Mold, mold clamping device, injection molding machine, and molding method of molded article

Abstract

The present disclosure provides a mold having a high degree of freedom in work performed near the mold. A guide pin (31) for guiding the closing of the molds (15, 16) is housed in a guide pin housing hole (33) opened in the parting surface (P). The leading end of the guide pin (31) protrudes from the parting surface (P) or retreats from the guide pin accommodating hole (33) by a predetermined drive mechanism (34, 36, 37, 38).

Description

Technical Field

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

[0002] The injection molding machine is provided with a clamping device for clamping the mold and an injection device for melting the injection material and injecting it into the mold. The so-called horizontal injection molding machine is provided with a clamping device arranged on a base and an injection device arranged on the side of the clamping device on the base. For example, as described in Patent Document 1, the mold provided in the clamping device is provided with a guide pin. That is, a guide pin is embedded in one mold, and a pin hole is opened in the other mold. When the pair of molds are clamped, the guide pin can be inserted into the pin hole to prevent misalignment and close the mold with high precision.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 4-197614 Summary of the invention

[0006] Problems to be Solved by the Invention

[0007] The mold can be closed with high precision by preventing the mold from being misaligned by the guide pins when closing the mold. However, the problem is also obvious. Since the guide pins protrude from the parting surface at one mold, there is a problem that the processing performed near the mold becomes complicated. For example, when a molded product formed in a mold is taken out by a robot arm, it is necessary to prevent the robot arm from colliding with the guide pins. In other words, the robot arm must be controlled to avoid the guide pins. Alternatively, when inserting an insert into a mold using a robot arm, it is also necessary to be careful not to collide with the guide pins.

[0008] In the present disclosure, a mold capable of simplifying a process performed near the mold is provided.

[0009] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0010] Means for solving problems

[0011] In the present disclosure, the guide pin is accommodated in the guide pin accommodation hole opened in the parting surface, and the front end of the guide pin is protruded from the parting surface or retracted into the guide pin accommodation hole by a predetermined driving mechanism.

[0012] Effects of the Invention

[0013] The present disclosure can improve the degree of freedom of work performed near a mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 1 is a front view showing the injection molding machine according to the first embodiment.

[0015] Figure 2 It is a front cross-sectional view showing a part of the mold clamping device and the mold according to the first embodiment.

[0016] Figure 3 It is a flowchart showing the process of the molding method of the molded article according to the first embodiment.

[0017] Figure 4A It is a front cross-sectional view showing a part of the mold clamping device and the mold according to the first embodiment.

[0018] Figure 4B It is a front cross-sectional view showing a part of the mold clamping device and the mold according to the first embodiment.

[0019] Figure 4C It is a front cross-sectional view showing a part of the mold clamping device and the mold according to the first embodiment.

[0020] Figure 4D It is a front cross-sectional view showing a part of the mold clamping device, the mold according to the first embodiment, and a pair of semi-molded products.

[0021] Figure 4E It is a front cross-sectional view showing a part of the mold clamping device, the mold according to the first embodiment, a pair of semi-molded products, and a heater.

[0022] Figure 4F It is a front cross-sectional view showing a part of the mold clamping device, the mold according to the first embodiment, and a pair of semi-molded products.

[0023] Figure 4G It is a front cross-sectional view showing a part of the mold clamping device, the mold and the molded product according to the first embodiment.

[0024] Figure 4H It is a front cross-sectional view showing a part of the mold clamping device, the mold and the molded product according to the first embodiment.

[0025] Figure 5 It is a front cross-sectional view showing a part of the mold clamping device and a mold according to a modified example of the first embodiment.

[0026] Fig. 6A It is a front cross-sectional view showing a part of an injection molding machine and a mold according to a second embodiment.

[0027] Figure 6B It 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.

[0028] Figure 6C It 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.

[0029] Fig.6D It 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.

[0030] Fig. 6E It 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.

[0031] Fig. 6F It 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.

[0032] Figure 6G It 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.

[0033] Description of Reference Numerals

[0034] 1 Injection molding machine 2 Mold clamping device

[0035] 3 Injection device 4 Control device

[0036] 7 Fixed plate 8 Movable plate

[0037] 9 Clamping shell 11 Tie rod

[0038] 13 Toggle mechanism 15 Fixed side mold

[0039] 16 Movable side mold 19 Heating cylinder

[0040] 20 Screw 22 Screw drive device

[0041] 23 Hopper 24 Injection nozzle

[0042] 25 Heater

[0043] 28 First recess 29 Second recess

[0044] 31 Guide pin 33 Guide pin receiving hole

[0045] 34 Cylinder 36 Piston

[0046] 37 supply and discharge part 38 spring

[0047] 39 Step portion 41 Guide hole

[0048] 43 Semi-molded product 44 End surface

[0049] 46 Heater 51 Base plate

[0050] 53 Air supply and exhaust

[0051] 55 First molding concave portion 56 First molding convex portion

[0052] 58 Second molding convex portion 59 Second molding concave portion

[0053] 61 Runner 63 Semi-molded product

[0054] 64 End face 67 Molded product

[0055] B Base

[0056] P Parting surface DETAILED DESCRIPTION

[0057] The specific implementation mode is described in detail below in conjunction with the accompanying drawings. However, the present invention is not limited to the following implementation modes. For the purpose of clear description, the following description and the accompanying drawings are appropriately simplified. In each figure, the same elements are marked with the same reference numerals, and repeated descriptions are omitted as required. In addition, in order to avoid confusion in the accompanying drawings, hatching is omitted in some parts.

[0058] [First embodiment]

[0059] <Injection molding machine>

[0060] like Figure 1 As shown, the injection molding machine 1 according to the first embodiment is a so-called horizontal injection molding machine. That is, the injection molding machine 1 according to the first embodiment includes a clamping device 2 provided on a base B, an injection device 3 provided on the base B to the side of the clamping device 2, and a control device 4 for controlling them. The molds 15 and 16 according to the first embodiment described in detail later are provided in the horizontal injection molding machine 1, but are not necessarily limited to the horizontal injection molding machine, and can also be provided in a vertical injection molding machine.

[0061] <Mold Clamping Device>

[0062] The mold clamping device 2 includes a fixed platen 7 fixed to a base B, a movable platen 8 slidably provided on the base B, and a mold clamping housing 9. The fixed platen 7 and the mold clamping housing 9 are connected by a plurality of tie rods 11, 11, ..., and the movable platen 8 is slidably provided between the fixed platen 7 and the mold clamping housing 9. The mold clamping mechanism, that is, the 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.

[0063] <Injection device>

[0064] The injection device 3 includes a heating cylinder 19, a screw 20 disposed in the heating cylinder 19, and a screw driving device 22. The heating cylinder 19 is supported by the screw driving device 22, and the screw 20 is driven in the rotational direction and the axial direction by the screw driving device 22. The heating cylinder 19 is provided with a hopper 23 and an injection nozzle 24. In addition, the heating cylinder 19 is provided with heaters 25, 25, ...

[0065] <Mold>

[0066] Reference Figure 2 The fixed side mold 15 and the movable side mold 16 according to the first embodiment are described. For the sake of convenience, the fixed side mold 15 is referred to as the first mold 15 and the movable side mold 16 is referred to as the second mold 16. The first mold 15 has a first recess 28 formed at the parting surface P, into which the semi-molded product is inserted as described later. Similarly, the second mold 16 also has a second recess 29 formed at the parting surface P, into which the semi-molded product is inserted as described later.

[0067] The first mold 15 is provided with guide pins 31, 31 for guiding when the mold is closed, and the characteristics of these guide pins 31, 31 are their structure and setting method. First, guide pin accommodating holes 33, 33 are opened at the parting surface P of the first mold 15, and the deep part of the guide pin accommodating holes 33, 33 is a cylinder 34, 34 with an enlarged diameter. The guide pins 31, 31 are placed in the guide pin accommodating holes 33, 33. The rear end of the guide pins 31, 31 is a piston part 36, 36 with an enlarged diameter, and is arranged to slide liquid-tightly on the inner circumferential surface of the cylinder 34, 34. The supply and discharge part 37 is connected to the bottom of the guide pin accommodating holes 33, 33, so that hydraulic oil is supplied and discharged from the outside to the cylinder 34, 34. That is, the hydraulic cylinder has the cylinder 34, 34 and the piston part 36, 36, and the guide pins 31, 31 are driven.

[0068] 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 outlets of the guide pin receiving holes 33, 33. Therefore, the springs 38, 38 apply force to the guide pins 31, 31 in the retreat direction (i.e., in the direction to retreat the guide pins 31, 31 into the guide pin receiving holes 33, 33). When hydraulic oil is supplied from the supply and discharge parts 37, 37, the piston parts 36, 36 are pressed against the force of the springs 38, 38, and the guide pins 31, 31 advance, and the front ends protrude from the parting surface P. On the other hand, when the hydraulic pressure of the hydraulic oil is zero or reduced, the guide pins 31, 31 retreat under the action of the springs 38, 38. That is, the guide pins 31, 31 retreat to the guide pin receiving holes 33, 33 and become hidden from the parting surface P. A hydraulic cylinder having cylinder portions 34, 34 and piston portions 36, 36 and springs 38, 38 may constitute one example of a driving mechanism. The first mold 15 may be provided with a guide pin mechanism having guide pins 31, 31 and a driving mechanism.

[0069] The second mold 16 is provided with guide holes 41, 41. As described below, when the first mold 15 and the second mold 16 are closed, the guide pins 31, 31 are inserted into the guide holes 41, 41, that is, they are guided. This prevents the molds 15, 16 from being misaligned, and the molds are closed and closed with high precision. It should be noted that in the description of the first embodiment, the first mold 15 is set on the fixed side mold 15, that is, the fixed plate 7, and the second mold 16 is set on the movable side mold 16, that is, the movable plate 8. However, the first mold 15 may also be set on the movable plate 8, and the second mold 16 may also be set on the fixed plate 7. That is, the guide pins 31, 31 may also be set on the mold on the movable plate 8 side instead of being set on the mold on the fixed plate 7 side.

[0070] <Molding method>

[0071] Since the dies 15 and 16 according to the first embodiment can be set to a state where the guide pins 31 and 31 are completely retracted (i.e., a state where the guide pins 31 and 31 are accommodated in the guide pin accommodation holes 33 and 33), an effect of high degree of freedom in operations near the dies 15 and 16 is obtained. In order to understand the degree of freedom in operations, a molding method of a molded product according to the first embodiment implemented using these dies 15 and 16 will be described.

[0072] First, if Figure 3 As shown, the mold opening step S01 is implemented. Figure 4AThe description will start with the mold-closing state shown in FIG. When the mold is closed, the guide pins 31, 31 move forward because the hydraulic oil is supplied from the supply and discharge parts 37, 37. That is, the guide pins 31, 31 protruding from the parting surface P are inserted into the guide holes 41, 41. From this state, the mold-closing device 2 is driven to open the mold. The mold-opening state is shown in FIG. Figure 4B shown.

[0073] Next, if Figure 3 As shown, the guide pin retraction step S02 is implemented. That is, the hydraulic pressure of the hydraulic oil applied from the supply and discharge parts 37, 37 is made zero, or the pressure is reduced. Figure 4C As shown, the guide pins 31, 31 retreat by the spring force of the springs 38, 38. The hydraulic oil is pushed out from the cylinders 34, 34 and discharged from the supply and discharge parts 37, 37. The front ends of the guide pins 31, 31 are substantially retracted from the parting surface P.

[0074] like Figure 3 As shown in FIG. 1 , the semi-molded product inserting step S03 is performed. Figure 4D As shown, the semi-molded products 43, 43 are inserted into the first recess 28 and the second recess 29 by a robot hand or the like. Since the guide pins 31, 31 are in a state of retreating from the parting surfaces P, P, the semi-molded products 43, 43 can be easily inserted. That is, the insertion operation of the semi-molded products 43, 43 has a high degree of freedom. After insertion, the end surfaces 44, 44 of the semi-molded products 43, 43 are in a state of facing each other.

[0075] Next, if Figure 3 As shown in FIG. 4 , a melting step S04 is performed. Figure 4E As shown, 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 retreating from the parting surfaces P, P, the heater 46 can be easily inserted. That is, the insertion operation of the heater 46 has a high degree of freedom. It should be noted that at this time, the mold opening amount can be adjusted by driving the mold clamping device 2 so that the gap between the end faces 44, 44 and the heater 46 becomes smaller. When the heater 46 is energized, the end faces 44, 44 melt in a short time. After melting, as shown in FIG. Figure 3 As shown, the heater retreat step S05 is performed. That is, the heater 46 is retreated.

[0076] Next, if Figure 3 As shown in FIG. 1 , the guide pin advancing step S06 is implemented. Figure 4F As shown, hydraulic oil is supplied from the supply and discharge parts 37, 37. As a result, hydraulic oil is supplied to the cylinder parts 34, 34, the piston parts 36, 36 are pushed out, and the guide pins 31, 31 move forward. That is, the guide pins 31, 31 protrude from the parting surface P.

[0077] Finally, if Figure 3 As shown in FIG. 5 , the welding step S07 is performed. Figure 4G As shown in FIG. 1 , mold clamping is performed in the mold clamping device 2. The guide pins 31, 31 are guided by the guide holes 41, 41, and the first mold 15 and the second mold 16 are clamped with high precision. The end faces 44, 44 of a pair of semi-molded products 43, 43 are welded to each other. When they are integrated by welding, a molded product 48 is obtained. When the mold is opened, as shown in FIG. Figure 4H As shown, the molded product 48 is obtained. It should be noted that the guide pins 31, 31 may be retracted before taking out the molded product 48. Thereby, the molded product 48 can be easily taken out without the guide pins 31, 31 becoming an obstacle.

[0078] [Modifications]

[0079] According to the first embodiment, the molds 15, 16 (see Figure 2 ) can be deformed. Figure 5 The molds 15A, 16A, 16A according to the modified example of the first embodiment are shown. In the molds 15A, 16A, 16A according to the modified example, the same reference numerals are given to the same components and structures as those in the first embodiment, and their description is omitted. The molds 15A, 16A, 16A according to the modified example are described with respect to the differences from the molds 15, 16 according to the first embodiment.

[0080] First, the second molds 16A, 16A according to the modified example are different from the first embodiment in that they are composed of two divided pieces. The two molds 16A, 16A are provided on the surface of the base plate 51 fixed to the movable platen 8 on the opposite side of the surface in contact with the movable platen 8. Figure 5 When these second molds 16A, 16A are in a sliding position in contact with each other, as shown in FIG. Figure 5 As shown, a recessed portion, namely, a second recessed portion 29A is formed.

[0081] The guide holes 41A, 41A formed in the second molds 16A, 16A and the guide pins 31A, 31A provided in the first mold 15A are not perpendicular to the parting surface but are inclined. That is, the guide holes 41A, 41A are formed to be inclined so as to move away from each other toward the depth of the holes. On the other hand, the guide pins 31A, 31A are formed to be inclined so as to move toward the depth of the guide pin receiving holes 33A, 33A, and the guide pins 31A, 31A are placed in these guide pin receiving holes. One guide pin 31A and the corresponding guide hole 41A, and the other guide pin 31A and the corresponding guide hole 41A have the same orientation.

[0082] In the modified example, the driving mechanism of the guide pins 31A and 31A is also different from that of the first embodiment. Specifically, the driving mechanism includes a cylinder. That is, the cylinder has a cylindrical portion 34 with an enlarged diameter at the deep end of the guide pin accommodating hole 33A and a piston portion 36 and 36 at the rear end of the guide pins 31A and 31A, and is provided with air supply and exhaust portions 52 and 53. Therefore, when air is supplied from the air supply and exhaust portions 52 and 52, the guide pins 31A and 31A protrude from the parting surface P, and when air is supplied from the air supply and exhaust portions 53 and 53, the guide pins 31A and 31A retreat from the parting surface P.

[0083] In the molds 15A, 16A, 16A according to the modified example, since the guide pins 31A, 31A can be retracted from the parting surface P in the same manner as in the first embodiment, the degree of freedom in the work near the molds 15A, 16A, 16A is high. It should be noted that, since the guide pins 31A, 31A are provided to protrude obliquely relative to the parting surface P as described above, when the mold clamping device 2 is driven to close the mold, when the guide pins 31A, 31A are inserted into the guide holes 41A, 41A, the two molds 16A, 16A slide in the direction of approaching each other. On the other hand, when the mold clamping device 2 is driven to open the mold, when the guide pins 31A, 31A are pulled out from the guide holes 41A, 41A, the two molds 16A, 16A slide in the direction of separating from each other.

[0084] [Second embodiment]

[0085] <Injection molding machine>

[0086] The second embodiment is described. In the second embodiment, only the mold is different from the first embodiment, and the other aspects are configured in the same manner as the first embodiment. Therefore, for the injection molding machine 1, the mold clamping device 2, the injection device 3, etc., the same reference numerals are marked on the same parts, and their descriptions are omitted.

[0087] <Mold>

[0088] Reference Fig. 6A The molds 15B and 16B according to the second embodiment are described. Figure 2) Similarly, the first mold 15B according to the second embodiment is also provided with a plurality of guide pins 31, 31. These guide pins 31, 31 have the same structure as the first embodiment. That is, the guide pins 31, 31 are placed in the guide pin receiving holes 33, 33 opened in the first mold 15B, and the deep part of the guide pin receiving holes 33, 33 is a cylinder part 34, 34 with an enlarged diameter, and the rear end of the guide pins 31, 31 is a piston part 36, 36 with an enlarged diameter. The guide pins 31, 31 protrude forward by the hydraulic oil supplied from the supply and discharge parts 37, 37, and when the applied hydraulic pressure becomes zero, they retreat from the parting surface P by the springs 38, 38. Similarly, in the second embodiment, in the second mold 16B, guide holes 41, 41 are also formed at the parting surface P.

[0089] Similar 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 at the center thereof. These recesses are recesses into which the semi-molded product is inserted.

[0090] The molds 15B and 16B according to the second embodiment are formed with a structure different from that of the first embodiment. That is, in the first mold 15B, a first molding concave portion 55 is formed above the first concave portion 28B at the parting surface P, and a first molding convex portion 56 is formed below the first concave portion 28B. Also, in the second mold 16B, a second molding convex portion 58 is formed above the second concave portion 29B at the parting surface P, and a second molding concave portion 59 is formed below the second concave portion 29B. In the first mold 15B, a flow channel 61 for the resin from the injection nozzle 24 to flow is connected to the first molding concave portion 55 and the first molding convex portion 56.

[0091] <Molding method>

[0092] The molding method of the molded product according to the second embodiment implemented by the molds 15B and 16B according to the second embodiment will be described. Fig. 6A As shown in FIG. 1 , the first mold 15B and the second mold 16B are clamped with the guide pins 31, 31 protruding from the parting surface P. Figure 6B As shown, one cavity is formed by the first molding concave portion 55 and the second molding convex portion 58, and one cavity is formed by the second molding concave portion 59 and the first molding convex portion 56. Resin is injected from the injection device 3. Thus, the resin is filled into these cavities, and semi-molded products 63, 63 are molded.

[0093] After the semi-molded products 63, 63 are cooled and solidified, the first mold 15B and the second mold 16B are opened. Figure 6CAs shown in FIG. 1 , the guide pins 31, 31 are retracted from the parting surface P. That is, the hydraulic pressure of the hydraulic oil applied from the supply and discharge parts 37, 37 is made zero, and the guide pins 31, 31 are retracted by the springs 38, 38. Fig.6D As shown, the semi-molded products 63, 63 are taken out from the first molding recess 55 and the second molding recess 59 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 retracted, the semi-molded products 63, 63 can be easily moved. When the semi-molded products 63, 63 are inserted into the first recess 28B and the second recess 29B, the end surfaces 64, 64 face each other.

[0094] like Fig. 6E As shown, a heater 66 is inserted between the first mold 15B and the second mold 16B to melt the end surfaces 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.

[0095] The heater 66 is retracted, and hydraulic oil is supplied from the supply and discharge sections 37, 37 to advance the guide pins 31, 31. Next, the mold is closed by the mold closing device 2. Fig. 6F As shown, the end faces 64, 64 of a pair of semi-molded products 63, 63 are welded to each other to obtain a molded product 67. At this time, resin is injected from the injection device 3 to newly mold a pair of semi-molded products 63', 63'. The mold clamping device 2 is driven to open the first mold 15B and the second mold 16B. Figure 6G As shown, the guide pins 31, 31 are retracted from the parting surface P to remove the molded product 67. Next, the newly molded pair of semi-molded products 63', 63' are moved to the first recess 28B and the second recess 29B, and the heater 66 (see Fig. 6E ) and the like, the molded product 67 can be continuously molded.

[0096] The invention of the inventors of the present invention has been specifically described above based on the embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. The above multiple examples can also be implemented in appropriate combinations.

Claims

1. A mold, characterized in that: Equipped with guide pins to guide mold closing, The guide pin is received in a guide pin receiving hole provided on the parting surface and driven by a predetermined driving mechanism. The front end of the guide pin protrudes from the parting surface or retracts into the guide pin receiving hole by the driving mechanism.

2. The mold according to claim 1, characterized in that: The driving mechanism includes a hydraulic cylinder and a spring. The hydraulic cylinder includes a cylindrical portion with an enlarged diameter at a deep portion of the guide pin receiving hole and a piston portion with an enlarged diameter at a rear end portion of the guide pin, and when hydraulic oil is supplied, the guide pin moves forward. The spring is provided to apply a force in a retreat direction to the guide pin, and when the supply of the hydraulic oil is stopped, the guide pin retreats to the guide pin receiving hole.

3. The mold according to claim 1, characterized in that: The driving mechanism comprises a fluid cylinder, The fluid cylinder includes a cylindrical portion with an enlarged diameter at a deep portion of the guide pin receiving hole and a piston portion with an enlarged diameter at a rear end portion of the guide pin, and is provided with two fluid supply ports. When the fluid is supplied from one of the fluid supply ports, the guide pin advances, and when the fluid is supplied from the other of the fluid supply ports, the guide pin retreats into the guide pin receiving hole.

4. The mold according to claim 3, characterized in that: The fluid cylinder is a hydraulic cylinder, and the fluid is hydraulic oil.

5. A mold clamping device, characterized in that: have: a fixed plate; and a movable plate that moves back and forth relative to the fixed plate, The fixed plate and the movable plate are provided with a pair of molds, The mold has a guide pin for guiding mold closing, The guide pin is received in a guide pin receiving hole provided on the parting surface and driven by a predetermined driving mechanism. The front end of the guide pin protrudes from the parting surface or retracts into the guide pin receiving hole by the driving mechanism.

6. The mold clamping device according to claim 5, characterized in that: The driving mechanism includes a hydraulic cylinder and a spring. The hydraulic cylinder includes a cylindrical portion with an enlarged diameter at a deep portion of the guide pin receiving hole and a piston portion with an enlarged diameter at a rear end portion of the guide pin, and when hydraulic oil is supplied, the guide pin moves forward. The spring is provided to apply a force in a retreat direction to the guide pin, and when the supply of the hydraulic oil is stopped, the guide pin retreats to the guide pin receiving hole.

7. The mold clamping device according to claim 5, characterized in that: The driving mechanism comprises a fluid cylinder, The fluid cylinder includes a cylindrical portion with an enlarged diameter at a deep portion of the guide pin receiving hole and a piston portion with an enlarged diameter at a rear end portion of the guide pin, and is provided with two fluid supply ports. When the fluid is supplied from one of the fluid supply ports, the guide pin advances, and when the fluid is supplied from the other of the fluid supply ports, the guide pin retreats into the guide pin receiving hole.

8. The mold clamping device according to claim 7, characterized in that: The fluid cylinder is a hydraulic cylinder, and the fluid is hydraulic oil.

9. An injection molding machine, characterized in that: Equipped with injection device and 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, and the fixed platen and the movable platen are provided with a pair of molds. The mold has a guide pin for guiding mold closing, The guide pin is received in a guide pin receiving hole provided on the parting surface and driven by a predetermined driving mechanism. The front end of the guide pin protrudes from the parting surface or retracts into the guide pin receiving hole by the driving mechanism.

10. The injection molding machine according to claim 9, characterized in that The driving mechanism includes a hydraulic cylinder and a spring. The hydraulic cylinder includes a cylindrical portion with an enlarged diameter at a deep portion of the guide pin receiving hole and a piston portion with an enlarged diameter at a rear end portion of the guide pin, and when hydraulic oil is supplied, the guide pin moves forward. The spring is provided to apply a force in a retreat direction to the guide pin, and when the supply of the hydraulic oil is stopped, the guide pin retreats to the guide pin receiving hole.

11. A method for molding a molded product, characterized in that: The molded product is molded using the first mold, the second mold and the heater, The first mold is formed with a first recessed portion for accommodating the first semi-molded product. The second mold is formed with a second recessed portion for accommodating the second semi-molded product. In the first mold, a guide pin receiving hole is opened at the parting surface, and a guide pin driven by a predetermined driving mechanism is arranged in the guide pin receiving hole. The molding method of the molded product comprises: A mold opening step, opening the first mold and the second mold; a guide pin retreating step of retreating the guide pin into the guide pin receiving hole by the driving mechanism; a semi-molded product inserting step of inserting the first semi-molded product and the second semi-molded product into the first recess and the second recess respectively; A melting step, inserting the heater between the first semi-molded product and the second semi-molded product to heat and melt the end surfaces of the first semi-molded product and the second semi-molded product in a non-contact manner; A heater retreat step, causing the heater to retreat; a guide pin advancing step of advancing the guide pin by the driving mechanism so that the front end of the guide pin protrudes from the parting surface; In the welding step, the first mold and the second mold are molded together, and the first semi-molded product and the second semi-molded product are pressure-welded to each other at the end surfaces to obtain a molded product.

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