JPH0512110U - Nozzle device of injection molding machine - Google Patents

Abstract

(57) [Abstract] [Purpose] Structurally excellent in resin leakage resistance, and avoiding the need for advanced mold processing and molding techniques for resin leakage prevention. [Structure] The nozzle body 59 is brought into contact with the outer wall of the molding die M,
In a nozzle device of an injection molding machine in which resin is injected into a resin injection hole H opened to the outer wall M from a nozzle hole 67 opened at a contact portion of the nozzle body 59 with respect to the molding die M, a molding die M of the nozzle body 59. An annular O-ring 83 that surrounds the nozzle hole 67 is provided at the contact portion with respect to. The contact between the nozzle body 59 and the molding die M is elastic material joining by the O-ring 83 instead of joining the metals.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a nozzle device for an injection molding machine.

[0002]

[Prior Art]

 In general, an injection molding machine has a nozzle device at the tip of an injection cylinder (injection cylinder), and a resin injection hole is formed in the outer wall of the mold through a nozzle hole provided in the nozzle body of the nozzle device. I am supposed to do it.

In this case, the connection between the nozzle body and the molding die is performed by advancing the entire injection cylinder with respect to the molding die so that the nozzle body is pressed against the outer wall of the molding die. Only by joining the metal between the nozzle body and the mold by touch pressure, resin leakage from the connection between the nozzle body and the mold during resin injection is prevented.

Further, when the mold cavity is fully filled with the resin by the injection device, the injection pressure acts as back pressure and acts as a force to push back the nozzle, whereby the tip of the nozzle comes into contact with the mold. There is a gap on the surface, which causes resin leakage.

[0005]

[Problems to be solved by the device]

 In general, the contact part of the nozzle body with respect to the mold, that is, the nozzle tip is hemispherical, and the outer wall of the mold with which the nozzle body abuts is a hemispherical concave part that matches the hemispherical shape of the nozzle tip. , A nozzle hole is provided in the center of the tip of the hemispherical nozzle, and a resin injection hole is provided in the center of the deepest bottom of the hemispherical recess of the mold, and the spherical body is used to connect the nozzle body and the mold. However, since this spherical fitting does not change the joining of metals, the processing accuracy of this spherical fitting, that is, the nozzle touch, greatly affects the resin leakage. This resin leakage not only wastes the resin but also causes loss of injection pressure, which prevents the holding pressure from being sufficiently applied to the injection-molded product during molding, resulting in deterioration of the quality of the injection-molded product and generation of defective products. Will occur.

For this reason, it is necessary to process the nozzle touch portion with sufficiently high accuracy, and if the nozzle touch surface has scratches or irregularities, the spherical fitting state between the nozzle body and the molding die can be achieved. Deteriorates, which causes resin leakage, so it is necessary to strictly manage the nozzle touch part.

Further, as is known as a molding die used in two-color molding, composite molding of different materials, and other special molding, a nozzle touch portion is provided on the dividing surface portion of the molding die, and this portion is provided. In a parting line injection type mold in which more resin is injected, a step difference between molds with the use of the mold deteriorates the spherical surface fitting state between the nozzle body and the mold. If there is a step between the molds, it is necessary to reprocess the nozzle touch part.

In any case, the fitting state of the nozzle body and the molding die with respect to the resin leakage is influenced by the processing accuracy of the fitting parts of the both, the maintenance state, and the positioning accuracy when mounting the molding die. Therefore, there is a problem in that advanced mold processing technology and molding technology are necessary to prevent resin leakage.

The present invention has been made by paying attention to the above-mentioned problems in the conventional injection molding machine, and is structurally excellent in resin leakage resistance, and has a high level of die processing technology for resin leakage prevention. It is an object of the present invention to provide a nozzle device for an injection molding machine that does not require molding technology.

[0010]

[Means for Solving the Problems]

 According to the present invention, the nozzle body is brought into contact with the outer wall of the molding die, and the resin injection hole opened to the outer wall is opened in the contact portion of the nozzle body with respect to the molding die. In a nozzle device of an injection molding machine for more resin injection, an annular elastic seal member that surrounds the nozzle hole is provided at a contact portion of the nozzle body with respect to a molding die. The nozzle device of the injection molding machine is further characterized in that the nozzle body is provided with a pressure receiving surface portion for exerting the resin injection pressure in the contact direction with the outer wall of the molding die.

[0011]

[Action]

 According to the above-mentioned configuration, the contact between the nozzle body and the molding die is replaced with the metal-to-metal joining by elastic material joining by the elastic seal member, and the adhesiveness thereof is higher than that of the metal-to-metal joining. As a result, it is improved without being sensitively affected by the processing accuracy of the nozzle touch portion, scratches and irregularities on the nozzle touch surface, and alignment accuracy.

When the nozzle body and the mold are brought into contact with each other via the elastic seal member, a gap is created between the nozzle body and the mold by the elastic seal member, and the resin that has entered the gap causes the nozzle body Force acts to separate the mold from the mold, which tries to reduce the nozzle touch pressure.However, the nozzle body is provided with a pressure receiving surface part that applies the resin injection pressure in the direction of contact with the outer wall of the mold. Then, the force due to the resin injection pressure acting on the pressure receiving surface section opposes the force trying to separate the nozzle body from the molding die, and the force trying to separate the nozzle body from the molding die depends on the resin injection pressure acting on the pressure receiving surface section. This is offset by the force, and a reduction in nozzle touch pressure is avoided.

[0013]

【Example】

 Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 4 shows an embodiment in which the nozzle device according to the present invention is applied to an in-line screw type injection molding machine. The injection molding machine has a forward / backward traveling substrate 7 which is connected to a moving table 5 of a rodless pneumatic cylinder device 3 for forward / backward movement on a base 1 and which moves forward / backward with respect to a molding die M.

An injection cylinder fixed base 9 is fixed to the forward / backward movement board 7, and the injection cylinder fixed base 9 fixedly supports the injection cylinder 11 in a horizontal state. The injection cylinder 11 is composed of a cylinder member 13 and a tapered nozzle holding member 15 attached to the tip of the cylinder member 13, and a resin injection chamber 17 is formed inside. In the resin injection chamber 17, an injection screw 19 is arranged rotatably around its own central axis and movable in the axial direction. The injection screw 19 is connected to the plunger shaft 21, and the plunger shaft 21 moves in the axial direction in a cylindrical manner with the rotary drive shaft 27 connected to the output shaft 25 of the screw rotation electric motor 23 fixed to the forward / reverse substrate 7. Engagement is possible in a torque transmission relationship, and is rotationally driven by the electric motor 23. Further, the plunger shaft 21 is connected to the piston rod 33 of the screw forward fluid pressure cylinder device 31 by the arm 29 so as to be driven in the axial direction.

A resin supply port 35 is provided in an intermediate portion of the cylinder member 13, and the resin supply port 35 is provided with a resin material supply tube 39 of a resin supply block 37 attached to the injection cylinder fixing base 9 so that resin is supplied from the resin material supply tube 39. Is supplied through the resin passage 41 of the resin supply block 37. A pneumatic cylinder device 43 for pumping resin material is attached to the resin supply block 37. The resin material pneumatic pneumatic cylinder device 43 is in contact with the piston 53 of the resin material supply tube 39 by the connecting plate 47, the push rod 49, and the push pad 51 connected to the piston rod 45. The piston 53 is pressed to the left in the figure in order to feed the resin to the resin supply port 35.

A nozzle device 55 having a valve is attached to the nozzle holding member 15. As shown in FIGS. 1 to 3, the nozzle device 55 has a nozzle main body 59 that is axially movably inserted into the tip hole 57 of the nozzle holding member 15. The nozzle body 59 extends through the tip hole 57 of the nozzle holding member 15, is located in the resin injection chamber 17 at the base side small diameter shaft portion 61, and is positioned at the tip side semi-spherical tip portion 63. It is located outside the injection chamber 17, and has a guide hole 65 penetrating in the axial direction in the center and a nozzle hole 67 continuous to this. The nozzle hole 67 is open at the center of the tip of the hemispherical tip 63. The guide hole 65 is open at the end of the small diameter shaft 61, but is fixed to the tip of the small diameter shaft 61 and closed by a cap-shaped pressure receiving member 69. A valve ring member 71 is externally fitted to the small diameter shaft portion 61.

A valve hole 73 is formed in the small-diameter shaft portion 61 so as to pass therethrough in the radial direction. The valve hole 73 is such that the valve seat surface 75 of the pressure receiving member 69 and the valve seat surface 77 of the valve ring member 71 are joined to each other when the nozzle body 59 is in the valve closed position as shown in FIG. As a result, the nozzle body 59 is shut off from the communication with the resin injection chamber 17, whereas the nozzle body 59 is displaced to the right with respect to the nozzle holding member 15 from the valve closing position in FIGS. (See), the valve seat surface 75 of the pressure receiving member 69 is separated from the joint with the valve seat surface 77 of the valve ring member 71, so that it communicates with the resin injection chamber 17. A compression coil spring 79 is provided between the stepped portion on the back side of the hemispherical tip 63 of the nozzle body 59 and the front end of the nozzle holding member 15. The compression coil spring 79 connects the nozzle body 59 to the nozzle body 59. The holding member 15 is urged to the left in FIGS. 1 and 2, that is, toward the valve closing position.

A circumferential groove 81 surrounding the nozzle hole 67 is formed in the hemispherical tip portion 63 of the nozzle body 59, and an O-ring 83 made of a rubber-like elastic body is fitted and mounted in the circumferential groove 81. ..

An O-ring 85 is attached to the outer periphery of the shaft portion where the nozzle body 59 fits into the tip hole 57 of the nozzle holding member 15 to prevent resin leakage from the tip hole 57.

The nozzle touch portion of the molding die M is a hemispherical recess R that receives the hemispherical tip 63 of the nozzle body 59, and a resin injection hole H is opened at the center of the deepest bottom of the hemispherical recess R. ing.

According to the above-described configuration, the resin supplied to the resin supply port 35 is kneaded and mixed by the rotation of the injection screw 19 by the screw rotation electric motor 23, and while being mixed into the resin injection chamber 17 by the screw pump action. On the other hand, the injection screw 19 retracts in the axial direction as the resin injection chamber 17 is filled with the resin. When the resin injection chamber 17 is filled with a predetermined amount of resin, the resin supply to the resin supply port 35 and the rotation of the injection screw 19 are stopped, and then the rodless pneumatic cylinder device 3 is used to form the forward / backward moving substrate 7 into the mold M. Is driven forward against.

As a result, the hemispherical tip 63 of the nozzle body 59 fits into the hemispherical recess R of the mold M, and comes into contact with the wall surface of the hemispherical tip 63 with the O-ring 83. When the forward / backward movement substrate 7 is further driven forward with respect to the molding die M, the compression coil spring 79 bends and the nozzle holding member 15 is displaced leftward with respect to the nozzle body 59 in FIGS. 1 and 2. As a result, the nozzle body 59 comes to be located at the valve opening position as shown in FIG. 2, and the O-ring 83 is moved by the rodless pneumatic cylinder device 3 by the forward drive force of the forward-backward moving base plate 7 to move the hemispherical recess R. It will be pressed against the wall.

As a result, the contact between the nozzle body 59 and the molding die M becomes elastic material contact by the O-ring 83, and airtight sealing is performed between the two, and thereafter, the screw forward fluid pressure cylinder device 3 When the resin in the resin injection chamber 17 is ejected from the nozzle hole 67 of the nozzle body 59 to the resin injection hole H of the molding die M by the forward movement of the injection screw 19 by the nozzle body 59 and the molding die M. Leakage to the outside from the abutting part of will be reliably avoided.

As described above, when the contact between the nozzle body 59 and the molding die M is made via the O-ring 83, a gap D due to the O-ring 83 is generated between the nozzle body 59 and the molding die M. When resin enters the gap D, a rightward force Fb in FIG. 2 that pulls the nozzle body 59 away from the mold M acts, but at this time, the force is applied to the right end surface of the pressure receiving member 69 in FIG. The injection pressure acts as a dynamic pressure to give a leftward force Fa to the nozzle main body 59 in FIG. 2, and this force Fa opposes the force Fb for separating the nozzle main body 59 from the mold M. As a result, the force Fb for pulling the nozzle body 59 away from the molding die M is offset by the force Fa caused by the resin injection pressure acting on the pressure receiving member 69, and the reduction of the nozzle touch pressure is avoided.

In the above, the present invention has been described in detail with respect to specific embodiments, but the present invention is not limited to this, and various embodiments are possible within the scope of the present invention. There will be no doubt to one of ordinary skill in the art.

[0027]

[Effect of the device]

 As can be understood from the above description, in the nozzle device of the injection molding machine according to the present invention, the contact between the nozzle body and the molding die is elastic material joining by the elastic seal member instead of joining the metals. The adhesiveness of this is improved without being sensitively affected by the machining accuracy of the nozzle touch part, scratches and irregularities on the nozzle touch surface, and alignment accuracy compared to the case of metal-to-metal joining, and the nozzle body and molding The mating condition related to resin leak resistance with the mold is less affected by the processing accuracy of the mating parts of both parties, the maintenance condition, and the positioning accuracy when mounting the mold. Eliminates the need for mold processing technology and molding technology.

When the nozzle body and the mold are brought into contact with each other via the elastic seal member, a gap is created between the nozzle body and the mold by the elastic seal member, and the resin that has entered the gap causes the nozzle to come into contact with the nozzle. A force acts to separate the main body from the molding die, which tries to reduce the nozzle touch pressure, but the resin injection pressure is exerted on the pressure receiving surface of the nozzle main body in the contact direction with the outer wall of the molding die. The force of the resin injection pressure acting on the pressure receiving surface portion opposes the force of separating the nozzle body from the molding die, and the force of separating the nozzle body from the molding die is offset by the force of the resin injection pressure acting on the pressure receiving surface portion. The reduction of the nozzle touch pressure is avoided.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a nozzle device of an injection molding machine according to the present invention in a valve open state.

FIG. 2 is a sectional view showing an embodiment of a nozzle device of an injection molding machine according to the present invention in a valve closed state.

FIG. 3 is a perspective view showing an embodiment of a nozzle device of an injection molding machine according to the present invention.

FIG. 4 is a cross-sectional view showing an embodiment in which the nozzle device according to the present invention is applied to an in-line screw type injection molding machine.

[Explanation of symbols]

 3 Rodless Pneumatic Cylinder Device 7 Forward / Backward Travel Board 11 Injection Cylinder 17 Resin Injection Chamber 19 Injection Screw 23 Screw Rotating Electric Motor 31 Screw Forward Fluid Pressure Cylinder Device 35 Resin Supply Port 39 Resin Material Supply Tube 43 Resin Material Pressure Pneumatic Cylinder Device 55 Nozzle device 59 Nozzle body 67 Nozzle hole 69 Pressure receiving member 73 Valve hole 83 O-ring

Claims (2)

[Scope of utility model registration request] 1. An injection molding machine in which a nozzle main body is brought into contact with an outer wall of a molding die, and resin is injected into a resin injection hole opened to the outer wall from a nozzle hole opened at a contact portion of the nozzle main body with respect to the molding die. In the nozzle device, an annular elastic seal member surrounding the nozzle hole is provided at a contact portion of the nozzle body with respect to the molding die, and the nozzle device of the injection molding machine is characterized. 2. An injection molding machine in which a nozzle main body is brought into contact with an outer wall of a molding die, and resin is injected into a resin injection hole opened to the outer wall from a nozzle hole opened in a contact portion of the nozzle main body with respect to the molding die. In the nozzle device, an annular elastic seal member surrounding the nozzle hole is provided at a contact portion of the nozzle body with respect to the molding die, and resin injection pressure is applied to the nozzle body in a contact direction with an outer wall of the molding die. A nozzle device for an injection molding machine, which is provided with a pressure receiving surface portion to be extended.