider and the rolling element by rolling the rolling element on the rolling surface provided on the guide rail, so the driving force required to move the split mold can be reduced.

1 is a partial cross-sectional view showing an injection molding machine according to an embodiment of the present invention. FIG. 2 is an explanatory view showing a mold open state of the mold device of FIG. 1 . FIG. 2 is an explanatory view showing a mold clamping state of the mold device of FIG. 1 . FIG. 4 is a front view showing the movable platen and split mold of FIG. 3 . 5 is a top cross-sectional view of the movable platen and split mold taken along line VV in FIG. 4. FIG. 6 is an enlarged view of region VI in FIG. 5 . FIG. 6 is an explanatory diagram showing the movable platen and split molds of FIG. 5 in a mold clamping state.

Below, the embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to each embodiment, and the components can be modified to be embodied without departing from the gist of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in each embodiment. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components of different embodiments may be appropriately combined.

Figure 1 is a partial cross-sectional view showing an injection molding machine 1 according to an embodiment of the present invention. The injection molding machine 1 shown in Figure 1 is, together with a mold device 2, a device for molding a molded product by injection molding. More specifically, the injection molding machine 1 of this embodiment can also be called an injection blow molding machine, and is used for injection blow molding (injection blow molding), in which a molding material is injected into an injection molding cavity to mold a preform, and then a fluid such as gas is supplied to the preform in a blow molding cavity to expand the preform, thereby producing a molded product.

In the illustrated example, the mold device 2 has a fixed mold 20, a movable mold 21, and an intermediate mold 22. The movable mold 21 and the intermediate mold 22 are provided so as to be movable toward and away from the fixed mold 20. The fixed mold 20 and the intermediate mold 22 are molds for defining the above-mentioned injection molding cavity inside (between each other). The intermediate mold 22 and the movable mold 21 are molds for defining the above-mentioned blow molding cavity. The mold device 2 can be attached to the injection molding machine 1 and replaced as appropriate depending on the shape of the molded product to be manufactured. Here, the mold device 2 is not considered to be part of the injection molding machine 1.

The injection molding machine 1 has an injection device 100, a moving device 200, and a clamping device 300.

(Injection unit)
The injection device 100 is a device for melting a molding material and injecting it into the mold device 2. The injection device 100 mainly includes a cylinder 101, a screw 102, a heater 103, and a motor box 104.

The position of each component may be described below using the terms "front side" and "rear side." These terms "front side" and "rear side" are used with respect to the fixed platen 301a described below, with the direction approaching the fixed platen 301a being the front side and the direction moving away from the fixed platen 301a being the rear side. For example, looking at the injection device 100 located to the right of the fixed platen 301a in FIG. 1, the left direction approaching the fixed platen 301a is the front side, and the right direction moving away from the fixed platen 301a is the rear side.

The cylinder 101 is a cylindrical member extending toward the mold device 2. The cross-sectional shape of the cylinder 101 is preferably circular, but may be other shapes. The cylinder 101 is provided with a supply port 101a and a nozzle 101b. The supply port 101a is an opening to which a hopper for feeding molding material into the cylinder 101 can be attached. The supply port 101a can be disposed on the rear side of the cylinder 101 and in front of the motor box 104. A water-cooled cylinder 101c using water cooling or the like can be provided near the supply port 101a. The nozzle 101b is an opening provided at the tip of the cylinder 101 close to the mold device 2. The cross-sectional area of the nozzle 101b is smaller than the cross-sectional area of the rear side of the cylinder 101.

The screw 102 is a longitudinal member inserted inside the cylinder 101. The central axis of the screw 102 preferably extends parallel to the central axis of the cylinder 101. Flights are provided in a spiral shape around the periphery of the screw 102. As the screw 102 rotates, molding material can be sent to the tip of the cylinder 101.

The heater 103 is disposed surrounding the outer periphery of the cylinder 101. The heater 103 is disposed around the cylinder 101 including the periphery of the nozzle 101b. The heater 103 may be in the shape of a band or the like. The heater 103 may be integrally formed in the axial direction, or may have multiple heater portions separated from each other in the axial direction (left and right direction in FIG. 1) as shown. The inside of the cylinder 101 may be heated to different temperatures depending on the position of each heater portion. A temperature sensor may be provided in each heater portion.

The motor box 104 is disposed behind the cylinder 101 and the screw 102. Although not shown in the figure, the motor box 104 contains a metering motor that rotates the screw 102 around its central axis to fill the tip of the cylinder 101 with a predetermined amount of molding material, an injection motor that moves the screw 102 forward and backward in both directions, toward and away from the mold device 2, and a pressure detection sensor that detects the pressure that the screw 102 receives from the molding material.

Although this injection molding machine 1 is an in-line screw type, it is also possible to make it a pre-plasticization type injection molding machine in which the plasticization cylinder and plasticization screw are structurally and functionally separated from the injection cylinder and injection plunger.

(Mobile device)
The moving device 200 is a device for moving the injection device 100 forward and backward relative to the mold device 2. The moving device 200 is provided, for example, below the motor box 104 of the injection device 100, and is an advance/retract drive mechanism for moving the injection device 100 forward and backward relative to a fixed platen 301a described below.

Various mechanisms can be used as the forward and backward drive mechanism that constitutes the moving device 200, but the moving device 200 shown in the figure includes a hydraulic pump 201, an electric or other pump operation motor 202 that operates the hydraulic pump 201, and a double-acting hydraulic cylinder 203 that receives hydraulic fluid from the hydraulic pump 201 and causes a piston rod, the tip of which is fixed to a fixed platen 301a, to move in and out.

The moving device 200 further includes a slide base 204 and a guide 205. The above-mentioned hydraulic pump 201, pump actuation motor 202, and hydraulic cylinder 203 are attached to the slide base 204. The guide 205 is laid on the frame Fr and can guide the linear motion of the slide base 204. The slide base 204 and the guide 205 realize the forward and backward displacement of the injection device 100 placed on the upper part of the slide base 204.

The moving device 200 makes it possible to move the injection device 100 away from the mold device 2 or to move the injection device 100 closer to the mold device 2, thereby pressing the nozzle 101b of the cylinder 101 of the injection device 100 against the mold device 2 with a predetermined pressure, a so-called nozzle touch.

(Mold clamping device)
The mold clamping device 300 is a device for opening and closing the mold device 2 between a mold clamping state and a mold open state. The mold clamping device 300 opens and closes the mold device 2 by displacing the movable mold 21 and the intermediate mold 22 relative to the fixed mold 20 of the mold device 2, and sets the mold device 2 in the mold clamping state, mold closed state, or mold open state.

The mold clamping device 300 of this injection molding machine 1 mainly has a mold holding mechanism 301 and a platen movement mechanism 302.

The mold holding mechanism 301 has a fixed platen 301a, a movable platen 301b, and an intermediate mold support frame 301c. The fixed platen 301a is disposed between the injection device 100 and the mold device 2, and is fixed to the frame Fr. The movable platen 301b is disposed so that the mold device 2 is located between the fixed platen 301a and the movable platen 301b, and is provided so as to be movable forward and backward with respect to the fixed platen 301a. The movable platen 301b and the intermediate mold support frame 301c are provided so as to be movable forward and backward independently of each other. The fixed platen 301a supports the fixed mold 20, the movable platen 301b supports the movable mold 21, and the intermediate mold support frame 301c supports the intermediate mold 22 so as to be freely rotatable.

One end of one or more tie bars 301d is attached to the fixed platen 301a. The other end of the tie bar 301d is attached to the rear platen 304, which will be described later. A guide member 301e that guides the advancement and retreat of the movable platen 301b and the intermediate mold support frame 301c is laid on the frame Fr.

At a position where the movable platen 301b and the intermediate mold support frame 301c are separated from the fixed platen 301a, the intermediate mold 22 is in an open state from the fixed mold 20 and the movable mold 21.
By moving the movable platen 301b and the intermediate mold support frame 301c toward the fixed platen 301a from the separated position where the intermediate mold 22 is open from the fixed mold 20 and the movable mold 21, the intermediate mold 22 enters a mold closed state in which it is closed relative to the fixed mold 20 and the movable mold 21.
By further moving the movable platen 301b and the intermediate mold support frame 301c closer to each other by the fixed platen 301a from the mold closed state, a mold clamping state is achieved in which the intermediate mold 22 is pressed against the fixed mold 20 and the movable mold 21.

Most of the clamping device 300, excluding the fixed platen 301a, is located to the left of the fixed platen 301a in FIG. 1, so when looking at most of the clamping device 300, the right side, which is closer to the fixed platen 301a, is the front side, and the left side, which is farther away from the fixed platen 301a, is the rear side.

The platen movement mechanism 302 is a mechanism for mainly moving the movable platen 301b. The platen movement mechanism 302 includes a rear platen 304 movably mounted on the frame Fr, a mold clamping motor 305 provided on the rear platen 304, a motion conversion mechanism 306 that converts the rotational motion of the mold clamping motor 305 into linear motion in the displacement direction of the movable platen 301b, and a toggle mechanism 307 that amplifies the force transmitted to the motion conversion mechanism 306 and transmits it to the movable platen 301b.

Of these, the motion conversion mechanism 306 can be various mechanisms capable of converting rotational motion into linear motion, but in this example, it is configured to include a screw shaft 306a that is driven to rotate by the mold clamping motor 305, and a nut 306b that is screwed onto the screw shaft 306a. The motion conversion mechanism 306 can also be a ball screw.

The toggle mechanism 307, which increases the transmission force from the motion conversion mechanism 306, is made up of multiple links 307a-307c that connect the rear platen 304 and nut 306b to the movable platen 301b and are swingably connected by joints. The number and shape of the links and joints can be changed as appropriate, but as shown in FIG. 1, a pair of links made up of links 307a-307c located above and below the crosshead 307d are swingably connected to the crosshead 307d that is connected to the nut 306b and extends in the vertical direction.

In addition to the above-mentioned mold clamping motor 305, a mold thickness adjustment motor 308 can also be provided on the rear platen 304. This mold thickness adjustment motor 308 functions to adjust the distance between the fixed platen 301a and the rear platen 304 by applying a rotational driving force to a nut that screws into a threaded portion formed on the other end of each tie bar 301d. This makes it possible to adjust the mold thickness so that the mold device 2 can be given the desired mold clamping force even when replacing the mold device 2 or changing the thickness of the mold device 2 due to temperature changes. Although not shown in the figure, it is possible to adjust the mold thickness even if the fixed platen is movable on the frame Fr and the rear platen is fixed.

The illustrated mold clamping device 300 is a horizontal type in which the moving direction of the movable platen 301b is parallel to the horizontal direction, but it can also be a vertical type in which the moving direction is vertical.

Next, the mold device 2 and the mold clamping device 300 will be described in more detail with reference to Figures 2 and 3. Figure 2 is an explanatory diagram showing the mold open state of the mold device 2 in Figure 1, and Figure 3 is an explanatory diagram showing the mold clamping state of the mold device 2 in Figure 1. Note that (a) of Figures 2 and 3 is an enlarged side view of the mold device 2, and (b) of Figures 2 and 3 is a cross-sectional view of the mold device 2 along line B-B in (a).

The intermediate mold 22 is rotatably supported by the intermediate mold support frame 301c via a rotating shaft 220. A driving means (not shown) is connected to the rotating shaft 220, and the intermediate mold 22 can be rotated so that the front and rear are reversed by the driving force of the driving means. The mold clamping device 300 has an intermediate mold moving mechanism 309 for moving the intermediate mold support frame 301c forward and backward relative to the fixed platen 301a. The intermediate mold moving mechanism 309 has a hydraulic cylinder 309a attached to the fixed platen 301a, and a piston rod 309b that is made movable forward and backward by the hydraulic cylinder 309a and has one end fixed to the intermediate mold support frame 301c. By this intermediate mold moving mechanism 309, the intermediate mold support frame 301c and the intermediate mold 22 can be moved forward and backward independently of the moving forward and backward of the movable platen 301b and the movable mold 21 by the platen moving mechanism 302. In addition, the hydraulic cylinder 309a of the intermediate mold moving mechanism 309 may be fixed to the movable platen 301b, and the intermediate mold support frame 301c may be capable of moving forward and backward together with the movable platen 301b, and may also be capable of moving forward and backward further relative to the movable platen 301b.

A plurality of convex mold portions 221 are protruding from both sides of the intermediate mold 22 in the front-rear direction. As shown particularly in FIG. 2B, the fixed mold 20 is provided with a plurality of fixed side concave mold portions 20a. In the mold clamping state shown in FIG. 3, the convex mold portion 221 of the intermediate mold 22 is inserted into the fixed side concave mold portion 20a, and an injection molding cavity corresponding to the shape of the preform PF is defined between the fixed side concave mold portion 20a and the convex mold portion 221. As shown in FIG. 2A, in the mold open state, the preform PF is held on the outer surface of the convex mold portion 221 pulled out from the fixed side concave mold portion 20a.

The movable mold 21 has a split mold 210 that can be split in a direction perpendicular to the moving direction of the movable platen 301b (mold width direction). The mold clamping device 300 has a split mold opening/closing mechanism 310 for opening and closing the split mold 210. The split mold opening/closing mechanism 310 has hydraulic cylinders 310a arranged on both sides of the movable mold 21, a piston rod 310b that can be moved forward and backward by the hydraulic cylinders 310a and one end of which is fixed to the split mold 210, and a split mold connecting member 310c that connects the split molds 210 that are displaced in the same direction in the mold width direction. In the mold clamping state shown in FIG. 3, the split mold 210 is closed and the convex mold portion 221 of the intermediate mold 22 is inserted into the split mold 210, and a blow molding cavity corresponding to the shape of the molded product MP is defined between the split mold 210 and the convex mold portion 221. As shown in FIG. 2B, in the mold open state, the split mold 210 is opened and the molded product MP molded by the movable mold 21 falls from the movable mold 21.

(Operation of injection molding machine)
The injection molding machine 1 described above operates to carry out the following steps.
With the mold device 2 in the mold open state shown in Figure 2, a mold closing process is performed in which the platen moving mechanism 302 moves the movable platen 301b toward the fixed platen 301a, and the intermediate mold moving mechanism 309 moves the intermediate mold support frame 301c toward the fixed platen 301a.

Next, with a predetermined amount of molding material already stored and arranged inside the injection unit 100 by measuring during the previous molding, which will be described later, a clamping process is performed in which the mold device 2 is clamped using the clamping device 300, as shown in FIG. 3. In the clamping process, an injection molding cavity is defined between the fixed mold 20 and the intermediate mold 22, and a blow molding cavity is defined between the movable mold 21 and the intermediate mold 22.

Then, the screw 102 advances to perform an injection process in which the molding material is filled into the injection molding cavity of the mold device 2. In the injection process, after the molding material is filled into the injection molding cavity, the screw 102 advances further to hold the molding material inside the tip of the injection device 100 at a predetermined pressure. The molding material filled into the injection molding cavity is then cooled and solidified. As a result, a preform PF is molded in the injection molding cavity. At this time, the molding material separately charged into the injection device 100 is melted while being sent toward the tip of the injection device 100 by the rotation of the screw 102 under heating by the heater 103, and a predetermined amount of molding material is measured and placed at the tip.

In parallel with the above-mentioned injection process, a blowing process is carried out in the blow molding cavity. A preform PF that has already been molded in the injection molding cavity before the intermediate mold 22 is inverted is placed in the blow molding cavity. In the blowing process, a fluid such as air or other gas is supplied to the preform PF, causing it to expand in the blow molding cavity and forming the molded product MP.

Then, the platen movement mechanism 302 and the intermediate mold movement mechanism 309 are operated to move the movable platen 301b and the intermediate mold support frame 301c away from the fixed platen 301a, and the mold opening process is performed to open the mold device 2.

After the mold opening step, the split mold opening/closing mechanism 310 is used to open the split mold 210 of the movable mold 21 to remove the molded product MP, and then a split mold opening/closing step is performed in which the split mold 210 of the movable mold 21 is closed.
Here, an intermediate mold rotation step is performed in which the intermediate mold 22 is inverted by a driving means connected to the rotation shaft 220 of the intermediate mold 22. As a result, the convex mold portion 221 of the intermediate mold 22 on the side from which the molded product MP was collected in the split mold opening and closing step faces the fixed side concave mold portion 20a of the fixed mold 20. On the other hand, the convex mold portion 221 of the intermediate mold 22 on the side from which the preform PF was molded in the injection step faces the split mold 210 of the movable mold 21 while holding the preform PF.
The intermediate mold rotating step can be carried out at approximately the same time as the split mold opening and closing step, or before or after the split mold opening and closing step.

In injection molding using the injection molding machine 1, the above-mentioned mold closing process, mold clamping process, injection process, blowing process, mold opening process, split mold opening/closing process, and intermediate mold rotation process are repeated.

Next, FIG. 4 is a front view showing the movable platen 301b and split mold 210 in FIG. 3, FIG. 5 is a cross-sectional view of the upper part of the movable platen 301b and split mold 210 taken along line V-V in FIG. 4, and FIG. 6 is an enlarged view of region VI in FIG. 5. Although FIG. 5 shows only the upper cross-section of the movable platen 301b and split mold 210, the configuration of the lower cross-section of the movable platen 301b and split mold 210 is similar to the configuration of the upper cross-section.

As shown in FIG. 4, the movable platen 301b supports a pair of split molds 210 that can be separated in a direction 40 (mold width direction) perpendicular to the advancing and retreating direction of the movable platen 301b. The pair of split molds 210 are arranged in front of the movable platen 301b and spaced apart from each other in the direction 40 perpendicular to the advancing and retreating direction. Each pair of split molds 210 has a first partial mold 41 and a second partial mold 42. The first and second partial molds 41, 42 are moved in opposite directions along the direction 40 perpendicular to the advancing and retreating direction when each split mold 210 is separated. That is, in FIG. 4, the first partial mold 41 is moved to the left, and the second partial mold 42 is moved to the right. The first and second partial molds 41, 42 each have a plurality of partial cavities 41a, 42a in the center of the height direction. The partial cavities 41a and 42a form a blow molding cavity when the first and second mold parts 41 and 42 are butted against each other.

The first mold sections 41 of each split mold 210 are connected to each other by a first connecting rod 410, and the second mold sections 42 of each split mold 210 are connected to each other by a second connecting rod 420. The upper and lower front portions of the first and second mold sections 41, 42 are provided with step portions 43 formed to be recessed rearward compared to the center portions of the first and second mold sections 41, 42 in the height direction. The first and second connecting rods 410, 420 are longitudinal members extending in the mold width direction. The first connecting rod 410 is fastened to the front surface of the step portion 43 of the first mold section 41. Similarly, the second connecting rod 420 is fastened to the front surface of the step portion 43 of the second mold section 42.

The movable platen 301b has a guide 5 that guides the movement of the split mold 210 (first and second part molds 41, 42). The guide 5 guides the movement of the split mold 210 in a direction 40 perpendicular to the forward and backward direction. The guide 5 has a plurality of guide rails 50, a plurality of sliders 51, and a plurality of rolling elements 52.

The multiple guide rails 50 are attached to the movable platen 301b so as to extend in a direction 40 perpendicular to the forward and backward direction. In this embodiment, a pair of guide rails 50 are disposed on the upper and lower parts of the movable platen 301b. The guide rails 50 are disposed spaced apart from each other in the height direction. The guide rails 50 may be located behind the first and second connecting rods 410, 420. The number of guide rails 50 is arbitrary, and for example, one guide rail 50 may be provided on each of the upper and lower parts of the movable platen 301b.

As shown particularly in Figures 5 and 6, the guide rail 50 can be a longitudinal member with a T-shaped cross section. The guide rail 50 is provided with a protrusion 500 that protrudes forward. The upper and lower surfaces of the protrusion 500 can form a rolling surface on which the rolling elements 52 roll. The rolling surface may have a groove that guides the rolling of the rolling elements 52 and extends along the direction 40 perpendicular to the forward and backward direction.

A plurality of sliders 51 are attached to a pair of split molds 210. In this embodiment, the sliders 51 are attached to the rear surfaces of the first and second part molds 41, 42 of each split mold 210, respectively. The sliders 51 are also attached to the upper and lower parts of the first and second part molds 41, 42, respectively. That is, eight sliders 51 are used in this embodiment. The sliders 51 can be positioned behind the fastening positions of the first and second connecting rods 410, 420 to the first and second part molds 41, 42.

The slider 51 is a member having an overall rectangular parallelepiped appearance. As shown in Figures 5 and 6, the slider 51 has a recess 510 at the rear, and is positioned so that the protrusion 500 of the guide rail 50 enters the recess 510. The slider 51 attached to the first part mold 41 and the slider 51 attached to the second part mold 42 may be associated with different guide rails 50.

Multiple rolling elements 52 are held by each slider 51. The rolling elements 52 are provided in the slider 51 so that they can roll on the rolling surface of the guide rail 50. The rolling elements 52 are arranged in opposing portions of the recess 510 so as to be exposed to the space within the recess 510, and are capable of rolling on the upper and lower surfaces of the protrusion 500 of the guide rail 50 that has entered the recess 510.

The rolling elements 52 of each slider 51 roll on the rolling surface of the guide rail 50, so that the split mold 210 (the first and second part molds 41, 42 of each split mold 210) can move together with each slider 51 and rolling element 52 in the direction 40 perpendicular to the forward and backward direction. This reduces the resistance generated when the split mold 210 moves, and reduces the driving force required to move the split mold 210.

Here, the movable platen 301b has a movable platen body 60, a guide rail mounting portion 61, a biasing member 62, and a movement restricting portion 63.

The movable platen body 60 is provided with an attachment housing space 600. The attachment housing space 600 is a space having a depth in the front-rear direction. The attachment housing space 600 extends over the entire movable range of the split mold 210 (first and second part molds 41, 42) in the direction 40 perpendicular to the forward and backward direction. The attachment housing space 600 is located at the top and bottom of the movable platen body 60.

The mounting portion accommodating space 600 is surrounded by an inner wall portion 601, an outer wall portion 602, a rear wall portion 603, and a side wall portion 604. The inner wall portion 601 is a wall portion of the movable platen body 60 arranged inside the mounting portion accommodating space 600 in the height direction, and the outer wall portion 602 is a wall portion of the movable platen body 60 arranged outside the mounting portion accommodating space 600 in the height direction. For example, the inner wall portion 601 that defines the upper mounting portion accommodating space 600 is located below the mounting portion accommodating space 600. Similarly, the outer wall portion 602 that defines the upper mounting portion accommodating space 600 is located above the mounting portion accommodating space 600. The rear wall portion 603 is a wall portion of the movable platen body 60 arranged at the back of the mounting portion accommodating space 600 in the front-rear direction. The side walls 604 are walls of the movable platen body 60 arranged on both sides of the mounting portion housing space 600 in the direction 40 perpendicular to the forward/reverse direction. At least one of the inner wall 601, the outer wall 602, the rear wall 603, and the side walls 604 may be separate members attached to the movable platen body 60.

The guide rail mounting portion 61 is a portion to which the guide rail 50 is attached, and is arranged in the mounting portion accommodation space 600 so as to be movable in the forward and backward direction (front-rear direction) of the movable platen 301b. That is, the mounting portion accommodation space 600 accommodates the guide rail mounting portion 61 so as to be movable in the forward and backward direction of the movable platen 301b. The movable platen main body 60 allows the guide rail mounting portion 61 to be movable in the forward and backward direction of the movable platen 301b. The guide rail mounting portion 61 is arranged in the upper and lower mounting portion accommodation spaces 600, respectively. The guide rail mounting portion 61 can be a plate-shaped member that extends long in the direction 40 perpendicular to the forward and backward direction as a whole, and can be composed of a member separate from the movable platen main body 60. The guide rail 50 is attached to the front surface of the guide rail mounting portion 61. The height and width of the guide rail mounting portion 61 can be approximately the same as the height (the distance between the outer surface of the inner wall portion 601 and the inner surface of the outer wall portion 602) and width (the distance between the inner surfaces of the side wall portions 604) of the mounting portion accommodation space 600. The forward and backward movement of the guide rail mounting portion 61 in the front-rear direction can be guided by the inner wall portion 601, the outer wall portion 602, and the side wall portion 604.

The biasing member 62 biases the guide rail mounting portion 61 in a direction (forward) approaching the fixed platen 301a. In this embodiment, the biasing member 62 has a spring 620 and a spacer 621 attached to the front end of the spring 620. The spring 620 and the spacer 621 are inserted through a hole 603a provided in the rear wall portion 603. The rear end of the spring 620 abuts against the bottom of the hole 603a, and the front surface of the spacer 621 abuts against the rear surface of the guide rail mounting portion 61.

The movement restricting portion 63 is disposed at a position closer to the fixed platen 301a than the guide rail mounting portion 61 (in front of the guide rail mounting portion 61), and is a portion for restricting the movement of the guide rail mounting portion 61 that approaches the fixed platen 301a from a predetermined position. In this embodiment, the movement restricting portion 63 is configured by a plate-shaped member fixed to the inner surface of the inner wall portion 601 and the front surface of the outer wall portion 602. The movement restricting portion 63 in this embodiment is a longitudinal member extending in the direction 40 perpendicular to the advancing and retreating direction over the entire area of the mounting portion accommodating space 600 related to the direction 40 perpendicular to the advancing and retreating direction. However, the movement restricting portion 63 may be a short-shaped member disposed at a distance from each other in the direction 40 perpendicular to the advancing and retreating direction. The movement restricting portion 63 may be an integral part of the inner surface of the inner wall portion 601 and the outer wall portion 602.

Next, the effect of the guide rail attachment portion 61 being provided so as to be movable forward and backward will be described with reference to Fig. 7. Fig. 7 is an explanatory diagram showing the movable platen 301b and the split mold 210 of Fig. 5 in a mold clamping state. In the mold clamping state, the movable platen 301b and the split mold 210 press against the intermediate mold 22 (see Fig. 3, etc.). At this time, the movable platen 301b and the split mold 210 are elastically deformed by the pressing force. As a result, the movable platen 301b and the split mold 210 are compressed as shown by the two-dot chain line in Fig. 7 , and the guide rail 50 and the like move relatively backward.

If the guide rail 50 and the like are fixed to the movable platen 301b, there is a risk that the guide rail 50 and the like will be damaged if the pressing force is large. In this embodiment, the guide rail mounting part 61 is movable in the forward and backward direction (front-rear direction) of the movable platen 301b, so that when the guide rail mounting part 61 receives a pressing force, the guide rail mounting part 61 moves backward together with the guide rail 50 and the like. This reduces the risk of the guide rail 50 and the like being damaged. The depth of the mounting part accommodating space 600 in the front-rear direction is set wider than the displacement width of the guide rail mounting part 61 during mold clamping. In other words, the depth of the mounting part accommodating space 600 is set so that the back surface of the guide rail mounting part 61 does not reach the front surface of the rear wall part 603 during mold clamping.

When the mold clamping is released, the guide rail mounting part 61 is moved in a direction (forward) approaching the fixed platen 301a by the biasing member 62. This returns the guide rail mounting part 61 to its original position. In particular, the movement restriction part 63 restricts the movement of the guide rail mounting part 61 forward, so that the position of the guide rail mounting part 61 is more accurately returned.

In such an injection molding machine 1, the rolling element 52 rolls on the rolling surface provided on the guide rail 50, so that the split mold 210 can move together with the slider 51 and the rolling element 52 in the direction 40 perpendicular to the forward and backward direction, thereby reducing the driving force required to move the split mold 210.

In addition, the guide rail mounting portion 61 to which the guide rail 50 is attached can move forward and backward in the forward and backward direction of the movable platen 301b, reducing the risk of damage to the guide rail 50, etc., during mold clamping.

In addition, the movable platen body 60 has an attachment portion accommodation space 600 that accommodates the guide rail attachment portion 61 so that it can move forward and backward in the forward and backward directions of the movable platen 301b, so that the risk of damage to the guide rail 50, etc., during mold clamping can be more reliably reduced.

In addition, the biasing member 62 biases the guide rail mounting portion 61 in a direction approaching the fixed platen 301a, so that the position of the guide rail mounting portion 61 can be more reliably returned to its original position when the mold clamping is released.

In addition, the movement restriction portion 63 restricts the movement of the guide rail mounting portion 61, so that the position of the guide rail mounting portion 61 can be returned more accurately when the mold clamping is released.

1: Injection molding machine 5: Guide 20: Fixed mold 21: Movable mold 41: First part mold 42: Second part mold 50: Guide rail 51: Slider 52: Rolling element 60: Movable platen body 61: Guide rail attachment portion 62: Pressing member 63: Movement restricting portion 210: Split mold 301a: Fixed platen 301b: Movable platen 600: Attachment portion accommodating space 620: Spring

Claims (5)

a stationary platen supporting a stationary mold;
a movable platen that is provided to be movable toward and away from the fixed platen and supports a pair of split dies that are separable in a direction perpendicular to the moving-back direction;
Equipped with
The movable platen has a guide that guides the movement of the split mold,
the guide includes a first guide attached to the movable platen and a second guide attached to each of the pair of split dies, the first guide and the second guide being configured to be movable forward and backward relative to the movable platen in a forward and backward direction of the movable platen .
Injection molding machine. The movable platen is
a mounting portion to which the first guide is attached;
a movable platen body that allows the attachment portion to move in a direction in which the movable platen moves;
having
2. The injection molding machine according to claim 1. The movable platen body has an attachment portion accommodating space that accommodates the attachment portion so that the attachment portion can be advanced and retreated in the advance/retract direction.
3. The injection molding machine according to claim 2. The movable platen is
a biasing member that biases the mounting portion in a direction toward the fixed platen,
4. The injection molding machine according to claim 2 or 3. The movable platen is
a movement restricting portion that restricts movement of the mounting portion that approaches the fixed platen beyond a predetermined position.
The injection molding machine according to any one of claims 2 to 4.