Abstract: An undercut processing mechanism is attached to and used in a molding die for forming a molded product having an undercut portion, and allows demolding of the undercut portion. The undercut processing mechanism includes: a holder attached to or formed integrally with the molding die; a sliding piece configured to be slidable relative to the holder such that a mold core is moved so as to demold the undercut portion; a retaining piece configured to retain the sliding piece such that the sliding piece is slidable; and a support wall configured to support the sliding piece so as to prevent the sliding piece from being tilted when the sliding piece slides. The sliding piece forms a part of the mold core for forming the undercut portion.

Abstract: A retaining unit comprising: a first member configured to be movable; a second member used in an unmovable fixed state; and a pressing element attached to the second member, and configured to press the first member to engage the first member with the second member, wherein the retaining unit is configured such that the first member can be moved by release of the engagement with the second member when a force at a predetermined level or higher is applied in a movement direction of the first member, and the pressing element is assembled with the second member to constitute a unit.

Abstract: An undercut processing mechanism is attached to and used in a molding die for forming a molded product having an undercut portion, and allows demolding of the undercut portion. The undercut processing mechanism includes: a holder attached to or formed integrally with the molding die; a sliding piece configured to be slidable relative to the holder such that a mold core is moved so as to demold the undercut portion; a retaining piece configured to retain the sliding piece such that the sliding piece is slidable; and a support wall configured to support the sliding piece so as to prevent the sliding piece from being tilted when the sliding piece slides. The sliding piece forms a part of the mold core for forming the undercut portion.

Abstract: A retaining unit includes: a movable ejector pin; a ring-shaped member used in a fixed state; and a ball plunger directly attached to the ejector pin or fixed to a fixing member attached to the ejector pin. The ball plunger is configured to press the ring-shaped member and engage the ejector pin with the ring-shaped member. When a force at a predetermined level or higher is applied to the ejector pin in a movement direction of the ejector pin, the engagement with the ring-shaped member is released so that the ejector pin is allowed to move. The ball plunger is incorporated into the ejector pin or the fixing member so as to be unitized together.

Abstract: A undercut processing mechanism includes: a sliding piece having a molding core for molding an undercut portion; a holder having a guide for guiding the sliding piece so that a molding core is detached from the undercut portion; and a retaining piece slidably accommodated in the holder and slidably engaged with the sliding piece. One of the holders and the retaining piece can advance/retract relative to the other thereof. The retaining piece has a first engagement element and a second engagement element to be engaged with the sliding piece. The sliding piece is guided via the first engagement element and the second engagement element so that the molding core is detached from the undercut portion and moves away from the molded product.

Abstract: An undercut processing mechanism that is installed in a molding die assembly configured to form a molded article having an undercut portion so as to allow demolding of the undercut portion, the undercut processing mechanism comprising: a pushing piece movable in a demolding direction of the molded article; a support element fixed to the pushing piece or formed so as to be integrated with the pushing piece and capable of supporting the undercut portion during movement of the pushing piece; a sliding piece configured to be slidable relative to the pushing piece and to move, in conjunction with movement of the pushing piece, in a direction intersecting the demolding direction of the molded article; and a retaining piece configured to retain the sliding piece such that the sliding piece is slidable.

Abstract: An undercut processing mechanism includes: a molding core for forming an undercut portion; an inclined pin slidable in a first direction inclined relative to a die opening direction of a molding die during the removal of a molded product from the die; and a guide rail for guiding the movement of the inclined pin. The inclined pin has a slide block movable in contact with the guide rail. The guide rail is so formed as to contact the slide block over the entire stroke of the inclined pin so that the first direction of movement of the inclined pin may be regulated, and is also so formed as to have a shape of a high bending rigidity in a particular direction of the slide block.

Abstract: An undercut processing mechanism is attached to and used in a molding die for forming a molded product having an undercut portion and allows the undercut portion, projecting in a direction intersecting a demolding direction of the molded product, to be demolded. The undercut processing mechanism includes: a holder attached to the molding die so as to be movable in a demolding direction of the molded product P; a sliding piece slidable relative to the holder and configured to form the undercut portion; and a retaining piece fixed to the molding die or formed so as to be integrated with the molding die, which retaining piece slidably retains the sliding piece. In demolding the molded product, the sliding piece moves in the direction in which the undercut portion can be demolded, by moving the holder in the demolding direction of the molded product.

Abstract: A projection mechanism of a molding die configured to mold a molded article by a fixed-side die and a movable-side die, the projection mechanism including: a projection pin using a reaction force of a spring as a drive source; and a first spring and a second spring configured to project the projection pin, wherein the first spring has a maximum reaction force in a die clamping state, and projects the projection pin while gradually reducing the reaction force in a projection process, and the second spring projects the projection pin with a constant reaction force while projecting the projection pin from the die clamping state, where stop of movement of the second projection pin during the projection process causes compression of the second spring to increase the reaction force of the second spring, thereby energizing the projection pin to further project the projection pin.

Abstract: A motion transmitting device comprising: a slider movable along a slider guide; and a connecting body movable along a connecting body guide, wherein the slider and the connecting body are disposed in contact with each other, each of the slider and the connecting body has a contact surface that is slidable, and the amount of displacement and/or the speed of displacement of an output end relative to an input end can be reduced or can be made equal to each other or increased through setting of the angle of a center axis line of the slider guide about a center axis line of the connecting body guide and/or the inclination angle of the contact surface.

Abstract: A projection mechanism of a molding die configured to mold a molded article by a fixed-side die and a movable-side die, the projection mechanism including: a projection pin using a reaction force of a spring as a drive source; and a first spring and a second spring configured to project the projection pin, wherein the first spring has a maximum reaction force in a die clamping state, and projects the projection pin while gradually reducing the reaction force in a projection process, and the second spring projects the projection pin with a constant reaction force while projecting the projection pin from the die clamping state, where stop of movement of the second projection pin during the projection process causes compression of the second spring to increase the reaction force of the second spring, thereby energizing the projection pin to further project the projection pin.

Abstract: An undercut processing mechanism is attached to and used in a molding die for forming a molded product having an undercut portion, and allows demolding of the undercut portion. The undercut processing mechanism includes: a holder attached to or formed integrally with the molding die; a sliding piece configured to be slidable relative to the holder such that a mold core is moved so as to demold the undercut portion; a retaining piece configured to retain the sliding piece such that the sliding piece is slidable; and a support wall configured to support the sliding piece so as to prevent the sliding piece from being tilted when the sliding piece slides. The sliding piece forms a part of the mold core for forming the undercut portion.

Abstract: An undercut processing mechanism includes: a molding core for forming an undercut portion; an inclined pin slidable in a first direction inclined relative to a die opening direction of a molding die during the removal of a molded product from the die; and a guide rail for guiding the movement of the inclined pin. The inclined pin has a slide block movable in contact with the guide rail. The guide rail is so formed as to contact the slide block over the entire stroke of the inclined pin so that the first direction of movement of the inclined pin may be regulated, and is also so formed as to have a shape of a high bending rigidity in a particular direction of the slide block.

Abstract: A motion transmitting device comprising: a slider movable along a slider guide; and a connecting body movable along a connecting body guide, wherein the slider and the connecting body are disposed in contact with each other, each of the slider and the connecting body has a contact surface that is slidable, and the amount of displacement and/or the speed of displacement of an output end relative to an input end can be reduced or can be made equal to each other or increased through setting of the angle of a center axis line of the slider guide about a center axis line of the connecting body guide and/or the inclination angle of the contact surface.

Abstract: A pair of mold cores (51, 52) for molding an undercut portion (P1) in a holder (30) installed inside a movable mold (13) are connected to and supported by a retaining piece (40) which is moved in the demolding direction, and at the time of demolding, the respective mold cores (51, 52) are guided by guide means (33, 34) from the molding position, where they are contacted with each other, to the mold release position, where they are separated from each other, being moved from one end side to the other end side of the retaining piece (40), in the mutually opposite directions so as to pass each other in the back and forth direction.

Abstract: A pair of mold cores (51, 52) for molding an undercut portion (P1) in a holder (30) installed inside a movable mold (13) are connected to and supported by a retaining piece (40) which is moved in the demolding direction, and at the time of demolding, the respective mold cores (51, 52) are guided by guide means (33, 34) from the molding position, where they are contacted with each other, to the mold release position, where they are separated from each other, being moved from one end side to the other end side of the retaining piece (40), in the mutually opposite directions so as to pass each other in the back and forth direction.

Abstract: An undercut processing mechanism can facilitate punching-out of undercut portions having various shapes spreading in the circumferential direction on the inside of a molded article. Split cores (61) that form an undercut molding core (60) are supported one by one at the leading end of slide members (50) disposed radially to face the center axis of an undercut portion (P3). Each slide member (50) is housed in a holder (40) so as to be slidable between a molding position where the split cores (61) are mutually disposed in the entire circumferential direction and a demolding position where the split cores (61) are mutually reduced in diameter.