JP2003103581A - Valve gate-type mold assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly adjust the temperature of a molding material running through a material passage provided at a valve device. SOLUTION: In the material passage 11, a gate side passage part 11a and a nozzle touch part 11c to which a nozzle 10 of an injection molding machine is connected, are joined together by a detour passage part 11b which makes a detour around a valve pin 46. Next, in order to drive the valve pin 46, an annular air cylinder device 51 is provided, encircling a valve body 21 with the material passage 11 formed internally. Band heaters 81, 82 and 83 are installed on the outer peripheral parts of a small diameter part 27 and a large diameter part 28 of a first valve body member 24 and the outer peripheral part of a second valve body member 25 respectively. Since the temperature is locally not high, the heat influence to an O-ring 59 of the air cylinder device 51 is not significant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve gate type mold apparatus used for injection molding of thermoplastic resin.

[0002]

Problems to be Solved by the Invention For example, Japanese Patent No. 2998.
As described in Japanese Patent Publication No. 144, etc., in a hot runner mold apparatus that heats a thermoplastic resin that is a molding material in a material passage to a gate to a product cavity and always keeps a molten state, the gate is controlled by a valve pin. A valve gate type mold device that opens and closes mechanically is known. The hot runner mold device is intended to increase the molding efficiency, and the gate is closed to prevent the resin from leaking from the gate when the mold is opened.

Generally, the valve pin moves linearly in the opening and closing directions of the fixed type and the movable type, and is coaxially positioned inside the gate side portion (gate side passage portion) of the material passage. . In addition, since the valve pin support is required and the valve pin must be driven by a driving device such as a fluid pressure cylinder device, the material passage should be a gate side passage part in order to avoid the valve pin support and the drive device. It has a part that bends from.

In the case of a valve gate type mold device having a plurality of pieces, since a branch portion, and therefore a bent portion, is necessarily required in the material passage, the bent portion for avoiding the valve pin supporting portion and the driving device as described above is required. It doesn't matter much. But,
In the case of a one-piece mold apparatus, the bent portion is not originally desirable. In other words, if the nozzle touch part to which the nozzle of the injection molding machine is connected and the gate side passage part are not aligned, even if the gate is located in the center of the product cavity, the gold will be drawn with respect to the nozzle. This may make it difficult to configure the mold device symmetrically, and the mold clamping force may not evenly act on the mold device. In addition, the contact pressure of the nozzle may not be evenly received.

Therefore, it is conceivable to position the nozzle touch portion and the gate side passage portion coaxially by, for example, curving the portion connecting the nozzle touch portion and the gate side passage portion in the material passage in an arc shape. In this case, it becomes difficult to incorporate a large fluid pressure cylinder device that drives the valve pin coaxially with the valve pin.

Further, as described above, the portion connecting the nozzle touch portion and the gate side passage portion in the material passage is curved in an arc shape, and the piston of the fluid pressure cylinder device and the valve pin are connected via a connecting member, In order to ensure proper operation of the valve pin, it is necessary to incorporate the fluid pressure cylinder device close to the material passage. Further, in a hydraulic cylinder device incorporated in this type of mold device, an airtight member such as an O-ring is used to maintain airtightness between the members. On the other hand, in order to always keep the molding material in a molten state, it is necessary to heat the material passage with a heater. Therefore, if an airtight member such as an O-ring is provided near the material passage, this airtight member receives the heat of the heater. Durability is expected to decrease.

The present invention is intended to solve such a problem and is capable of evenly receiving the contact pressure of the nozzle, reliably operating the valve pin, and providing a material passage provided in the valve device. It is an object of the present invention to provide a valve gate type mold device which can regulate the temperature of a molding material flowing through the mold uniformly and which has excellent durability of a cylinder device.

[0008]

According to a first aspect of the invention, there is provided a valve gate type mold device, wherein an outer peripheral surface of the first valve body member has the gate side passage portion inside. And a portion having the bypass passage portion is a large-diameter portion having a larger diameter, and the heater is provided with a small-diameter portion and a large-diameter portion of the first valve body member. The heaters are provided on the outer peripheral portion of the portion and on the outer peripheral portion of the second valve body member, respectively, and the heaters are provided so that the temperature can be controlled respectively.

At the time of molding, a plurality of molds are closed to form a product cavity between these molds, and a fluid pressure cylinder device drives a valve pin to open a gate, and a nozzle of a molding machine is touched by a nozzle touch portion. Inject the molding material into. The molding material flows from the nozzle touch portion through the bypass passage portion and the gate side passage portion, and then flows into the product cavity from the gate. After the molding material is filled in the product cavity, the valve cylinder is driven by the fluid pressure cylinder device to close the gate. Further, after the molding material in the product cavity is cooled and solidified, the mold is opened and the molded product is taken out. After that, the mold is closed again and molding is repeated, but the molding material in the material passage is always kept in a molten state by the heating of the heater. In the material passage, while the valve pin is located in the gate side passage portion, the bypass passage portion bypasses the valve pin and the nozzle touch portion is located coaxially with the gate side passage portion. It is possible to configure the mold device symmetrically with respect to the nozzle. Further, the fluid pressure cylinder device has an annular shape surrounding the valve body having the material passage therein, and can generate a large driving force. Furthermore, the arm that connects the fluid pressure cylinder device and the valve pin can evenly transmit the force from the fluid pressure cylinder device to the valve pin.

Then, heating is controlled by heaters respectively provided on the outer peripheral portions of the small diameter portion and the large diameter portion of the first valve body member and the outer peripheral portion of the second valve body member so that the entire material passage is made uniform. It can be heated, and compared with the case where the valve body is partially heated, the valve body is heated evenly, so there is no partial high temperature,
The airtight member of the hydraulic cylinder device that surrounds the valve body is not exposed to high temperatures.

According to a second aspect of the present invention, in the valve gate mold apparatus according to the first aspect of the present invention, in the piston of the fluid pressure cylinder device, the arm member on the inner peripheral wall of the annular fluid pressure cylinder device is provided. Sealing materials that are in close contact with the inner peripheral wall are provided at positions sandwiching the through-holes.

Thus, even though there is a through hole for connecting the piston and the valve pin in the inner peripheral wall of the fluid pressure cylinder device, the drive fluid for the fluid pressure cylinder device is prevented from leaking from this through hole. To be done.

According to a third aspect of the present invention, in the valve gate mold apparatus according to the first or second aspect of the present invention, there is only one product cavity formed between the mold bodies, and one material passage and one gate. Is the only one.

Particularly in the case of such a single-piece valve gate type mold apparatus, it is significant to position the nozzle touch portion and the gate side passage portion coaxially in the material passage.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the valve gate mold apparatus of the present invention will be described below with reference to FIGS. 1 is a fixed die, 2 is a movable die, and these fixed die 1 and movable die 2 which are die bodies move in the vertical direction (die opening / closing direction) shown in FIG. One product cavity 3 having a product shape is formed. The fixed mold 1 is fixed to the fixed side mold plate 6, the fixed side receiving plate 7 fixed to the back surface of the fixed side mold plate 6, that is, the surface opposite to the movable mold 2, and the back side of the fixed side receiving plate 7. The fixed side mounting plate 8 is provided. The fixed side attachment plate 8 is attached to a fixed side platen of an injection molding machine (not shown).

The stationary mold 1 has one material passage 11 to which the nozzle 10 of the injection molding machine is connected, one gate 12 for opening the material passage 11 to the product cavity 3, and the gate 12 mechanically. And a valve device 13 that opens and closes.
The gate 12 is embedded in the fixed side template 6 and fixed in the gate bush 14, and the product cavity 3
Is formed on the fixed-side template 6 so as to communicate with each other.

Next, the structure of the valve device 13 will be described. The valve device 13 has a valve body 21 having the material passage 11 therein. The valve body 21 is located in through holes 22 and 23 formed in the fixed-side receiving plate 7 and the fixed-side mounting plate 8, and its tip is located in the gate bush 14. The valve body 21 is composed of a first valve body member 24 and a second valve body member 25 coaxially fixed by a bolt 26 on the side of the first valve body member 24 opposite to the gate 12. ing. The outer peripheral surface of the first valve body member 24 has a small diameter portion 27 on the gate 12 side and a large diameter portion 28 with a larger diameter on the opposite side. These small parts 27
The large-diameter portion 28 and the large-diameter portion 28 are both substantially cylindrical.
The outer peripheral surface of the second valve body member 25 is also substantially cylindrical, but its diameter is equal to the diameter of the large diameter portion 28 of the first valve body member 24.

An annular cylinder end face plate 31, which also serves as a locate ring, is fixed by bolts 32 on the surface of the fixed side mounting plate 8 opposite to the fixed side receiving plate 7 so as to surround the second valve body member 25. Has been done. The inner peripheral ring portion 33 of the cylinder end face plate 31 is in contact with the engagement step portion 34 on the end face of the second valve body member 25. A step surface 35 between the small diameter portion 27 and the large diameter portion 28 of the first valve body member 24 is in contact with the surface of the fixed side receiving plate 7 opposite to the fixed side mounting plate 8. In this way, the large diameter portion 28 of the first valve body member 24 and the second valve body member 25 are fixed to the fixed side receiving plate 7 and the cylinder end face plate.
It is clamped and fixed by 31 and. Further, the fixing ring 29 fixed to the tip of the small diameter portion 27 of the first valve body member 24 on the gate 12 side is the gate bush.
Fitted on the inner surface of 14. In other parts, a gap for heat insulation is provided between the outer peripheral surfaces of the first valve body member 24 and the second valve body member 25 and the inner peripheral surfaces of the gate bush 14 and the through holes 22, 23. Has been formed.

In the small diameter portion 27 of the first valve body member 24, the gate side passage portion 11 of the material passage 11 is provided.
a is formed. The gate side passage portion 11a is parallel to the die opening / closing direction of the fixed die 1 and the movable die 2. Further, in the large-diameter portion 28 of the first valve body member 24, a part of a bypass passage portion 11b which communicates with one end of the gate side passage portion 11a and is inclined with respect to the mold opening / closing direction is formed. There is. Further, a nest 41 is embedded and fixed in the center of the end surface of the second valve body member 25 on the opposite side to the first valve body member 24, and is fixed to the exposed end surface portion of the nest 41. Is the nozzle touch portion of the material passage 11.
11c is formed. The nozzle touch portion 11c is connected to the nozzle 10 of the injection molding machine, and is located coaxially with the gate side passage portion 11a. That is, the nozzle touch portion 11c is located on the same straight line as the gate side passage portion 11a in the mold opening / closing direction. In addition, the material passage 11 extends from the insert 41 to the second valve body member 25.
The remaining portion of the bypass passage portion 11b is formed.
This connects the nozzle touch portion 11c and the material passage 11 in the first valve body member 24. The bypass passage portion 11b is positioned as a whole off the straight line connecting the gate side passage portion 11a and the nozzle touch portion 11c.

A valve pin 46, which is coaxial with the gate 12 and opens and closes the gate 12, is supported in the valve body 21 so as to be linearly movable within a predetermined range in the mold opening and closing direction. The valve pin 46 coaxially penetrates the inside of the gate side passage portion 11a. And valve pin 4
A gate closing portion 47 that is removably fitted into the gate 12 is formed at a tip end portion of the gate 6 on the gate 12 side. The valve pin 46 is slidably fitted in the guide bush 48 fixedly embedded in the large diameter portion 28 on the large diameter portion 28 side of the first valve body member 24. It is supported by. On the other hand, the gate blocking portion 47 side of the valve pin 46 is supported by being always slidably fitted between a plurality of supporting blades 49 formed to project on the inner peripheral surface of the gate side passage portion 11a. . The tip of the gate-side passage portion 11a on the gate 12 side has a reduced diameter, and is a small diameter portion 50 into which the valve pin 46 is removably fitted.

The valve pin 46 is driven by an air cylinder device 51 which is a fluid pressure cylinder device as a driving device incorporated in the fixed side mounting plate 8. This air cylinder device 51
Has a substantially annular shape surrounding the valve body 21.
The substantially annular cylinder 52 of the air cylinder device 51 is
The cylinder end face plate 31, the inner peripheral side cylinder member 31A on one end side integrally provided on the cylinder end face plate 31, the inner peripheral side cylinder member 53 on the other end side, the outer peripheral side cylinder member 54, and the cylinder 52 It is constituted by the cylinder corresponding portion 8A of the fixed type mounting plate 8 forming the other end wall. Among them, the cylinder end face plate 31 forms one end wall 52A of the cylinder 52, and the inner peripheral side cylinder members 31A and 53 having the same circular shape form the inner peripheral wall of the cylinder 52, and the outer peripheral side cylinder. The member 54 forms the outer peripheral wall of the cylinder 52.

A substantially annular piston 55 is supported in the cylinder 52 so as to be slidable within a predetermined range in the mold opening / closing direction. The piston 55 is composed of a first piston member 57 and a second piston member 58 which are axially connected by a bolt 56. Further, at both ends of the inner peripheral surface and the outer peripheral surface of the piston 55, there are provided O-rings 59 as sealing materials which are in close contact with the inner peripheral wall and the outer peripheral wall of the cylinder 52, respectively. Are mounted in the mounting grooves 59A formed in the piston members 57 and 58, respectively.

The outer peripheral cylinder member 54 is mounted in a cylindrical mounting hole 61 formed in the fixed mold mounting plate 8,
The mounting hole 61 is concentric with the through hole 23. An O-ring 62 as a sealing material is provided between the outer periphery of the outer cylinder member 54 and the mounting hole 61, and the O ring 62 is mounted in a mounting groove 62A formed on the outer periphery of the outer cylinder member 54. There is.

An O-ring 59 as a sealing material is provided between the other end of the inner cylinder member 53 and the cylinder-corresponding portion 8A. This O-ring 59 is the other end of the inner cylinder member 53. It is mounted between the outer peripheral angular step portion 53A and the step portion 23A on one end side of the through hole 23, and the outer periphery of the outer angular step portion 53A is engaged with the inner periphery of the step portion 23A. The step portion 23A is formed continuously with the cylinder corresponding portion 8A. Further, the inner peripheral side flange members 31A and 53 are butted at a butted portion 63.

Further, an opening air inlet 66 and a closing air inlet 67 are formed at both ends of the outer peripheral side cylinder member 54, respectively. These opening air inlets 66
The closing air inlet 67 communicates with the opening air passage 68 and the closing air passage 69 formed in the fixed side mounting plate 8, respectively.

Further, the gate 12 at the valve pin 46 is
The end portion on the opposite side is located in the groove 71 formed in the second piston member 58. The bypass passage portion 11b of the material passage 11 is located 90 ° away from the concave groove 71,
It bypasses the valve pin 46. Also, the groove 71
An arm 72 is fixed to the valve pin 46 inside. This fixing is based on that the arm body 72 and the valve pin retainer 74 fixed to the arm body 72 by the bolt 73 sandwich the flange portion 75 formed at the end portion of the valve pin 46. A spacer ring 76 is axially interposed between the flange portion 75 and the arm body 72, and the valve pin 46 is rotatably connected to the arm body 72. In this case, a stepped hole 101 is formed in the center of the arm portion 72, and the tip end side of the valve pin 46 is inserted into the stepped hole 101, and the stepped hole 101 is provided between the stepped portion 101A and the flange portion 75. The spacer ring 76 is arranged, and the valve pin retainer 74 retains the proximal end side of the flange portion 75. The arm 72 has linear arms 72A and 72A.
These arm portions 72A, 72A extend radially from the valve pin 46 in two directions, penetrate the concave groove 71 of the second piston member 58, and extend toward the outer peripheral side of the arms 72A, 72A. The part is protruding. Furthermore, the ends of both arms 72A, 72A are
The inner cylinder member 31A and the inner cylinder member
It penetrates through the through holes 77 formed between the cylinder 53 and 53 and projects into the cylinder 52. The ends of the arms 72A and 72A have a first piston member 57 and a second piston member 58.
It is sandwiched by and fixed to the piston 55. In this case, a sandwiching groove 78 is provided between the first piston member 57 and the second piston member 58, the arm portion 72A is arranged in the sandwiching groove 78, and both piston members 57, The arm portion 72A can be fixed by connecting 58 in the axial direction. In this way, the valve pin 46 is connected to the piston 55 via the arm 72.
Are linked to. The bypass passage portion of the material passage 11
11b is located 90 ° away from the arm 72. In addition, the pair of O-rings 59 on the inner circumference of the piston 55 are
It is located so as to sandwich the through hole 77 in the inner peripheral wall of 52.

Reference numeral 79 is a movable side mold plate of the movable mold 2.

In such a valve gate type mold device, the material passage 11 is heated on the small diameter portion 27, the large diameter portion 28 of the first valve body member 24 and the outer peripheral surface of the second valve body member 25. Band heaters 81, 82, and 83 are provided. Also, together with the band heaters 81, 82, 83, the first
On the small diameter portion 27, the large diameter portion 28 of the valve main body member 24 and the outer peripheral surface of the second valve main body member 25, temperature sensors 81A, 82A and 83A including thermocouples are provided. The heater 81 of the small diameter portion 27 of the first valve body member 24 is covered with a tubular heater cover 84. Further, the band heater 81 and the temperature sensor 81A are electrically connected to the temperature control means 85, the band heater 82 and the temperature sensor 82A are electrically connected to the temperature control means 86, and the band heater 83.
And the temperature sensor 83A are electrically connected to the temperature control means 87, and each temperature control means 85, 86, 87 is based on the temperature measured by the corresponding temperature sensor 81A, 82A, 83A, and the corresponding band heater 81. , 82, 83 are controlled to control the temperatures of the small diameter portion 27, the large diameter portion 28, and the second valve body member 25 of the first valve body member 24 to the set temperatures.

Next, the operation of the above configuration will be described. At the time of molding, the fixed mold 1 and the movable mold 2 are closed,
A product cavity 3 is formed between the fixed mold 1 and the movable mold 2. When the mold is opened, the gate 12 is closed by the valve pin 46. After the mold is closed, air is introduced into the air cylinder device 51 from the opening air passage 68 and the opening air inlet 66, and the closing air inlet is also opened. Air is caused to flow out from 67 and the closing air passage 69, and the piston 55 is moved in a direction away from the movable mold 2 as shown by a solid line in FIG. The arm 72 and the valve pin 46 also move integrally with the piston 55, and the gate closing portion 47 of the valve pin 46 comes out of the gate 12 to open the gate 12. In this state, the molten thermoplastic resin as the molding material is injected from the nozzle 10 of the injection molding machine. This resin is the material passage inside the valve body 21.
11, that is, the nozzle touch portion 11c, the bypass passage portion 11b, the gate side passage portion 11a, the gap between the support blades 49, and the small diameter portion 50.
Through the gate 12 into the product cavity 3.

After the resin is filled in the product cavity 3, the gate 12 is closed after holding pressure. Therefore, air is introduced into the air cylinder device 51 from the closing air inlet 67 and the closing air passage 69, and the opening air passage is formed.
Air is made to flow out from the opening 68 and the opening air inlet 66, and the piston 55 is moved toward the movable die 2 as shown by the chain line in FIG. The arm 72 and the valve pin 46 also move integrally with the piston 55, and the gate closing portion 47 of the valve pin 46 is fitted into the gate 12 to close the gate 12.
Then, after the resin in the product cavity 3, that is, the product, is sufficiently cooled and solidified, the fixed mold 1 and the movable mold 2 are opened, and the molded product is taken out.

Thereafter, the fixed mold 1 and the movable mold 2 are closed again, and the above molding cycle is repeated. Meanwhile, heating of the band heaters 81, 82, 83 provided on the outer peripheral portions of the small diameter portion 27 and the large diameter portion 28 of the first valve body member 24 and the outer peripheral portion of the second valve body member 25 is controlled, Material passage 11
Can be heated evenly. As a result, the valve body can be heated more uniformly than in the case where the small diameter portion 27 is heated in the valve body member 24 as in the prior art, the temperature does not become high locally, and the liquid pressure surrounding the valve body 21 is reduced. The O-ring, which is the airtight member of the cylinder device 51, is not exposed to high temperatures.

As described above, in this embodiment, in accordance with claim 1, the fixed mold 1 and the movable mold 2, which are a plurality of mold bodies that open and close each other to form the product cavity 3 between them when the mold is closed, and these fixed molds. A valve device (13) for opening and closing a gate (12) provided in a fixed mold (1) having a material passage (11) to which a nozzle (10) of a molding machine is connected among the mold (1) and the movable mold (2) The valve device 13 includes a valve body 21 having a material passage 11 therein, a valve pin 46 that is coaxial with the gate 12 and is built in the valve body 13 to linearly move to open and close the gate 12. Valve pin
A drive device for driving 46 and a heater provided on the outer peripheral portion of the valve body 21 for heating the material passage 11 are provided.
Reference numeral 11 denotes a gate side passage portion 11a on the gate 12 side in which the valve pin 46 is coaxially located inside, and gate side passage portion 11a on the end surface of the valve body 21 opposite to the gate 12 side.
The nozzle touch portion 11c coaxially located with the nozzle 10 of the molding machine and the gate touch passage portion 11a and the nozzle touch portion 11c which are located outside the straight line connecting the gate touch passage portion 11a and the nozzle touch portion 11c. The drive device comprises an annular fluid pressure cylinder device 51 surrounding the valve body 21, and the piston 55 and the valve pin 46 of the fluid pressure cylinder device 51 connect the valve body 21 to the valve body 21. Connected by the penetrating arm 72, the valve body 21
Is composed of a first valve body member 24 and a second valve body member 25 fixed on the side opposite to the gate 12 of the first valve body member 24. The passage portion 11a and a part of the bypass passage portion 11b are formed, and the nozzle touch portion 11c and the remaining portion of the bypass passage portion 11b are formed in the second valve body member 25, and the outer peripheral surface of the first valve body member 24 is formed. The portion having the gate side passage portion 11a therein is the small diameter portion 27, and the bypass passage portion is formed.
A portion having 11b is a large-diameter portion 28 having a larger diameter, and the band heaters 81, 82, and 83, which are heaters, are connected to the small-diameter portion 27 of the first valve body member 24 and the outer peripheral portion of the large-diameter portion 28. Since the band heaters 81, 82, and 83 are respectively provided on the outer peripheral portion of the valve body member 25 of No. 2 so as to be able to control the temperature, the bypass passage portion 11b bypasses the valve pin 46 and the nozzle touch portion 11c becomes the gate side passage portion. Since it is positioned coaxially with 11a, it becomes possible to configure the mold device symmetrically with respect to the nozzle 10. Also, air cylinder device
Reference numeral 51 is an annular shape that surrounds the valve body 21 having the material passage 11 inside, and is capable of generating a large driving force. Further, the arm 72 connecting the air cylinder device 51 and the valve pin 46 can evenly transmit the force from the air cylinder device 51 to the valve pin 46. In particular, the small diameter portion 27 and the large diameter portion 28 of the first valve body member 24.
By controlling the heating by the band heaters 81, 82, 83 respectively provided on the outer peripheral portion of the valve body member 25 and the outer peripheral portion of the second valve body member 25, the entire material passage 11 can be heated uniformly and the valve body 21 can be partially heated. Since the valve body 21 is heated more uniformly than in the case where the air is heated, the temperature of the valve body 21 does not rise locally and the temperature of the airtight member such as the O-ring 59 of the air cylinder device 51 surrounding the valve body 21 rises to a high temperature. Never exposed. In this way, the thermoplastic resin can be surely kept in a molten state in the entire material passage 11, and it is not necessary to raise the heating temperature of the heater portion excessively for heating the portion far from the heater. It is also possible to prevent local overheating.

As described above, in this embodiment, the second aspect
Corresponding to, in the piston 55 of the air cylinder device 51 which is a fluid pressure cylinder device, the through hole 77 through which the arm body 72 of the inner cylinder member 31A, 53 which is the inner wall of the annular air cylinder device 51 penetrates is formed. An O-ring that is a sealing material that is in close contact with the inner cylinder members 31A, 53 at the sandwiching position.
Since the respective 59 are provided, even though there is a through hole 77 for connecting the piston 55 and the valve pin 46, the drive fluid for the air cylinder device 51 is prevented from leaking through the through hole 77.

As described above, in this embodiment, the third aspect
Corresponding to the above, since there is only one product cavity 3 formed between the fixed mold 1 and the movable mold 2, and there is also only one material passage 11 and one gate 12, a single-piece valve gate type mold device is provided. In the case of, the nozzle touch part in the material passage 11
By positioning 11c and the gate-side passage portion 11a coaxially, the mold clamping force can be uniformly applied to the mold device, and stable operation can be performed.

In the material passage 11 provided corresponding to only one product cavity 3, the gate side passage portion 11a positioned coaxially with the gate 12 and the valve pin 46 for opening / closing the gate 12 is provided. Since the nozzle touch portion 11c and the nozzle touch portion 11c are connected to each other by the bypass passage portion 11b that bypasses the support portion of the valve pin 46, the gate side passage portion 11 is provided despite the linear valve pin 46 positioned coaxially with the gate 12.
It is possible to position a and the nozzle touch portion 11c coaxially. As a result, the gate 12 and the nozzle touch portion 11c to the product cavity 3 can be positioned on the central axis of the mold device, so that the mold device can be configured symmetrically with the nozzle 10 as a reference. Thereby, the mold clamping force can be uniformly applied to the mold device, and the second
The advantage that the contact pressure of the nozzle 10 can be evenly received by the valve body member 25 is obtained.

Further, since the valve body 21 is constituted by the second valve body member 24 and the second valve body member 25, and the bypass passage portion 11b is formed across both valve body members 24, 25, the manufacturing process is improved. This bypass passage portion 11b can be easily configured.

As the fluid pressure cylinder device for driving the valve pin 46, a hydraulic cylinder device or the like can be used in addition to the air cylinder device 51 as in the above-mentioned embodiment. It is possible to avoid problems such as stains due to. And, since the air cylinder device 51 is configured in an annular shape surrounding the valve body 21,
Despite the air cylinder device 51, a large force can be obtained to drive the valve pin 46, and the valve pin 46 can be reliably operated. In addition, the piston 55 and valve pin 46 of the air cylinder device 51
And the arm 72 that is located radially with respect to this valve pin 46.
Since it is connected by the valve pin 46, the force of the air cylinder device 51 can be applied to the valve pin 46 evenly.
Can be operated more reliably without tilting.

Further, the piston of the air cylinder device 51
A through hole for penetrating the arm body 72 that connects the valve pin 46 with the valve pin 46.
77 is required on the inner peripheral wall of the cylinder 52 of the air cylinder device 51, but since a pair of O-rings 59 are provided with the through hole 77 sandwiched therebetween, it is possible to ensure the leakage of air, which is the driving fluid of the air cylinder device 51. It can be prevented.

Further, since the valve pin 46 is rotatably connected to the center of the arm 72, the arms 72A, 72A on both sides are pistoned.
The valve pin 46 can be smoothly driven by the movement of the arm 72 connected to 55. A stepped hole 101 is formed in the center of the arm portion 72, and the tip end side of the valve pin 46 is inserted into the stepped hole 101, and the spacer ring is provided between the stepped portion 101A of the stepped hole 101 and the flange portion 75. 76 is arranged and the base end side of the flange portion 75 is pressed by the valve pin retainer 74 to hold the arm portion.
Since the valve pin 46 is connected to the 72, adjust the thickness of the spacer ring 76, and press the spacer ring 76 and the valve pin retainer.
By sandwiching the flange 75 with 74, the valve pin 46
The axial position of the can be easily adjusted. Further, a sandwiching groove 78 is provided between the first piston member 57 and the second piston member 58, the arm portion 72A is arranged in this sandwiching groove 78, and both piston members 57, 58 are attached by the bolt 56. The arm portion 72A can be fixed by axially coupling the piston portion 55A.
Can be assembled and the arm portion 72A can be fixed at the same time, and the position of the valve pin 46 can be adjusted by adjusting the position of the arm body 72 in the length direction at the time of fixing.

The present invention is not limited to the above embodiment, but various modifications can be made. For example,
In the above-described embodiment, the arm body 72 that connects the piston 55 of the air cylinder device 51 and the valve pin 46 is formed into a substantially linear shape, and the arm portion of the arm body 72 is separated by 180 ° from the piston 55.
The valve pin may be connected to the piston of the annular fluid pressure cylinder device by a radial arm extending in three directions, and the piston of the annular fluid pressure cylinder device may be provided with four arms. The valve pin may be connected by a cross-shaped arm portion, or the arm body 72 may have five or more arm portions.

[0041]

According to the valve gate mold apparatus of the first aspect of the invention, the outer peripheral surface of the first valve main body member has a portion having the gate side passage portion therein as a small diameter portion. In addition, the portion having the bypass passage portion is a large-diameter portion having a larger diameter, and the heater is connected to the small-diameter portion of the first valve body member and the outer peripheral portion of the large-diameter portion and the second portion.
Since each of the heaters is provided on the outer peripheral portion of the valve body member and the temperature of each heater is controllable, the mold device can be configured symmetrically with respect to the nozzle, and thereby the mold clamping force is applied to the mold device. It is possible to obtain the advantages that the nozzles can be made to act evenly, and the contact pressure of the nozzle can be evenly received by the mold device. Further, the valve pin driving device is composed of an annular fluid pressure cylinder device surrounding the valve body, and the piston of this fluid pressure cylinder device and the valve pin are connected by the arm radially located with respect to this valve pin. It can be operated reliably. In particular, the entire material passage can be heated evenly, and the valve body is heated evenly as compared with the case where the valve body is partially heated. The airtight member of the surrounding hydraulic cylinder device is not exposed to high temperatures.

According to the valve gate mold apparatus of the second aspect of the present invention, in addition to the effect of the first aspect of the invention, in the piston of the fluid pressure cylinder apparatus, in the annular fluid pressure cylinder apparatus, Sealing materials that are in close contact with the inner peripheral wall are provided at positions on the peripheral wall that sandwich the through hole that the arm body penetrates, and the drive fluid of the fluid pressure cylinder device is prevented from leaking from this through hole.

According to the invention of claim 3, in addition to the effect of the invention of claim 1, there is only one product cavity formed between the molds, and there is also only one material passage and one gate. Therefore, in the case of such a single-piece valve gate type mold device, it is effective to position the nozzle touch portion and the gate side passage portion coaxially in the material passage.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a first embodiment of a valve gate type mold device of the present invention. The cross-sectional position differs by 90 ° on the left and right of the central axis.

FIG. 2 is a partially enlarged sectional view of the same.

FIG. 3 is a plan view of a part of the same, in which a second valve body member and a cylinder end face plate are attached above the central axis and a second valve body member and a cylinder end face plate are attached below the central axis. The removed state is shown.

[Explanation of symbols]

1 Fixed type 2 Movable type 3 product cavity 10 nozzles 11 Material passage 11a Gate side passage 11b Detour passage 11c Nozzle touch part 12 gates 13 Valve device 24 First valve body member 25 Second valve body member 27 Small portion 28 Large diameter part 46 valve pin 51 Air cylinder device (fluid pressure cylinder device) 55 piston 59 O-ring (sealing material) 72 Arms 77 through hole 81 band heater (heater) 82 band heater (heater) 83 band heater (heater)

Claims (3)

[Claims] 1. A material passage having a plurality of mold bodies which are opened and closed to form a product cavity between the mold bodies when the mold is closed, and a material passage having a material passage to which a nozzle of a molding machine is connected. And a valve device that opens and closes a gate that opens the product cavity to the product cavity.
A valve body having a material passage therein, a valve pin that is located coaxially with the gate, is built into the valve body, and linearly moves to open and close the gate, a drive device that drives the valve pin, and the valve. A heater for heating the material passage, which is provided on an outer peripheral portion of the main body, wherein the material passage has a gate side passage portion on the gate side in which the valve pin is coaxially located inside; and a gate in the valve body. And a nozzle touch portion which is located on the opposite end surface and is coaxial with the gate side passage portion and to which the nozzle of the molding machine is connected, and is located away from a straight line connecting the gate side passage portion and the nozzle touch portion. The drive device includes an annular fluid pressure cylinder device that surrounds the valve body, and includes a bypass passage portion that connects the gate-side passage portion and the nozzle touch portion. A piston of the fluid pressure cylinder device and the valve pin are connected by an arm penetrating the valve body, the valve body including a first valve body member and a gate in the first valve body member. A second valve body member fixed to the opposite side, the first valve body member forming a part of the gate side passage portion and the bypass passage portion, and the second valve body member having the nozzle. The remaining portion of the touch portion and the bypass passage portion is formed, and the outer peripheral surface of the first valve body member is
A portion having the gate side passage portion inside is a small diameter portion, and a portion having the bypass passage portion is a large diameter portion having a larger diameter, and the heater is connected to the first valve body member. A valve gate type mold device, wherein the heaters are provided on the outer peripheral portions of the small-diameter portion and the large-diameter portion and on the outer peripheral portion of the second valve body member, respectively, so that the heaters can be temperature-controlled. 2. A piston of the fluid pressure cylinder device, wherein a sealing material that is in close contact with the inner circumferential wall is provided at a position sandwiching a through hole through which the arm body penetrates in the inner circumferential wall of the annular fluid pressure cylinder device. The valve gate mold apparatus according to claim 1, wherein the valve gate mold apparatus is provided. 3. The valve gate mold apparatus according to claim 1, wherein there is only one product cavity formed between the molds, and there is also only one material passage and one gate. .