Mold, mold clamping device, injection molding machine, and molding method for molded product

Abstract

To provide a mold that allows a high degree of freedom in operations to be performed in the vicinity of the mold.SOLUTION: A guide pin (31) for guiding the closing of molds (15, 16) is stored in a guide pin housing hole (33) formed in a parting line (P). The guide pin (31) is configured so that its tip can be caused to protrude from the parting line (P) or retracted into the guide pin housing hole (33) by a predetermined drive mechanism (34, 36, 37, 38).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a mold having a guide pin, a mold clamping device in which the mold is provided, an injection molding machine, and a molding method for a molded product. [Background technology]

[0002] An injection molding machine includes a clamping device that clamps a mold, and an injection device that melts an injection material and injects it into the mold. A so-called horizontal injection molding machine includes a clamping device provided on a bed, and an injection device provided on the bed to the side of the clamping device. The mold provided in the clamping device is provided with a guide pin, as described in Patent Document 1, for example. That is, a guide pin is embedded in one mold, and a pin hole is formed in the other mold. When the pair of molds are clamped, the guide pin is inserted into the pin hole to prevent misalignment and allow for accurate mold clamping. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-197614 Summary of the Invention [Problem to be solved by the invention]

[0004] When clamping the mold, the guide pins prevent the mold from shifting, allowing the mold to be clamped with high precision. However, there are also problems. The guide pins protrude from the parting line of one of the molds, which complicates the processing performed near the mold. For example, when a molded product molded in the mold is removed by a robot hand or the like, it is necessary to prevent the robot hand from colliding with the guide pin. In other words, the robot hand must be controlled to avoid the guide pin. The same is true when inserting an insert product into the mold by a robot hand or the like, and care must be taken not to collide with the guide pin.

[0005] In the present disclosure, a mold is provided that can simplify processing performed in the vicinity of the mold.

[0006] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0007] In the present disclosure, the guide pin is stored in a guide pin storage hole formed in the parting line, and a predetermined drive mechanism is used to move the guide pin so that its tip protrudes from the parting line or retracts into the guide pin storage hole. Effect of the Invention

[0008] The present disclosure allows for greater freedom in the work carried out near the mold. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a front view showing an injection molding machine according to a first embodiment. [Diagram 2] 1 is a front cross-sectional view showing a part of a mold clamping device and a mold according to a first embodiment. [Diagram 3] 1 is a flowchart showing steps of a molding method for a molded product according to a first embodiment. [Figure 4A]1 is a front cross-sectional view showing a part of a mold clamping device and a mold according to a first embodiment. [Figure 4B] 1 is a front cross-sectional view showing a part of a mold clamping device and a mold according to a first embodiment. [Figure 4C] 1 is a front cross-sectional view showing a part of a mold clamping device and a mold according to a first embodiment. [Figure 4D] 2 is a front cross-sectional view showing a part of a mold clamping device, a mold according to a first embodiment, and a pair of semi-molded products. FIG. [Figure 4E] 2 is a front cross-sectional view showing a part of a mold clamping device, a mold according to a first embodiment, a pair of semi-molded products, and a heater. FIG. [Figure 4F] 2 is a front cross-sectional view showing a part of a mold clamping device, a mold according to a first embodiment, and a pair of semi-molded products. FIG. [Figure 4G] 1 is a front cross-sectional view showing a part of a mold clamping device, a mold according to a first embodiment, and a molded product. [Figure 4H] 1 is a front cross-sectional view showing a part of a mold clamping device, a mold according to a first embodiment, and a molded product. [Diagram 5] 4 is a front cross-sectional view showing a part of a mold clamping device and a mold according to a modified example of the first embodiment. FIG. [Figure 6A] FIG. 6 is a front cross-sectional view showing a part of an injection molding machine and a mold according to a second embodiment. [Figure 6B] FIG. 11 is a front cross-sectional view showing a part of an injection molding machine, a mold according to a second embodiment, and a pair of semi-molded products. [Figure 6C] FIG. 11 is a front cross-sectional view showing a part of an injection molding machine, a mold according to a second embodiment, and a pair of semi-molded products. [Figure 6D] FIG. 11 is a front cross-sectional view showing a part of an injection molding machine, a mold according to a second embodiment, a pair of semi-molded products, and a heater. [Figure 6E] 11 is a front cross-sectional view showing a part of an injection molding machine, a mold according to a second embodiment, a molded product, and a pair of semi-molded products. FIG. [Figure 6F] 11 is a front cross-sectional view showing a part of an injection molding machine, a mold according to a second embodiment, a molded product, and a pair of semi-molded products. FIG. [Figure 6G] 11 is a front cross-sectional view showing a part of an injection molding machine, a mold according to a second embodiment, a molded product, and a pair of semi-molded products. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Specific embodiments will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. In order to clarify the description, the following description and drawings are appropriately simplified. In each drawing, the same elements are given the same reference numerals, and duplicated descriptions are omitted as necessary. In addition, hatching is omitted in some parts to avoid cluttering the drawings.

[0011] [First embodiment] <Injection molding machine> The injection molding machine 1 according to the first embodiment is a so-called horizontal type, as shown in Fig. 1. That is, the injection molding machine 1 according to the first embodiment includes a mold clamping device 2 provided on a bed B, an injection device 3 provided on the bed B to the side of the mold clamping device 2, and a control device 4 that controls these. Molds 15 and 16 according to the first embodiment, which will be described in detail later, are provided in this horizontal type injection molding machine 1, but the present invention is not limited to the horizontal type and may be provided in a vertical type injection molding machine.

[0012] <Mold clamping device> The mold clamping device 2 includes a fixed platen 7 fixed to a bed B, a movable platen 8 slidably provided on the bed B, and a mold clamping housing 9. The fixed platen 7 and the mold clamping housing 9 are connected by a plurality of tie bars 11, 11, ..., and the movable platen 8 is slidable between the fixed platen 7 and the mold clamping housing 9. A mold clamping mechanism, that is, a toggle mechanism 13 in this embodiment, is provided between the mold clamping housing 9 and the movable platen 8. The fixed platen 7 and the movable platen 8 are provided with a fixed side mold 15 and a movable side mold 16 according to the first embodiment, respectively. Therefore, when the toggle mechanism 13 is driven, the molds 15 and 16 are opened and closed.

[0013] <Injection device> The injection device 3 includes a heating cylinder 19, a screw 20 provided in the heating cylinder 19, and a screw drive device 22. The heating cylinder 19 is supported by the screw drive device 22, and the screw 20 is driven in the rotational direction and the axial direction by the screw drive device 22. The heating cylinder 19 is provided with a hopper 23 and an injection nozzle 24. The heating cylinder 19 is also provided with heaters 25, 25, ...

[0014] <Mold> The fixed mold 15 and the movable mold 16 according to the first embodiment will be described with reference to Fig. 2. For convenience, the fixed mold 15 will be described below as the first mold 15 and the movable mold 16 as the second mold 16. The first mold 15 has a first recess 28 formed at a parting line P, into which a semi-molded product is inserted, as will be described later. Similarly, the second mold 16 has a second recess 29 formed at a parting line P, into which a semi-molded product is inserted, as will be described later.

[0015] The first mold 15 is provided with guide pins 31, 31 for guiding during mold clamping, and these guide pins 31, 31 are characterized by their structure and the way in which they are provided. First, guide pin storage holes 33, 33 are opened in the parting line P of the first mold 15, and the back of the guide pin storage holes 33, 33 is a cylinder portion 34, 34 with an enlarged diameter. The guide pins 31, 31 are inserted into the guide pin storage holes 33, 33. The rear end of the guide pins 31, 31 is a piston portion 36, 36 with an enlarged diameter, which slides liquid-tight on the inner circumferential surface of the cylinder portion 34, 34. The supply and discharge portions 37, 37 are connected to the bottom of the guide pin storage holes 33, 33, so that pressure oil is supplied and discharged from the outside to the cylinder portion 34, 34. In other words, the cylinder portion 34, 34 and the piston portion 36, 36 constitute a hydraulic cylinder, and the guide pins 31, 31 are driven.

[0016] The guide pins 31, 31 are provided with springs 38, 38. One end of the springs 38, 38 contacts the piston parts 36, 36, and the other end contacts the step parts 39, 39 near the outlet of the guide pin storage holes 33, 33. Therefore, the springs 38, 38 apply force to the guide pins 31, 31 in the backward direction, that is, in the direction in which the guide pins 31, 31 are retreated into the guide pin storage holes 33, 33. When pressure oil is supplied from the supply and discharge parts 37, 37, the piston parts 36, 36 are pushed against the force of the springs 38, 38, and the guide pins 31, 31 advance, and their tips protrude from the parting line P. On the other hand, when the oil pressure of the pressure oil is reduced or made zero, the guide pins 31, 31 are retreated by the force of the springs 38, 38. In other words, the guide pins 31, 31 retreat into the guide pin storage holes 33, 33, and are hidden from the parting line P.

[0017] The second mold 16 has guide holes 41, 41. When the first and second molds 15, 16 are clamped, the guide pins 31, 31 are inserted into the guide holes 41, 41 as described below. In other words, they are guided. This prevents the molds 15, 16 from being misaligned, and the molds are closed and clamped with high precision. In the description of the first embodiment, the first mold 15 is provided on the fixed side mold 15, i.e., the fixed platen 7, and the second mold 16 is provided on the movable side mold 16, i.e., the movable platen 8. However, the first mold 15 may be provided on the movable platen 8, and the second mold 16 may be provided on the fixed platen 7. In other words, the guide pins 31, 31 may be provided on the mold on the movable platen 8, not on the mold on the fixed platen 7.

[0018] <Forming method> Since the molds 15, 16 according to the first embodiment can be set in a state in which the guide pins 31, 31 are completely retracted, that is, stored in the guide pin storage holes 33, 33, an effect is obtained in that there is a high degree of freedom in operations in the vicinity of the molds 15, 16. In order to understand the degree of freedom in operations, a molding method for a molded product according to the first embodiment, which is carried out using these molds 15, 16, will be described.

[0019] First, the mold opening step S01 is performed as shown in Fig. 3. The description will start from the state where the mold clamping unit 2 is clamped as shown in Fig. 4A. When the mold is clamped, pressure oil is supplied from the supply and discharge units 37, 37, so the guide pins 31, 31 move forward. In other words, the guide pins 31, 31 protruding from the parting line P are inserted into the guide holes 41, 41. From this state, the mold clamping unit 2 is driven to open the mold. The mold open state is shown in Fig. 4B.

[0020] Next, as shown in Fig. 3, a guide pin retraction step S02 is performed. That is, the oil pressure of the pressurized oil applied from the supply and discharge parts 37, 37 is set to zero or reduced. Then, as shown in Fig. 4C, the guide pins 31, 31 are retracted by the spring force of the springs 38, 38. The pressurized oil is pushed out from the cylinder parts 34, 34 and discharged from the supply and discharge parts 37, 37. The tips of the guide pins 31, 31 are substantially retracted from the parting line P.

[0021] As shown in Fig. 3, a semi-molded product insertion step S03 is carried out. That is, as shown in Fig. 4D, a robot hand or the like is used to insert semi-molded products 43, 43 into the first and second recesses 28, 29, respectively. Since the guide pins 31, 31 are retracted from the parting lines P, P, the semi-molded products 43, 43 can be easily inserted. In other words, there is a high degree of freedom in the insertion work of the semi-molded products 43, 43. When inserted, the end faces 44, 44 of the semi-molded products 43, 43 face each other.

[0022] Next, as shown in FIG. 3, a melting step S04 is performed. That is, as shown in FIG. 4E, a heater 46 such as an infrared heater or a carbon heater is inserted between a pair of semi-molded products 43, 43 in a non-contact manner. Since the guide pins 31, 31 are in a state of being retreated from the parting lines P, P, the heater 46 can be easily inserted. That is, the degree of freedom in inserting the heater 46 is high. At this time, the mold clamping device 2 may be driven to adjust the mold opening amount so that the gap between the end faces 44, 44 and the heater 46 becomes small. When the heater 46 is energized, the end faces 44, 44 melt in a short time. After melting, a heater retreat step S05 is performed as shown in FIG. 3. That is, the heater 46 is retreated.

[0023] Next, as shown in Fig. 3, a guide pin advance step S06 is performed. That is, as shown in Fig. 4F, pressure oil is supplied from the supply and discharge parts 37, 37. Then, pressure oil is supplied to the cylinder parts 34, 34 to push out the piston parts 36, 36, and the guide pins 31, 31 advance. That is, the guide pins 31, 31 protrude from the parting line P.

[0024] Finally, as shown in FIG. 3, the welding step S07 is performed. That is, as shown in FIG. 4G, the mold is clamped by the mold clamping device 2. The guide pins 31, 31 are guided by the guide holes 41, 41, and the first and second molds 15, 16 are clamped with high precision. The end faces 44, 44 of the pair of semi-molded products 43, 43 are welded together. When they are integrated by welding, a molded product 48 is obtained. When the mold is opened, a molded product 48 is obtained as shown in FIG. 4H. Note that the guide pins 31, 31 may be retracted prior to removing the molded product 48. In this case, the molded product 48 can be easily removed without being hindered by the guide pins 31, 31.

[0025] [Variations] The molds 15, 16 (see FIG. 2) according to the first embodiment can be modified. FIG. 5 shows molds 15A, 16A, 16A according to modified examples of the first embodiment. In the molds 15A, 16A, 16A according to these modified examples, the same members and structures as those in the first embodiment are given the same reference numerals and the description thereof is omitted. The molds 15A, 16A, 16A according to the modified examples will be described with respect to the differences from the molds 15, 16 according to the first embodiment.

[0026] First, the second mold 16A, 16A according to the modified example differs from the first embodiment in that it is composed of two separate pieces. These two molds 16A, 16A are provided slidably in the direction of the arrow in Fig. 5 on the surface of the base plate 51 fixed to the movable platen 8 opposite the surface that contacts the movable platen 8. When these second molds 16A, 16A reach a sliding position where they contact each other, one recess, i.e., second recess 29A, is formed as shown in Fig. 5.

[0027] The guide holes 41A, 41A formed in the second mold 16A, 16A and the guide pins 31A, 31A provided in the first mold 15A are not perpendicular to the parting line but are oblique, which is also different from the first embodiment. That is, the guide holes 41A, 41A are formed obliquely so as to move away from each other toward the back of the hole. On the other hand, the guide pins 31A, 31A are formed obliquely so that the guide pin storage holes 33A, 33A approach each other toward the back of the hole, and the guide pins 31A, 31A are inserted in these. The guide hole 41A corresponding to one guide pin 31A and the guide hole 41A corresponding to the other guide pin 31A are oriented in the same direction.

[0028] In the modified example, the drive mechanism of the guide pins 31A, 31A is also different from that of the first embodiment. Specifically, the drive mechanism is made of an air cylinder. That is, the air cylinder is composed of the enlarged cylinder portion 34 at the back of the guide pin storage hole 33A, 33A and the piston portion 36, 36 at the rear end of the guide pin 31A, 31A, and is provided with air supply and discharge portions 52, 53, .... Therefore, when air is supplied from the air supply and discharge portions 52, 52, the guide pins 31A, 31A are pushed out from the parting line P, and when air is supplied from the air supply and discharge portions 53, 53, the guide pins 31A, 31A are retracted from the parting line P.

[0029] In the molds 15A, 16A, 16A according to the modified example, the guide pins 31A, 31A can be retreated from the parting line P in the same manner as in the first embodiment, so that the degree of freedom of work in the vicinity of the molds 15A, 16A, 16A is high. As described above, the guide pins 31A, 31A are designed to protrude obliquely with respect to the parting line P, so that when the mold clamping device 2 is driven to close the molds, the two molds 16A, 16A slide in a direction approaching each other when the guide pins 31A, 31A are inserted into the guide holes 41A, 41A. On the other hand, when the mold clamping device 2 is driven to open the molds, the two molds 16A, 16A slide in a direction away from each other when the guide pins 31A, 31A are pulled out of the guide holes 41A, 41A.

[0030] [Second embodiment] <Injection molding machine> A second embodiment will be described. The second embodiment is configured similarly to the first embodiment except for the mold. Therefore, the same reference numbers are used for the same members of the injection molding machine 1, the mold clamping device 2, the injection device 3, etc., and the description will be omitted.

[0031] <Mold> The molds 15B and 16B according to the second embodiment will be described with reference to FIG. 6A. The first mold 15B according to the second embodiment is also provided with a plurality of guide pins 31, 31, as in the first embodiment (see FIG. 2). These guide pins 31, 31 have the same configuration as in the first embodiment. That is, the guide pins 31, 31 are inserted into guide pin storage holes 33, 33 formed in the first mold 15B, and the backs of the guide pin storage holes 33, 33 are expanded cylinder parts 34, 34, and the rear ends of the guide pins 31, 31 are expanded piston parts 36, 36. The guide pins 31, 31 are pushed forward by pressure oil supplied from the supply and discharge parts 37, 37, and are retracted from the parting line P by the springs 38, 38 when the applied oil pressure becomes zero. Similarly, in the second embodiment, the second mold 16B has guide holes 41, 41 formed at the parting line P.

[0032] Similarly to the first embodiment, the molds 15B and 16B according to the second embodiment also have a first recess 28B and a second recess 29B formed in the center thereof, which are recesses into which a semi-molded product is inserted.

[0033] The molds 15B and 16B according to the second embodiment have a structure different from that of the first embodiment. That is, in the first mold 15B, a first molding recess 55 is formed above the first recess 28B at the parting line P, and a first molding protrusion 56 is formed below the first recess 28B. In the second mold 16B, a second molding protrusion 58 is formed above the second recess 29B at the parting line P, and a second molding recess 59 is formed below the second recess 29B. In the first mold 15B, a runner 61 through which resin flows from the injection nozzle 24 is connected to the first molding recess 55 and the first molding protrusion 56.

[0034] <Forming method> A molding method for a molded product according to the second embodiment, which is carried out by the molds 15B and 16B according to the second embodiment, will be described. As shown in FIG. 6A, the first and second molds 15B and 16B are clamped in a state in which the guide pins 31, 31 are protruded from the parting line P. Then, as shown in FIG. 6B, one cavity is formed from the first molding recess 55 and the second molding protrusion 58, and one cavity is formed from the second molding recess 59 and the first molding protrusion 56. Resin is injected from the injection device 3. Then, the resin is filled into these cavities, and semi-molded products 63, 63 are molded.

[0035] When the semi-molded products 63, 63 are cooled and solidified, the first and second dies 15B, 16B are opened. As shown in FIG. 6C, the guide pins 31, 31 are withdrawn from the parting line P. That is, the hydraulic pressure of the pressure oil applied from the supply and discharge parts 37, 37 is set to zero, and the guide pins 31, 31 are withdrawn by the springs 38, 38. As shown in FIG. 6D, the semi-molded products 63, 63 are taken out of the first molding recess 55 and the second molding recess 59, respectively, by a robot hand or the like, and inserted into the first recess 28B and the second recess 29B. Since the guide pins 31, 31 are withdrawn, the semi-molded products 63, 63 can be easily moved. When the semi-molded products 63, 63 are inserted into the first and second recesses 28B, 29B, the end faces 64, 64 face each other.

[0036] 6E, a heater 66 is inserted between the first and second molds 15B, 16B to melt the end faces 64, 64 of the pair of semi-molded products 63, 63. Since the guide pins 31, 31 are retracted, the heater 66 can be easily inserted.

[0037] The heater 66 is withdrawn, and pressure oil is supplied from the supply and discharge parts 37, 37 to advance the guide pins 31, 31. Next, the mold is clamped by the mold clamping device 2. Then, as shown in FIG. 6F, the pair of semi-molded products 63, 63 are welded at their end faces 64, 64 to obtain a molded product 67. At this time, resin is simultaneously injected from the injection device 3 to mold a new pair of semi-molded products 63', 63'. The mold clamping device 2 is driven to open the first and second molds 15B, 16B. As shown in FIG. 6G, the guide pins 31, 31 are withdrawn from the parting line P, and the molded product 67 is taken out. Thereafter, the newly molded pair of semi-molded products 63', 63' are moved to the first and second recesses 28B, 29B, and the heater 66 (see FIG. 6E) is inserted, and similar steps are performed, whereby the molded products 67 can be molded continuously.

[0038] Although the invention made by the present inventor has been specifically described above based on the embodiment, it goes without saying that the present invention is not limited to the embodiment already described, and various modifications are possible without departing from the gist of the invention. The above-described examples may be implemented in appropriate combination. [Explanation of symbols]

[0039] 1 Injection molding machine 2 Mold clamping device 3 Injection unit 4 Control unit 7 Fixed plate 8 Movable plate 9 Clamping housing 11 Tie bar 13 Toggle mechanism 15 Fixed side mold 16 Movable mold 19 Heating cylinder 20 Screw 22 Screw drive device 23 Hopper 24 Injection nozzle 25 Heater 28 First recess 29 Second recess 31 Guide pin 33 Guide pin storage hole 34 Cylinder section 36 Piston section 37 Supply and exhaust section 38 Spring 39 Step 41 Guide hole 43 Semi-molded product 44 End face 46 Heater 51 Base plate 53 Air supply and exhaust section 55 First molding concave portion 56 First molding convex portion 58 Second molding convex portion 59 Second molding concave portion 61 Runner 63 Semi-molded product 64 End face 67 Molded product B Bed P Parting Line

Claims

1. Equipped with guide pins to guide mold closing, The guide pin is accommodated in a guide pin accommodation hole formed in the parting line and is driven by a predetermined drive mechanism. The die is configured so that the tip of the guide pin is protruded from the parting line and retracted into the guide pin storage hole by the drive mechanism.

2. The drive mechanism includes a hydraulic cylinder and a spring. The hydraulic cylinder is composed of a cylinder portion having an enlarged diameter at the back of the guide pin receiving hole and a piston portion having an enlarged diameter at the rear end of the guide pin, and the guide pin moves forward when pressure oil is supplied thereto.

2. The mold according to claim 1, wherein the spring is provided to apply a force in a retracting direction to the guide pin, so that the guide pin is retracted into the guide pin storage hole when the supply of pressure oil is stopped.

3. the drive mechanism comprises a fluid cylinder; The fluid cylinder is composed of a cylinder portion having an enlarged diameter at the back of the guide pin receiving hole and a piston portion having an enlarged diameter at the rear end of the guide pin, and is provided with two fluid supply ports; 2. The mold according to claim 1, wherein the guide pin advances when fluid is supplied from one of the fluid supply ports, and the guide pin retracts into the guide pin storage hole when fluid is supplied from the other of the fluid supply ports.

4. The mold according to claim 3 , wherein the fluid cylinder is a hydraulic cylinder and the fluid is pressurized oil.

5. A fixed plate and A movable platen that moves forward and backward relative to the fixed platen, A pair of dies are provided on the fixed platen and the movable platen, The mold is provided with a guide pin for guiding mold closing, The guide pin is accommodated in a guide pin accommodation hole formed in the parting line and is driven by a predetermined drive mechanism. The drive mechanism causes a tip of the guide pin to be protruded from the parting line and retracted into the guide pin storage hole.

6. The drive mechanism includes a hydraulic cylinder and a spring. The hydraulic cylinder is composed of a cylinder portion having an enlarged diameter at the back of the guide pin receiving hole and a piston portion having an enlarged diameter at the rear end of the guide pin, and the guide pin moves forward when pressure oil is supplied thereto.

6. The mold clamping device according to claim 5, wherein the spring is provided to apply a force to the guide pin in a retracting direction, so that the guide pin is retracted into the guide pin storage hole when the supply of pressure oil is stopped.

7. the drive mechanism comprises a fluid cylinder; The fluid cylinder is composed of a cylinder portion having an enlarged diameter at the back of the guide pin receiving hole and a piston portion having an enlarged diameter at the rear end of the guide pin, and is provided with two fluid supply ports; 6. The mold clamping device according to claim 5, wherein the guide pin advances when fluid is supplied from one of the fluid supply ports, and the guide pin retracts into the guide pin storage hole when fluid is supplied from the other of the fluid supply ports.

8. The mold clamping apparatus according to claim 7 , wherein the fluid cylinder is a hydraulic cylinder and the fluid is pressure oil.

9. An injection device; A mold clamping device, The mold clamping device includes a fixed platen and A movable platen that moves forward and backward relative to the fixed platen, A pair of dies are provided on the fixed platen and the movable platen, The mold is provided with a guide pin for guiding mold closing, The guide pin is accommodated in a guide pin accommodation hole formed in the parting line and is driven by a predetermined drive mechanism. the drive mechanism causes a tip of the guide pin to be protruded from the parting line and retracted into the guide pin storage hole.

10. The drive mechanism includes a hydraulic cylinder and a spring. The hydraulic cylinder is composed of a cylinder portion having an enlarged diameter at the back of the guide pin receiving hole and a piston portion having an enlarged diameter at the rear end of the guide pin, and the guide pin moves forward when pressure oil is supplied thereto.

10. The injection molding machine according to claim 9, wherein the spring is provided to apply a force to the guide pin in a retracting direction, so that the guide pin is retracted into the guide pin storage hole when the supply of pressure oil is stopped.

11. a first mold having a first recess formed therein for accommodating a first semi-molded product; a second mold having a second recess formed therein in which a second semi-molded product is housed; A molding method for molding a molded product using a heater, comprising: a guide pin receiving hole is formed in a parting line of the first mold, and a guide pin driven by a predetermined drive mechanism is provided in the guide pin receiving hole; a mold opening step of opening the first mold and the second mold; a guide pin retracting step of retracting the guide pin into the guide pin storage hole by the driving mechanism; a semi-molded product inserting step of inserting a first semi-molded product and a second semi-molded product into the first recess and the second recess, respectively; a melting step of inserting the heater between the first and second semi-molded products to heat and melt the end surfaces of the first and second semi-molded products in a non-contact manner; a heater retraction step of retracting the heater; a guide pin advancement process in which the driving mechanism advances the guide pin so that the tip of the guide pin protrudes from the parting line; a welding step of clamping the first and second dies together to pressure-weld the end faces of the first and second semi-molded products to obtain a molded product.

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